GRACE监测青藏高原及邻区陆地水储量变化结果的可变性

摘要

We use 5 sets of GRACE data to invert the trend rates of terrestrial water storage change (TWSC) in the Tibetan plateau and adjacent areas,together with 4 types of de-striping filters and 2 types of smoothing filtersto show the variability of the results.S&W (P2M8) method with the varied-width sliding windows destripes more effectively,and the inverted lake water and glacier ice signals show a good consistency in the signal positions with those observed by ICESat-1 satellite altimetry.For Gaussian filter and Fan filter,the magnitudes of the main signals differ by 10-30 ％.Smoothing filtering usually lowers the magnitudes of the signals and reduces the spatial resolution.Even some signals of lake water and glacier ice are found to disappear.The results inverted by CSR/GFZ/JPL gravity data are close to each other and the CSR results are least impacted by the strips.The two JPL mass models MAS/MAS_S also show similar results,with the exception of a big difference in the western Plateau.Great differences are found between the results inverted from three gravity models that are calculated from two mass models.The S&W (P2M8) de-striping filter and the GRACE gravity model CSR is suggested for monitoring TWSC in the study areas.%结合4种不同的去相关滤波和2种平滑滤波,利用5组GRACE数据反演了青藏高原及邻区陆地水储量变化趋势,研究了结果的可变性.结果表明,采用S&W(P2M8)变宽度滑动窗口去条带效果较好,其结果中的湖水、冰川信号与卫星测高观测的信号位置具有较好的一致性.高斯滤波的异常幅值与扇形滤波相差10％～30％,平滑处理后异常幅值减少,观测分辨率降低,部分湖和冰川信号甚至消失.CSR/GFZ/JPL重力场模型反演的结果相近,但CSR去条带效果最好;JPL质量模型MAS/MAS_S的结果也相近,但在高原西部有较大差异.重力场模型与质量模型的结果相差很大.在利用GRACE卫星监测本地区陆地水储量变化时,推荐使用S&W(P2M8)去条带滤波器、CSR重力场模型数据.