Academic literature on the topic 'Diurnal heating'
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Journal articles on the topic "Diurnal heating"
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Jiang, Qingfang. "On Offshore Propagating Diurnal Waves." Journal of the Atmospheric Sciences 69, no. 5 (May 1, 2012): 1562–81. http://dx.doi.org/10.1175/jas-d-11-0220.1.
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Abstract Characteristics and dynamics of offshore diurnal waves induced by land–sea differential heating are examined using linear theory. Two types of heating profiles are investigated, namely a shallow heating source confined within an atmospheric boundary layer (BL) and a deep heating source located above the boundary layer. It is demonstrated that a boundary layer top inversion or a more stable layer aloft tends to partially trap diurnal waves in the BL and consequently extend perturbations well offshore. The wave amplitude decays with offshore distance due to BL friction and leakage of energy into the free atmosphere. The dependence of trapped waves on the inversion height and strength, atmosphere stratification, latitude, BL friction, and background winds is investigated. Diurnal waves generated by a deep heating source extending well above the BL are characterized by longer wavelengths, faster propagation, and substantially longer e-folding decay distances than waves induced by a BL source. For the latter, BL friction has little impact on the e-folding decay distance, as waves are mostly located in the free atmosphere rather than in a frictional BL.
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Navarro, Erika L., Gregory J. Hakim, and Hugh E. Willoughby. "Balanced Response of an Axisymmetric Tropical Cyclone to Periodic Diurnal Heating." Journal of the Atmospheric Sciences 74, no. 10 (September 27, 2017): 3325–37. http://dx.doi.org/10.1175/jas-d-16-0279.1.
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Abstract A modified version of the Sawyer–Eliassen equation is applied to determine the impact of periodic diurnal heating on a balanced vortex. The TC diurnal cycle is a coherent signal that arises in the cirrus canopy. However, despite thorough documentation in the literature, the dynamical mechanism remains unknown. Recent work demonstrates that periodic radiative heating in the TC outflow layer is linked with an anomalous upper-level circulation; this heating is also associated with a cycle of latent heating in the lower troposphere that corresponds to a cycle in storm intensity. Using a method that is analogous to the Sawyer–Eliassen equation, but for solutions having the same time scale as time-periodic forcing, these distributions are analyzed to determine the effect of periodic diurnal heating on an axisymmetric vortex. Results for periodic heating in the lower troposphere show an overturning circulation that resembles the Sawyer–Eliassen solution. The model simulates positive perturbations in the azimuthal wind field of 2.5 m s−1 near the radius of maximum wind. Periodic heating near the top of the vortex produces a local overturning response in the region of heating and an inertia–buoyancy wave response in the storm environment. Comparison of the results from the modified Sawyer–Eliassen equation to those of an idealized axisymmetric solution for both heating distributions shows similarities in the structure of the perturbation wind fields, suggesting that the axisymmetric TC diurnal cycle is primarily a balanced response driven by periodic heating.
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Johnson, Richard H., Paul E. Ciesielski, Tristan S. L’Ecuyer, and Andrew J. Newman. "Diurnal Cycle of Convection during the 2004 North American Monsoon Experiment." Journal of Climate 23, no. 5 (March 1, 2010): 1060–78. http://dx.doi.org/10.1175/2009jcli3275.1.
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Abstract The diurnal cycle of summer monsoon convection in the coastal, mountainous region of northwestern Mexico is investigated using data from the 2004 North American Monsoon Experiment (NAME). Data from a special sounding network consisting of research and operational sites have been quality controlled and combined with surface, wind profiler, and pibal observations to create a gridded dataset over the NAME domain. This study concentrates on results from the interior portion of the NAME sounding network, where gridded analysis fields are independent of model data. Special attention is given to surface and pibal observations along the western slope of the Sierra Madre Occidental (SMO) in order to obtain an optimal analysis of the diurnally varying slope flows. Results show a prominent sea-breeze–land-breeze cycle along the western slopes of the SMO. There is a deep return flow above the afternoon sea breeze as a consequence of the elevated SMO immediately to the east. The upslope flow along the western slope of the SMO is delayed until late morning, likely in response to early morning low clouds over the SMO crest and reduced morning insolation over the west-facing slopes. The diurnal cycle of the net radiative heating rate is characterized by a net cooling during most of the daytime except for net heating in the lower and upper troposphere at midday. The diurnal cycle of the apparent heat source Q1 minus the radiative heating rate QR (providing a measure of net condensational heating) and the apparent moisture sink Q2 over the SMO is indicative of shallow convection around noon, deep convection at 1800 LT, evolving to stratiform precipitation by midnight, consistent with the radar-observed diurnal evolution of precipitation over this coastal mountainous region as well as the typical evolution of tropical convective systems across a wide range of spatial and temporal scales. Convection over the Gulf of California is strikingly different from that over land, namely, heating and moistening are confined principally to the lower troposphere below 700 hPa, peaking during the nighttime hours.
