Journal articles on the topic 'Surface-Subsurface transfers'
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1
Yao, Changfeng, Lufei Ma, Yongxia Du, Junxue Ren, and Dinghua Zhang. "Surface integrity and fatigue behavior in shot-peening for high-speed milled 7055 aluminum alloy." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 231, no. 2 (August 8, 2016): 243–56. http://dx.doi.org/10.1177/0954405415573704.
Abstract:
The influence of shot-peening parameters on surface integrity of 7055 aluminum alloy is investigated based on shot-peening experiments. Surface integrity measurements, fatigue fracture analysis and fatigue life tests are conducted to reveal the effect of surface integrity on crack initiation and fatigue life. The results show that surface roughness increases significantly, and irregular pits and bumps appear on surface after shot-peening; grain on subsurface is refined and produces a shift and distortion in the pellets hit direction; compressive stress can be detected on all machined surfaces. Shot-peening parameters have significant impact on micro-hardness. In comparison with the milled specimen, fatigue life of peened specimens is improved by about 23.8, 3.96 and 1.01 times. Fatigue source zone transfers from stress concentration location on surface to subsurface due to the lower surface roughness and lager residual compressive stress.
2
Peña, Francisco, Fernando Nardi, Assefa Melesse, Jayantha Obeysekera, Fabio Castelli, René M. Price, Todd Crowl, and Noemi Gonzalez-Ramirez. "Compound flood modeling framework for surface–subsurface water interactions." Natural Hazards and Earth System Sciences 22, no. 3 (March 10, 2022): 775–93. http://dx.doi.org/10.5194/nhess-22-775-2022.
Abstract:
Abstract. Compound floods are an active area of research in which the complex interaction between pluvial, fluvial, coastal and groundwater flooding are analyzed. A number of studies have simulated the compound flooding impacts of precipitation, river discharge and storm surge variables with different numerical models and linking techniques. However, groundwater flooding is often neglected in flood risk assessments due to its sporadic frequency (as most regions have water tables sufficiently low that do not exacerbate flooding conditions), isolated impacts and considerably lower severity with respect to other types of flooding. This paper presents a physics-based, loosely coupled modeling framework using FLO-2D and MODFLOW-2005 that is capable of simulating surface–subsurface water interactions. FLO-2D, responsible for the surface hydrology and infiltration processes, transfers the infiltration volume as recharge to MODFLOW-2005 until the soil absorption capacity is exceeded, while MODFLOW-2005 returns exchange flow to the surface when the groundwater heads are higher than the surface depth. Three events characterized by short-duration intense precipitation, average tide levels and unusually high water table levels are used to assess the relevance of groundwater flooding in the Arch Creek Basin, a locality in North Miami particularly prone to flooding conditions. Due to limitations in water level observations, the model was calibrated based on properties that have experienced repetitive flooding losses and validated using image-based volunteer geographic information (VGI). Results suggest that groundwater-induced flooding is localized, and high groundwater heads influence pluvial flooding as the shallow water table undermines the soil infiltration capacity. Understanding groundwater flood risk is of particular interest to low-elevation coastal karst environments as the sudden emergence of the water table at ground surface can result in social disruption, adverse effects to essential services and damage to infrastructure. Further research should assess the exacerbated impacts of high tides and sea level rise on water tables under current and future climate projections.
3
Gatel, Laura, Claire Lauvernet, Nadia Carluer, Sylvain Weill, and Claudio Paniconi. "Sobol Global Sensitivity Analysis of a Coupled Surface/Subsurface Water Flow and Reactive Solute Transfer Model on a Real Hillslope." Water 12, no. 1 (December 30, 2019): 121. http://dx.doi.org/10.3390/w12010121.
Abstract:
The migration and fate of pesticides in natural environments is highly complex. At the hillslope scale, the quantification of contaminant fluxes and concentrations requires a physically based model. This class of model has recently been extended to include coupling between the surface and the subsurface domains for both the water flow and solute transport regimes. Due to their novelty, the relative importance of and interactions between the main model parameters has not yet been fully investigated. In this study, a global Sobol sensitivity analysis is performed on a vineyard hillslope for a one hour intensive rain event with the CATHY (CATchment HYdrology) integrated surface/subsurface model. The event-based simulation involves runoff generation, infiltration, surface and subsurface solute transfers, and shallow groundwater flow. The results highlight the importance of the saturated hydraulic conductivity K s and the retention curve shape parameter n and they reveal a strong role for parameter interactions associated with the exchange processes represented in the model. The mass conservation errors generated by the model are lower than 1% in 99.7% of the simulations. Boostrapping analysis of sampling methods and errors associated with the Sobol indices highlights the relevance of choosing a large sampling size (at least N = 1000) and raises issues associated with rare but extreme output results.
4
Coombs, J. M., and T. Barkay. "Molecular Evidence for the Evolution of Metal Homeostasis Genes by Lateral Gene Transfer in Bacteria from the Deep Terrestrial Subsurface." Applied and Environmental Microbiology 70, no. 3 (March 2004): 1698–707. http://dx.doi.org/10.1128/aem.70.3.1698-1707.2004.
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ABSTRACT Lateral gene transfer (LGT) plays a vital role in increasing the genetic diversity of microorganisms and promoting the spread of fitness-enhancing phenotypes throughout microbial communities. To date, LGT has been investigated in surface soils, natural waters, and biofilm communities but not in the deep terrestrial subsurface. Here we used a combination of molecular analyses to investigate the role of LGT in the evolution of metal homeostasis in lead-resistant subsurface bacteria. A nested PCR approach was employed to obtain DNA sequences encoding PIB-type ATPases, which are proteins that transport toxic or essential soft metals such as Zn(II), Cd(II), and Pb(II) through the cell wall. Phylogenetic incongruencies between a 16S rRNA gene tree and a tree based on 48 PIB-type ATPase amplicons and sequences available for complete bacterial genomes revealed an ancient transfer from a member of the β subclass of the Proteobacteria (β-proteobacterium) that may have predated the diversification of the genus Pseudomonas. Four additional phylogenetic incongruencies indicate that LGT has occurred among groups of β- and γ-proteobacteria. Two of these transfers appeared to be recent, as indicated by an unusual G+C content of the PIB-type ATPase amplicons. This finding provides evidence that LGT plays a distinct role in the evolution of metal homeostasis in deep subsurface bacteria, and it shows that molecular evolutionary approaches may be used for investigation of this process in microbial communities in specific environments.
5
de Rooij, G. H. "Big and small: menisci in soil pores affect water pressures, dynamics of groundwater levels, and catchment-scale average matric potentials." Hydrology and Earth System Sciences Discussions 7, no. 5 (September 1, 2010): 6491–523. http://dx.doi.org/10.5194/hessd-7-6491-2010.
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Abstract. Soil water is confined behind the menisci of its water-air interface. Catchment-scale fluxes (groundwater recharge, evaporation, transpiration, precipitation, etc.) affect the matric potential, and thereby the interface curvature and the configuration of the phases. In turn, these affect the fluxes (except precipitation), creating feedbacks between pore-scale and catchment-scale processes. Tracking pore-scale processes beyond the Darcy scale is not feasible. Instead, for a simplified system based on the classical Darcy's Law and Laplace-Young Law we i) clarify how menisci transfer pressure from the atmosphere to the soil water, ii) examine large-scale phenomena arising from pore-scale processes, and iii) analyze the relationship between average meniscus curvature and average matric potential. In stagnant water, changing the gravitational potential or the curvature of the air-water interface changes the pressure throughout the water. Adding small amounts of water can thus profoundly affect water pressures in a much larger volume. The pressure-regulating effect of the interface curvature showcases the meniscus as a pressure port that transfers the atmospheric pressure to the water with an offset directly proportional to its curvature. This property causes an extremely rapid rise of phreatic levels in soils once the capillary fringe extends to the soil surface and the menisci flatten. For large bodies of subsurface water, the curvature and vertical position of any meniscus quantify the uniform hydraulic potential under hydrostatic equilibrium. During unit-gradient flow, the matric potential corresponding to the mean curvature of the menisci should provide a good approximation of the intrinsic phase average of the matric potential.
6
Fang, Yilin, Xingyuan Chen, Jesus Gomez Velez, Xuesong Zhang, Zhuoran Duan, Glenn E. Hammond, Amy E. Goldman, Vanessa A. Garayburu-Caruso, and Emily B. Graham. "A multirate mass transfer model to represent the interaction of multicomponent biogeochemical processes between surface water and hyporheic zones (SWAT-MRMT-R 1.0)." Geoscientific Model Development 13, no. 8 (August 7, 2020): 3553–69. http://dx.doi.org/10.5194/gmd-13-3553-2020.
Abstract:
Abstract. Surface water quality along river corridors can be modulated by hyporheic zones (HZs) that are ubiquitous and biogeochemically active. Watershed management practices often ignore the potentially important role of HZs as a natural reactor. To investigate the effect of hydrological exchange and biogeochemical processes on the fate of nutrients in surface water and HZs, a novel model, SWAT-MRMT-R, was developed coupling the Soil and Water Assessment Tool (SWAT) watershed model and the reaction module from a flow and reactive transport code (PFLOTRAN). SWAT-MRMT-R simulates concurrent nonlinear multicomponent biogeochemical reactions in both the channel water and its surrounding HZs, connecting the channel water and HZs through hyporheic exchanges using multirate mass transfer (MRMT) representation. Within the model, HZs are conceptualized as transient storage zones with distinguished exchange rates and residence times. The biogeochemical processes within HZs are different from those in the channel water. Hyporheic exchanges are modeled as multiple first-order mass transfers between the channel water and HZs. As a numerical example, SWAT-MRMT-R is applied to the Hanford Reach of the Columbia River, a large river in the United States, focusing on nitrate dynamics in the channel water. Major nitrate contaminants entering the Hanford Reach include those from the legacy waste, irrigation return flows (irrigation water that is not consumed by crops and runs off as point sources to the stream), and groundwater seepage resulting from irrigated agriculture. A two-step reaction sequence for denitrification and an aerobic respiration reaction is assumed to represent the biogeochemical transformations taking place within the HZs. The spatially variable hyporheic exchange rates and residence times in this example are estimated with the basin-scale Networks with EXchange and Subsurface Storage (NEXSS) model. Our simulation results show that (1), given a residence time distribution, how the exchange fluxes to HZs are approximated when using MRMT can significantly change the amount of nitrate consumption in HZs through denitrification and (2) source locations of nitrate have a different impact on surface water quality due to the spatially variable hyporheic exchanges.
