Potential Impact of Clay Pan Soils on Simulation Results of a Land Surface Model.

Land surface models provide inputs necessary to run atmospheric models predicting both weather patterns and climate changes. Latent and sensible heat are two LSM outputs that are affected by soil moisture.  The NOAH-MP community land surface model currently does not consider vertically heterogeneous soil texture information.  Texas has a Clay Pan Major Land Resource Area (MLRA) where there is a significant and abrupt increase in clay content with depth, and it is likely that this change in texture has large impacts on soil moisture storage and the subsequent latent and sensible heat outputs.  We will explore this concept using a trusted soil hydrology model: the Root Zone and Water Quality Model 2 (RZWQM2).  Comparisons of vertically homogeneous and heterogeneous soil will be made and compared with results from the homogeneous NOAH-MP model.  We will also compare model results with soil moisture measurements from several locations in Texas.