Journal articles: 'Regional flux'

1

Doran, J. C., J. M. Hubbe, R. R. Kirkham, W. J. Shaw, C. D. Whiteman, F. J. Barnes, D. Cooper, et al. "The Boardman Regional Flux Experiment." Bulletin of the American Meteorological Society 73, no. 11 (November 1992): 1785–95. http://dx.doi.org/10.1175/1520-0477(1992)073<1785:tbrfe>2.0.co;2.

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2

Zerrik, E., H. Bourray, and A. El Jai. "Regional flux reconstruction for parabolic systems." International Journal of Systems Science 34, no. 12-13 (October 2003): 641–50. http://dx.doi.org/10.1080/00207720310001601028.

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3

Zerrik, E., A. Kamal, and A. Boutoulout. "Regional flux target with minimum energy." IEE Proceedings - Control Theory and Applications 149, no. 4 (July 1, 2002): 349–56. http://dx.doi.org/10.1049/ip-cta:20020455.

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4

Liu, Junjie, Latha Baskaran, Kevin Bowman, David Schimel, A. Anthony Bloom, Nicholas C. Parazoo, Tomohiro Oda, et al. "Carbon Monitoring System Flux Net Biosphere Exchange 2020 (CMS-Flux NBE 2020)." Earth System Science Data 13, no. 2 (February 10, 2021): 299–330. http://dx.doi.org/10.5194/essd-13-299-2021.

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Abstract. Here we present a global and regionally resolved terrestrial net biosphere exchange (NBE) dataset with corresponding uncertainties between 2010–2018: Carbon Monitoring System Flux Net Biosphere Exchange 2020 (CMS-Flux NBE 2020). It is estimated using the NASA Carbon Monitoring System Flux (CMS-Flux) top-down flux inversion system that assimilates column CO2 observations from the Greenhouse Gases Observing Satellite (GOSAT) and NASA's Observing Carbon Observatory 2 (OCO-2). The regional monthly fluxes are readily accessible as tabular files, and the gridded fluxes are available in NetCDF format. The fluxes and their uncertainties are evaluated by extensively comparing the posterior CO2 mole fractions with CO2 observations from aircraft and the NOAA marine boundary layer reference sites. We describe the characteristics of the dataset as the global total, regional climatological mean, and regional annual fluxes and seasonal cycles. We find that the global total fluxes of the dataset agree with atmospheric CO2 growth observed by the surface-observation network within uncertainty. Averaged between 2010 and 2018, the tropical regions range from close to neutral in tropical South America to a net source in Africa; these contrast with the extra-tropics, which are a net sink of 2.5±0.3 Gt C/year. The regional satellite-constrained NBE estimates provide a unique perspective for understanding the terrestrial biosphere carbon dynamics and monitoring changes in regional contributions to the changes of atmospheric CO2 growth rate. The gridded and regional aggregated dataset can be accessed at https://doi.org/10.25966/4v02-c391 (Liu et al., 2020).

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Makar, P. A., S. Gravel, V. Chirkov, K. B. Strawbridge, F. Froude, J. Arnold, and J. Brook. "Heat flux, urban properties, and regional weather." Atmospheric Environment 40, no. 15 (May 2006): 2750–66. http://dx.doi.org/10.1016/j.atmosenv.2005.11.061.

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6

Robusté, Francesc. "Network simulation, tolls and some conjectures on regional development: the case of Catalonia." Flux 10, no. 17 (1994): 33–40. http://dx.doi.org/10.3406/flux.1994.993.

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7

Mazur, A. A., O. K. Makovetskaya, S. V. Pustovojt, and N. S. Brovchenko. "Flux-cored wires at the world and regional markets of welding consumables (Review)." Paton Welding Journal 2015, no. 6 (June 28, 2015): 63–69. http://dx.doi.org/10.15407/tpwj2015.06.15.

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Wang, Guoying, Xiaoping Wu, Lufeng Mo, and Jizhong Zhao. "SCFSen: A Sensor Node for Regional Soil Carbon Flux Monitoring." Sensors 18, no. 11 (November 16, 2018): 3986. http://dx.doi.org/10.3390/s18113986.

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Estimation of regional soil carbon flux is very important for the study of the global carbon cycle. The spatial heterogeneity of soil respiration prevents the actual status of regional soil carbon flux from being revealed by measurements of only one or a few spatial sampling positions, which are usually used by traditional studies for the limitation of measurement instruments, so measuring in many spatial positions is very necessary. However, the existing instruments are expensive and cannot communicate with each other, which prevents them from meeting the requirement of synchronous measurements in multiple positions. Therefore, we designed and implemented an instrument for soil carbon flux measuring based on dynamic chamber method, SCFSen, which can measure soil carbon flux and communicate with each other to construct a sensor network. In its working stage, a SCFSen node measures the concentration of carbon in the chamber with an infrared carbon dioxide sensor for certain times periodically, and then the changing rate of the measurements is calculated, which can be converted to the corresponding value of soil carbon flux in the position during the short period. A wireless sensor network system using SCFSens as soil carbon flux sensing nodes can carry out multi-position measurements synchronously, so as to obtain the spatial heterogeneity of soil respiration. Furthermore, the sustainability of such a wireless sensor network system makes the temporal variability of regional soil carbon flux can also be obtained. So SCFSen makes thorough monitoring and accurate estimation of regional soil carbon flux become more feasible.

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9

Deng, F., D. B. A. Jones, D. K. Henze, N. Bousserez, K. W. Bowman, J. B. Fisher, R. Nassar, et al. "Inferring regional sources and sinks of atmospheric CO2 from GOSAT XCO2 data." Atmospheric Chemistry and Physics Discussions 13, no. 10 (October 10, 2013): 26327–88. http://dx.doi.org/10.5194/acpd-13-26327-2013.

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Abstract. We have examined the utility of retrieved column-averaged, dry-air mole fractions of CO2 (XCO2) from the Greenhouse Gases Observing Satellite (GOSAT) for quantifying monthly, regional flux estimates of CO2, using the GEOS-Chem four-dimensional variational (4D-Var) data assimilation system. We focused on assessing the potential impact of biases in the GOSAT CO2 data on the regional flux estimates. Using different screening and bias correction approaches, we selected three different subsets of the GOSAT XCO2 data for the 4D-Var inversion analyses, and found that the inferred global fluxes were consistent across the three XCO2 inversions. However, the GOSAT observational coverage was a challenge for the regional flux estimates. In the northern extratropics, the inversions were more sensitive to North American fluxes than to European and Asian fluxes due to the lack of observations over Eurasia in winter and over eastern and southern Asia in summer. The regional flux estimates were also sensitive to the treatment of the residual bias in the GOSAT XCO2 data. The largest differences obtained were for Temperate North America and Temperate South America, for which the largest spread between the inversions was 1.02 Pg C and 0.96 Pg C, respectively. In the case of Temperate North America, one inversion suggested a strong source, whereas the second and third XCO2 inversions produced a weak and strong sink, respectively. Despite the discrepancies in the regional flux estimates between the three XCO2 inversions, the a posteriori CO2 distributions were in good agreement (with a mean difference between the three inversions of typically less than 0.5 ppm) with independent data from the Total Carbon Column Observing Network (TCCON), the surface flask network, and from the HIAPER Pole-to-Pole Observations (HIPPO) aircraft campaign. The discrepancy in the regional flux estimates from the different inversions, despite the agreement of the global flux estimates, suggests the need for additional work to determine the minimum spatial scales at which we can reliably quantify the fluxes using GOSAT XCO2. The fact that the a posteriori CO2 from the different inversions were in good agreement with the independent data although the regional flux estimates differed significantly, suggests that innovative ways of exploiting existing datasets, and possibly additional observations, are needed to better evaluate the inferred regional flux estimates.