7
Barboni, Alexandre, Ayah Lazar, Alexandre Stegner, and Evangelos Moschos. "Lagrangian eddy tracking reveals the Eratosthenes anticyclonic attractor in the eastern Levantine Basin." Ocean Science 17, no. 5 (September 15, 2021): 1231–50. http://dx.doi.org/10.5194/os-17-1231-2021.
Abstract:
Abstract. Statistics of anticyclonic eddy activity and eddy trajectories in the Levantine Basin over the 2000–2018 period are analyzed using the DYNED-Atlas database, which links automated mesoscale eddy detection by the Angular Momentum Eddy Detection and Tracking Algorithm (AMEDA) algorithm to in situ oceanographic observations. This easternmost region of the Mediterranean Sea, delimited by the Levantine coast and Cyprus, has a complex eddying activity, which has not yet been fully characterized. In this paper, we use Lagrangian tracking to investigate the eddy fluxes and interactions between different subregions in this area. The anticyclonic structure above the Eratosthenes Seamount is identified as hosting an anticyclone attractor, constituted by a succession of long-lived anticyclones. It has a larger radius and is more persistent (staying in the same position for up to 4 years with successive merging events) than other eddies in this region. Quantification of anticyclone flux shows that anticyclones that drift towards the Eratosthenes Seamount are mainly formed along the Israeli coast or in a neighboring area west of the seamount. The southeastern Levantine area is isolated, with no anticyclone transfers to or from the western part of the basin, defining the effective attraction basin for the Eratosthenes anticyclone attractor. Co-localized in situ profiles inside eddies provide quantitative information on their subsurface physical anomaly signature, whose intensity can vary greatly with respect to the dynamical surface signature intensity. Despite interannual variability, the so-called Eratosthenes anticyclone attractor stores a larger amount of heat and salt than neighboring anticyclones, in a deeper subsurface anomaly that usually extends down to 500 m. This suggests that this attractor could concentrate heat and salt from this subbasin, which will impact the properties of intermediate water masses created there.
8
Stramler, Kirstie, Anthony D. Del Genio, and William B. Rossow. "Synoptically Driven Arctic Winter States." Journal of Climate 24, no. 6 (March 15, 2011): 1747–62. http://dx.doi.org/10.1175/2010jcli3817.1.
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Abstract The dense network of the Surface Heat Budget of the Arctic (SHEBA) observations is used to assess relationships between winter surface and atmospheric variables as the SHEBA site came under the influence of cyclonic and anticyclonic atmospheric circulation systems. Two distinct and preferred states of subsurface, surface, atmosphere, and clouds occur during the SHEBA winter, extending from the oceanic mixed layer through the troposphere and preceded by same-sign variations in the stratosphere. These states are apparent in distributions of surface temperature, sensible heat and longwave radiation fluxes, ocean heat conduction, cloud-base height and temperature, and in the atmospheric humidity and temperature structure. Surface and atmosphere are in radiative–turbulent–conductive near-equilibrium during a warm opaquely cloudy-sky state, which persists up to 10 days and usually occurs during the low surface pressure phase of a baroclinic wave, although occasionally occurs during the high surface pressure phase because of low, scattered clouds. Clouds occurring in this state have near-unity emissivity and the lowest bases in the vicinity of, or below, the temperature inversion peak. A cold radiatively clear-sky state persists up to two weeks, and occurs only in the high surface pressure phase of a baroclinic wave. The radiatively clear state has clouds that are too tenuous when surface based or, irrespective of opacity, located too far aloft to contribute significantly to the surface energy budget. There is a 13-K surface temperature difference between the two states, and atmospheric inversion peak temperatures are linearly related to the surface temperature in both states. The snow–sea ice interface temperature oscillates over the course of the winter season, as it cools during the radiatively clear state and is warmed from atmospheric emission above and ocean heat conduction from below during the opaquely cloudy state. Analysis of satellite data over the Arctic from 70°–90°N indicates that the radiatively clear and opaquely cloudy states observed at SHEBA may be representative of the entire Arctic basin. The results suggest that model formulation inadequacies should be easier to diagnose if modeled energy transfers are compared with observations using process-based metrics that acknowledge the bimodal nature of the Arctic ocean–ice–snow–atmosphere column, rather than monthly and regionally averaged quantities. Climate change projections of thinner Arctic sea ice and larger advective water vapor influxes into the Arctic could yield different frequencies of occupation of the radiatively clear and opaquely cloudy states and higher wintertime temperatures of SHEBA ocean, ice, snow, atmosphere, and clouds—in particular, a wintertime warming of the snow–sea ice interface temperature.
9
Gupta, Aniket, Alix Reverdy, Jean-Martial Cohard, Basile Hector, Marc Descloitres, Jean-Pierre Vandervaere, Catherine Coulaud, et al. "Impact of distributed meteorological forcing on simulated snow cover and hydrological fluxes over a mid-elevation alpine micro-scale catchment." Hydrology and Earth System Sciences 27, no. 1 (January 10, 2023): 191–212. http://dx.doi.org/10.5194/hess-27-191-2023.
Abstract:
Abstract. From the micro- to the mesoscale, water and energy budgets of mountainous catchments are largely driven by topographic features such as terrain orientation, slope, steepness, and elevation, together with associated meteorological forcings such as precipitation, solar radiation, and wind speed. Those topographic features govern the snow deposition, melting, and transport, which further impacts the overall water cycle. However, this microscale variability is not well represented in Earth system models due to coarse resolutions. This study explores the impact of precipitation, shortwave radiation, and wind speed on the water budget distribution over a 15.28 ha small, mid-elevation (2000–2200 m) alpine catchment at Col du Lautaret (France). The grass-dominated catchment remains covered with snow for 5 to 6 months per year. The surface–subsurface coupled distributed hydrological model ParFlow-CLM is used at a very high resolution (10 m) to simulate the impacts on the water cycle of meteorological variability at very small spatial and temporal scales. These include 3D simulations of hydrological fluxes with spatially distributed forcing of precipitation, shortwave radiation, and wind speed compared to 3D simulations of hydrological fluxes with non-distributed forcing. Our precipitation distribution method encapsulates the spatial snow distribution along with snow transport. The model simulates the dynamics and spatial variability of snow cover using the Common Land Model (CLM) energy balance module and under different combinations of distributed forcing. The resulting subsurface and surface water transfers are computed by the ParFlow module. Distributed forcing leads to spatially heterogeneous snow cover simulation, which becomes patchy at the end of the melt season and shows a good agreement with the remote sensing images (mean bias error (MBE) = 0.22). This asynchronous melting results in a longer melting period compared to the non-distributed forcing, which does not generate any patchiness. Among the distributed meteorological forcings tested, precipitation distribution, including snow transport, has the greatest impact on spatial snow cover (MBE = 0.06) and runoff. Shortwave radiation distribution has an important impact, reducing evapotranspiration as a function of the slope orientation (decreasing the slope between observed and simulated evapotranspiration from 1.55 to 1.18). For the primarily east-facing catchment studied here, distributing shortwave radiation helps generate realistic timing and spatial heterogeneity in the snowmelt at the expense of an increase in the mean bias error (from 0.06 to 0.22) for all distributed forcing simulations compared to the simulation with only distributed precipitation. Distributing wind speed in the energy balance calculation has a more complex impact on our catchment, as it accelerates snowmelt when meteorological conditions are favorable but does not generate snow patches at the end of our test case. This shows that slope- and aspect-based meteorological distribution can improve the spatio-temporal representation of snow cover and evapotranspiration in complex mountain terrain.
10
Eeckman, Judith, Hélène Roux, Audrey Douinot, Bertrand Bonan, and Clément Albergel. "A multi-sourced assessment of the spatiotemporal dynamics of soil moisture in the MARINE flash flood model." Hydrology and Earth System Sciences 25, no. 3 (March 24, 2021): 1425–46. http://dx.doi.org/10.5194/hess-25-1425-2021.
Abstract:
Abstract. The MARINE (Model of Anticipation of Runoff and INundations for Extreme events) hydrological model is a distributed model dedicated to flash flood simulation. Recent developments of the MARINE model are explored in this work. On one hand, transfers of water through the subsurface, formerly relying on water height, now take place in a homogeneous soil column based on the soil saturation degree (SSF model). On the other hand, the soil column is divided into two layers, which represent, respectively, the upper soil layer and the deep weathered rocks (SSF–DWF model). The aim of the present work is to assess the accuracy of these new representations for the simulation of soil moisture during flash flood events. An exploration of the various products available in the literature for soil moisture estimation is performed. The efficiency of the models for soil saturation degree simulation is estimated with respect to several products either at the local scale or spatially distributed: (i) the gridded soil moisture product provided by the operational modeling chain SAFRAN-ISBA-MODCOU; (ii) the gridded soil moisture product provided by the LDAS-Monde assimilation chain, which is based on the ISBA-A-gs land surface model and assimilating satellite derived data; (iii) the upper soil water content hourly measurements taken from the SMOSMANIA observation network; and (iv) the Soil Water Index provided by the Copernicus Global Land Service (CGLS), which is derived from Sentinel-1 C-SAR and ASCAT satellite data. The case study is performed over two French Mediterranean catchments impacted by flash flood events over the 2017–2019 period. The local comparison of the MARINE outputs with the SMOSMANIA measurements, as well as the comparison at the basin scale of the MARINE outputs with the gridded LDAS-Monde and CGLS data, lead to the following conclusion: both the dynamics and the amplitudes of the soil saturation degree simulated with the SSF and SSF–DWF models are better correlated with both the SMOSMANIA measurements and the LDAS-Monde data than the outputs of the base model. Finally, the soil saturation degree simulated by the two-layers model for the deep layer is compared to the soil saturation degree provided by the LDAS-Monde product at corresponding depths. In conclusion, the developments presented for the representation of subsurface flow in the MARINE model enhance the soil saturation degree simulation during flash floods with respect to both gridded data and local soil moisture measurements.
