青藏高原MODIS逐日无云积雪面积数据集 (2002-2015年)  

MODIS daily cloud-free snow cover products over Tibetan Plateau(2002–2015)

作　　者：邱玉宝 郭华东 除多[2] 张欢 施建成 石利娟 郑照军[4] 拉巴卓玛 Qiu Yubao;Guo Huadong;Chu Duo;Zhang Huan;Shi Jiancheng;ShiLijuan;Zheng Zhaojun;Laba Zhuoma

机构地区：[1]中国科学院遥感与数字地球研究所,中国科学院数字地球重点实验室,北京100094 [2]西藏自治区气象局,西藏高原大气环境科学研究所,拉萨850000 [3]中国科学院遥感与数字地球研究所,遥感科学国家重点实验室,北京100010 [4]中国气象局国家卫星中心,北京100081

出　　处：《中国科学数据（中英文网络版）》2016年第1期1-11,共11页China Scientific Data

基　　金：公益性(气象)行业专项“青藏高原遥感积雪气候数据集建设”(GYHY201206040);国家自然科学基金重点项目(ABCC计划,41120114001);国家自然科学基金面上项目(41371351);中国科学院“一三五”规划项目等支持

摘　　要：青藏高原积雪对于能量和水循环起着重要的反馈和调节作用,其消融过程也直接影响着融雪性河流流量的变化,积雪的存在以及长时间变化等也是区域气候、生态和灾害的影响和响应敏感因素之一。中分辨率成像光谱仪(MODIS)具有高时空分辨率的特点,被广泛应用于积雪遥感动态监测。青藏高原地区积雪的赋存变化较快,高原周边高山区具有冰雪资源丰富,大气对流活跃等特点,而光学遥感往往受云的影响,在日时间尺度上积雪覆盖监测需要考虑去云问题。在充分考虑青藏高原的地形和山地积雪特征的情况下,本套数据集采用了多种去云过程和步骤相结合,逐步实现保持积雪分类精度的情况下,完成逐日积雪的云量消除,形成了“青藏高原MODIS逐日无云积雪面积”的逐步综合分类算法,完成了“青藏高原MODIS逐日无云积雪面积数据集(2002~2015年)”。论文选取2009年10月1日至2011年4月30日中的两个积雪季为算法研究和精度验证试验数据,采用研究区145个地面台站提供的雪深数据作为地面参考。结果表明,在高原地区,当积雪深度>3 cm时,无云积雪产品总分类精度达到96.6%,积雪分类精度达89.0%,整个算法流程对MODIS积雪产品去云的精度损失较低,数据可靠性较高。Snow cover over Tibetan Plateau plays an important role in regional water and energy circulation.Snow ablation also affects downstream rivers.Snow parameters and their longterm changes are sensitive factors affecting and responding to regional climate,influencing ecology and disasters.Moderate-resolution imaging spectrometer(MODIS)is widely used for remotely sensing snow due to its high spatio-temporal resolution.However,snow over Tibetan Plateau is distributed patchily and changes rapidly with unexpected atmospheric convection and precipitation.Also,because optical remote sensing is influenced severely by clouds,daily snow cover monitoring is a challenge requiring to remove cloud cover instances.Engaged in Tibetan Plateau’s terrain complexity and snow spatio-temporal characteristics,this paper presents a compound method by combining different cloud removal algorithms,giving a MODIS daily cloud-free snow cover algorithm for Tibetan Plateau,as well as MODIS daily cloud-free snow cover products(2002–2015).The accuracy of the snow cover products is then verified against experimental data observed from 145 ground stations during two winter periods from October 1,2009 to April 30,2011.Results show that,when snow depth exceeds 3 cm,the general classification accuracy is 96.6%and the snow classification accuracy is 89.0%.Accuracy was well controlled in each step,which provided a good algorithm for removing clouds from the MODIS snow cover imagery.A multilanguage operational process was developed and the daily,cloud-free climatological snow cover products over Tibetan Plateau were released as a free utility online.

关 键 词：青藏高原 MODIS 逐日无云积雪面积数据集 

分 类 号：P426.635[天文地球—大气科学及气象学]