New evidence for effects of land cover in China on summer climate

The effects of land cover in different regions of China on summer climate are studied by lagged correlation analysis using NOAA/AVHRR normalized difference vegetation index (NDVI) data for the period of 1981-1994 and temperature,precipitation data of 160 meteorological stations in China. The results show that the correlation coefficients between NDVI in previous season and summer precipitation are positive in most regions of China, and the lagged correlations showa significant difference between regions. The stronger correlations between NDVI in previous winter and precipitation in summer occur in Central China and the Tibetan Plateau, and the correlations between spring NDVI and summer precipitation in the eastern arid/semi- arid region and the Tibetan Plateau are more significant. Vegetation changes have more sensitive feedback effects on climate in thethree regions (eastern arid/semi-arid region, Central China and Tibetan Plateau). The lagged correlations between NDVI and precipitation suggest that, on interannual time scales, land cover affects summer precipitation to a certain extent.The correlations between NDVI in previous season and summer temperature show more complex, and the lagged responses of temperature to vegetation are weaker compared with precipitation, and they are possibly related to the global warming which partly cover up the correlations.