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Evans, Rebecca C., and David S. Nolan. "Balanced and Radiating Wave Responses to Diurnal Heating in Tropical Cyclone–Like Vortices Using a Linear Nonhydrostatic Model." Journal of the Atmospheric Sciences 76, no. 8 (August 1, 2019): 2575–97. http://dx.doi.org/10.1175/jas-d-18-0361.1.
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Abstract The diurnal cycle (DC) in the cirrus canopy of tropical cyclones (TCs) is a well-documented phenomenon. While early studies linked the DC in the area of the cirrus canopy to a DC in the strength of eyewall convection, later studies considered it a direct response to the DC of radiation in the cirrus canopy. In this study, an idealized linear model is used to examine the extent to which linear dynamics can capture the DC in TCs, in particular the transition between balanced and radiating responses to diurnal heating. The model heat forcing is physically motivated by the diabatic heating output from a realistic simulation, which illustrates the presence of a DC in moist convective heating and radiative heating in the eyewall, and a DC in radiative heating in the cirrus canopy. This study finds that the DCs of heating in the eyewall yield a response that is restricted to inside the RMW by the high inertial stability in the inner core. The DC of radiative heating in the cirrus canopy yields a response throughout the entire cyclone. Lower-frequency responses, of diurnal and semidiurnal frequency, are balanced throughout much of the cyclone. High-frequency waves with periods under 8 h, created at sunrise and sunset, can radiate outward and downward. These results indicate that diurnal responses are balanced in the majority of a TC and originate in the cirrus canopy, instead of the eyewall. The DC in cirrus canopy vertical motion also appears to originate in the cirrus canopy.
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VICHARE, GEETA, and R. RAJARAM. "Diurnal and semi-diurnal tidal structures due to O2, O3 and H2O heating." Journal of Earth System Science 122, no. 5 (October 2013): 1207–17. http://dx.doi.org/10.1007/s12040-013-0353-4.
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Wall, Casey J., Joel R. Norris, Blaž Gasparini, William L. Smith, Mandana M. Thieman, and Odran Sourdeval. "Observational Evidence that Radiative Heating Modifies the Life Cycle of Tropical Anvil Clouds." Journal of Climate 33, no. 20 (October 15, 2020): 8621–40. http://dx.doi.org/10.1175/jcli-d-20-0204.1.
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AbstractA variety of satellite and ground-based observations are used to study how diurnal variations of cloud radiative heating affect the life cycle of anvil clouds over the tropical western Pacific Ocean. High clouds thicker than 2 km experience longwave heating at cloud base, longwave cooling at cloud top, and shortwave heating at cloud top. The shortwave and longwave effects have similar magnitudes during midday, but only the longwave effect is present at night, so high clouds experience a substantial diurnal cycle of radiative heating. Furthermore, anvil clouds are more persistent or laterally expansive during daytime. This cannot be explained by variations of convective intensity or geographic patterns of convection, suggesting that shortwave heating causes anvil clouds to persist longer or spread over a larger area. It is then investigated if shortwave heating modifies anvil development by altering turbulence in the cloud. According to one theory, radiative heating drives turbulent overturning within anvil clouds that can be sufficiently vigorous to cause ice nucleation in the updrafts, thereby extending the cloud lifetime. High-frequency air motion and ice-crystal number concentration are shown to be inversely related near cloud top, however. This suggests that turbulence depletes or disperses ice crystals at a faster rate than it nucleates them, so another mechanism must cause the diurnal variation of anvil clouds. It is hypothesized that radiative heating affects anvil development primarily by inducing a mesoscale circulation that offsets gravitational settling of cloud particles.
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Kelly, Patrick, and Brian Mapes. "Land Surface Heating and the North American Monsoon Anticyclone: Model Evaluation from Diurnal to Seasonal." Journal of Climate 23, no. 15 (August 1, 2010): 4096–106. http://dx.doi.org/10.1175/2010jcli3332.1.
