基于AMSR-E的冬季罗斯冰架冰间湖薄冰冰厚反演

Estimation of Thin Ice Thickness in the Ross Ice Shelf Polynya Based on AMSR-E Data

利用AMSR-E 36GHz、89 GHz亮度温度计算出的极化比(PR)与热力学冰厚比较,建立了一种针对南极罗斯冰架冰间湖的AMSR-E薄冰反演算法。热力学冰厚由用MODIS晴空下的表面温度数据、ERA-Interim气象数据,根据表面热通量平衡公式反演得到。在排除混合像元以及水汽对89 GHz数据的干扰后,分别对36、89 GHz的AMSR-E亮温极化比拟合指数模型,反演罗斯冰架冰间湖中的0~0.2 m的薄冰冰厚,均方根误差分别为0.003 5 m和0.005 3 m。

In this study, we developed an algorithm for thin ice thickness in the Ross Ice Shelf Polynya(RISP) by comparing the polarization ratio of 36 GHz and 89 GHz advanced microwave scanning radiometer earth observing system(AMSR-E) data and thermal ice thickness respectively. The thermal ice thickness was estimated from a heat budget calculation on the upper surface of snow or ice from the clear-sky moderate-resolution imaging spectroradiometer(MODIS) surface temperature product(MOD29) and ERA-interim forcing data. For improving accuracy of the algorithm, the following 4 kind of pixels were removed, containing both ice shelf and ocean, mixing different ice type, the ice concentration were lower than 80%, and the 89 GHz pixels which were contaminated by water vapor. We developed two exponentially algorithms for 36 GHz and 89 GHz AMSR-E polarization ratio data, and the RMSE are 0.003 5 and 0.005 3 meter. Using this algorithm, we could calculate the thin ice thickness in the RISP in 0~0.2 m.