Geoscience and Remote Sensing, Delft University of Technology, Delft, Netherlands.
Astrodynamics and Space Missions, Delft University of Technology, Delft, Netherlands.
Sci Rep. 2019 Jul 29;9(1):10908. doi: 10.1038/s41598-019-47340-z.
Satellite radar altimetry has been providing estimates of global mean sea level (GMSL) since 1992. The early TOPEX record originates from two identical instruments, which requires the estimation of an intermission bias and careful handling of the problematic first part of the record. Calibration of TOPEX is crucial to obtain a continuous and consistent record, which is needed to quantify any recent acceleration. We propose a novel approach to calibrate TOPEX altimeter data using sea surface height differences at crossovers of TOPEX and ERS. Tide gauges are only used to determine a drift in one of the two datasets. We provide a new and more accurate estimate of the intra-mission bias, which leads to a much reduced GMSL acceleration over the whole record. Hence, the conundrum of an uncertain GMSL acceleration from altimetry is still unsolved, in spite of recent opposite claims, and in contrast to the expected effect of ocean warming and continental freshwater fluxes.
卫星雷达测高技术自 1992 年以来一直提供全球平均海平面（GMSL）的估计值。早期的 TOPEX 记录来自两个完全相同的仪器，这就需要估计一个间隙偏差，并仔细处理记录的有问题的第一部分。TOPEX 的校准对于获得连续一致的记录至关重要，这是量化任何近期加速的必要条件。我们提出了一种使用 TOPEX 和 ERS 交叉点的海面高度差来校准 TOPEX 测高仪数据的新方法。验潮站仅用于确定两个数据集之一的漂移。我们提供了一个新的、更准确的任务内偏差估计值，这导致整个记录中的 GMSL 加速度大大降低。因此，尽管最近有相反的说法，但尽管存在海洋变暖以及大陆淡水通量的预期影响，测高技术中不确定的 GMSL 加速度之谜仍未解决。
