TY - JOUR
T1 - Assessment of observed and model-derived soil moisture-evaporative fraction relationships over the United States southern great plains
AU - Ford, Trent W.
AU - Wulff, Christoph O.
AU - Quiring, Steven M.
N1 - Publisher Copyright:
© 2014. American Geophysical Union. All Rights Reserved.
PY - 2014/6/16
Y1 - 2014/6/16
N2 - The relationship between soil moisture (SM) and evaporative fraction (EF) is an important component of land-atmosphere interactions. Frequently, land-atmosphere studies are based on land-surface models and not on observations. This study examines SM-EF interactions over the United States Southern Great Plains using both in situ observations and simulations from the Variable Infiltration Capacity hydrologic model. Specifically, we evaluate how the relationship between SM and EF varies by season, we determine why these variations occur, and we compare model-derived and observed SM-energy flux relationships. Data from four sites (2004–2008) that are part of the United States Department of Energy’s Atmospheric Radiation Measurement—Southern Great Plains network are used in this study. Results show that SM-EF interactions in both the model and observations are in general agreement with the evaporative regime theory described in past studies. That is, EF is a linear function of SM when SM is between the wilting point and the critical value, and when SM is above the critical value, EF is not dependent on SM. However, SM-EF relationships vary substantially from year to year. EF is a linear function of SM only when daily net radiation is above normal. Our results suggest that the strength of SM-EF interactions is not solely controlled by soil wetness but is also strongly influenced by daily net radiation and meteorological conditions.
AB - The relationship between soil moisture (SM) and evaporative fraction (EF) is an important component of land-atmosphere interactions. Frequently, land-atmosphere studies are based on land-surface models and not on observations. This study examines SM-EF interactions over the United States Southern Great Plains using both in situ observations and simulations from the Variable Infiltration Capacity hydrologic model. Specifically, we evaluate how the relationship between SM and EF varies by season, we determine why these variations occur, and we compare model-derived and observed SM-energy flux relationships. Data from four sites (2004–2008) that are part of the United States Department of Energy’s Atmospheric Radiation Measurement—Southern Great Plains network are used in this study. Results show that SM-EF interactions in both the model and observations are in general agreement with the evaporative regime theory described in past studies. That is, EF is a linear function of SM when SM is between the wilting point and the critical value, and when SM is above the critical value, EF is not dependent on SM. However, SM-EF relationships vary substantially from year to year. EF is a linear function of SM only when daily net radiation is above normal. Our results suggest that the strength of SM-EF interactions is not solely controlled by soil wetness but is also strongly influenced by daily net radiation and meteorological conditions.
UR - http://www.scopus.com/inward/record.url?scp=84903300376&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84903300376&partnerID=8YFLogxK
U2 - 10.1002/2014JD021490
DO - 10.1002/2014JD021490
M3 - Article
AN - SCOPUS:84903300376
SN - 0148-0227
VL - 119
SP - 6279
EP - 6291
JO - Journal of Geophysical Research
JF - Journal of Geophysical Research
IS - 11
ER -