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Deng, F., D. B. A. Jones, D. K. Henze, N. Bousserez, K. W. Bowman, J. B. Fisher, R. Nassar, et al. "Inferring regional sources and sinks of atmospheric CO2 from GOSAT XCO2 data." Atmospheric Chemistry and Physics 14, no. 7 (April 11, 2014): 3703–27. http://dx.doi.org/10.5194/acp-14-3703-2014.

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Abstract. We have examined the utility of retrieved column-averaged, dry-air mole fractions of CO2 (XCO2) from the Greenhouse Gases Observing Satellite (GOSAT) for quantifying monthly, regional flux estimates of CO2, using the GEOS-Chem four-dimensional variational (4D-Var) data assimilation system. We focused on assessing the potential impact of biases in the GOSAT CO2 data on the regional flux estimates. Using different screening and bias correction approaches, we selected three different subsets of the GOSAT XCO2 data for the 4D-Var inversion analyses, and found that the inferred global fluxes were consistent across the three XCO2 inversions. However, the GOSAT observational coverage was a challenge for the regional flux estimates. In the northern extratropics, the inversions were more sensitive to North American fluxes than to European and Asian fluxes due to the lack of observations over Eurasia in winter and over eastern and southern Asia in summer. The regional flux estimates were also sensitive to the treatment of the residual bias in the GOSAT XCO2 data. The largest differences obtained were for temperate North America and temperate South America, for which the largest spread between the inversions was 1.02 and 0.96 Pg C, respectively. In the case of temperate North America, one inversion suggested a strong source, whereas the second and third XCO2 inversions produced a weak and strong sink, respectively. Despite the discrepancies in the regional flux estimates between the three XCO2 inversions, the a posteriori CO2 distributions were in good agreement (with a mean difference between the three inversions of typically less than 0.5 ppm) with independent data from the Total Carbon Column Observing Network (TCCON), the surface flask network, and from the HIAPER Pole-to-Pole Observations (HIPPO) aircraft campaign. The discrepancy in the regional flux estimates from the different inversions, despite the agreement of the global flux estimates suggests the need for additional work to determine the minimum spatial scales at which we can reliably quantify the fluxes using GOSAT XCO2. The fact that the a posteriori CO2 from the different inversions were in good agreement with the independent data although the regional flux estimates differed significantly, suggests that innovative ways of exploiting existing data sets, and possibly additional observations, are needed to better evaluate the inferred regional flux estimates.

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11

Lindemann, Matthias, Robert Maass, and Georg Sauter. "Final report on regional comparison EURAMET.PR-K4: luminous flux." Metrologia 52, no. 1A (January 1, 2015): 02001. http://dx.doi.org/10.1088/0026-1394/52/1a/02001.

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12

Parazoo, Nicholas C., Roisin Commane, Steven C. Wofsy, Charles D. Koven, Colm Sweeney, David M. Lawrence, Jakob Lindaas, Rachel Y. W. Chang, and Charles E. Miller. "Detecting regional patterns of changing CO2 flux in Alaska." Proceedings of the National Academy of Sciences 113, no. 28 (June 27, 2016): 7733–38. http://dx.doi.org/10.1073/pnas.1601085113.

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With rapid changes in climate and the seasonal amplitude of carbon dioxide (CO2) in the Arctic, it is critical that we detect and quantify the underlying processes controlling the changing amplitude of CO2 to better predict carbon cycle feedbacks in the Arctic climate system. We use satellite and airborne observations of atmospheric CO2 with climatically forced CO2 flux simulations to assess the detectability of Alaskan carbon cycle signals as future warming evolves. We find that current satellite remote sensing technologies can detect changing uptake accurately during the growing season but lack sufficient cold season coverage and near-surface sensitivity to constrain annual carbon balance changes at regional scale. Airborne strategies that target regular vertical profile measurements within continental interiors are more sensitive to regional flux deeper into the cold season but currently lack sufficient spatial coverage throughout the entire cold season. Thus, the current CO2 observing network is unlikely to detect potentially large CO2 sources associated with deep permafrost thaw and cold season respiration expected over the next 50 y. Although continuity of current observations is vital, strategies and technologies focused on cold season measurements (active remote sensing, aircraft, and tall towers) and systematic sampling of vertical profiles across continental interiors over the full annual cycle are required to detect the onset of carbon release from thawing permafrost.

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13

TURNER, D. P., M. GÖCKEDE, B. E. LAW, W. D. RITTS, W. B. COHEN, Z. YANG, T. HUDIBURG, R. KENNEDY, and M. DUANE. "Multiple constraint analysis of regional land-surface carbon flux." Tellus B 63, no. 2 (February 6, 2011): 207–21. http://dx.doi.org/10.1111/j.1600-0889.2011.00525.x.

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14

Wang, Muyin, and Jan Paegle. "Impact of analysis uncertainty upon regional atmospheric moisture flux." Journal of Geophysical Research: Atmospheres 101, no. D3 (March 1, 1996): 7291–303. http://dx.doi.org/10.1029/95jd02896.

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15

Sotarauta, Markku. "Constant Flux Makes Regional Studies ‘Amoeba’ Strong: Evolution of Regional Studies in Tampere, Finland." Regions Magazine 291, no. 1 (August 6, 2013): 3–4. http://dx.doi.org/10.1080/13673882.2013.10739973.

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16

Barles, G., A. Briani, E. Chasseigne, and C. Imbert. "Flux-limited and classical viscosity solutions for regional control problems." ESAIM: Control, Optimisation and Calculus of Variations 24, no. 4 (October 2018): 1881–906. http://dx.doi.org/10.1051/cocv/2017076.

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The aim of this paper is to compare two different approaches for regional control problems: the first one is the classical approach, using a standard notion of viscosity solutions, which is developed in a series of works by the three first authors. The second one is more recent and relies on ideas introduced by Monneau and the fourth author for problems set on networks in another series of works, in particular the notion of flux-limited solutions. After describing and even revisiting these two very different points of view in the simplest possible framework, we show how the results of the classical approach can be interpreted in terms of flux-limited solutions. In particular, we give much simpler proofs of three results: the comparison principle in the class of bounded flux-limited solutions of stationary multidimensional Hamilton–Jacobi equations and the identification of the maximal and minimal Ishii’s solutions with flux-limited solutions which were already proved by Monneau and the fourth author, and the identification of the corresponding vanishing viscosity limit, already obtained by Vinh Duc Nguyen and the fourth author.

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17

Wang, Hesong, Gensuo Jia, Anzhi Zhang, and Chen Miao. "Assessment of Spatial Representativeness of Eddy Covariance Flux Data from Flux Tower to Regional Grid." Remote Sensing 8, no. 9 (September 8, 2016): 742. http://dx.doi.org/10.3390/rs8090742.

