Impact of the Rice Paddy Standing Water Layer on Micrometeorology: A Coupled WRF-Rice Paddy Model Study

To investigate the heat storage of the standing water layer of rice paddy fields on micrometeorology, we couple a rice paddy model with the mesoscale Weather Research and Forecasting (WRF) model. The coupled model (RICE) was run for three different days in June 2019, corresponding to the early rice growing season with low LAI, at a site surrounded by rice paddy fields in Boseong, South Korea. The coupled model was evaluated using 1.5 m eddy covariance observations, 15 surface weather station observations, and 5 levels (20, 80, 160, 260, and 300 m) of meteorological tower observations and compared with WRF default (DEF) and irrigation (IRRI) simulations. The results show that IRRI and RICE reduced the RMSEs of the surface sensible (H) and latent (LH) heat fluxes by more than 23% compared to DEF. RICE showed better performance in simulating H, LH, and RH_2m compared to IRRI. However, the improvements of RICE were less pronounced for T_2m, WIND_10m, and vertical profile of micrometeorological variables.