Increase in vegetation greenness and decrease in springtime warming over east Asia

This study investigates the impact of increased vegetation greening on the springtime temperature over east Asia for 1982-2000. An analysis of station-based temperature records and satellite-measure normalized difference vegetation index (NDVI) indicates that slight warming (<0.4°C 10-yr ^-1) occurred over regions that experienced large increase in NDVI (≥0.08 10-yr^-1). On the contrary, strong warming (≥0.8°C 10-yr^-1) occurred over regions that exhibited minor changes in NDVI (<0.04 10-yr^-1). For the most part, this inverse NDVI-temperature relationship observed with the daily maximum temperature. Thus, it is suggested that the decrease in warming was mostly attributable to the increase in evapotranspiration associated with increased vegetation greening. Earlier vegetation growth may have further strengthened the effect of this vegetation-evaporation on spring temperature.