The impact of land use and land cover changes on East Asian summer monsoon precipitation using the WRF‐mosaic approach

Abstract

AbstractBased on satellite‐derived land surface data, the impact of land use and land cover (LULC) changes between the 1980s and 2010s on the monsoon‐related circulation and precipitation over East Asia was explored using the Weather Research and Forecasting (WRF) regional climate model with the mosaic approach, which could consider subgrid‐scale LULC characteristics and the corresponding changes. Simulated results using the satellite‐based LULC data show that the monsoon‐related precipitation and rain belt movement could be well reproduced, whereas the precipitation was generally overestimated. In terms of the general effect of LULC changes between the 1980s and 2010s, the precipitation decreased in the north and increased in the south. Significant subregional characteristics are apparent in China, especially with respect to East Asian summer monsoon (EASM)‐related precipitation. The increased roughness induced weakened near‐surface wind speeds in the southern part of the EASM region, while the decreased roughness resulted in intensified values in the northern part. Meanwhile, the impacted EASM‐related circulation and moisture flux, which could be well explained by the LULC changes induced, influenced the pressure gradient and temperature gradient at low to middle latitudes, resulting in a weakened moisture flux from the southwest and the southeast, whereas it intensified from the South China Sea and at middle to high latitudes. In general, with weakened moisture flux at low to high latitudes, the EASM‐related rain belt's northward movement was restrained. Although the enhanced westerly currents contributed to the increased moisture flux at middle to high latitudes, the precipitation there decreased due to the stronger weakened northward moisture flux.