中国地区MODIS地表反照率反演结果的时空分布研究

应用2003—2015年MODIS地表反照率反演质量数据MCD43A2,统计分析中国地区MODIS地表反照率反演质量的时空分布特征,结果表明:1)中国地区MODIS地表反照率反演质量在空间分布上具有明显的差异,高质量全反演结果(质量标记0)主要分布在东北、华北、西北地区和西南地区的中西部;当量反演结果(质量标记3)主要分布在华东、华中、华南地区和西南地区的中东部;填充值(质量标记15)主要分布在华中、华南、华东地区及西南地区的部分区域。2)在东北、华北和西北地区,只有春、夏和秋季才有超过60%的区域可能获得高精度MODIS地表反照率;可能获得高精度M ODIS地表反照率的区域,在西南地区全年各时段都只有40%~60%,在华东、华中和华南地区全年各时段都不足20%。3)各地当量反演结果的比例一般不足50%,华东和华中地区夏季和秋季当量反演结果的比例超过40%;4)华中和华东地区夏季和冬季,以及华南地区春、夏和冬季,填充值的比例超过50%,华南和华中地区最高甚至超过80%。

Analysis of the distribution of MODIS albedo inversion in China

In this paper,using MODIS albedo retrieval quality data MCD43A2,the spatial and temporal distribution characteristics of surface albedo retrieval quality over China during the period of 2003-2015 are statistically analyzed.The results are as follows:(1)There was a clear difference in the spatial distribution of MODIS surface albedo retrieval quality in China.The albedo retrievals with the best quality of full inversion(flagged as 0)were mainly distributed in northern,northeastern,northwestern,and the Midwestern region of southwestern China.The albedo retrievals with the magnitude inversion(flagged as 3) were mainly distributed in eastern,central,southern,and the mid eastern region of southwestern China.The fill value(flagged as 15) was mainly distributed in some regions of central,southern,eastern and southwestern China.(2)In spring,summer and fall,the areas of only northeastern,northern and northwestern China had more than 60% which could be obtained with high accuracy MODIS surface albedo,so as to meet the climate and land-surface model accuracy requirements.In addition,only 40%-60% of the area of southwestern China and less than 20% of that of eastern,central and southern China could be obtained with high accuracy MODIS surface albedo to meet the climate and land-surface model accuracy requirements throughout the year.(3)The percentage of the magnitude inversion is low,being generally less than 50%,all throughout China.Meanwhile,that in eastern and central China is more than 40% in summer and autumn.In central and eastern China in summer and winter,as well as in southern China in spring,summer and winter,the percentage of the fill value is relatively high(above 50%),especially in southern and central China,where the figure reaches up to 80%.