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18

Im, Eun Ho, Darius M. Adams, and Gregory S. Latta. "The impacts of changes in federal timber harvest on forest carbon sequestration in western Oregon." Canadian Journal of Forest Research 40, no. 9 (September 2010): 1710–23. http://dx.doi.org/10.1139/x10-110.

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This study examines the potential impacts of changes in federal timber harvest, acting through regional log markets, on the sequestration of carbon in forests and forest products in western Oregon. We construct a dynamic model of the region’s log markets in which market prices, log consumption at mills, and timber harvests and timber inventories on private, federal, and state forests are endogenous. Absent any policies regulating forest carbon sequestration, simulations show that regional carbon flux in forests and forest products would gradually decline as federal harvest rises from recent historical levels. If regional forest carbon flux were constrained to meet some minimum target, however, projections indicate that there would be opportunities for substituting carbon sequestration between federal and nonfederal lands through coordination of harvests across ownerships. We find that relatively small reductions in average private harvest could offset substantial losses of carbon flux on federal timberlands caused by increased federal harvest. One mechanism for achieving the changes needed in private harvest to meet a regional carbon flux target would be a carbon tax/subsidy program or a carbon offset market. For example, if federal owners offered timber for sale equal to the maximum sustainable level under the Northwest Forest Plan, our analysis indicates that a carbon price of roughly $US 19 per tonne of carbon would be sufficient to induce private owners to undertake the harvest and management modifications necessary to maintain regional forest carbon flux at its level in the early 2000s.

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19

Thomas, Christopher M., Bo Dong, and Keith Haines. "Inverse Modeling of Global and Regional Energy and Water Cycle Fluxes using Earth Observation Data." Journal of Climate 33, no. 5 (March 1, 2020): 1707–23. http://dx.doi.org/10.1175/jcli-d-19-0343.1.

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AbstractThe NASA Energy and Water Cycle Study (NEWS) climatology is a self-consistent coupled annual and seasonal cycle solution for radiative, turbulent, and water fluxes over Earth’s surface using Earth observation data covering 2000–09. Here we seek to improve the NEWS solution, particularly over the ocean basins, by considering spatial covariances in the observation errors (some evidence for which is found by comparing five turbulent flux products over the oceans) and by introducing additional horizontal transports from ocean reanalyses as weak constraints. By explicitly representing large error covariances between surface heat flux components over the major ocean basins we retain the flux contrasts present in the original data and infer additional heat losses over the North Atlantic Ocean, more consistent with a strong Atlantic overturning. This change does not alter the global flux balance but if only the errors in evaporation and precipitation are correlated then those fluxes experience larger adjustments (e.g., the surface latent heat flux increases to 85 ± 2 W m−2). Replacing SeaFlux v1 with J-OFURO v3 (Japanese Ocean Flux Data Sets with Use of Remote Sensing Observations) ocean fluxes also leads to a considerable increase in the global latent heat loss as well as a larger North Atlantic heat loss. Furthermore, including a weak constraint on the horizontal transports of heat and freshwater from high-resolution ocean reanalyses improves the net fluxes over the North Atlantic, Caribbean Sea, and Arctic Ocean, without any impact on the global flux balances. These results suggest that better characterized flux uncertainties can greatly improve the quality of the optimized flux solution.

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Vecchi, G. A., T. Delworth, R. Gudgel, S. Kapnick, A. Rosati, A. T. Wittenberg, F. Zeng, et al. "On the Seasonal Forecasting of Regional Tropical Cyclone Activity." Journal of Climate 27, no. 21 (October 24, 2014): 7994–8016. http://dx.doi.org/10.1175/jcli-d-14-00158.1.

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Abstract Tropical cyclones (TCs) are a hazard to life and property and a prominent element of the global climate system; therefore, understanding and predicting TC location, intensity, and frequency is of both societal and scientific significance. Methodologies exist to predict basinwide, seasonally aggregated TC activity months, seasons, and even years in advance. It is shown that a newly developed high-resolution global climate model can produce skillful forecasts of seasonal TC activity on spatial scales finer than basinwide, from months and seasons in advance of the TC season. The climate model used here is targeted at predicting regional climate and the statistics of weather extremes on seasonal to decadal time scales, and comprises high-resolution (50 km × 50 km) atmosphere and land components as well as more moderate-resolution (~100 km) sea ice and ocean components. The simulation of TC climatology and interannual variations in this climate model is substantially improved by correcting systematic ocean biases through “flux adjustment.” A suite of 12-month duration retrospective forecasts is performed over the 1981–2012 period, after initializing the climate model to observationally constrained conditions at the start of each forecast period, using both the standard and flux-adjusted versions of the model. The standard and flux-adjusted forecasts exhibit equivalent skill at predicting Northern Hemisphere TC season sea surface temperature, but the flux-adjusted model exhibits substantially improved basinwide and regional TC activity forecasts, highlighting the role of systematic biases in limiting the quality of TC forecasts. These results suggest that dynamical forecasts of seasonally aggregated regional TC activity months in advance are feasible.

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Loeb, Norman G., David R. Doelling, Hailan Wang, Wenying Su, Cathy Nguyen, Joseph G. Corbett, Lusheng Liang, Cristian Mitrescu, Fred G. Rose, and Seiji Kato. "Clouds and the Earth’s Radiant Energy System (CERES) Energy Balanced and Filled (EBAF) Top-of-Atmosphere (TOA) Edition-4.0 Data Product." Journal of Climate 31, no. 2 (January 2018): 895–918. http://dx.doi.org/10.1175/jcli-d-17-0208.1.

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The Clouds and the Earth’s Radiant Energy System (CERES) Energy Balanced and Filled (EBAF) top-of-atmosphere (TOA), Edition 4.0 (Ed4.0), data product is described. EBAF Ed4.0 is an update to EBAF Ed2.8, incorporating all of the Ed4.0 suite of CERES data product algorithm improvements and consistent input datasets throughout the record. A one-time adjustment to shortwave (SW) and longwave (LW) TOA fluxes is made to ensure that global mean net TOA flux for July 2005–June 2015 is consistent with the in situ value of 0.71 W m−2. While global mean all-sky TOA flux differences between Ed4.0 and Ed2.8 are within 0.5 W m−2, appreciable SW regional differences occur over marine stratocumulus and snow/sea ice regions. Marked regional differences in SW clear-sky TOA flux occur in polar regions and dust areas over ocean. Clear-sky LW TOA fluxes in EBAF Ed4.0 exceed Ed2.8 in regions of persistent high cloud cover. Owing to substantial differences in global mean clear-sky TOA fluxes, the net cloud radiative effect in EBAF Ed4.0 is −18 W m−2 compared to −21 W m−2 in EBAF Ed2.8. The overall uncertainty in 1° × 1° latitude–longitude regional monthly all-sky TOA flux is estimated to be 3 W m−2 [one standard deviation (1 σ)] for the Terra-only period and 2.5 W m−2 for the Terra– Aqua period both for SW and LW fluxes. The SW clear-sky regional monthly flux uncertainty is estimated to be 6 W m−2 for the Terra-only period and 5 W m−2 for the Terra– Aqua period. The LW clear-sky regional monthly flux uncertainty is 5 W m−2 for Terra only and 4.5 W m−2 for Terra– Aqua.

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22

Fisher, Andrew T., Kenneth D. Mankoff, Slawek M. Tulaczyk, Scott W. Tyler, and Neil Foley. "High geothermal heat flux measured below the West Antarctic Ice Sheet." Science Advances 1, no. 6 (July 2015): e1500093. http://dx.doi.org/10.1126/sciadv.1500093.