11
Van De Ven, Cole J. C., and Kevin G. Mumford. "Aqueous and surface expression of subsurface GHGs: Subsurface mass transfer effects." Water Research 170 (March 2020): 115327. http://dx.doi.org/10.1016/j.watres.2019.115327.
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Paquette, Michel, Daniel Fortier, Melissa Lafrenière, and Warwick F. Vincent. "Periglacial slopewash dominated by solute transfers and subsurface erosion on a High Arctic slope." Permafrost and Periglacial Processes 31, no. 4 (May 16, 2020): 472–86. http://dx.doi.org/10.1002/ppp.2066.
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Santana, D. S., E. P. Pacheco, W. G. Vale, and M. V. S. Chaves. "Model of the pression transfer apply on an alfisol from Tabuleiros Costeiros." Scientific Electronic Archives 13, no. 7 (July 1, 2020): 1. http://dx.doi.org/10.36560/1372020960.
Abstract:
The cohesive subsurface horizon of the Arfisol of Tabuleiros Costeiros, reduces the effective depth of these soils, compromising the yield and longevity of the perennial crops. This pedogenetic limitation can be potentiated when the pressure applied on the surface of the Ap horizon, during the traffic of agricultural machinery is transmitted to deeper horizons, AB or Bt, at higher levels the load-bearing capacity of these layers. The objective of this research was to mathematically model the transfer of pressures applied to the surface of the Ap horizon of an Alfisol for subsurface layers, relating the pressure applied to the soil profile moisture. With the experiment developed in the Laboratory of Soils and Plant Nutrition of Embrapa Tabuleiros Costeiros, it was concluded that moisture has a damping effect on the pressure transmitted from upper layers to subsurface. The pressure transmitted to the subsurface shows an exponential function with negative correlation as a function of depth, independent of the applied pressure on the surface. The increase in the contact area for the application of pressures on the soil surface, attenuates the transmission of pressure to lower layers when compared to the same pressure applied in smaller areas
14
Turner, B. L., and P. M. Haygarth. "Phosphorus Leaching Under Cut Grassland." Water Science and Technology 39, no. 12 (June 1, 1999): 63–67. http://dx.doi.org/10.2166/wst.1999.0530.
Abstract:
Phosphorus (P) transfer from agricultural land to surface waters can contribute to eutrophication, excess algal growth and associated water quality problems. Grasslands have a high potential for P transfer, as they receive P inputs as mineral fertiliser and concentrates cycled through livestock manures. The transfer of P can occur through surface and subsurface pathways, although the capacity of most soils to fix inorganic P has meant that subsurface P transfer by leaching mechanisms has often been perceived as negligible. We investigated this using large-scale monolith lysimeters (135 cm deep, 80 cm diameter) to monitor leachate P under four grassland soil types. Leachate was collected during the 1997–98 drainage year and analysed for a range of P fractions. Mean concentrations of total P routinely exceeded 100 μg l−1 from all soil types and, therefore, exceeded P concentrations above which eutrophication and algal growth can occur. The majority of the leachate P was in algal-available Mo-reactive (inorganic) forms, although a large proportion occurred in unreactive (organic) forms. We suggest that subsurface transfer by leaching can represent a significant mechanism for agricultural P transfer from some soils and must be given greater consideration as a potential source of diffuse P pollution to surface waters.
15
Cheng, Yiwei, Marc Stieglitz, and Feifei Pan. "A Simple Method to Evolve Daily Ground Temperatures from Surface Air Temperatures in Snow-Dominated Regions." Journal of Hydrometeorology 11, no. 6 (December 1, 2010): 1395–404. http://dx.doi.org/10.1175/2010jhm1240.1.
Abstract:
Abstract A simple model is developed to evolve daily ground temperatures from surface air temperatures (SATs) in snow-dominated areas. Ground surface temperatures (GSTs) are calculated by propagating the daily SAT through the snowpack, and attenuating the signal amplitude. Subsequent subsurface heat transfer is then modeled using the analytical solution of the one-dimensional heat conduction equation. The thermal impacts of nonconductive heat transfer processes and seasonal freeze thaw are implicitly represented by the time-dependent apparent thermal diffusivity of the subsurface. The model is tested in four snow-dominated regions: Barrow, Council, Ivotuk (all in Alaska) and Reynolds Creek Experimental Watershed (in Idaho). The model captures the seasonal evolution of the ground temperature at all sites. The model demonstrates the feasibility of simulating subsurface temperatures using only air temperature and snow depth.
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Wu, Yehan, Ruixue Fang, Laihong Shen, and Hongcun Bai. "Dual mechanisms in hydrogen reduction of copper oxide: surface reaction and subsurface oxygen atom transfer." RSC Advances 14, no. 14 (2024): 9985–95. http://dx.doi.org/10.1039/d4ra01240b.
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Hills, Benjamin H., Joel T. Harper, Toby W. Meierbachtol, Jesse V. Johnson, Neil F. Humphrey, and Patrick J. Wright. "Processes influencing heat transfer in the near-surface ice of Greenland's ablation zone." Cryosphere 12, no. 10 (October 8, 2018): 3215–27. http://dx.doi.org/10.5194/tc-12-3215-2018.
Abstract:
Abstract. To assess the influence of various heat transfer processes on the thermal structure of near-surface ice in Greenland's ablation zone, we compare in situ measurements with thermal modeling experiments. A total of seven temperature strings were installed at three different field sites, each with between 17 and 32 sensors and extending up to 21 m below the ice surface. In one string, temperatures were measured every 30 min, and the record is continuous for more than 3 years. We use these measured ice temperatures to constrain our modeling experiments, focusing on four isolated processes and assessing the relative importance of each for the near-surface ice temperature: (1) the moving boundary of an ablating surface, (2) thermal insulation by snow, (3) radiative energy input, and (4) subsurface ice temperature gradients below the seasonally active near-surface layer. In addition to these four processes, transient heating events were observed in two of the temperature strings. Despite no observations of meltwater pathways to the subsurface, these heating events are likely the refreezing of liquid water below 5–10 m of cold ice. Together with subsurface refreezing, the five heat transfer mechanisms presented here account for measured differences of up to 3 ∘C between the mean annual air temperature and the ice temperature at the depth where annual temperature variability is dissipated. Thus, in Greenland's ablation zone, the mean annual air temperature is not a reliable predictor of the near-surface ice temperature, as is commonly assumed.
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van Dalum, Christiaan T., Willem Jan van de Berg, and Michiel R. van den Broeke. "Impact of updated radiative transfer scheme in snow and ice in RACMO2.3p3 on the surface mass and energy budget of the Greenland ice sheet." Cryosphere 15, no. 4 (April 13, 2021): 1823–44. http://dx.doi.org/10.5194/tc-15-1823-2021.
Abstract:
Abstract. Radiative transfer in snow and ice is often not modeled explicitly in regional climate models. In this study, we evaluate a new englacial radiative transfer scheme and assess the surface mass and energy budget for the Greenland ice sheet in the latest version of the regional climate model RACMO2, version 2.3p3. We also evaluate the modeled (sub)surface temperature and melt, as radiation penetration now enables internal heating. The results are compared to the previous model version and are evaluated against stake measurements and automatic weather station data of the K-transect and PROMICE projects. In addition, subsurface snow temperature profiles are compared at the K-transect, Summit, and southeast Greenland. The surface mass balance is in good agreement with observations, with a mean bias of −31 mm w.e. yr−1 (−2.67 %), and only changes considerably with respect to the previous RACMO2 version around the ice margins and near the percolation zone. Melt and refreezing, on the other hand, are changed more substantially in various regions due to the changed albedo representation, subsurface energy absorption, and meltwater percolation. Internal heating leads to higher snow temperatures in summer, in agreement with observations, and introduces a shallow layer of subsurface melt. Hence, this study shows the consequences and necessity of radiative transfer in snow and ice for regional climate modeling of the Greenland ice sheet.
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Liston, Glen E., Jan-Gunnar Winther, Oddbjørn Bruland, Hallgeir Elvehøy, and Knut Sand. "Below-surface ice melt on the coastal Antarctic ice sheet." Journal of Glaciology 45, no. 150 (1999): 273–85. http://dx.doi.org/10.3189/s0022143000001775.
