Evaluation of Long-term Soil Moisture Proxies in the U.S. Great Plains

Soil moisture plays an important role in land-atmosphere interactions through both surface energy and water balances. However, despite its importance, there are few long-term records of observed soil moisture for investigating long-term spatial and temporal variations of soil moisture. Hence, it is necessary to find suitable approximations of soil moisture observations. 5 drought indices and 5 land surface models will be compared with observed soil moisture over the U.S. Great Plains from 2003 to 2012. Standardized Precipitation Index (SPI), Standardized Precipitation-Evapotranspiration Index (SPEI), Palmer Drought Severity Index (PDSI), Crop Moisture Index (CMI) and Effective Precipitation (EF) will be calculated by PRISM data. The soil moisture simulations of Community Land Model (CLM), Sacramento Model (SAC), Noah Land Surface Model (Noah-LSM), Variable Infiltration Capacity (VIC) and TOPMODEL (TOP) will be derived from The University of Washington Surface Water Monitor. The evaluation will focus on two main aspects: variations and persistence. The results will support further research investigating long-term variations in soil moisture–climate interactions.