SUMMARY

Annual sea level variations in the Red Sea have amplitudes of 15–20 cm as observed using various techniques such as tide gauges, satellite altimetry and recently Gravity Recovery and Climate Experiment (GRACE) satellite data. In this study, we demonstrate that Global Navigation Satellite System (GNSS) observations can also be used to measure the effect of these sea level variations. The extra water mass presses on the seafloor, which causes horizontal and vertical deformations. Using time-series from 10 coastal GNSS stations, we observe annual horizontal and vertical loading displacements with amplitudes of 2–5 mm. When correcting for atmospheric, hydrological and surface water loading and a residual geocentre motion, significant annual signals of approximately 0.5 and 2 mm are still observed for the horizontal and vertical components, respectively. In the northern Red Sea, the observed annual signals and predicted annual sea level loading show good agreement. This confirms that the signal is mostly a result of the variations in water mass and thermal expansion. Furthermore, we conclude that the uncertainties in the hydrological model over Ethiopia and Eritrea influence the loading over the southern Red Sea, which was underestimated in previous studies using GRACE data.

中文翻译：

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使用GNSS观测到的红海年度海平面变化

概要

使用潮汐仪，卫星测高仪和最近的重力恢复与气候实验（GRACE）卫星数据等各种技术，红海的年度海平面变化幅度为15–20 cm。在这项研究中，我们证明了全球导航卫星系统（GNSS）的观测值也可用于测量这些海平面变化的影响。多余的水压在海底上，从而导致水平和垂直变形。使用来自10个沿海GNSS站的时间序列，我们观察到了2-5 mm振幅的年度水平和垂直荷载位移。在校正大气，水文和地表水负荷以及残余的地心运动时，水平和垂直分量仍然观测到大约0.5和2 mm的重要年度信号，分别。在北部红海，观测到的年度信号和预测的年度海平面负荷显示出良好的一致性。这证实了该信号主要是水量和热膨胀变化的结果。此外，我们得出的结论是，埃塞俄比亚和厄立特里亚的水文模型的不确定性影响了南部红海的负荷，这在先前使用GRACE数据的研究中被低估了。