10:15 AM - 10:30 AM
[AAS04-06] Role of land-atmosphere interaction in 2016 East Asia heat wave: Impact of soil moisture initialization
Keywords:Heat wave, Soil moisture initialization, Land-atmosphere interaction
The impact of soil moisture initialization on the land-atmosphere interaction in 2016 East Asia heat wave was explored by using the Land Information System (LIS) and Weather Research and Forecast (WRF) model. In order to obtain realistic initial soil moisture conditions, various meteorological variables from the National Centers for Environmental Prediction (NCEP) Global Data Assimilation System (GDAS) analysis field and Integrated Multi-satellitE Retrievals for Global Precipitation Measurement observation (IMERGE) data were used for atmospheric forcings of Noah Land Surface Model (Noah-LSM). In addition, the Soil Moisture Active Passive (SMAP) satellite observation data was assimilated during Noah-LSM simulation, by applying the ensemble Kalman filter data assimilation technique. The produced soil moisture data from the off-line Noah-LSM experiment were used as the initial condition of the WRF model.
As a result of the off-line Noah-LSM experiment, Noah-LSM simulated drier soil moisture conditions over Mongolia at initial date compared to soil moisture data from the NCEP Final analysis (FNL) data. To investigate the impact of soil moisture initialization, we conducted two experiments using the WRF model; the CTL and LIS experiments where initial soil moisture fields were from the FNL data and the LIS, respectively. LIS experiment simulated more realistic surface air temperature (SAT) and 500-hPa geopotential height (GPH) over East Asia. Especially, the initialization had a more effect over Mongolia during the late period. The difference in SAT (LIS-CTL experiment) at week 1 was directly induced from lower latent heat flux release. Then, GPH difference in the mid-to-upper atmosphere became strong and spatially expanded, and the positive SAT difference again increased.
Through the study, we found that the soil moisture initialization spatiotemporally improved the simulation performance of the 2016 East Asia heat wave by representing realistic land-atmosphere interactions over Mongolia.
As a result of the off-line Noah-LSM experiment, Noah-LSM simulated drier soil moisture conditions over Mongolia at initial date compared to soil moisture data from the NCEP Final analysis (FNL) data. To investigate the impact of soil moisture initialization, we conducted two experiments using the WRF model; the CTL and LIS experiments where initial soil moisture fields were from the FNL data and the LIS, respectively. LIS experiment simulated more realistic surface air temperature (SAT) and 500-hPa geopotential height (GPH) over East Asia. Especially, the initialization had a more effect over Mongolia during the late period. The difference in SAT (LIS-CTL experiment) at week 1 was directly induced from lower latent heat flux release. Then, GPH difference in the mid-to-upper atmosphere became strong and spatially expanded, and the positive SAT difference again increased.
Through the study, we found that the soil moisture initialization spatiotemporally improved the simulation performance of the 2016 East Asia heat wave by representing realistic land-atmosphere interactions over Mongolia.