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Abstract Data from several regional and global models (including model-based analysis data) are compared with field data from the North American Monsoon Experiment (NAME), from observational sites as well as satellite retrievals. On the regional scale (NAME tier 1.5), sensible heating is shown to exceed latent and is furthermore concentrated in the lower half of the troposphere, so in considering the North American monsoon (NAM) midlevel anticyclone, the authors focus on radiative and turbulent energy fluxes at the surface. Models exhibit large discrepancies in their simulation of the mean diurnal cycle of these fluxes as well as in their sensitivity of evaporative fraction to recent rainfall. Most of the models examined have too much net radiation due to excessive shortwave surface flux (too little cloud) and too much sensible heating. These high biases in sensible heating appear to drive overpredictions of both the daily and seasonal rise of 500-hPa heights in the NAM anticyclone. This diurnal–seasonal resemblance suggests that calibrating surface heating processes using readily field-observed diurnal variations could lead to improvements in seasonal-time-scale NAM simulations.
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Hughes, Kenneth G., James N. Moum, and Emily L. Shroyer. "Heat Transport through Diurnal Warm Layers." Journal of Physical Oceanography 50, no. 10 (October 1, 2020): 2885–905. http://dx.doi.org/10.1175/jpo-d-20-0079.1.
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AbstractPenetration of solar radiation in the upper few meters of the ocean creates a near-surface, stratified diurnal warm layer. Wind stress accelerates a diurnal jet in this layer. Turbulence generated at the diurnal thermocline, where the shear of the diurnal jet is concentrated, redistributes heat downward via mixing. New measurements of temperature and turbulence from fast thermistors on a surface-following platform depict the details of this sequence in both time and depth. Temporally, the sequence at a fixed depth follows a counterclockwise path in logϵ–logN parameter space. This path also captures the evolution of buoyancy Reynolds number (a proxy for the anisotropy of the turbulence) and Ozmidov scale (a proxy for the outer vertical length scale of turbulence in the absence of the free surface). Vertically, the solar heat flux always leads to heating of fluid parcels in the upper few meters, whereas the turbulent heat flux divergence changes sign across the depth of maximum vertical temperature gradient, cooling fluid parcels above and heating fluid parcels below. In general, our measurements of fluid parcel heating or cooling rates of order 0.1°C h−1 are consistent with our estimates of heat flux divergence. In weak winds (<2 m s−1), sea surface temperature (SST) is controlled by the depth-dependent absorption of solar radiation. In stronger winds, turbulent mixing controls SST.
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Li, Yanping, and Ronald B. Smith. "Observation and Theory of the Diurnal Continental Thermal Tide." Journal of the Atmospheric Sciences 67, no. 9 (September 1, 2010): 2752–65. http://dx.doi.org/10.1175/2010jas3384.1.
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Abstract Harmonic analysis of summer Automated Surface Observing System (ASOS) data over North America shows sun-following diurnal temperature and pressure oscillations with amplitudes increasing in the western United States (i.e., 5–8 K and 60–120 hPa, respectively) due to larger sensible heating in the dryer western terrains. The phases of temperature and pressure (i.e., 220° and 110°) are constant with longitude after an interfering eastward propagating wave is subtracted. Tidal amplitudes and phases shift significantly with season. A linear Boussinesq model with thermal forcing can reproduce these observed oscillations with properly selected parameters. The model neglects global effects to focus on a single transect across a single ideal continent. A damping parameter α ranging from 5 × 10−5 to 9 × 10−5 s−1, comparable to the inertia and Coriolis parameters, is needed to explain the temperature phase lag relative to local solar noon (40°–50°C). The phase lag between surface pressure minimum and temperature maximum (45°–70°C) requires a 3–5-h time delay between surface and elevated heating. The ratio of pressure and temperature amplitude requires a heating depth varying between 550 (winter) and 1250 m (summer). Both the heating delay and depth are consistent with a vertical heat diffusivity of about K = 10 m2 s−1 in winter, but K theory gives inconsistent summer K values. The observed tide amplitude requires diurnal heating amplitudes in the range of 100–250 W m−2. When the model is applied to an inhomogeneous continent, it is possible to obtain a clearer idea of how wide a region must be to approach the tidal (i.e., long-wave) limit. Traveling diurnal heating generates gentle tides over the large uniform interior regions but causes vigorous sea breezes and mountain–plain circulations in regions of heating gradient. These gradient regions have significant vertical motions and are moderately sensitive to the Coriolis force and the mean wind speed. Surprisingly, these local circulations do not alter the phases of the temperature and pressure oscillations, in agreement with observations.
