skip to main content

DOE PAGESDOE PAGES

Title: The influence of land cover on surface energy partitioning and evaporative fraction regimes in the U.S. Southern Great Plains

Land-atmosphere interactions are important to climate prediction, but the underlying effects of surface forcing of the atmosphere are not well understood. In the U.S. Southern Great Plains, grassland/pasture and winter wheat are the dominant land covers but have distinct growing periods that may differently influence land-atmosphere coupling during spring and summer. Variables that influence surface flux partitioning can change seasonally, depending on the state of local vegetation. We use surface observations from multiple sites in the U.S. Department of Energy Atmospheric Radiation Measurement Southern Great Plains Climate Research Facility and statistical modeling at a paired grassland/agricultural site within this facility to quantify land cover influence on surface energy balance and variables controlling evaporative fraction (latent heat flux normalized by the sum of sensible and latent heat fluxes). We demonstrate that the radiative balance and evaporative fraction are closely related to green leaf area at both winter wheat and grassland/pasture sites and that the early summer harvest of winter wheat abruptly shifts the relationship between evaporative fraction and surface state variables. Prior to harvest, evaporative fraction of winter wheat is strongly influenced by leaf area and soil-atmosphere temperature differences. After harvest, variations in soil moisture have a stronger effect on evaporativemore » fraction. Finally, this is in contrast with grassland/pasture sites, where variation in green leaf area has a large influence on evaporative fraction throughout spring and summer, and changes in soil-atmosphere temperature difference and soil moisture are of relatively minor importance.« less
Authors:
ORCiD logo [1] ; ORCiD logo [2] ; ORCiD logo [3] ; ORCiD logo [1] ; ORCiD logo [1] ; ORCiD logo [2]
  1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Climate and Ecosystem Sciences Division
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Climate and Ecosystem Sciences Division; Univ. of California, Berkeley, CA (United States). Energy and Resources Group
  3. Univ. of Nebraska, Lincoln, NE (United States). Dept. of Biological Sciences Engineering
Publication Date:
Grant/Contract Number:
AC02-05CH11231
Type:
Accepted Manuscript
Journal Name:
Journal of Geophysical Research: Atmospheres
Additional Journal Information:
Journal Volume: 122; Journal Issue: 11; Journal ID: ISSN 2169-897X
Publisher:
American Geophysical Union
Research Org:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; 58 GEOSCIENCES; land-atmosphere interactions; water-energy interactions; agricultural systems
OSTI Identifier:
1475013

Bagley, Justin E., Kueppers, Lara M., Billesbach, Dave P., Williams, Ian N., Biraud, Sébastien C., and Torn, Margaret S.. The influence of land cover on surface energy partitioning and evaporative fraction regimes in the U.S. Southern Great Plains. United States: N. p., Web. doi:10.1002/2017JD026740.
Bagley, Justin E., Kueppers, Lara M., Billesbach, Dave P., Williams, Ian N., Biraud, Sébastien C., & Torn, Margaret S.. The influence of land cover on surface energy partitioning and evaporative fraction regimes in the U.S. Southern Great Plains. United States. doi:10.1002/2017JD026740.
Bagley, Justin E., Kueppers, Lara M., Billesbach, Dave P., Williams, Ian N., Biraud, Sébastien C., and Torn, Margaret S.. 2017. "The influence of land cover on surface energy partitioning and evaporative fraction regimes in the U.S. Southern Great Plains". United States. doi:10.1002/2017JD026740. https://www.osti.gov/servlets/purl/1475013.
@article{osti_1475013,
title = {The influence of land cover on surface energy partitioning and evaporative fraction regimes in the U.S. Southern Great Plains},
author = {Bagley, Justin E. and Kueppers, Lara M. and Billesbach, Dave P. and Williams, Ian N. and Biraud, Sébastien C. and Torn, Margaret S.},
abstractNote = {Land-atmosphere interactions are important to climate prediction, but the underlying effects of surface forcing of the atmosphere are not well understood. In the U.S. Southern Great Plains, grassland/pasture and winter wheat are the dominant land covers but have distinct growing periods that may differently influence land-atmosphere coupling during spring and summer. Variables that influence surface flux partitioning can change seasonally, depending on the state of local vegetation. We use surface observations from multiple sites in the U.S. Department of Energy Atmospheric Radiation Measurement Southern Great Plains Climate Research Facility and statistical modeling at a paired grassland/agricultural site within this facility to quantify land cover influence on surface energy balance and variables controlling evaporative fraction (latent heat flux normalized by the sum of sensible and latent heat fluxes). We demonstrate that the radiative balance and evaporative fraction are closely related to green leaf area at both winter wheat and grassland/pasture sites and that the early summer harvest of winter wheat abruptly shifts the relationship between evaporative fraction and surface state variables. Prior to harvest, evaporative fraction of winter wheat is strongly influenced by leaf area and soil-atmosphere temperature differences. After harvest, variations in soil moisture have a stronger effect on evaporative fraction. Finally, this is in contrast with grassland/pasture sites, where variation in green leaf area has a large influence on evaporative fraction throughout spring and summer, and changes in soil-atmosphere temperature difference and soil moisture are of relatively minor importance.},
doi = {10.1002/2017JD026740},
journal = {Journal of Geophysical Research: Atmospheres},
number = 11,
volume = 122,
place = {United States},
year = {2017},
month = {5}
}