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The geothermal heat flux is a critical thermal boundary condition that influences the melting, flow, and mass balance of ice sheets, but measurements of this parameter are difficult to make in ice-covered regions. We report the first direct measurement of geothermal heat flux into the base of the West Antarctic Ice Sheet (WAIS), below Subglacial Lake Whillans, determined from the thermal gradient and the thermal conductivity of sediment under the lake. The heat flux at this site is 285 ± 80 mW/m2, significantly higher than the continental and regional averages estimated for this site using regional geophysical and glaciological models. Independent temperature measurements in the ice indicate an upward heat flux through the WAIS of 105 ± 13 mW/m2. The difference between these heat flux values could contribute to basal melting and/or be advected from Subglacial Lake Whillans by flowing water. The high geothermal heat flux may help to explain why ice streams and subglacial lakes are so abundant and dynamic in this region.

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Zhang, X., X. Lee, T. J. Griffis, J. M. Baker, and W. Xiao. "Estimating greenhouse gas fluxes from an agriculture-dominated landscape using multiple planetary boundary layer methods." Atmospheric Chemistry and Physics Discussions 14, no. 3 (February 3, 2014): 3231–67. http://dx.doi.org/10.5194/acpd-14-3231-2014.

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Abstract. Quantification of regional greenhouse gas (GHG) fluxes is essential for establishing mitigation strategies and evaluating their effectiveness. Here, we used multiple top-down approaches and multiple trace gas observations at a tall tower to estimate GHG regional fluxes and evaluate the GHG fluxes derived from bottom-up approaches. We first applied the eddy covariance, equilibrium, inverse modeling (CarbonTracker), and flux aggregation methods using three years of carbon dioxide (CO2) measurements on a 244 m tall tower in the Upper Midwest, USA. We then applied the equilibrium method for estimating methane (CH4) and nitrous oxide (N2O) fluxes with one-month high-frequency CH4 and N2O gradient measurements on the tall tower and one-year concentration measurements on a nearby tall tower, and evaluated the uncertainties of this application. The results indicate that: (1) the flux aggregation, eddy covariance, the equilibrium method, and the CarbonTracker product all gave similar seasonal patterns of the regional CO2 flux (105–106 km2), but that the equilibrium method underestimated the July CO2 flux by 52–69%. (2) The annual budget varied among these methods from 74 to −131 g C-CO2 m−2 yr−1, indicating a large uncertainty in the annual CO2 flux estimation. (3) The regional CH4 and N2O emissions according to a top-down method were at least six and two times higher than the emissions from a bottom-up inventory (Emission Database for Global Atmospheric Research), respectively. (4) The global warming potentials of the CH4 and N2O emissions were equal in magnitude to the cooling benefit of the regional CO2 uptake. The regional GHG budget, including both biological and anthropogenic origins, is estimated at 7 ± 160 g CO2 eq m−2 yr−1.

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Zhang, X., X. Lee, T. J. Griffis, J. M. Baker, and W. Xiao. "Estimating regional greenhouse gas fluxes: an uncertainty analysis of planetary boundary layer techniques and bottom-up inventories." Atmospheric Chemistry and Physics 14, no. 19 (October 10, 2014): 10705–19. http://dx.doi.org/10.5194/acp-14-10705-2014.

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Abstract. Quantification of regional greenhouse gas (GHG) fluxes is essential for establishing mitigation strategies and evaluating their effectiveness. Here, we used multiple top-down approaches and multiple trace gas observations at a tall tower to estimate regional-scale GHG fluxes and evaluate the GHG fluxes derived from bottom-up approaches. We first applied the eddy covariance, equilibrium, inverse modeling (CarbonTracker), and flux aggregation methods using 3 years of carbon dioxide (CO2) measurements on a 244 m tall tower in the upper Midwest, USA. We then applied the equilibrium method for estimating CH4 and N2O fluxes with 1-month high-frequency CH4 and N2O gradient measurements on the tall tower and 1-year concentration measurements on a nearby tall tower, and evaluated the uncertainties of this application. The results indicate that (1) the flux aggregation, eddy covariance, the equilibrium method, and the CarbonTracker product all gave similar seasonal patterns of the regional CO2 flux (105−106 km2, but that the equilibrium method underestimated the July CO2 flux by 52–69%. (2) The annual budget varied among these methods from −54 to −131 g C–CO2 m−2 yr−1, indicating a large uncertainty in the annual CO2 flux estimation. (3) The regional CH4 and N2O emissions according to a top-down method were at least 6 and 2 times higher than the emissions from a bottom-up inventory (Emission Database for Global Atmospheric Research), respectively. (4) The global warming potentials of the CH4 and N2O emissions were equal in magnitude to the cooling benefit of the regional CO2 uptake. The regional GHG budget, including both biological and anthropogenic origins, is estimated at 7 ± 160 g CO2 equivalent m−2 yr−1.

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Yang, Ge, Lisa A. Cameron, Paul S. Maddox, Edward D. Salmon, and Gaudenz Danuser. "Regional variation of microtubule flux reveals microtubule organization in the metaphase meiotic spindle." Journal of Cell Biology 182, no. 4 (August 18, 2008): 631–39. http://dx.doi.org/10.1083/jcb.200801105.

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Continuous poleward movement of tubulin is a hallmark of metaphase spindle dynamics in higher eukaryotic cells and is essential for stable spindle architecture and reliable chromosome segregation. We use quantitative fluorescent speckle microscopy to map with high resolution the spatial organization of microtubule flux in Xenopus laevis egg extract meiotic spindles. We find that the flux velocity decreases near spindle poles by ∼20%. The regional variation is independent of functional kinetochores and centrosomes and is suppressed by inhibition of dynein/dynactin, kinesin-5, or both. Statistical analysis reveals that tubulin flows in two distinct velocity modes. We propose an association of these modes with two architecturally distinct yet spatially overlapping and dynamically cross-linked arrays of microtubules: focused polar microtubule arrays of a uniform polarity and slower flux velocities are interconnected by a dense barrel-like microtubule array of antiparallel polarities and faster flux velocities.

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Espy, P. J., R. E. Hibbins, G. R. Swenson, J. Tang, M. J. Taylor, D. M. Riggin, and D. C. Fritts. "Regional variations of mesospheric gravity-wave momentum flux over Antarctica." Annales Geophysicae 24, no. 1 (March 7, 2006): 81–88. http://dx.doi.org/10.5194/angeo-24-81-2006.

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Abstract. Images of mesospheric airglow and radar-wind measurements have been combined to estimate the difference in the vertical flux of horizontal momentum carried by high-frequency gravity waves over two dissimilar Antarctic stations. Rothera (67° S, 68° W) is situated in the mountains of the Peninsula near the edge of the wintertime polar vortex. In contrast, Halley (76° S, 27° W), some 1658 km to the southeast, is located on an ice sheet at the edge of the Antarctic Plateau and deep within the polar vortex during winter. The cross-correlation coefficients between the vertical and horizontal wind perturbations were calculated from sodium (Na) airglow imager data collected during the austral winter seasons of 2002 and 2003 at Rothera for comparison with the 2000 and 2001 results from Halley reported previously (Espy et al., 2004). These cross-correlation coefficients were combined with wind-velocity variances from coincident radar measurements to estimate the daily averaged upper-limit of the vertical flux of horizontal momentum due to gravity waves near the peak emission altitude of the Na nightglow layer, 90km. The resulting momentum flux at both stations displayed a large day-to-day variability and showed a marked seasonal rotation from the northwest to the southwest throughout the winter. However, the magnitude of the flux at Rothera was about 4 times larger than that at Halley, suggesting that the differences in the gravity-wave source functions and filtering by the underlying winds at the two stations create significant regional differences in wave forcing on the scale of the station separation.