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Ushijima, Yusuke, and Yutaka Yoshikawa. "Mixed Layer Depth and Sea Surface Warming under Diurnally Cycling Surface Heat Flux in the Heating Season." Journal of Physical Oceanography 49, no. 7 (July 2019): 1769–87. http://dx.doi.org/10.1175/jpo-d-18-0230.1.
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AbstractIn the present study, large-eddy simulations (LESs) were performed to investigate mixed layer depth (MLD) and sea surface warming (SSW) under diurnally cycling surface heat flux in the heating season, in which a mixed layer (ML) is shoaling on intraseasonal time scales. The LES results showed that the diurnal cycle makes the MLD greater (smaller) at lower (higher) latitudes than the MLD without the cycle. Time scales of the wind-induced shear and the surface heat are a key to understand this latitudinal dependence of the diurnal cycle effects. The wind-induced shear-driven turbulence developed from early morning and became strongest at half the inertial period (Ti/2), while nighttime cooling weakened the ML stratification until the end of the nighttime (T24 = 24 h). At lower latitudes where Ti/2 > T24 (lower than 15°), the shear-driven turbulence continued to grow after T24 and determined the time of the greatest MLD. Thus, the shear-driven turbulence shaped the latitudinal dependence of the MLD, though convective turbulence helped further deepening of the ML. At higher latitudes (Ti/2 < T24), on the other hand, the shear-driven turbulence ceased growing before the nighttime cooling ended. However, reduced stratification due to the nighttime cooling supported the shear-driven turbulence to continue deepening the ML. Thus, the nighttime cooling shaped the latitudinal dependence of the MLD at higher latitudes. The MLD change induced by the diurnal cycle altered the SSW rate. At higher latitudes, the diurnal cycle is expected to reduce the MLD and increase the SSW by 10% in the heating season.
Dissertations / Theses on the topic "Diurnal heating"
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Thomas, Karen. "A Lagrangian study of the diurnal heating of the Upper Ocean." Thesis, University of Southampton, 1986. https://eprints.soton.ac.uk/427132/.
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Kelly, Patrick. "Evaluation of Land-Atmosphere Interactions in Models of the North American Monsoon." Scholarly Repository, 2008. http://scholarlyrepository.miami.edu/oa_theses/118.
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Improving diurnal errors in surface-based heating processes in models might be a promising step towards improved seasonal simulation of the North American Monsoon (NAM). This study isolates model errors in the surface energy budget and examines diurnal heating implications for seasonal development of the NAM 500hPa anticyclone and 850-500hPa thickness ridge using observations and multi-model output. Field data from the 2004 North American Monsoon Experiment (NAME) and satellite estimates are used to evaluate land-atmosphere interactions in regional and global models as part of the North American Monsoon Model Assessment Project 2 (NAMAP2). Several key findings about heating in the NAM emerge: ? Models exhibit considerable differences in surface radiation of the NAM, beginning with albedo (Fig. 3.1). All models have highly-biased albedo throughout summer (Fig. 3.2). ? Observed net surface radiation is around 125 Wm-2 over land in the NAM region in summer (Table 3.5). Models overestimate it by an average of about 20 Wm-2, despite their high albedo, apparently due to deficiencies in cloud radiative forcing. ? Partitioning of this net radiation into latent and sensible fluxes to the atmosphere differs substantially among models. Sensitivity of this partitioning to rainfall also varies widely among models, and appears clearly excessive in some models relative to observations (Fig. 4.10). ? Total sensible heating exceeds latent heating in the NAM (Table 4.1), since it covers a much larger area than the rainy core region (Fig. 4.11). ? Inter-model differences in sensible heating can be traced consistently from surface heat flux (Table 5.1), to PBL diurnal evolution (Fig. 5.1), to diurnal thickening of the lower troposphere (Fig. 5.2). ? Seasonal biases in the NAM?s synoptic structure correspond well to diurnal heating biases (Fig. 5.3, Fig. 5.5), suggesting that diurnal cycle studies from a single field season may suffice to inform physical process improvements that could impact seasonal simulation and forecasting. These NAMAP2 results highlight the range of uncertainty and errors in contemporary models, including those defining US national weather forecasting capability. Model experimentation will be necessary to fully interpret the lessons and harvest the fruits of this offline inter-comparison exercise.