Abstract:
AbstractIn the Jutulgryta area of Dronning Maud Land, Antarctica, subsurface melting of the ice sheet has been observed. The melting takes place during the summer months in blue-ice areas under conditions of below-freezing air and surface temperatures. Adjacent snow-covered regions, having the same meteorological and climatic conditions, experience little or no subsurface melting. To help explain and understand the observed melt-rate differences in the blue-ice and snow-covered areas, a physically based numerical model of the coupled atmosphere, radiation, snow and blue-ice system has been developed. The model comprises a heat-transfer equation which includes a spectrally dependent solar-radiation source term. The penetration of radiation into the snow and blue ice depends on the solar-radiation spectrum, the surface albedo and the snow and blue-ice grain-sizes and densities. In addition, the model uses a complete surface energy balance to define the surface boundary conditions. It is run over the full annual cycle, simulating temperature profiles and melting and freezing quantities throughout the summer and winter seasons. The model is driven and validated using field observations collected during the Norwegian Antarctic Research Expedition (NARE) 1996–97. The simulations suggest that the observed differences between subsurface snow and blue-ice melting can be explained largely by radiative and heat-transfer interactions resulting from differences in albedo, grain-size and density between the two mediums.
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Liston, Glen E., Jan-Gunnar Winther, Oddbjørn Bruland, Hallgeir Elvehøy, and Knut Sand. "Below-surface ice melt on the coastal Antarctic ice sheet." Journal of Glaciology 45, no. 150 (1999): 273–85. http://dx.doi.org/10.1017/s0022143000001775.
Abstract:
AbstractIn the Jutulgryta area of Dronning Maud Land, Antarctica, subsurface melting of the ice sheet has been observed. The melting takes place during the summer months in blue-ice areas under conditions of below-freezing air and surface temperatures. Adjacent snow-covered regions, having the same meteorological and climatic conditions, experience little or no subsurface melting. To help explain and understand the observed melt-rate differences in the blue-ice and snow-covered areas, a physically based numerical model of the coupled atmosphere, radiation, snow and blue-ice system has been developed. The model comprises a heat-transfer equation which includes a spectrally dependent solar-radiation source term. The penetration of radiation into the snow and blue ice depends on the solar-radiation spectrum, the surface albedo and the snow and blue-ice grain-sizes and densities. In addition, the model uses a complete surface energy balance to define the surface boundary conditions. It is run over the full annual cycle, simulating temperature profiles and melting and freezing quantities throughout the summer and winter seasons. The model is driven and validated using field observations collected during the Norwegian Antarctic Research Expedition (NARE) 1996–97. The simulations suggest that the observed differences between subsurface snow and blue-ice melting can be explained largely by radiative and heat-transfer interactions resulting from differences in albedo, grain-size and density between the two mediums.
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van Dalum, Christiaan T., Willem Jan van de Berg, and Michiel R. van den Broeke. "Sensitivity of Antarctic surface climate to a new spectral snow albedo and radiative transfer scheme in RACMO2.3p3." Cryosphere 16, no. 3 (March 29, 2022): 1071–89. http://dx.doi.org/10.5194/tc-16-1071-2022.
Abstract:
Abstract. This study investigates the sensitivity of modeled surface melt and subsurface heating on the Antarctic ice sheet to a new spectral snow albedo and radiative transfer scheme in the Regional Atmospheric Climate Model (RACMO), version 2.3p3 (Rp3). We tune Rp3 to observations by performing several sensitivity experiments and assess the impact on temperature and melt by incrementally changing one parameter at a time. When fully tuned, Rp3 compares well with in situ and remote sensing observations of surface mass and energy balance, melt, near-surface and (sub)surface temperature, albedo and snow grain specific surface area. Near-surface snow temperature is especially sensitive to the prescribed fresh snow specific surface area and fresh dry snow metamorphism. These processes, together with the refreezing water grain size and subsurface heating, are important for melt around the margins of the Antarctic ice sheet. Moreover, small changes in the albedo and the aforementioned processes can lead to an order of magnitude overestimation of melt, locally leading to runoff and a reduced surface mass balance.
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Torres‐Verdín, Carlos, and Francis X. Bostick. "Implications of the Born approximation for the magnetotelluric problem in three‐dimensional environments." GEOPHYSICS 57, no. 4 (April 1992): 587–602. http://dx.doi.org/10.1190/1.1443272.
Abstract:
A first‐order Born approximation is obtained for the integral equations governing the surface magnetotelluric response over a three‐dimensional earth. Although accurate only in cases of low resistivity contrasts, the resulting expressions: (1) exhibit a linear relationship between a spatial perturbation in subsurface resistivity and the ensuing perturbation on the surface field response, and, more importantly, (2) allow arbitrary degrees of complexity in the geometrical characteristics of the subsurface. The linear system solutions derived from the Born approximation are studied by examining the properties of their associated kernels. These kernels may be thought of as a suite of horizontal magnetotelluric “wavelets” weighting the subsurface resistivity distribution at different depth levels. Analytical expressions for the wavelets are obtained in the wavenumber domain, thus generating a suite of magnetotelluric “transfer functions.” Expressions for the latter are particularized to the cases of one‐ and two‐dimensional geolectric media yielding results consistent with the characteristics of the magnetotelluric fields known to hold in these low‐order environments. Inspection of the electric transfer functions reveals severe sensitivity to near‐surface lateral variations of resistivity, which persists even at deep sensing frequencies. This near‐surface sensitivity is the result of an additive term in the electric field transfer functions, the static component, acting as a spatial highpass filter of the lateral variations of surface resistivity. A second additive component in the electric transfer functions, the induction component, functions as a spatial lowpass filter of the lateral variations in subsurface resistivity, and is primarily responsible for the inductive part of the surface electric field response. A common problem in magnetotelluric interpretation, the electric static effect can be reduced by inverting the role of the static component, i.e., by spatially low‐pass filtering the surface electric field. The suggested low‐pass filter for such an operation is one for which the cutoff wavenumber increases with frequency and is therefore insensitive to the response from the induction component. Low‐pass filtering of the surface electric field is best implemented in the field if the electric dipoles are deployed end‐to‐end continuously along a survey path. The magnetic field transfer functions, on the other hand, exhibit a single induction term with band‐pass filter properties which may actually lead to some amount of local distortion on the measured surface magnetic field. We propose to reduce this distortion by referring all electric field measurements to the primary magnetic field within the survey area. The primary magnetic field components, in turn, can be estimated by the spatial average of the magnetic measurements acquired at an array of magnetic stations. The suggested procedures for both the acquisition and processing of natural electric and magnetic field data encompass altogether a novel adaptation of the magnetotelluric method.
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Yan, Huo, and Hui Juan Li. "Defect Recognition for Honeycomb Sandwich Composites Using Pulsed Thermography." Advanced Materials Research 773 (September 2013): 542–48. http://dx.doi.org/10.4028/www.scientific.net/amr.773.542.
Abstract:
Typical defects such as delamination and water/oil ingression existed in honeycomb composites during manufacturing and in-service period. The defects can reduce the performance of the composites significantly. The paper presented a nondestructive defect recognition method for honeycomb composites using pulsed thermography. In this study, based on analysis of the heat transfer in the object with two different medias, the relationship between the surface temperature and the thermal property of subsurface defects has been deduced; the surface temperature expression is put forward to consider the interaction of subsurface defects. In order to simulate the defects, CFRP sandwiched sample with different subsurface defects (debonding, water in the honeycomb core and oil in the honeycomb core) of the same volume inserted in the machined flat-bottom holes, the sample is heated with a short pulse of light, and the sample surface temperature is captured by infrared camera, and the data is processed to measure thermal diffusivity for the subsurface defects. The order of the measured thermal diffusivity is according with the theoretical value. The experiment results provide the feasibility of different defects recognition, and the influence factors are discussed.
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Lu, Yang, Aidin J. Golrokh, and MD Aminul Islam. "Concrete Pavement Service Condition Assessment Using Infrared Thermography." Advances in Materials Science and Engineering 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/3829340.
Abstract:
Infrared thermography (IRT), an effective nondestructive testing method, is used to obtain an initial evaluation of the concrete pavement surface and near surface in a time effective manner. In this paper, the effect of the depth of delamination inside concrete pavement on infrared thermography technique is studied for bridge decks inspection. To be able to mimic the delamination in subsurface, two Styrofoam cubes have been inserted in different depth near the surface of the concrete cylinder. After heating up the specimen, thermal images were taken from the surface using an infrared thermal camera to evaluate the effect of subsurface defects on detection sensitivity and accuracy. We also investigated the precision to which the shape and the size of the subsurface anomalies can be perceived using an uncooled thermal camera. To achieve this goal, we used image processing technique to accurately compute the size of delamination in order to compare it with the actual size. In addition, distance/thermal graph is used to detect the presence of the defect underneath the concrete surface. Furthermore, thermal transfer modeling was adopted in this paper to assist the setup of this experiment and the results are compared with laboratory findings.
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Caldwell, S. G., and J. J. Wert. "Surface and Subsurface Behavior of Selected Al-Cu Alloys in Sliding Wear." Journal of Tribology 107, no. 3 (July 1, 1985): 379–87. http://dx.doi.org/10.1115/1.3261085.
Abstract:
As materials are pushed to higher levels of performance, the nature of friction and wear phenomena occurring in sliding contact is of even greater importance in view of energy efficiency and maintained functional integrity. The present study investigated unlubricated sliding wear from the standpoint of transfer layer behavior. Microscopic studies of selected Al-4.5 Cu structures confirmed that asperity contact damage is very localized, as was the case for previously studied solid solutions. The subsurface region was found to consist of very fine crystallites lacking a stable, definable texture. Macroscopic wear testing was performed by three different methods using Cu-Al solid solutions. It was demonstrated that test multiplicity has the advantages of establishing machine-dependent results and also showing conditions for which a given parameter is rate controlling. Surface-sensitive tests using aluminum bronzes are dominated by surface oxide effects. The soft Cu2O component of films on low percentage solute alloys behaves as a solid lubricant. When tests are employed that produce more severe wear, bulk properties of the substrate predominate except for alloys with highly abrasive surface oxides. Results of this study have been found to be in good correlation with related transfer layer investigations.