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27

Overland, James E., Philip Turet, and Abraham H. Oort. "Regional Variations of Moist Static Energy Flux into the Arctic." Journal of Climate 9, no. 1 (January 1996): 54–65. http://dx.doi.org/10.1175/1520-0442(1996)009<0054:rvomse>2.0.co;2.

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Cleugh, Helen A., Ray Leuning, Qiaozhen Mu, and Steven W. Running. "Regional evaporation estimates from flux tower and MODIS satellite data." Remote Sensing of Environment 106, no. 3 (February 2007): 285–304. http://dx.doi.org/10.1016/j.rse.2006.07.007.

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Lampitt, R. S., and A. N. Antia. "Particle flux in deep seas: regional characteristics and temporal variability." Deep Sea Research Part I: Oceanographic Research Papers 44, no. 8 (August 1997): 1377–403. http://dx.doi.org/10.1016/s0967-0637(97)00020-4.

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McConachie, I. "Regional and Systemic Oxygen Delivery/Uptake Relations and Lactate Flux." American Review of Respiratory Disease 146, no. 5_pt_1 (November 1992): 1367. http://dx.doi.org/10.1164/ajrccm/146.5_pt_1.1367.

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Kumar, B. Praveen, Meghan F. Cronin, Sudheer Joseph, M. Ravichandran, and N. Sureshkumar. "Latent Heat Flux Sensitivity to Sea Surface Temperature: Regional Perspectives." Journal of Climate 30, no. 1 (January 2017): 129–43. http://dx.doi.org/10.1175/jcli-d-16-0285.1.

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A global analysis of latent heat flux (LHF) sensitivity to sea surface temperature (SST) is performed, with focus on the tropics and the north Indian Ocean (NIO). Sensitivity of LHF state variables (surface wind speed Ws and vertical humidity gradients Δq) to SST give rise to mutually interacting dynamical (Ws driven) and thermodynamical (Δq driven) coupled feedbacks. Generally, LHF sensitivity to SST is pronounced over tropics where SST increase causes Ws (Δq) changes, resulting in a maximum decrease (increase) of LHF by ~15 W m−2 (°C)−1. But the Bay of Bengal (BoB) and north Arabian Sea (NAS) remain an exception that is opposite to the global feedback relationship. This uniqueness is attributed to strong seasonality in monsoon Ws and Δq variations, which brings in warm (cold) continental air mass into the BoB and NAS during summer (winter), producing a large seasonal cycle in air–sea temperature difference ΔT (and hence in Δq). In other tropical oceans, surface air is mostly of marine origin and blows from colder to warmer waters, resulting in a constant ΔT ~ 1°C throughout the year, and hence a constant Δq. Thus, unlike other basins, when the BoB and NAS are warming, air temperature warms faster than SST. The resultant decrease in ΔT and Δq contributes to decrease the LHF with increased SST, contrary to other basins. This analysis suggests that, in the NIO, LHF variability is largely controlled by thermodynamic processes, which peak during the monsoon period. These observed LHF sensitivities are then used to speculate how the surface energetics and coupled feedbacks may change in a warmer world.

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IKEDA, Hideaki, Tsuyoshi AMA, Kengo HASHIMOTO, and Toshikazu TAKEDA. "Nonlinear Behavior under Regional Neutron Flux Oscillations in BWR Cores." Journal of Nuclear Science and Technology 38, no. 5 (May 2001): 312–23. http://dx.doi.org/10.1080/18811248.2001.9715035.

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Bechtold, P., E. Bazile, F. Guichard, P. Mascart, and E. Richard. "A mass-flux convection scheme for regional and global models." Quarterly Journal of the Royal Meteorological Society 127, no. 573 (April 2001): 869–86. http://dx.doi.org/10.1002/qj.49712757309.

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Hamman, Joseph, Bart Nijssen, Andrew Roberts, Anthony Craig, Wieslaw Maslowski, and Robert Osinski. "The coastal streamflow flux in the Regional Arctic System Model." Journal of Geophysical Research: Oceans 122, no. 3 (March 2017): 1683–701. http://dx.doi.org/10.1002/2016jc012323.

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Banić, Josip. "The Venetian takeover of the Margraviate of Istria (1411–1421)." History in flux 1, no. 1 (December 21, 2019): 41–77. http://dx.doi.org/10.32728/flux.2019.1.3.

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The paper analyzes the incorporation of the Aquileian Margraviate of Istria into the expanding Venetian state in the first half of the fifteenth century. By analyzing this modality of a passage and comparing it to the integration formulae Venice employed in the rest of the Patriarchate of Aquileia, the author uncovers similarities and contrasts between the two models of incorporation. It is argued that Aquileian communities in Istria underwent a remodeling of communal institutions in order to mirror the salient administrative aspects of other Venetian subject centers on the Peninsula. This process, dubbed regional homogenization, did not take place throughout Aquileian Friuli. Finally, the paper deals with instances of negotiations between the newly annexed Istrian communities and the central government in Venice, demonstrating that this interplay resulted in re-negotiated governmental hierarchies that benefitted both the state’s capital and the subject centers.

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Miglietta, F., B. Gioli, Y. Brunet, R. W. A. Hutjes, A. Matese, C. Sarrat, and A. Zaldei. "Sensible and latent heat flux from radiometric surface temperatures at the regional scale: methodology and validation." Biogeosciences Discussions 6, no. 1 (February 10, 2009): 1945–78. http://dx.doi.org/10.5194/bgd-6-1945-2009.

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Abstract. The CarboEurope Regional Experiment Strategy (CERES) was designed to develop and test a range of methodologies to assess regional surface energy and mass exchange of a large study area in the south-western part of France. This paper describes a methodology to estimate sensible and latent heat fluxes on the basis of net radiation, surface radiometric temperature measurements and information obtained from available products derived from the Meteosat Second Generation (MSG) geostationary meteorological satellite, weather stations and ground-based eddy covariance towers. It is based on a simplified bulk formulation of sensible heat flux that considers the degree of coupling between the vegetation and the atmosphere and estimates latent heat as the residual term of net radiation. Estimates of regional energy fluxes obtained in this way are validated at the regional scale by means of a comparison with direct flux measurements made by airborne eddy-covariance. The results show an overall good matching between airborne fluxes and estimates of sensible and latent heat flux obtained from radiometric surface temperatures that holds for different weather conditions and different land use types. The overall applicability of the proposed methodology to regional studies is discussed.

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Miglietta, F., B. Gioli, Y. Brunet, R. W. A. Hutjes, A. Matese, C. Sarrat, and A. Zaldei. "Sensible and latent heat flux from radiometric surface temperatures at the regional scale: methodology and evaluation." Biogeosciences 6, no. 10 (October 2, 2009): 1975–86. http://dx.doi.org/10.5194/bg-6-1975-2009.