Book chapters on the topic "Diurnal heating"
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Allahdadi, Mohammad Nabi, and Chunyan Li. "Numerical Experiment of Stratification Induced by Diurnal Solar Heating Over the Louisiana Shelf." In Modeling Coastal Hypoxia, 1–22. Cham: Springer International Publishing, 2017. http://dx.doi.org/10.1007/978-3-319-54571-4_1.
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Whiteman, C. David. "Four Factors That Determine Climate." In Mountain Meteorology. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780195132717.003.0007.
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Climate differs from one location to another because of differences in • latitude, the angular distance north or south from the equator • altitude, the height above sea level • continentality, the distance from the sea • exposure to regional circulations, including winds and ocean currents. The latitude of a given site determines the length of the day and the angle of incoming sunlight and therefore the amount of solar radiation received at that site. Seasonal and diurnal (day—night) variations in the amount of solar radiation received cause seasonal and diurnal variations in the weather. Near the equator, the days of the year are all about the same length, and the noon sun is nearly overhead year-round. Because day length and solar angle change little with the season, there is little seasonal variability in the weather. In the polar regions, on the other hand, the sun does not rise at all in the winter, and in the summer it never sets, although it remains low in the sky. Thus, polar weather has a high seasonal variability, but a low diurnal variability. In the midlatitudes, the climate is characterized by both seasonal and diurnal changes. Except at the equator, day length varies throughout the year. In the Northern Hemisphere, the longest day of the year is at the summer solstice (June 21), the shortest day of the year is at the winter solstice (December 21), and the day is 12 hours long on the vernal and autumnal equinoxes (March 20 and September 22). The altitude angle of the sun also varies throughout the year, with an increase of about 47° from winter to summer. The more direct summer sunlight produces more heating than the slanted rays of the winter sun. The latitude of a given site affects its climate not only because it determines the angle of solar radiation and the length of a day, but also because it determines the site’s exposure to latitudinal belts of surface high and low pressure that encircle the earth.
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Nagorskiy, Petr Mikhailovich, Mikhail Vsevolodovich Kabanov, and Konstantin Nikolaevich Pustovalov. "The Influence of Smoke From Forest Fires on the Meteorological and Electrical Characteristics of the Atmosphere." In Predicting, Monitoring, and Assessing Forest Fire Dangers and Risks, 322–44. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-1867-0.ch014.
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The impact of smoke from forest fires in western Siberia on meteorological, atmospheric electric, and aerological variables has been analyzed. The anomalous distribution of water vapor in the atmosphere associated with the peculiarities of the evaporation regime and the absence of advective moisture transfer over the southern regions of Western Siberia during the fires. With an increase in the height of the homogeneous surface smoke layer with an unchanged aerosol optical thickness, the cooling of the earth's surface and heating of the atmosphere was weakened. The smoke plume spreads predominantly in the middle of the troposphere, creating aerosol layers elevated above the ground, the lower part of which had a negative volume charge. The effect of diurnal variations in the electrical field in the near-surface layer, differs from the known similar effects.
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Kaimal, J. C., and J. J. Finnigan. "Flow Over Flat Uniform Terrain." In Atmospheric Boundary Layer Flows. Oxford University Press, 1994. http://dx.doi.org/10.1093/oso/9780195062397.003.0004.
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We start with the simplest of boundary layers, that over an infinite flat surface. Here we can assume the flow to be horizontally homogeneous. Its statistical properties are independent of horizontal position; they vary only with height and time. This assumption of horizontal homogeneity is essential in a first approach to understanding a process already complicated by such factors as the earth's rotation, diurnal and spatial variations in surface heating, changing weather conditions, and the coexistence of convective and shear-generated turbulence. It allows us to ignore partial derivatives of mean quantities along the horizontal axes (the advection terms) in the governing equations. Only ocean surfaces come close to the idealized infinite surface. Over land we settle for surfaces that are locally homogeneous, flat plains with short uniform vegetation, where the advection terms are small enough to be negligible. If, in addition to horizontal homogeneity, we can assume stationarity, that the statistical properties of the flow do not change with time, the time derivatives in the governing equations vanish as well. This condition cannot be realized in its strict sense because of the long-term variabilities in the atmosphere. But for most applications we can treat the process as a sequence of steady states. The major simplification it permits is the introduction of time averages that represent the properties of the process and not those of the averaging time. These two conditions clear the way for us to apply fluid dynamical theories and empirical laws developed from wind tunnel studies to the atmosphere's boundary layer. We can see why micrometeorologists in the 1950s and 1960s scoured the countryside for flat uniform sites. The experiments over the plains of Nebraska, Kansas, and Minnesota (USA), Kerang and Hay (Australia), and Tsimliansk (USSR) gave us the first inklings of universal behavior in boundary layer turbulence. Our concept of the atmospheric boundary layer (ABL) and its vertical extent has changed significantly over the last few decades.
