中国大陆地表净辐射估算及其时空变化特征

Estimation of Surface Net Radiation and Its Spatio-temporal Variation Characteristics Over China's Mainland

地表净辐射(R)是陆地生态系统水、热、碳循环过程中的重要参数,准确地估算R并分析其时空变化特征对气候变化和能量平衡等研究具有重要意义.本文基于CMFD再分析资料和GLASS地表反照率数据集估算1982~2017年中国大陆逐日R,用GIS空间分析技术、Mann-Kendall趋势分析方法和R/S分析法揭示其时间动态特征与空间演变规律.结果表明:(1)CMFD中逐日气温、相对湿度、向下短波辐射和估算的高时空分辨率的R在中国大陆各区域具有较高的精准度,具有良好的适用性;(2)1982~2017年中国大陆地区R呈微弱上升趋势;西北内陆河流域和黄河流域R呈上升趋势,其他流域R呈下降趋势,其中海河流域和淮河流域下降趋势最为显著;(3)中国大陆R年内变化呈正态分布,最大值出现在6月份;(4)中国大陆R在8月份下降速率最大,4月份上升速率最大.

Surface net radiation(R) is an important parameter of water, carbon and energy cycle in terrestrial ecosystems.Accurate estimation of Rand analysis of its spatio-temporal variations are a critical study in climate change and energy balance research.CMFD reanalysis dataset and GLASS(Global Land Surface Satellite Products) surface albedo dataset were used to estimate daily Rover China's Mainland during 1982~2017.GIS spatial analysis technology, R/S method and Mann-Kendall trend analysis method were used to reveal Rspatio-temporal variation characteristics.The results show that(1)Daily temperature, relative humidity and downward shortwave radiation products provided by CMFD reanalysis dataset, and estimated high spatial and temporal resolution Rdataset have good applicability over China's Mainland.(2)Rshows a slight upward trend over China's Mainland during 1982~2017.Rin Northwest Inland Basin and Yellow River Basin shows an upward trend, while it in the other basins shows a downward trend with the most significant trend in Haihe River Basin and Huaihe River Basin.(3)The Rinter-annual change is normally distributed, and the maximum Rappears in June.(4)Rover China's Mainland drops the fastest in August and rises the fastest in April.