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Abstract. The CarboEurope Regional Experiment Strategy (CERES) was designed to develop and test a range of methodologies to assess regional surface energy and mass exchange of a large study area in the South-Western part of France. This paper describes a methodology to estimate sensible and latent heat fluxes on the basis of net radiation, surface radiometric temperature measurements and information obtained from available products derived from the Meteosat Second Generation (MSG) geostationary meteorological satellite, weather stations and ground-based eddy covariance towers. It is based on a simplified bulk formulation of sensible heat flux that considers the degree of coupling between the vegetation and the atmosphere and estimates latent heat as the residual term of net radiation. Estimates of regional energy fluxes obtained in this way are validated at the regional scale by means of a comparison with direct flux measurements made by airborne eddy-covariance. The results show an overall good matching between airborne fluxes and estimates of sensible and latent heat flux obtained from radiometric surface temperatures that holds for different weather conditions and different land use types. The overall applicability of the proposed methodology to regional studies is discussed.

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Aklan, Anna Katalin. "Inspired by Gandhi." History in flux 2, no. 2 (December 23, 2020): 115–24. http://dx.doi.org/10.32728/flux.2020.2.6.

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The leader of the Indian independence movement, Mahatma Gandhi, left an invaluable legacy: he proved to the world that it was possible to achieve political aims without the use of violence. He was the first political activist to develop strategies of nonviolent mass resistance based on a solid philosophical and uniquely religious foundation. Since Gandhi’s death in 1948, in many parts of the world, this legacy has been received and continued by others facing oppression, inequality, or a lack of human rights. This article is a tribute to five of the most faithful followers of Gandhi who have acknowledged his inspiration for their political activities and in choosing nonviolence as a political method and way of life: Khan Abdul Ghaffar Khan, Martin Luther King, Louis Massignon, the Dalai Lama, and Malala Yousafzai. This article describes their formative leadership and their significance and impact on regional and global politics and history.

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Yu, Tao, Qiang Zhang, and Rui Sun. "Comparison of Machine Learning Methods to Up-Scale Gross Primary Production." Remote Sensing 13, no. 13 (June 23, 2021): 2448. http://dx.doi.org/10.3390/rs13132448.

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Eddy covariance observation is an applicable way to obtain accurate and continuous carbon flux at flux tower sites, while remote sensing technology could estimate carbon exchange and carbon storage at regional and global scales effectively. However, it is still challenging to up-scale the field-observed carbon flux to a regional scale, due to the heterogeneity and the unstable air conditions at the land surface. In this paper, gross primary production (GPP) from ground eddy covariance systems were up-scaled to a regional scale by using five machine learning methods (Cubist regression tree, random forest, support vector machine, artificial neural network, and deep belief network). Then, the up-scaled GPP were validated using GPP at flux tower sites, weighted GPP in the footprint, and MODIS GPP products. At last, the sensitivity of the input data (normalized difference vegetation index, fractional vegetation cover, shortwave radiation, relative humidity and air temperature) to the precision of up-scaled GPP was analyzed, and the uncertainty of the machine learning methods was discussed. The results of this paper indicated that machine learning methods had a great potential in up-scaling GPP at flux tower sites. The validation of up-scaled GPP, using five machine learning methods, demonstrated that up-scaled GPP using random forest obtained the highest accuracy.

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Huntzinger, D. N., S. M. Gourdji, K. L. Mueller, and A. M. Michalak. "A systematic approach for comparing modeled biospheric carbon fluxes across regional scales." Biogeosciences 8, no. 6 (June 21, 2011): 1579–93. http://dx.doi.org/10.5194/bg-8-1579-2011.

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Abstract. Given the large differences between biospheric model estimates of regional carbon exchange, there is a need to understand and reconcile the predicted spatial variability of fluxes across models. This paper presents a set of quantitative tools that can be applied to systematically compare flux estimates despite the inherent differences in model formulation. The presented methods include variogram analysis, variable selection, and geostatistical regression. These methods are evaluated in terms of their ability to assess and identify differences in spatial variability in flux estimates across North America among a small subset of models, as well as differences in the environmental drivers that best explain the spatial variability of predicted fluxes. The examined models are the Simple Biosphere (SiB 3.0), Carnegie Ames Stanford Approach (CASA), and CASA coupled with the Global Fire Emissions Database (CASA GFEDv2), and the analyses are performed on model-predicted net ecosystem exchange, gross primary production, and ecosystem respiration. Variogram analysis reveals consistent seasonal differences in spatial variability among modeled fluxes at a 1° × 1° spatial resolution. However, significant differences are observed in the overall magnitude of the carbon flux spatial variability across models, in both net ecosystem exchange and component fluxes. Results of the variable selection and geostatistical regression analyses suggest fundamental differences between the models in terms of the factors that explain the spatial variability of predicted flux. For example, carbon flux is more strongly correlated with percent land cover in CASA GFEDv2 than in SiB or CASA. Some of the differences in spatial patterns of estimated flux can be linked back to differences in model formulation, and would have been difficult to identify simply by comparing net fluxes between models. Overall, the systematic approach presented here provides a set of tools for comparing predicted grid-scale fluxes across models, a task that has historically been difficult unless standardized forcing data were prescribed, or a detailed sensitivity analysis performed.

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Ishizawa, Misa, Douglas Chan, Doug Worthy, Elton Chan, Felix Vogel, and Shamil Maksyutov. "Analysis of atmospheric CH4 in Canadian Arctic and estimation of the regional CH4 fluxes." Atmospheric Chemistry and Physics 19, no. 7 (April 8, 2019): 4637–58. http://dx.doi.org/10.5194/acp-19-4637-2019.

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Abstract. The Canadian Arctic (> 60∘ N, 60–141∘ W) may undergo drastic changes if the Arctic warming trend continues. For methane (CH4), Arctic reservoirs are large and widespread, and the climate feedbacks from such changes may be potentially substantial. Current bottom-up and top-down estimates of the regional CH4 flux range widely. This study analyzes the recent observations of atmospheric CH4 from five arctic monitoring sites and presents estimates of the regional CH4 fluxes for 2012–2015. The observational data reveal sizeable synoptic summertime enhancements in the atmospheric CH4 that are distinguishable from background variations, which indicate strong regional fluxes (primarily wetland and biomass burning CH4 emissions) around Behchoko and Inuvik in the western Canadian Arctic. Three regional Bayesian inversion modelling systems with two Lagrangian particle dispersion models and three meteorological datasets are applied to estimate fluxes for the Canadian Arctic and show relatively robust results in amplitude and temporal variations across different transport models, prior fluxes, and subregion masking. The estimated mean total CH4 flux for the entire Canadian Arctic is 1.8±0.6 Tg CH4 yr−1. The flux estimate is partitioned into biomass burning of 0.3±0.1 Tg CH4 yr−1 and the remaining natural (wetland) flux of 1.5±0.5 Tg CH4 yr−1. The summer natural CH4 flux estimates clearly show inter-annual variability that is positively correlated with surface temperature anomalies. The results indicate that years with warmer summer conditions result in more wetland CH4 emissions. More data and analysis are required to statistically characterize the dependence of regional CH4 fluxes on the climate in the Arctic. These Arctic measurement sites will aid in quantifying the inter-annual variations and long-term trends in CH4 emissions in the Canadian Arctic.