Conference papers on the topic "Diurnal heating"
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Wilson, John P., Maciej Murakowski, Christopher A. Schuetz, and Dennis W. Prather. "Simulations of polarization dependent contrast during the diurnal heating cycle for passive millimeter-wave imagery." In SPIE Optical Engineering + Applications, edited by Joseph A. Shaw and Daniel A. LeMaster. SPIE, 2013. http://dx.doi.org/10.1117/12.2022534.
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Nielson, Jordan, and Kiran Bhaganagar. "Using LES to Understand Wake Evolution During the Diurnal Cycle." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-52045.
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Numerical study using actuator-line method based Large Eddy Simulation (LES) has been performed to understand the role of atmospheric stability on the wake effects of horizontal-axis full-scale 5-MW wind turbine (WT). The paper will specifically focus on using specific instances in the diurnal cycle corresponding to stable, neutral and unstable ABL state to gain understanding on the transient aerodynamics of a wind turbine throughout the diurnal cycle. Capturing accurate Atmospheric Boundary Layer (ABL) characteristics is key factor in improving the accuracy of WT model predictions as turbulence developed in the ABL has potential to adversely affect the fatigue lifetime and performance of wind turbines. ABL simulations for the diurnal cycle are performed to isolate the key ABL metrics such as surface momentum flux, boundary layer height, surface temperature flux, wind shear, and temperature gradient that influence the wake evolution of WT. Precursor ABL inflow is generated for the WT simulations. The positive heat flux on the surface causes high vertical velocity fluctuations described with streaks and updraft motions during the day while surface cooling rates result in increased shear and strong temperature gradients during the night. The surface temperature, geostrophic wind velocity, heating/cooling rates, and period of the diurnal cycle are varied in different simulations to compare turbulent statistics and the helical vortices of the wind turbine wake. The results have revealed surface temperature and surface flux are the important ABL metrics that have a strong effect on altering the turbulence in the WT wake. In addition, instabilities related to WT blade rotation exhibit sensitivity to ABL metrics. The positive heat flux shows higher mixing and causes large wake movement in the day-time conditions. The results aid in quantifying the movement of the wake at different times of the diurnal cycle. During night-time conditions mixing is low, causing slower wake recovery times. This is the first study to clearly isolate the key ABL metrics that influence the full-scale WT near-wake effects The study has implications in improving the predictions of WT power loss due to wake deficits. Further, this study sets an important direction on future modeling studies in identifying the ABL conditions in a diurnal cycle that influence the WT wake evolution.
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Zhang, Yuanchong, and William B. Rossow. "Seasonal and regional diurnal variations of cloud effects on atmospheric profiles of radiative heating/cooling from ISCCP-FD product." In RADIATION PROCESSES IN THE ATMOSPHERE AND OCEAN (IRS2012): Proceedings of the International Radiation Symposium (IRC/IAMAS). AIP, 2013. http://dx.doi.org/10.1063/1.4804856.
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Soontornchainacksaeng, Thanakom. "Parameters Analysis and Potential of Energy Storage Case Study : Solar collector for diurnal water heating and nocturnal water cooling." In Thermal Sciences 2000. Proceedings of the International Thermal Science Seminar Bled. Connecticut: Begellhouse, 2000. http://dx.doi.org/10.1615/ichmt.2000.thersieprocvol2.50.
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Sivov, Tihomir G., Raul Palacios-Gamez, and B. Rabi Baliga. "Computational Modeling of Thermal Energy Storage in Rock Beds." In ASME 2010 3rd Joint US-European Fluids Engineering Summer Meeting collocated with 8th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-31130.