26
MacAyeal, Douglas R., Alison F. Banwell, Emile A. Okal, Jinqiao Lin, Ian C. Willis, Becky Goodsell, and Grant J. MacDonald. "Diurnal seismicity cycle linked to subsurface melting on an ice shelf." Annals of Glaciology 60, no. 79 (December 17, 2018): 137–57. http://dx.doi.org/10.1017/aog.2018.29.
Abstract:
ABSTRACTSeismograms acquired on the McMurdo Ice Shelf, Antarctica, during an Austral summer melt season (November 2016–January 2017) reveal a diurnal cycle of seismicity, consisting of hundreds of thousands of small ice quakes limited to a 6–12 hour period during the evening, in an area where there is substantial subsurface melting. This cycle is explained by thermally induced bending and fracture of a frozen surface superimposed on a subsurface slush/water layer that is supported by solar radiation penetration and absorption. A simple, one-dimensional model of heat transfer driven by observed surface air temperature and shortwave absorption reproduces the presence and absence (as daily weather dictated) of the observed diurnal seismicity cycle. Seismic event statistics comparing event occurrence with amplitude suggest that the events are generated in a fractured medium featuring relatively low stresses, as is consistent with a frozen surface superimposed on subsurface slush. Waveforms of the icequakes are consistent with hydroacoustic phases at frequency $ {\bf \gt} \bf 75\,{\bf Hz}$ and flexural-gravity waves at frequency $ \bf {\bf \lt}25\,{\bf Hz}$. Our results suggest that seismic observation may prove useful in monitoring subsurface melting in a manner that complements other ground-based methods as well as remote sensing.
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Mellor, George. "Pressure–Slope Momentum Transfer in Ocean Surface Boundary Layers Coupled with Gravity Waves." Journal of Physical Oceanography 43, no. 10 (October 1, 2013): 2173–84. http://dx.doi.org/10.1175/jpo-d-13-068.1.
Abstract:
Abstract The paper focuses on the consequences of including surface and subsurface, wind-forced pressure–slope momentum transfer into the oceanic water column, a transfer process that competes with now-conventional turbulence transfer based on mixing coefficients. Horizontal homogeneity is stipulated as is customary when introducing a new surface boundary layer model or significantly new vertical momentum transfer physics to an existing model. An introduction to pressure–slope momentum transfer is first provided by a phase-resolved, vertically dependent analytical model that excludes turbulence transfer. There follows a discussion of phase averaging; an appendix is an important adjunct to the discussion. Finally, a coupled wave–circulation model, which includes pressure–slope and turbulence momentum transfer, is presented and numerically executed. The calculated temperatures compare well with measurements from ocean weather station Papa.
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Wang, Yuyang, Chengjian Wu, Jinyan Tang, Mingyu Duan, Jian Chen, Bing-Feng Ju, and Yuan-Liu Chen. "Measurement of Sub-Surface Microstructures Based on a Developed Ultrasonic Atomic Force Microscopy." Applied Sciences 12, no. 11 (May 27, 2022): 5460. http://dx.doi.org/10.3390/app12115460.
Abstract:
Accurate and non-destructive technology for detection of subsurface defect has become a key requirement with the emergence of various ultra-precision machining technologies and the application of ultra-precision components. The combination of acoustic technique for sub-surface detection and atomic force microscopy (AFM) for measurement with high resolution is a potential method for studying the subsurface structure of workpiece. For this purpose, contact-resonance AFM (CR-AFM) is a typical technique. In this paper, a CR-AFM system with a different principle from commercially available instruments is set up and used for the detection of sub-surface Si samples with grating structures and covered by different thickness of highly oriented pyrolytic graphite (HOPG). The influence of subsurface burial depth on the detection capability is studied by simulations and experiments. The thickest HOPG film allowing for sub-surface measurement by the proposed method is verified to be about 30 μm, which is much larger than the feature size of the subsurface microstructure. The manuscript introduces the difference between this subsurface topography measurement principle and the commercially available AFM measurement principle, and analyzes its advantages and disadvantages. The experimental results demonstrates that the technique has the capability to reveal sub-surface microstructures with relatively large buried depth and is potential for engineering application in ultra-precision technologies.
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Gilbert, A., C. Vincent, D. Six, P. Wagnon, L. Piard, and P. Ginot. "Modeling near-surface firn temperature in a cold accumulation zone (Col du Dôme, French Alps): from a physical to a semi-parameterized approach." Cryosphere 8, no. 2 (April 17, 2014): 689–703. http://dx.doi.org/10.5194/tc-8-689-2014.
Abstract:
Abstract. Analysis of the thermal regime of glaciers is crucial for glacier hazard assessment, especially in the context of a changing climate. In particular, the transient thermal regime of cold accumulation zones needs to be modeled. A modeling approach has therefore been developed to determine this thermal regime using only near-surface boundary conditions coming from meteorological observations. In the first step, a surface energy balance (SEB) model accounting for water percolation and radiation penetration in firn was applied to identify the main processes that control the subsurface temperatures in cold firn. Results agree well with subsurface temperatures measured at Col du Dôme (4250 m above sea level (a.s.l.)), France. In the second step, a simplified model using only daily mean air temperature and potential solar radiation was developed. This model properly simulates the spatial variability of surface melting and subsurface firn temperatures and was used to accurately reconstruct the deep borehole temperature profiles measured at Col du Dôme. Results show that percolation and refreezing are efficient processes for the transfer of energy from the surface to underlying layers. However, they are not responsible for any higher energy uptake at the surface, which is exclusively triggered by increasing energy flux from the atmosphere due to SEB changes when surface temperatures reach 0 °C. The resulting enhanced energy uptake makes cold accumulation zones very vulnerable to air temperature rise.
30
Gilbert, A., C. Vincent, D. Six, P. Wagnon, L. Piard, and P. Ginot. "Modeling near-surface firn temperature in a cold accumulation zone (Col du Dôme, French Alps): from a physical to a semi-parameterized approach." Cryosphere Discussions 7, no. 6 (November 19, 2013): 5541–78. http://dx.doi.org/10.5194/tcd-7-5541-2013.
Abstract:
Abstract. Analysis of the thermal regime of glaciers is crucial for glacier hazard assessment, especially in the context of a changing climate. In particular, the transient thermal regime of cold accumulation zones needs to be modeled. A modeling approach has therefore been developed to determine this thermal regime using only near-surface boundary conditions coming from meteorological observations. In the first step, a surface energy-balance (SEB) model accounting for water percolation was applied to identify the main processes that control the subsurface temperatures in cold firn. Results agree well with subsurface temperatures measured at Col du Dôme (4250 m a.s.l., France). In the second step, a simplified model using only daily mean air temperature and potential solar radiation was developed. This model properly simulates the spatial variability of surface melting and subsurface firn temperatures and was used to accurately reconstruct the deep borehole temperature profiles measured at Col du Dôme. Results show that percolation and refreezing are efficient processes for the transfer of energy from the surface to underlying layers. However, they are not responsible for any higher energy uptake at the surface, which is exclusively triggered by increasing energy flux from the atmosphere due to SEB changes when surface temperature reach 0 °C. The resulting enhanced energy uptake makes cold accumulation zones very vulnerable to air temperature rise.
31
Macher, Wolfgang, Norbert Kömle, Yuri Skorov, Ladislav Rezac, Günter Kargl, and Patrick Tiefenbacher. "3D thermal modeling of two selected regions on comet 67P and comparison with Rosetta/MIRO measurements." Astronomy & Astrophysics 630 (September 20, 2019): A12. http://dx.doi.org/10.1051/0004-6361/201834798.
Abstract:
Context. The Microwave Instrument for the Rosetta Orbiter (MIRO) was one of the key instruments of the Rosetta mission, which acquired a wealth of data, in particular as the orbiter moved in the close environment of comet 67P/Churyumov-Gerasimenko (August 2014–September 2016). It was the only instrument of the Rosetta payload that was able to measure temperatures in the near-subsurface layers of the cometary nucleus down to a depth of some centimeters. This range is most relevant for understanding the mechanisms of cometary activity. Aims. We simulate the 3D temperature distribution for two selected regions that were observed by MIRO in March 2015 when the comet was at a distance of about 2 au from the Sun. The importance of a full 3D treatment for a realistic subsurface temperature distribution and the thermal heat balance in the uppermost subsurface is investigated in comparison with analogous 1D simulations. Methods. For this purpose, we developed a numerical heat transfer model of the surface as well as the near-subsurface regions. It enabled us to solve the heat transfer equation in the subsurface volume with appropriate radiation boundary conditions taken into account. The comparison with 1D simulations was made on the basis of the same solar irradiation history. Results. Although the temperature gradient is predominantly normal to the comet surface, we still find that tangential flows may be responsible for local temperature differences of up to 30 K (a few Kelvin on the average) in the uppermost subsurface layers. From the results of the 3D simulations, we calculated the MIRO antenna temperature. A comparison with the actual measurements shows good agreement for the MIRO submillimeter channel, but there is a notable discrepancy for the millimeter channel. This last assessment is not related to the use of the 3D model; potential causes are discussed in some detail with a view to future studies.
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Seyar, Mohammad Hussain, and Tofael Ahamed. "Development of an IoT-Based Precision Irrigation System for Tomato Production from Indoor Seedling Germination to Outdoor Field Production." Applied Sciences 13, no. 9 (April 29, 2023): 5556. http://dx.doi.org/10.3390/app13095556.
