通过卫星重力测量观察到的海平面的低静态变化:1993-2022年
Yufeng Nie1, Jianli Chen1,2,3, Guodong Xu1
1Department of Land Surveying and Geo-Informatics, The Hong Kong Polytechnic University, Hong Kong, China.
概括
来自SLR和GRACE/GRACE-FO的卫星重力测量提供了三十年的重静态海平面变化. 这些估计与其他质量变化数据保持一致,有助于缩小全球平均海平面上升预算.
科学领域:
- 地球科学 地球科学 地球科学
- 地质物理学 地质物理学
- 海洋学 海洋学 海洋学
背景情况:
- 全球平均海平面上升 (GMSL) 是气候变化的关键指标.
- 准确估计GMSL的组成部分,包括静态海平面 (BSL) 变化,对于理解其驱动因素至关重要.
- 卫星重力测量为地球质量再分配提供了一个独特的视角.
研究的目的:
- 通过使用卫星重力测量数据,推导和分析三十年的重静态海平面变化.
- 来自卫星激光测距 (SLR) 和重力恢复和气候实验 (GRACE) 和GRACE后续 (GRACE-FO) 任务的估计进行交叉验证.
- 通过比较基于重力测量的BSL与温度变化和高度测量观测来协调全球平均海平面上升预算.
主要方法:
- 利用SLR和GRACE/GRACE-FO的可变时间重力场来估计自1993年以来的低静态海平面变化.
- 计算不同时期的BSL变化率 (1993-2022年和2003-2022年).
- 通过比较卫星引力测量得出的BSL估计与冰盖,冰川和陆地储水变化的独立估计,并协调GMSL预算.
主要成果:
- 单反相机数据显示,在1993-2022年期间,BSL的变化率为1.75 ± 0.59毫米/年.
- 在2003-2022年期间,BSL速率增加到2.16 ± 0.59毫米/年 (SLR) 和2.13 ± 0.38毫米/年 (GRACE/-FO),这是由于格陵兰岛的冰损失加速.
- 卫星重力测量估计显示,与个体质量变化成分以及从高度测量和热度测量数据中得出的GMSL速率有很好的一致性.
结论:
- 卫星重力测量,特别是从SLR和GRACE/GRACE-FO,提供了强大的,长期记录的静态海平面变化.
- 观察到的BSL加速与冰川融化的增加有关,主要来自格陵兰岛.
- 当结合热体和静电贡献时,GMSL上升预算成功关闭,验证了这些测量技术的准确性.
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