Spatiotemporal changes of snow cover over the Tibetan plateau based on cloud-removed moderate resolution imaging spectroradiometer fractional snow cover product from 2001 to 2011
Spatiotemporal changes of snow cover over the Tibetan plateau based on cloud-removed moderate resolution imaging spectroradiometer fractional snow cover product from 2001 to 2011
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DOI：
10.1117/1.jrs.7.073582
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发表时间：
2013-01
影响因子：
1.7
通讯作者：
Zhiguang Tang;Jian Wang;Hongyi Li;Lili Yan
中科院分区：
文献类型：
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作者：
Zhiguang Tang;Jian Wang;Hongyi Li;Lili Yan
摘要利用2001 - 2011年青藏高原中分辨率成像光谱仪（MODIS）逐日积雪覆盖率（FSC）数据和现场温度数据，研究了青藏高原积雪变化。首先，在晴朗的天空条件下的MODIS FSC数据的准确性进行了评估，通过与陆地卫星30米观测比较。然后，我们描述了一个云间隙填充（CGF）的方法，使用三次样条插值算法来填补云造成的数据间隙。最后，利用MODIS数据提取的积雪面积和积雪日数（SCD），分析了积雪的时空变化。结果表明，在晴空条件下，MODIS FSC数据的平均绝对误差约为0.098。CGF方法是有效的云减少（总的平均绝对误差为0.092的检索FSC数据）。在11年中，积雪的年际和季节内变化都很大。较高的积雪与巨大的山脉相对应。不同海拔地区积雪的积累期和融化期不同。分别有34.14%（5.56%）和24.75%（3.9%）的研究区土壤干重呈下降和上升趋势。积雪的年际波动可以解释为积雪和原位温度之间的高度负相关，特别是在2月，4月，5月，8月和9月的一些海拔高度。
Abstract Snow cover changes over the Tibetan plateau (TP) are examined using moderate resolution imaging spectroradiometer (MODIS) daily fractional snow cover (FSC) data from 2001 to 2011 as well as in situ temperature data. First, the accuracy of the MODIS FSC data under clear sky conditions is evaluated by comparing with Landsat 30-m observations. Then we describe a cloud-gap-filled (CGF) method using cubic spline interpolation algorithm to fill in data gaps caused by clouds. Finally, the spatial and temporal changes of snow cover are analyzed on the basis of the MODIS-derived snow-covered area and snow-covered days (SCD) data. Results show that the mean absolute error of MODIS FSC data under clear sky condition is about 0.098 over the TP. The CGF method is efficient in cloud reduction (overall mean absolute error of the retrieved FSC data is 0.092). There is a very high inter-annual and intra-seasonal variability of snow cover in the 11 years. The higher snow cover corresponds well with the huge mountains. The accumulation and melt periods of snow cover vary in different elevation zones. About 34.14% (5.56% with a significant decline) and 24.75% (3.9% with a significant increase) of the study area presents declining and increasing trend in SCD, respectively. The inter-annual fluctuation of snow cover can be explained by the high negative correlations observed between the snow cover and the in situ temperature, especially in some elevations of February, April, May, August, and September.