Abstract:
Proper irrigation management, especially for tomatoes that are sensitive to water, is the key to ensuring sustainable tomato production. Using a low-cost sensor coupled with IoT technology could help to achieve precise control of the moisture content in the plant root-zone soil and apply water on demand with minimum human intervention. An IoT-based precision irrigation system was developed for growing Momotaro tomato seedlings inside a dark chamber. Four irrigation thresholds, 5%, 8%, 12%, and 15%, and two irrigation systems, surface and subsurface drip irrigation, were compared to assess which threshold and irrigation system referred the ideal tomato seedling growth. As a result, the 12% soil moisture threshold applied through the subsurface drip irrigation system significantly (p < 0.05) increased tomato seedling growth in soil composed of a main blend of peat moss, vermiculite, and perlite. Furthermore, in two repeated experiments, a subsurface drip irrigation system with 0.86 distribution uniformity used 10% less water than the surface drip irrigation system. The produced tomato seedlings were transplanted to open fields for further assessment. A low-power wide area networking (LoRaWAN) protocol was developed with remote monitoring and controlling capability for irrigation management. Two irrigation systems, including surface and subsurface drip irrigations, were used to compare which system resulted in higher tomato yields. The results showed that the subsurface drip irrigation system with 0.74 distribution uniformity produced 1243 g/plant, while each plant produced 1061 g in the surface drip irrigation system treatment. The results also indicated that the LoRaWAN-based subsurface drip irrigation system was suitable under outdoor conditions with easy operation and robust controlling capability for tomato production.
33
Menberg, K., P. Blum, B. L. Kurylyk, and P. Bayer. "Observed groundwater temperature response to recent climate change." Hydrology and Earth System Sciences 18, no. 11 (November 6, 2014): 4453–66. http://dx.doi.org/10.5194/hess-18-4453-2014.
Abstract:
Abstract. Climate change is known to have a considerable influence on many components of the hydrological cycle. Yet, the implications for groundwater temperature, as an important driver for groundwater quality, thermal use and storage, are not yet comprehensively understood. Furthermore, few studies have examined the implications of climate-change-induced groundwater temperature rise for groundwater-dependent ecosystems. Here, we examine the coupling of atmospheric and groundwater warming by employing stochastic and deterministic models. Firstly, several decades of temperature time series are statistically analyzed with regard to climate regime shifts (CRSs) in the long-term mean. The observed increases in shallow groundwater temperatures can be associated with preceding positive shifts in regional surface air temperatures, which are in turn linked to global air temperature changes. The temperature data are also analyzed with an analytical solution to the conduction–advection heat transfer equation to investigate how subsurface heat transfer processes control the propagation of the surface temperature signals into the subsurface. In three of the four monitoring wells, the predicted groundwater temperature increases driven by the regime shifts at the surface boundary condition generally concur with the observed groundwater temperature trends. Due to complex interactions at the ground surface and the heat capacity of the unsaturated zone, the thermal signals from distinct changes in air temperature are damped and delayed in the subsurface, causing a more gradual increase in groundwater temperatures. These signals can have a significant impact on large-scale groundwater temperatures in shallow and economically important aquifers. These findings demonstrate that shallow groundwater temperatures have responded rapidly to recent climate change and thus provide insight into the vulnerability of aquifers and groundwater-dependent ecosystems to future climate change.
34
Wang, Shichao, Jun Song, Junru Guo, Yanzhao Fu, Yu Cai, and Linhui Wang. "The Investigation of the Response Mechanism of SST and Chlorophyll to Super Typhoon “Rey” in the South China Sea." Water 16, no. 4 (February 18, 2024): 603. http://dx.doi.org/10.3390/w16040603.
Abstract:
As one of the most significant disturbance sources in the upper marine environment of the South China Sea, tropical cyclones (typhoons) serve as a typical research subject for investigating the energy transfer process between the ocean and atmosphere. Utilizing satellite remote sensing data and focusing on Typhoon Rey No. 22’s transit event in 2021, this study quantitatively analyzes typhoon-induced energy input through heat pumping and cold suction at both surface and subsurface levels of the ocean. Additionally, it explores the response characteristics and feedback mechanisms of sea surface temperature (SST) and chlorophyll-a concentration (Chl-a) in the South China Sea to typhoon events. The research results show that the SST variation along the typhoon track displayed an asymmetric pattern, with a more pronounced warming on the right side and a cold anomaly lasting for 3–5 days on the left side. The subsurface warm anomaly dominated on the right side, showing a maximum temperature difference of 1.54 °C, whereas Ekman suction-induced upwelling led to cooling effects both at the subsurface and surface level on the left side, resulting in a maximum temperature difference of −3.28 °C. During the typhoon event, there was a significant decrease in sea surface heat flux, reaching 323.36 W/m2, accompanied by corresponding changes in SST due to processes such as upwelling, seawater mixing, and air–sea heat transfer dynamics where anomalies arising from oceanic dynamic processes and exchange through sea surface heat flux contributed equally. Furthermore, strong suction-induced upwelling during the typhoon influenced chlorophyll concentration within the central and western regions of the South China Sea (13.5° N–16.5° N, 111° E–112.5° E), resulting in significant enhancement and reaching its peak value at approximately 0.65 mg/L. The average chlorophyll concentration increased by approximately 0.31 mg/L.
35
Hu, Xuanyu, Bastian Gundlach, Ingo von Borstel, Jürgen Blum, and Xian Shi. "Effect of radiative heat transfer in porous comet nuclei: case study of 67P/Churyumov-Gerasimenko." Astronomy & Astrophysics 630 (September 20, 2019): A5. http://dx.doi.org/10.1051/0004-6361/201834631.
Abstract:
Context. Radiative heat transfer occurs in a porous medium, such as regolith on planetary bodies. Radiation enhances the efficiency of heat transport through the subsurface, effecting a strong temperature dependence of thermal conductivity. However, this effect has been omitted in many studies of comet 67P/Churyumov-Gerasimenko (67P). Aims. We concisely review the method for characterizing radiative heat transfer and present a generic treatment in thermal modeling. In particular, we study the impact of radiative heat transfer on 67P subject to both diurnal and seasonal variations of insolation. Methods. We adapted a numerical model based on the Crank–Nicolson scheme to estimate the subsurface temperatures and water production rate of 67P, where conductivity may vary with depth. Results. Radiative heat transfer is efficient during the day near the surface but it dicreases at night, which means that more energy is deposited underneath the diurnal thermal skin. The effect increases with pore size and accordingly, with the size of the constituent aggregates of the nucleus. It also intensifies with decreasing heliocentric distance. Close to perihelion, within 2 au, for example, radiation may raise the temperature by more than 20 K at a depth of 5 cm, compared with a purely conductive nucleus. If the nucleus is desiccated and composed of centimeter-sized aggregates, the subsurface at 0.5 m may be warmed to above 180 K. Conclusions. Radiative heat transfer is not negligible if the nucleus of 67P consists of aggregates that measure millimeters or larger. To distinguish its role and ascertain the pore size of the subsurface, measurements of temperatures from a depth of ~1 cm down to several decimeters are most diagnostic. The water production rate of the nucleus, on the other hand, does not provide a useful constraint.
36
Abromavičius, Giedrius, Martynas Skapas, and Remigijus Juškėnas. "Enhancing Laser Damage Resistance of Co2+:MgAl2O4 Crystal by Plasma Etching." Applied Sciences 13, no. 2 (January 14, 2023): 1150. http://dx.doi.org/10.3390/app13021150.
Abstract:
Co2+:MgAl2O4 crystals are successfully used as passive Q-switches within the cavity of erbium glass lasers. Their limited resistance to laser radiation might also put constraints on the generated output peak power. Usually, polishing of optical substrates induces a contaminated Beilby layer and damages the subsurface layer, which leads to a considerably lower optical resistance of the obtained surface. Low-energy oxygen plasma etching using different depths of 50, 100, 250 and 400 nm was performed on polished crystals. The surface morphology by atomic force microscopy, transmission spectra, subsurface structure by transmission electron microscopy and the LIDT (R(1)-in-1) using 1540 nm nanosecond pulses were analyzed. It was demonstrated that plasma etching substantially increased the initial crystal surface LIDT. It also allowed the removal of the damaged subsurface layer and almost maintained the initial surface roughness. The presented results demonstrated the good potential of oxygen plasma etching for obtaining highly laser-damage-resistant Co2+:MgAl2O4 crystals for high-power laser applications.
37
Menberg, K., P. Blum, B. L. Kurylyk, and P. Bayer. "Observed groundwater temperature response to recent climate change." Hydrology and Earth System Sciences Discussions 11, no. 3 (March 28, 2014): 3637–73. http://dx.doi.org/10.5194/hessd-11-3637-2014.
Abstract:
Abstract. Climate change is known to have a considerable influence on many components of the hydrological cycle. Yet, the implications for groundwater temperature, as an important driver for groundwater quality, thermal use and storage, are not yet comprehensively understood. Furthermore, few studies have examined the implications of climate change-induced groundwater temperature rise for groundwater-dependent ecosystems. Here, we examine the coupling of atmospheric and groundwater warming by employing stochastic and deterministic models. Firstly, several decades of temperature time-series are statistically analyzed with regard to abrupt climate regime shifts (CRS) in the long-term mean. The observed abrupt increases in shallow groundwater temperatures can be associated with preceding positive shifts in regional surface air temperatures, which are in turn linked to global air temperature changes. The temperature data are also analyzed with an analytical solution to the conduction-advection heat transfer equation to investigate how subsurface heat transfer processes control the propagation of the surface temperature signals into the subsurface. In three of the four monitoring wells, the predicted groundwater temperature increases driven by the regime shifts at the surface boundary condition generally concur with the observed groundwater temperature trends. Due to complex interactions at the ground surface and the heat capacity of the unsaturated zone, the thermal signals from distinct changes in air temperature are damped and delayed in the subsurface, causing a more gradual increase in groundwater temperatures. These signals can have a significant impact on large-scale groundwater temperatures in shallow and economically important aquifers. These findings demonstrate that shallow groundwater temperatures have responded rapidly to recent climate change and thus provide insight into the vulnerability of aquifers and groundwater-dependent ecosystems to future climate change.
