AUTHOR=Meng Chunlei , Jin Haidong , Jin Bo 

TITLE=Parameterization of soil evaporation and coupled transport of moisture and heat for arid and semiarid regions

JOURNAL=Frontiers in Earth Science

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2023.1151405

DOI=10.3389/feart.2023.1151405

ISSN=2296-6463

ABSTRACT=Soil moisture is an important parameter in numerical weather forecasting and climate projection studies; it is extremely important for arid and semiarid areas. Different from those in relative wet areas, for arid and semiarid areas, mechanisms associated with the transport, condensation and evaporation of water vapor in soil interior cannot be neglected. In this paper, schemes associated with soil evaporation and coupled transport of soil moisture and heat were developed for the Integrated Urban land Model (IUM) to improve the simulation of soil moisture in arid and semiarid areas. The whole layer soil evaporation (WSE) scheme was developed to improve the simulation of soil evaporation. The soil inner layer water vapor transport is considered as a part of WSE. The transports of and water and heat in inner soil were linked by the phase change of water. The NASA Soil Moisture Active Passive (SMAP) mission Level-4 Soil Moisture product and 10 cm volumetric soil moisture observations in 358 autonomic soil moisture observation sites were used for validating the simulation results. The results indicate after using the WSE scheme and considering the coupled transport of moisture and heat in soil interior, the simulation of soil moisture was improved definitely. For June, July and August, the biases of soil moisture simulation decrease about 22.5%, 34.4%, and 27.5%, respectively; while the RMSEs decrease about 7.0%, 8.7% and 9.6%, respectively. The improvement of soil moisture simulation indicates in arid and semiarid areas, soil water vapor transport is important and cannot be neglected.