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Thermal energy storage (TES) systems are commonly employed for enhancing the efficiency of commercial and residential heating and cooling systems, by matching thermal energy supply and demand during summer-winter, day-night, and peak-off-peak periods. TES in these systems is usually achieved by changing the temperature of materials (sensible systems) and/or inducing solid-liquid phase change (latent heat systems). Such systems are also categorized as seasonal (long-term) and diurnal (short-term). In this work, the focus is on sensible diurnal TES systems consisting of rock beds, with air as the working fluid. They are relatively simple, easy to construct, inexpensive, and quite effective for many solar energy and building engineering applications. Numerous publications on rock-bed TES systems are available, but there is an urgent need for efficient computational methods for designing and optimizing them. The contributions of this work are the following: proposal of cost-effective mathematical models of fluid flow and heat transfer in rock beds; adaptation of a finite volume method (FVM) for the solution of this model; applications of this FVM to two test problems (with analytical solutions) and one demonstration problem; proposal of suitable thermofluid performance evaluation criteria for the rock-bed TES systems of interest; and presentation and discussions of the results.
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Neophytou, Marina K. A., Harindra J. S. Fernando, Ekaterina Batchvarova, Mats Sandberg, Jos Lelieveld, and Eleonora Tryphonos. "A Scaling Law for the Urban Heat Island Phenomenon: Deductions From Field Measurements and Comparisons With Existing Results From Laboratory Experiments." In ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/fedsm2014-21819.
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We report results from a multi-scale field experiment conducted in Cyprus in July 2010 in order to investigate the Urban Heat Island (UHI) in Nicosia capital city and its interaction with multi-scale meteorological phenomena taking place in the broader region. Specifically, the results are analysed and interpreted in terms of a non-dimensional/scaling parameter dictating the urban heat island circulation reported from laboratory experiments (Fernando et al, 2010). We find that the field measurements obey the same scaling law during the day, in the absence of any other flow phenomena apart from the urban heating. During the night we find that the deduced non-dimensional value reduces to half (compared to that during the day); this is due to the presence of katabatic winds from Troodos mountains into the urban center of Nicosia and their cooling effect superimposed on diurnal urban heating. Based on this deduction, the impact of various proposed heat island mitigation measures in urban planning can be evaluated.
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Soontornchainacksaeng, Thanakom. "Abstract of "Parameters Analysis and Potential of Energy Storage Case Study : Solar collector for diurnal water heating and nocturnal water cooling."." In Thermal Sciences 2000. Proceedings of the International Thermal Science Seminar Bled. Connecticut: Begellhouse, 2000. http://dx.doi.org/10.1615/ichmt.2000.thersieprocvol2.490.
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Robinson, Brian S., and M. Keith Sharp. "Reducing Unwanted Gains During the Cooling Season From a Heat Pipe Augmented Passive Solar Heating System." In ASME 2012 6th International Conference on Energy Sustainability collocated with the ASME 2012 10th International Conference on Fuel Cell Science, Engineering and Technology. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/es2012-91289.
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The heat pipe augmented solar heating system significantly reduces heating loads relative to other conventional passive space heating systems [1–3]. Yet unwanted thermal gains during the cooling season from passive solar systems increase cooling loads and, in extreme cases, may even increase overall space conditioning loads relative to a nonsolar building. The objective of this study was to compare the effectiveness of several design modifications and control strategies for the heat pipe wall to reduce unwanted gains. MATLAB was used to simulate four different unwanted gains reduction mechanisms: 1. shading to block beam radiation from striking the collector, 2. an opaque cover to block all radiation from striking the collector, 3. a mechanical valve in the adiabatic section to eliminate convective heat transfer through the heat pipe into the room, and 4. switching the elevations of the evaporator and condenser sections of the heat pipe to provide heat transfer out of the room during the cooling season. For each mechanism, three different control strategies were evaluated: 1. Seasonal control, for which the prescribed mechanism is deployed at the beginning and removed at the end of the cooling season, 2. ambient temperature-based control, for which the mechanism is deployed if the forecast for the next hour (based on TMY3 weather data) is greater than 65°F, and 3. room temperature-based control, for which the mechanism is deployed if auxiliary cooling was required for the previous hour. For the seasonal strategy, the months for which the unwanted gains reduction mechanism should be deployed to minimize overall space conditioning loads were estimated with a season determination ratio (SD), defined as the monthly ratio of unwanted gains to heating load. Results suggested that SD may be a ‘universal’ parameter that can be applied across a range of climates for quick assessment of its optimal cooling season. With TMY3 data for Louisville, KY, the heat pipe system performed best with ambient temperature-based control. The mechanical valve was the best single mechanism. While in many cases the combination of the valve with a cover or shading produced slightly better performance than the mechanical valve alone, these additional reductions were small. Switching elevations of the evaporator and condenser sections produced little cooling, because of the low thermal emittance of the absorber and low thermal transmittance of the cover, and for the Louisville climate, small diurnal temperature swings during the summer.