38
Ognean, T. "A New Dimensionless Criterion for the Oxygen Transfer Efficiency in Both Surface and Subsurface Aeration Systems." Water Science and Technology 26, no. 9-11 (November 1, 1992): 2531–34. http://dx.doi.org/10.2166/wst.1992.0780.
Abstract:
The effect of power consumption on oxygen transfer efficiency has been evaluated in both surface and subsurface aeration systems. For this purpose a new dimensionless number To, named “efficiency criterion”, has been proposed.Using this number, the efficiency of different aeration systems could be compared.The comparison has been achieved by taking into consideration the data furnished by full-scale experimental models.The results have proved that of two aerators with identical diameters and the same rotational velocity reaching the maximum To, the one with a higher power consumption had a higher efficiency.The results regarding the subsurface aeration systems show that the efficiency of aeration equipment can be continuously increased if the bubbles' diameters are decreased.
39
Guerlin, Th, H. Niedrig, and M. Sternberg. "Investigation of Ion Beam Sputter Mechanisms by Electron Beam Techniques." Proceedings, annual meeting, Electron Microscopy Society of America 48, no. 2 (August 12, 1990): 386–87. http://dx.doi.org/10.1017/s0424820100135538.
Abstract:
The mechanisms of unisotropic atomic emission from single crystals under ion bombardment (Ar+, E < 25keV) have been investigated by depositing the sputtered atoms in a semi-spherical collector. A subsequent determination of the thickness distributions of the deposited films by electron backscattering gives the total angular atomic emission distribution, showing maxima in certain crystallographic directions of the sputtered target crystal: Wehner spots.Several mechanisms for the appearance of spot patterns are discussed in the literature:1.For normal incidence of the ions collision cascades are assumed with finally isotropic momentum distributions within the target crystal. Then a momentum transfer to atoms near the target surface may be possible by the following models (fig. 1):1a.Collision sequences along close packed atomic chains (e.g. the <110> direction in fcc crystals). If the residual collision energy exceeds the surface binding energy the atom at the surface end of the chain is emitted into the chain direction: Focusson model (fig. 1a).1b.Emission of subsurface atoms through potential minima between surface atoms (fig. 1b), and emission of surface atoms by central collision of subsurface atoms (fig. 1c). Both processes lead to emission into preferred directions: Surface model.
40
Kosai, Koji, Yugang Zhao, and Jiwang Yan. "Crack Propagation Behavior of Fused Silica during Cyclic Indentation under Incremental Loads." Applied Sciences 12, no. 13 (June 29, 2022): 6589. http://dx.doi.org/10.3390/app12136589.
Abstract:
Fused silica is an important optical material with important applications, where the surface must be precisely machined without subsurface damage. In this study, multi-cyclic indentations under incremental loads were performed on fused silica using two kinds of indenters to clarify the mechanisms of crack generation and propagation induced by precision grinding. It was found that incremental loading cyclic nanoindentation induced various patterns of subsurface cracking and surface spalling. Four kinds of surface spalling were identified at different locations around an indent, the temporal formation mechanisms of which were clarified by microscopic observation and topographical measurement. Load–displacement curve analysis demonstrated that incremental propagation of lateral cracks during early indentation cycles caused large-scale brittle fractures during later cycles. Compared with a Berkovich indenter, a cube-corner indenter caused more significant brittle fractures and surface spalling. The findings in this study will deepen the understanding of subsurface damaging mechanism of fused silica and other brittle solids caused by cyclic tool-workpiece interactions in grinding and other mechanical machining processes.
41
Boulet, Anne-K., Sergio A. Prats, Maruxa C. Malvar, Oscar González-Pelayo, Celeste O. A. Coelho, Antonio J. D. Ferreira, and Jan J. Keizer. "Surface and subsurface flow in eucalyptus plantations in north-central Portugal." Journal of Hydrology and Hydromechanics 63, no. 3 (September 1, 2015): 193–200. http://dx.doi.org/10.1515/johh-2015-0015.
Abstract:
Abstract In the Baixo Vouga region of north-central Portugal, forests occupy half of the territory, of which two thirds are Eucalypts plantations. The hydrological implications of this large-scale introduction of eucalypt are unknown and the aim of this exploratory study, realized in the Caramulo Mountains, was to describe overland flow (OLF), subsurface flow (SSF) and stream flow (Q) in a catchment dominated by Eucalyptus plantations. The main conclusions are that annual OLF rate is low, spatially heterogeneous between 0.1% and 6% and concentrated during the wet season as saturation excess, particularly as return flow. Infiltration-excess OLF due to the strong soil water repellence (SWR) is dominant during dry season, but produces residual runoff amount. SSF is the principal mechanism of runoff formation. It originates from matrix flow and pipe flow at the soil-bedrock interface, principally during the wet season. Matrix flow is correlated with soil moisture (SM) content, with a threshold of 25 %. Pipe flow starts with saturation of soil bottom but without saturation of the entire soil profile, due to a large network of macropores. Stream flow response is highly correlated with matrix flow behaviour in timing and intensity. SWR induces a very patchy moistening of the soil, concentrates the fluxes and accelerates them almost 100 times greater than normal percolation of the water in the matrix.
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Huynh, Thi My Dung, Van Hiep Huynh, Minh Triet Pham, Kyra Kamille A. Toledo, and Tan Hung Nguyen. "Numerical Modelling Study of Subsurface Drainage of Permeable Friction Course Considering Road Geometric Designs." Applied Sciences 13, no. 22 (November 17, 2023): 12428. http://dx.doi.org/10.3390/app132212428.
Abstract:
This study aimed to evaluate the subsurface drainage of a permeable friction course (PFC) via two-dimensional finite element analysis. To achieve the scope, PFCs with equivalent water flow paths of length values of 10, 15, 20, and 30 m and slope values of 0.5%, 2%, 4%, 6%, and 8% were modelled based on FEniCS and implemented entirely in Python programing language to extract the time for surface ponding according to a range of rainfall intensities. The results show that when the rainfall intensity and the length of equivalent water flow path of the PFC rose, the time for surface ponding decreased. For instance, with a rainfall intensity of 10 mm/h and a slope of 0.5%, when the length of equivalent water flow path increased by 20 m, the time for surface ponding dropped by 21 min. Moreover, when the slope of the equivalent water flow path and the thickness of the PFC increased, the time for surface ponding increased. For instance, with a rainfall intensity of 10 mm/h, and a PFC with an equivalent length of 10 m, when the slope increased by 16 times, the time for surface ponding increased more than two times. The current study highlights that the thickness of the PFC has the most influence on subsurface drainage. The findings of this study indicate that at high rainfall intensities, the subsurface drainage of a PFC is not sensitive to its geometric design. Further experimental investigations are needed to evaluate and validate the subsurface drainage of a PFC considering permeability, rutting, and environmental factors.
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Bressac, Matthieu, Thibaut Wagener, Nathalie Leblond, Antonio Tovar-Sánchez, Céline Ridame, Vincent Taillandier, Samuel Albani, et al. "Subsurface iron accumulation and rapid aluminum removal in the Mediterranean following African dust deposition." Biogeosciences 18, no. 24 (December 15, 2021): 6435–53. http://dx.doi.org/10.5194/bg-18-6435-2021.
Abstract:
Abstract. Mineral dust deposition is an important supply mechanism for trace elements in the low-latitude ocean. Our understanding of the controls of such inputs has been mostly built on laboratory and surface ocean studies. The lack of direct observations and the tendency to focus on near-surface waters prevent a comprehensive evaluation of the role of dust in oceanic biogeochemical cycles. In the frame of the PEACETIME project (ProcEss studies at the Air-sEa Interface after dust deposition in the MEditerranean sea), the responses of the aluminum (Al) and iron (Fe) cycles to two dust wet deposition events over the central and western Mediterranean Sea were investigated at a timescale of hours to days using a comprehensive dataset gathering dissolved and suspended particulate concentrations, along with sinking fluxes. Dissolved Al (dAl) removal was dominant over dAl released from dust. The Fe/Al ratio of suspended and sinking particles revealed that biogenic particles, and in particular diatoms, were key in accumulating and exporting Al relative to Fe. By combining these observations with published Al/Si ratios of diatoms, we show that adsorption onto biogenic particles, rather than active uptake, represents the main sink for dAl in Mediterranean waters. In contrast, systematic dissolved Fe (dFe) accumulation occurred in subsurface waters (∼ 100–1000 m), while dFe input from dust was only transient in the surface mixed layer. The rapid transfer of dust to depth, the Fe-binding ligand pool in excess to dFe in subsurface (while nearly saturated in surface), and low scavenging rates in this particle-poor depth horizon are all important drivers of this subsurface dFe enrichment. At the annual scale, this previously overlooked mechanism may represent an additional pathway of dFe supply for the surface ocean through diapycnal diffusion and vertical mixing. However, low subsurface dFe concentrations observed at the basin scale (< 0.5 nmol kg−1) cause us to question the residence time for this dust-derived subsurface reservoir and hence its role as a supply mechanism for the surface ocean, stressing the need for further studies. Finally, these contrasting responses indicate that dAl is a poor tracer of dFe input in the Mediterranean Sea.
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Liu, Xinqi, Lingyu Yin, Hongtu He, Youze Ma, Qiuju Zheng, Laixi Sun, Fang Wang, Jiaxin Yu, and Yong Cai. "Effect of H2O2 Treatment on Mechanical and Mechanochemical Properties of Fused Silica." Applied Sciences 13, no. 13 (June 28, 2023): 7636. http://dx.doi.org/10.3390/app13137636.
