The responses of surface albedo to climatic changes in Xilin Gol grassland
锡林郭勒草原地表反照率对气候变化的响应

This study assessed the reliability of Moderate Resolution Imaging Spectroradiometer(MODIS)-derived land surface albedo products for Xilin Gol grassland,illustrated the seasonal cycles and inter-annual variations of land surface albedo in Xilin Gol grassland,and analyzed correlations between surface albedo variations and climatic changes.The results show MODIS-derived dataset is able to capture seasonal cycle and inter-annual variations of surface albedo,though there is a difference between the MODIS-derived albedo and ground instrumental measurements.The MODIS-derived dataset illustrates that the seasonal cycle patterns of surface albedo vary with spectrum.For the visible band surface albedo,the seasonal cycle presents a "V"-shaped variation with the bottom in the first ten days of August.For the near-infrared band surface albedo,the seasonal cycle is "U"-shaped with the bottom in the period from June to September.However,both visible band surface albedo and near-infrared band surface albedo had consistent inter-annual variations.Moreover,the inter-annual variations of surface albedo were partly attributed to climatic variations.The effects of temperature were significant in the early(April to May) and late(September to November) growth season.The correlation coefficients between temperature and surface albedo were-0.67 and 0.63 in the early and late growth season,respectively.The effects of precipitation were significant through out the growth season.The correlation coefficients between precipitation and surface albedo ranged from-0.54 to-0.76.It is worthy noting that the effects of precipitation were usually lagged by 2-3 months.