Numerical simulation of local circulation in the lake area around Daejeon, Korea

Local circulation in a lake region is simulated using mesoscale model WRF and the characteristics of local circulation and lake effect are examined in this study. Simulation area is near Daechung lake over Daejeon, Korea. Numerical simulation has conducted in a clear day of summer and winter season that high pressure system is located over the Korean Peninsula. It is shown that difference of temperature between lake and land area is maximized at daytime in summer and the difference is decreased during winter and nighttime. Therefore, lake breeze intensity is maximized during daytime of summer and weakened in winter. Lake breeze influenced up to 1.2km altitude. Lake breeze circulation is generated around 09LST and decays around 18LST with a maximum intensity at 15LST. Landuse data of the model has improved using 30m resolution data of Korea Ministry of Environment. Numerical simulation results near lake have improved with a modification of landuse data. Sensitivity experiment about remove of the lake indicates that temperature and wind speed are decreased by lake. WRF model forecast colder than observation in the 2m temperature. In order to improve the cold bias of air temperature, land data assimilation has adopted in this study. Initial data for numerical simulation has improved using GLDAS (Global Land Data Assimilation System) data which is produced GSFC/NASA. The improvement of WRF model results would be presented in the conference.