Abstract:
The surface properties of fused silica (FS) change after H2O2 treatment, but the surface and subsurface damage behaviors and their mechanisms under various physical contact conditions have not been elucidated yet. This work investigated the effect of H2O2 treatment on mechanical and mechanochemical properties of FS surface. The results show that the hydrophilicity and adsorbed water film thickness of the FS surface increase with the concentration of H2O2 solution. The surface damage, nanowear, and subsurface deformation of FS caused by indentation increase with the concentration of H2O2 solution, while the nanohardness and reduced modulus decrease. Further analysis revealed that the water activity on the FS surface plays a critical role in reducing the mechanical and mechanochemical properties. In addition, the treatment with H2O2 solution on the FS surface shows a weakly corrosive effect, which implies the H2O2 treatment can be an alternative method to remove the surface defects on FS optics.
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Kurylyk, B. L., C. P. A. Bourque, and K. T. B. MacQuarrie. "Potential surface temperature and shallow groundwater temperature response to climate change: an example from a small forested catchment in east-central New Brunswick (Canada)." Hydrology and Earth System Sciences 17, no. 7 (July 11, 2013): 2701–16. http://dx.doi.org/10.5194/hess-17-2701-2013.
Abstract:
Abstract. Global climate models project significant changes to air temperature and precipitation regimes in many regions of the Northern Hemisphere. These meteorological changes will have associated impacts to surface and shallow subsurface thermal regimes, which are of interest to practitioners and researchers in many disciplines of the natural sciences. For example, groundwater temperature is critical for providing and sustaining suitable thermal habitat for cold-water salmonids. To investigate the surface and subsurface thermal effects of atmospheric climate change, seven downscaled climate scenarios (2046–2065) for a small forested catchment in New Brunswick, Canada were employed to drive the surface energy and moisture flux model, ForHyM2. Results from these seven simulations indicate that climate change-induced increases in air temperature and changes in snow cover could increase summer surface temperatures (range −0.30 to +3.49 °C, mean +1.49 °C), but decrease winter surface temperatures (range −1.12 to +0.08 °C, mean −0.53 °C) compared to the reference period simulation. Thus, changes to the timing and duration of snow cover will likely decouple changes in mean annual air temperature (mean +2.11 °C) and mean annual ground surface temperature (mean +1.06 °C). Projected surface temperature data were then used to drive an empirical surface to groundwater temperature transfer function developed from measured surface and groundwater temperature. Results from the empirical transfer function suggest that changes in groundwater temperature will exhibit seasonality at shallow depths (1.5 m), but be seasonally constant and approximately equivalent to the change in the mean annual surface temperature at deeper depths (8.75 m). The simulated increases in future groundwater temperature suggest that the thermal sensitivity of baseflow-dominated streams to decadal climate change may be greater than previous studies have indicated.
46
Kurylyk, B. L., C. P. A. Bourque, and K. T. B. MacQuarrie. "Potential surface temperature and shallow groundwater temperature response to climate change: an example from a small forested catchment in east-central New Brunswick (Canada)." Hydrology and Earth System Sciences Discussions 10, no. 3 (March 13, 2013): 3283–326. http://dx.doi.org/10.5194/hessd-10-3283-2013.
Abstract:
Abstract. Global climate models project significant changes to the air temperature and precipitation regimes in some regions of the Northern Hemisphere. These meteorological changes will have associated impacts to the surface and shallow subsurface thermal regimes, which are of interest to practitioners and researchers in many disciplines of the natural sciences. For example, groundwater temperature is critical for providing and sustaining suitable thermal habitat for cold-water salmonids. To investigate the surface and subsurface thermal effects of atmospheric climate change, seven downscaled climate scenarios (2046–2065) for a small forested catchment in New Brunswick, Canada were employed to drive the surface energy and moisture flux model, ForHyM2. Results from these seven simulations indicate that climate change-induced increases in air temperature and changes in snow cover could increase summer surface temperatures (range −0.30 to +3.49 °C, mean +1.49 °C), but decrease winter surface temperatures (range −1.12 to +0.08 °C, mean −0.53 °C) compared to the reference period simulation. Thus, changes to the timing and duration of snow cover will likely decouple changes in average annual air temperature (mean +2.11 °C) and average annual ground surface temperature (mean +1.06 °C). The projected surface temperature data were then used to drive an empirical surface to groundwater temperature transfer function developed from measured surface temperature and depth-dependent groundwater temperature. Results from the empirical transfer function indicated that the change in groundwater temperature will exhibit seasonality at shallow depths (1.5 m), but be seasonally constant and approximately equivalent to the change in the mean annual surface temperature at deeper depths (8.75 m). The increases in future groundwater temperature suggest that the thermal sensitivity of baseflow-dominated stream to decadal climate change may be greater than previous studies have indicated. The ecological significance of these findings is discussed.
47
Hemmerle, Hannes, Sina Hale, Ingo Dressel, Susanne A. Benz, Guillaume Attard, Philipp Blum, and Peter Bayer. "Estimation of Groundwater Temperatures in Paris, France." Geofluids 2019 (June 17, 2019): 1–11. http://dx.doi.org/10.1155/2019/5246307.
Abstract:
Subsurface temperature data is usually only accessible as point information with a very limited number of observations. To spatialize these isolated insights underground, we usually rely on interpolation methods. Unfortunately, these conventional tools are in many cases not suitable to be applied to areas with high local variability, like densely populated areas, and in addition are very vulnerable to uneven distributions of wells. Since thermal conditions of the surface and shallow subsurface are coupled, we can utilize this relationship to estimate shallow groundwater temperatures from satellite-derived land surface temperatures. Here, we propose an estimation approach that provides spatial groundwater temperature data and can be applied to natural, urban, and mixed environments. To achieve this, we combine land surface temperatures with anthropogenic and natural processes, such as downward heat transfer from buildings, insulation through snow coverage, and latent heat flux in the form of evapotranspiration. This is demonstrated for the city of Paris, where measurements from as early as 1977 reveal the existence of a substantial subsurface urban heat island (SUHI) with a maximum groundwater temperature anomaly of around 7 K. It is demonstrated that groundwater temperatures in Paris can be well predicted with a root mean squared error of below 1 K by means of satellite-derived land surface images. This combined approach is shown to improve existing estimation procedures that are focused either on rural or on urban conditions. While they do not detect local hotspots caused by small-scaled heat sources located underground (e.g., sewage systems and tunnels), the findings for the city of Paris for the estimation of large-scale thermal anomalies in the subsurface are promising. Thus, the new estimation procedure may also be suitable for other cities to obtain a more reliable insight into the spatial distribution of urban ground and groundwater temperatures.
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Webb, Ralph L. "Donald Q. Kern Lecture Award Paper: Odyssey of the Enhanced Boiling Surface." Journal of Heat Transfer 126, no. 6 (December 1, 2004): 1051–59. http://dx.doi.org/10.1115/1.1834615.
Abstract:
This paper traces the evolution of enhanced boiling surfaces. Early work was highly empirical and done in industrial research. The 1968 Milton patent [“Heat Exchange System,” U.S. Patent 3,696,861] described the first porous coated surface, and the 1972 Webb patent [“Heat Transfer Surface Having a High Boiling Heat Transfer Coefficient,” U.S. Patent 3,521,708] described a “structured” tube surface geometry. The first fundamental understanding of the “pore-and-tunnel” geometry was published by Nakayama in 1980 [Nakayama, W., Daikoku, T., Kuwahara, H., and Nakajima, T. 1980, “Dynamic Model of Enhanced Boiling Heat Transfer on Porous Surfaces Part I: Experimental Investigation,” J. Heat Transfer, 102, pp. 445–450]. Webb and Chien’s flow visualization allowed observation of the evaporation in the subsurface tunnels [Chien, L.-H., and Webb, R. L., 1998, “Visualization of Pool Boiling on Enhanced Surfaces,” Exp. Fluid Thermal Sci., 16b, pp. 332–341]. They also performed an experimental parametric study that defines the effect of pore diameter and pitch on the boiling performance. The progression of work on analytical boiling models is also reviewed.
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Harishidayat, Dicky, Abdullatif Al-Shuhail, Giovanni Randazzo, Stefania Lanza, and Anselme Muzirafuti. "Reconstruction of Land and Marine Features by Seismic and Surface Geomorphology Techniques." Applied Sciences 12, no. 19 (September 24, 2022): 9611. http://dx.doi.org/10.3390/app12199611.
Abstract:
Seismic reflection utilizes sound waves transmitted into the subsurface, reflected at rock boundaries, and recorded at the surface. Interpretation of their travel times and amplitudes are the key for reconstructing various geomorphological features across geological time (e.g., reefs, dunes, and channels). Furthermore, the integration of surface geomorphology technique mapping, such as digital elevation models, with seismic geomorphology can increase land and marine feature modelling and reduce data uncertainty, as well. This paper presents an overview of seismic and surface geomorphology techniques and proposes an integrated workflow for better geological mapping, 3D surface imaging, and reconstruction. We intend to identify which techniques are more often used and which approaches are more appropriate for better output results. We noticed that an integration of surface and subsurface geomorphology techniques could be beneficial for society in landscape mapping, reservoir characterization, and city/regional planning.
50
Stango, R. J., R. A. Fournelle, and S. Chada. "Morphology of Surfaces Generated by Circular Wire Brushes." Journal of Engineering for Industry 117, no. 1 (February 1, 1995): 9–15. http://dx.doi.org/10.1115/1.2803285.
Abstract:
The characteristic surface that is generated during orthogonal wire brushing of a flat 6061-T6 aluminum workpart is examined in this paper. Scanning electron microscopy is used for characterizing the surface topography, whereas subsurface microstructure and properties of the brushed region are evaluated by both metallography and microhardness measurements. The unique topographical characteristics of the contact zone suggest material removal and subsequent redeposition onto the workpart. On the basis of the experimental observations, a qualitative theory is advanced which identifies transfer mechanisms for removal and redeposition of aluminum alloy.