Re-evaluation of MODIS MCD43 Greenland albedo accuracy and trends
Re-evaluation of MODIS MCD43 Greenland albedo accuracy and trends
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DOI：
10.1016/j.rse.2013.07.023
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发表时间：
2013-11
影响因子：
13.5
通讯作者：
J. Stroeve;J. Box;Zhuosen Wang;C. Schaaf;A. Barrett
中科院分区：
文献类型：
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作者：
J. Stroeve;J. Box;Zhuosen Wang;C. Schaaf;A. Barrett
在这项研究中，中分辨率成像光谱仪（MODIS）结合Terra（MOD）和Aqua（MYD）的16天连续产品（MCD 43）的准确性进行了评估，通过比较11年的原位测量在格陵兰冰盖上的17个自动气象站。考虑到现场观测的准确性问题，结果表明，利用所有高质量，无云的MODIS反演给出了物理上真实的冰盖的太阳天顶角小于75°，均方根误差为0.067（RMSE）和总的平均偏差为+ 0.022（与MODIS数据偏差略高于现场数据）。利用这组数据，记录了2000年至2012年冰盖的变化。分析显示，在13年的数据记录中，夏季冰盖的冰温呈负趋势，近年来格陵兰西部的冰温持续呈负异常。在2012年夏季，广泛的表面融化导致格陵兰地区6月、7月和8月的平均温度异常，相对于2000年至2009年的-0.044，显著增加了总吸收的太阳辐射和表面融化量。
In this study, the accuracy of the MODerate resolution Imaging Spectroradiometer (MODIS) combined Terra (MOD) and Aqua (MYD) 16-day albedo product (MCD43) is evaluated through comparisons with eleven years of in situ measurements at 17 automatic weather stations on the Greenland Ice Sheet. Taking into consideration accuracy issues with in situ observations, results show that utilizing all high-quality, cloud-free MODIS retrievals gives physically realistic ice sheet albedo values for solar zenith angles less than 75°, with a root-mean-square error of 0.067 (RMSE) and an overall mean bias of + 0.022 (with the MODIS data biased slightly high relative to the in situ data). Using this data set, changes in ice sheet albedo from 2000 to 2012 are documented. Analysis reveals negative trends in ice sheet albedo during summer over the 13-year data record, with persistent negative albedo anomalies in recent years over western Greenland. During summer 2012, extensive surface melt resulted in a Greenland area-averaged albedo anomaly for June, July August relative to 2000–2009 of − 0.044 that significantly increased the amount of total absorbed solar radiation and surface melt.