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Yeh, Pat J.-F., and J. S. Famiglietti. "Regional Groundwater Evapotranspiration in Illinois." Journal of Hydrometeorology 10, no. 2 (April 1, 2009): 464–78. http://dx.doi.org/10.1175/2008jhm1018.1.

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Abstract The role of shallow unconfined aquifers in supplying water for evapotranspiration (i.e., groundwater evaporation) is investigated in this paper. Recent results from regional land surface modeling have indicated that in shallow water table areas, a large portion of evapotranspiration comes directly from aquifers. However, little field evidence at the regional scale has been reported to support this finding. Using a comprehensive 19-yr (1984–2002) monthly hydrological dataset on soil moisture, water table depth, and streamflow in Illinois, regional recharge to and evaporation from groundwater are estimated by using soil water balance computation. The 19-yr mean groundwater recharge is estimated to be 244 mm yr−1 (25% of precipitation), with uncertainty ranging from 202 to 278 mm yr−1. During the summer, the upward capillary flux from the shallow aquifer helps to maintain a high rate of evapotranspiration. Groundwater evaporation (negative groundwater recharge) occurs during the period of July–September, with a total of 31.4 mm (10% of evapotranspiration). Analysis of the relative soil saturation at 11 depths from 0 to 2 m deep supports the dominance of groundwater evaporation across the water table in dry periods. The zero-flux plane separating the recharge zone from the evapotranspiration zone propagates downward from about 70- to 110-cm depth during summer, reflecting the water supply from progressively lower layers for evapotranspiration. Despite its small magnitude, neglecting regional groundwater evaporation in shallow groundwater areas would result in underestimated root-zone soil moisture and hence evapotranspiration by as large as 20% in the dry summer seasons.

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Chan, E., D. Chan, M. Ishizawa, F. Vogel, J. Brioude, A. Delcloo, Y. Wu, and B. Jin. "Investigation of error sources in regional inverse estimates of greenhouse gas emissions in Canada." Atmospheric Chemistry and Physics Discussions 15, no. 16 (August 26, 2015): 22715–79. http://dx.doi.org/10.5194/acpd-15-22715-2015.

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Abstract. Inversion models can use atmospheric concentration measurements to estimate surface fluxes. This study is an evaluation of the errors in a regional flux inversion model for different provinces of Canada, Alberta (AB), Saskatchewan (SK) and Ontario (ON). Using CarbonTracker model results as the target, the synthetic data experiment analyses examined the impacts of the errors from the Bayesian optimisation method, prior flux distribution and the atmospheric transport model, as well as their interactions. The scaling factors for different sub-regions were estimated by the Markov chain Monte Carlo (MCMC) simulation and cost function minimization (CFM) methods. The CFM method results are sensitive to the relative size of the assumed model-observation mismatch and prior flux error variances. Experiment results show that the estimation error increases with the number of sub-regions using the CFM method. For the region definitions that lead to realistic flux estimates, the numbers of sub-regions for the western region of AB/SK combined and the eastern region of ON are 11 and 4 respectively. The corresponding annual flux estimation errors for the western and eastern regions using the MCMC (CFM) method are -7 and -3 % (0 and 8 %) respectively, when there is only prior flux error. The estimation errors increase to 36 and 94 % (40 and 232 %) resulting from transport model error alone. When prior and transport model errors co-exist in the inversions, the estimation errors become 5 and 85 % (29 and 201 %). This result indicates that estimation errors are dominated by the transport model error and can in fact cancel each other and propagate to the flux estimates non-linearly. In addition, it is possible for the posterior flux estimates having larger differences than the prior compared to the target fluxes, and the posterior uncertainty estimates could be unrealistically small that do not cover the target. The systematic evaluation of the different components of the inversion model can help in the understanding of the posterior estimates and percentage errors. Stable and realistic sub-regional and monthly flux estimates for western region of AB/SK can be obtained, but not for the eastern region of ON. This indicates that it is likely a real observation-based inversion for the annual provincial emissions will work for the western region whereas; improvements are needed with the current inversion setup before real inversion is performed for the eastern region.

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van der Laan, Sander, Swagath Manohar, Alex Vermeulen, Fred Bosveld, Harro Meijer, Andrew Manning, Michiel van der Molen, and Ingrid van der Laan-Luijkx. "Inferring 222Rn soil fluxes from ambient 222Rn activity and eddy covariance measurements of CO2." Atmospheric Measurement Techniques 9, no. 11 (November 21, 2016): 5523–33. http://dx.doi.org/10.5194/amt-9-5523-2016.

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Abstract. We present a new methodology, which we call Single Pair of Observations Technique with Eddy Covariance (SPOT-EC), to estimate regional-scale surface fluxes of 222Rn from tower-based observations of 222Rn activity concentration, CO2 mole fractions and direct CO2 flux measurements from eddy covariance. For specific events, the regional (222Rn) surface flux is calculated from short-term changes in ambient (222Rn) activity concentration scaled by the ratio of the mean CO2 surface flux for the specific event to the change in its observed mole fraction. The resulting 222Rn surface emissions are integrated in time (between the moment of observation and the last prior background levels) and space (i.e. over the footprint of the observations). The measurement uncertainty obtained is about ±15 % for diurnal events and about ±10 % for longer-term (e.g. seasonal or annual) means. The method does not provide continuous observations, but reliable daily averages can be obtained. We applied our method to in situ observations from two sites in the Netherlands: Cabauw station (CBW) and Lutjewad station (LUT). For LUT, which is an intensive agricultural site, we estimated a mean 222Rn surface flux of (0.29 ± 0.02) atoms cm−2 s−1 with values > 0.5 atoms cm−2 s−1 to the south and south-east. For CBW we estimated a mean 222Rn surface flux of (0.63 ± 0.04) atoms cm−2 s−1. The highest values were observed to the south-west, where the soil type is mainly river clay. For both stations good agreement was found between our results and those from measurements with soil chambers and two recently published 222Rn soil flux maps for Europe. At both sites, large spatial and temporal variability of 222Rn surface fluxes were observed which would be impractical to measure with a soil chamber. SPOT-EC, therefore, offers an important new tool for estimating regional-scale 222Rn surface fluxes. Practical applications furthermore include calibration of process-based 222Rn soil flux models, validation of atmospheric transport models and performing regional-scale inversions, e.g. of greenhouse gases via the SPOT 222Rn-tracer method.

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Ning, Jia. "Effects of Cropland Expansion on the Regional Land Surface Radiative Energy Balance and Heat Fluxes in Northern China." Applied Sciences 11, no. 4 (February 9, 2021): 1556. http://dx.doi.org/10.3390/app11041556.

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Land use change can impact the land surface radiation budget and energy balance by changing surface biophysical processes. Based on satellite remote sensing data and land use data from 2000 to 2015, we quantitatively estimated radiative forcing induced by cropland expansion during the early 21st century in northern China. The results showed that heat flux from the land surface to the atmosphere due to cropland expansion was quite variable in different climate zones. The heat flux increased in humid North China, whereas it decreased in arid Northwest China, semiarid Inner Mongolia, and humid Northeast China. Cropland expansion from woodland areas led to a general decline in the land surface heat flux to the atmosphere, which led to a cooling effect on the climate. The surface heat flux to the atmosphere due to cropland expansion in grassland areas displayed significant variations in different climate zones. The surface heat flux decreased only in humid Northeast China and arid Northwest China. The net surface radiation and latent heat flux both increased when grasslands were changed into cropland, but to different extents, which produced the differences in the surface heat flux to the atmosphere between different zones.