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Mirza, Kazim, and Kelly Kissock. "An Analytical Solution for Dynamic Thermal Transmission Loads." In ASME 2007 Energy Sustainability Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/es2007-36094.
Full textAbstract:
Thermal mass in building envelopes reduces the magnitude of diurnal conductive loads and, in some cases, reduces energy use for heating and cooling. In general, dynamic simulation is required to estimate the magnitude of these effects. This paper seeks to derive closed-form expressions of thermal time lag and amplitude dampening through building envelope structures, to aid in the design process before detailed simulation is performed, and to improve intuition about the effects of thermal mass in buildings. An analytical solution for the temperature distribution through an infinite wall subjected to a sinusoidal temperature boundary condition is derived. The solution is verified by comparison with a finite element solution. Next, it is hypothesized that the analytical solution for an infinite wall could also describe the temperature variation on the inside surface of a finite wall. The hypothesis is tested by comparing the temperature distribution predicted by the analytical solution to the temperature distribution predicted by a finite element model of a finite wall. The results confirm that analytical solution adequately described the temperature variation in a finite wall. Based on the analytical solution, separate closed-form expressions of time delay and amplitude dampening for thermal load transmission through building envelopes are derived. The use of these expressions is demonstrated for light frame and concrete walls.
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Bandyopadhyay, Arkasama, and Anirban Bhattacharya. "Residential Appliance Usage Patterns From Overall Energy Consumption Data: A Statistical Machine Learning Approach." In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-70122.
Full textAbstract:
Abstract Large energy-intensive domestic appliances like heating, ventilation, and air-conditioning systems, electric water heaters, refrigerators, clothes washers, dishwashers, and dryers can together comprise about 58% of annual residential electricity consumption in the US. Accurate knowledge of domestic appliance-level energy usage patterns can help energy modelers and electric utilities design optimal demand response programs in residential communities. However, while the widespread installation of residential smart meters in the US over the past decade has enabled electric utilities to collect diurnal individual household-level electricity consumption profiles, it is extremely rare to find location-specific, short-interval, disaggregated appliance-level data for individual residences. This study develops a novel methodology to reliably predict future domestic appliance energy consumption profiles based primarily on overall electricity consumption and local weather data. The model is demonstrated using fifteen-minute interval appliance-level empirical energy consumption data for a test-bed of 25 single-family detached homes in Austin, TX from Pecan Street Inc. — a non-profit entity based in Austin. Although the training of our model utilizes historical appliance profiles, the results obtained from this analysis can be used to reliably and accurately predict time-granular appliance-level energy consumption patterns (not only on/off times) using only the overall electricity consumption profile of the household. Thus, this study opens up the possibility for energy modelers to reliably forecast domestic appliance electricity consumption profiles without having appliance-level historical energy usage datasets available.
Reports on the topic "Diurnal heating"
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Iselin, Columbus O'Donnell. Preliminary report on the prediction of "Afternoon Effect". Woods Hole Oceanographic Institution, December 2022. http://dx.doi.org/10.1575/1912/29562.
Full textAbstract:
With moderate or light winds and a clear sky the diurnal heating which occurs near the sea surface can cause a serious reduction in the range of submarine detection, especially on shallow targets. This has usually been called the “afternoon effect", although as will be noticed below the ranges often remain short long after sun down. The heating of surface waters which causes such sharp downward refraction can of course be noted on a bathythermograph record, provided pen vibration does not confuse the upper part of the trace. Unfortunately it is the upper 20 or 30 feet of a bathythermograph curve which in the case of ships moving faster than 12 knots is often somewhat difficult to read with sufficient certainty. Moreover, in planning a days operations it is clearly desirable to know in advance how much reduction in range may be expected from diurnal warming.