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Stoll, Rob, and Fernando Porté-Agel. "Surface Heterogeneity Effects on Regional-Scale Fluxes in Stable Boundary Layers: Surface Temperature Transitions." Journal of the Atmospheric Sciences 66, no. 2 (February 1, 2009): 412–31. http://dx.doi.org/10.1175/2008jas2668.1.

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Abstract Large-eddy simulation, with recently developed dynamic subgrid-scale models, is used to study the effect of heterogeneous surface temperature distributions on regional-scale turbulent fluxes in the stable boundary layer (SBL). Simulations are performed of a continuously turbulent SBL with surface heterogeneity added in the form of streamwise transitions in surface temperature. Temperature differences between patches of 6 and 3 K are explored with patch length scales ranging from one-half to twice the equivalent homogeneous boundary layer height. The surface temperature heterogeneity has important effects on the mean wind speed and potential temperature profiles as well as on the surface heat flux distribution. Increasing the difference between the patch temperatures results in decreased magnitude of the average surface heat flux, with a corresponding increase in the mean potential temperature in the boundary layer. The simulation results are also used to test existing models for average surface fluxes over heterogeneous terrain. The tested models fail to fully represent the average turbulent heat flux, with models that break the domain into homogeneous subareas grossly underestimating the heat flux magnitude over patches with relatively colder surface temperatures. Motivated by these results, a new parameterization based on local similarity theory is proposed. The new formulation is found to correct the bias over the cold patches, resulting in improved average surface heat flux calculations.

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Winter, Jonathan M., Jeremy S. Pal, and Elfatih A. B. Eltahir. "Coupling of Integrated Biosphere Simulator to Regional Climate Model Version 3." Journal of Climate 22, no. 10 (May 15, 2009): 2743–57. http://dx.doi.org/10.1175/2008jcli2541.1.

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Abstract A description of the coupling of Integrated Biosphere Simulator (IBIS) to Regional Climate Model version 3 (RegCM3) is presented. IBIS introduces several key advantages to RegCM3, most notably vegetation dynamics, the coexistence of multiple plant functional types in the same grid cell, more sophisticated plant phenology, plant competition, explicit modeling of soil/plant biogeochemistry, and additional soil and snow layers. A single subroutine was created that allows RegCM3 to use IBIS for surface physics calculations. A revised initialization scheme was implemented for RegCM3–IBIS, including an IBIS-specific prescription of vegetation and soil properties. To illustrate the relative strengths and weaknesses of RegCM3–IBIS, one 4-yr numerical experiment was completed to assess ability of both RegCM3–IBIS (with static vegetation) and RegCM3 with its native land surface model, Biosphere–Atmosphere Transfer Scheme 1e (RegCM3–BATS1e), to simulate the energy and water budgets. Each model was evaluated using the NASA Surface Radiation Budget, FLUXNET micrometeorological tower observations, and Climate Research Unit Time Series 2.0. RegCM3–IBIS and RegCM3–BATS1e simulate excess shortwave radiation incident and absorbed at the surface, especially during the summer months. RegCM3–IBIS limits evapotranspiration, which allows for the correct estimation of latent heat flux, but increases surface temperature, sensible heat flux, and net longwave radiation. RegCM3–BATS1e better simulates temperature, net longwave radiation, and sensible heat flux, but systematically overestimates latent heat flux. This objective comparison of two different land surface models will help guide future adjustments to surface physics schemes within RegCM3.

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Deschacht, Nick, and Anne Winter. "Micro-Mobility in Flux." Journal of Migration History 5, no. 1 (April 25, 2019): 1–30. http://dx.doi.org/10.1163/23519924-00501005.

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In this article we use new, unique data on population composition and socio-economic structure for the c. 670 municipalities of the Belgian provinces of East Flanders, West Flanders and Antwerp in 1796, 1815 and 1846, in order to gain insight into the changing patterns of local migration intensity from the late eighteenth to the mid-nineteenth century. Although so-called micro-mobility is often disregarded in migration studies, this article argues that a spatial and diachronic analysis of local migration rates provides insight into the dynamics of social and economic change in relation to migration behaviour. The data show that the proportion of non-native residents varied strongly in accordance with different regional economies at the end of the eighteenth century, but that spatial variation declined markedly as overall migration rates converged on a higher average level by the mid-nineteenth century – leading to a re-interpretation of the mobility transition hypothesis.

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Jin, Rui, Tan Yu, Bangyi Tao, Weizeng Shao, Song Hu, and Yongliang Wei. "Influence of the Nocturnal Effect on the Estimated Global CO2 Flux." Remote Sensing 14, no. 13 (July 3, 2022): 3192. http://dx.doi.org/10.3390/rs14133192.

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We found that significant errors occurred when diurnal data instead of diurnal–nocturnal data were used to calculate the daily sea-air CO2 flux (F). As the errors were mainly associated with the partial pressure of CO2 in seawater (pCO2w) and the sea surface temperature (SST) in the control experiment, pCO2w and SST equations were established, which are called the nocturnal effect of the CO2 flux. The root-mean-square error between the real daily CO2 flux (Freal) and the daily CO2 flux corrected for the nocturnal effect (Fcom) was 11.93 mmol m−2 d−1, which was significantly lower than that between the Freal value and the diurnal CO2 flux (Fday) (46.32 mmol m−2 d−1). Thus, the errors associated with using diurnal data to calculate the CO2 flux can be reduced by accounting for the nocturnal effect. The mean global daily CO2 flux estimated based on the nocturnal effect and the sub-regional pCO2w algorithm (cor_Fcom) was −6.86 mol m−2 y−1 (September 2020–August 2021), which was smaller by 0.75 mol m−2 y−1 than that based solely on the sub-regional pCO2w algorithm (day_Fcom). That is, compared with day_Fcom, the global cor_Fcom value overestimated the CO2 sink of the global ocean by 10.89%.

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Qu, Yi, Feng Wu, Haiming Yan, Bangrong Shu, and Xiangzheng Deng. "Possible Influence of the Cultivated Land Reclamation on Surface Climate in India: A WRF Model Based Simulation." Advances in Meteorology 2013 (2013): 1–9. http://dx.doi.org/10.1155/2013/312716.

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Land use/cover change (LUCC) has become one of the most important factors for the global climate change. As one of the major types of LUCC, cultivated land reclamation also has impacts on regional climate change. Most of the previous studies focused on the correlation and simulation analysis of historical LUCC and climate change, with few explorations for the impacts of future LUCC on regional climate, especially impacts of the cultivated land reclamation. This study used the Weather Research and Forecasting (WRF) model to forecast the changes of energy flux and temperature based on the future cultivated land reclamation in India and then analyzed the impacts of cultivated land reclamation on climate change. The results show that cultivated land reclamation will lead to a large amount of land conversions, which will overall result in the increase in latent heat flux of regional surface as well as the decrease in sensible heat flux and further lead to changes of regional average temperature. Furthermore, the impact on climate change is seasonally different. The cultivated land reclamation mainly leads to a temperature decrease in the summer, while it leads to a temperature increase in the winter.

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Journal articles on the topic 'Regional flux'

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