Progress and prospect of GRACE Mascon product and its application
-
摘要: 2002年重力卫星GRACE的成功发射极大地促进了地球科学多个领域,包括全球海平面变化、极地冰盖与高山冰川消融、水文以及固体地球等多个领域的发展. 然而,GRACE观测数据主要是以球谐系数的形式给出,需要应用者进行一系列预处理才可以得到对应的物理量. 为了克服此困难,也为了提高GRACE恢复重力场地空间分辨率,相关机构在近些年推出了新一代GRACE观测数据产品,即Mascon产品. 该产品的初衷是便于非大地测量和地球物理专业的人使用,比如水文学家、海洋学家,它无需进行任何后处理过程,使用上更加方便. 然而,尽管Mascon产品以较高的空间分辨率(如1°)给出,但是,该产品的应用范围以及其实际的分辨率等都是科学家们非常关注的问题. 目前科学家们已经对该产品在不同流域尺度以及不同应用领域上的适用性问题进行了系统性地评估. 本文综合介绍了Mascon产品的基本原理和方法、三家Mascon产品的差异,并梳理了该产品和球谐系数产品之间在一些具体物理问题的应用中的适用性以及应该注意的问题,为广大科研工作者提供科学依据和使用参考.Abstract: The success of the launch of GRACE in 2002 has greatly promoted the development of Earth Science, especially in many fields such as global sea level change, polar ice sheet and Alpine glacier melting, hydrology and solid earth. However, GRACE observation data are mainly given in the form of spherical harmonic coefficients, so users need to carry out a series of pre-processing to get specific physical quantities. In order to overcome this difficulty and enhance the spatial resolution, relevant organizations have released a new generation of GRACE products, named Mascon products. The original intention of this product is to be convenient for people who are not majoring in Geodesy and Geophysics, such as hydrologists and oceanographers, and it does not need any post-processing process, so it is more convenient to use. Although Mascon product gives a high spatial resolution (such as 1°), scientists are very concerned about the actual resolution and the application scope of the product. At present, scientists have systematically evaluated and applied the applicability of this product in different watershed scales and different application fields. In this paper, we introduce the basic principles and methods of Mascon products, compares the differences between the three Mascon products, and combs the applicability of the products and spherical harmonic coefficient products in the application of some specific physical problems as well as the problems that should be paid attention to, so as to provide scientific basis and use reference for the majority of scientific researchers.
-
Key words:
- gravity satellites /
- GRACE /
- Mascon /
- Terrestrial Water Storage (TWS) /
- seismic /
- climate change
-
图 1 JPL Mascon产品的格网划分(修改自Watkins et al., 2015)
Figure 1. Definition of JPL Mascon products (modified from Watkins et al., 2015)
图 2 全球TWSA长期趋势的阶振幅,用EWH表示,包括5种产品:CSR Mascon、未经过滤波的球谐系数、经过300 km高斯滤波的球谐系数、加入了尺度因子的格网球谐系数的阶振幅曲线比较. 其中Mascon产品展开到120阶(修改自Zhang L et al., 2019)
Figure 2. Degree amplitudes of global long-term trend TWSA expressed in EWH for five data sets: the CSR Mascon products, spherical harmonic solutions without any filter, spherical harmonic solutions applying a Gaussian filter with radius of 300km, spherical harmonic solutions applying a DDK4 filter, Gridded spherical harmonic solutions (modified from Zhang L et al., 2019)
图 3 JPL Mascon产品对陆地信号泄露到海洋的处理(Watkins et al., 2015). 色彩标尺为2011年4月质量异常,用等效水高表示
Figure 3. The correcting for leakage errors due to mascon placement over land/ocean boundaries of JPL Mascon products (Watkins et al., 2015). The color bar refers to the mass anomalies for April 2011 of EWH
图 4 CSR Mascon求解过程中,正则化球谐系数计算的全球RMS值泄露误差改正. (a)正则化球谐系数计算的全球RMS值;(b)为了避免泄露误差,经过重新调整后的全球RMS值(Save et al., 2016)
Figure 4. Correction of the leakage of the global RMS grid of the variability of the regularized spherical harmonic solutions. (a) Global RMS grid of the variability of the regularized spherical harmonic solutions; (b) Readjustment global RMS from Fig. (a) (Save et al., 2016)
图 5 GRACE产品在南美洲陆地水储量长期趋势的比较. (a)CSR Mascon;(b)Tellus官网格网球谐系数产品(加入了尺度因子);(c)JPL Mascon(修改自Save et al., 2016)
Figure 5. Comparison of the long-term trend of the TWS among GRACE products in South America. (a) CSR Mascon; (b) Tellus land Grids from the official website (added the scale factors); (c) JPL Mascon (modified from Save et al., 2016)
图 6 (a)南极、格林兰岛冰盖与阿拉斯加湾冰川的GSFC Mascon块设置;(b)利用这种Mascon设置估算的格林兰岛冰盖2004~2010年年均质量平衡(修改自Luthcke et al., 2013)
Figure 6. (a) The defined of the GSFC Mascon of the Antarctic and Greenland ice sheets and Gulf of Alaska glaciers. (b) The mean annual mass balances of the Greenland ice sheets during 2004~2010 (modified from Luthcke et al., 2013)
图 7 Jacob等(2012)对全球冰川覆盖地区的Mascon块设置
Figure 7. Mascons for the ice-covered regions considered by Jacob et al. (2012)
图 8 Yang等(2020)利用Mascon产品评估不同水文模型在澳大利亚流域的准确性. 其中子图(a)~(g)为不同水文模型;(h)是JPL、CSR、GSFC Mascon结果的平均
Figure 8. Yang et al. (2020) using the Mascon products to evaluate the accuracy of different water models in Australian basin. (a)~(g) are water models, (h) is the average of the results of JPL, CSR, and GSFC Mascon
图 9 利用直接法、反演法和JPL Mascon估计的全球海平面变化(修改自 Uebbing et al., 2019)
Figure 9. The global sea level change estimated by direct, inversion methods and JPL Mascon (modified from Uebbing et al., 2019)
图 10 CSR、JPL Mascon和球谐系数产品在面积大小不同的176个流域的陆地水储量估计不确定性(修改自Scanlon et al., 2016)
Figure 10. The uncertainty of the TWSA of the 176 basins with different area observed from CSR、JPL Mascon and spherical harmonic products (modified from Scanlon et al., 2016)
图 11 CSR Mascon、球谐系数经过DDK4滤波以及加入了尺度因子的格网球谐系数产品在龙羊峡水库的月重力场恢复. 可以看到在反映龙羊峡水位抬升事件上,Mascon表现并没有其余两个球谐系数产品结果好(修改自Zhang L et al., 2019)
Figure 11. The monthly gravity field of Longyangxia reservoir is restored by CSR mascon, spherical harmonic coefficient filtered by DDK4 and grid spherical harmonic coefficient product with scale factor. It can be seen that mascon's performance is not as good as the other two spherical harmonic coefficient products in reflecting the water level rise event of Longyangxia reservoir (modified from Zhang L et al., 2019)
图 12 GRACE恢复的东日本大地震同震重力信号. (a)CSR Mascon产品的同震重力信号;(b)图(a)经过300 km高斯滤波;(c)CSR球谐系数产品的同震重力信号(Zhang et al., 2020)
Figure 12. The coseismic gravity signal of the great east Japan earthquake recovered by grace. (a) Coseismic gravity signal of CSR mascon products; (b) Fig. (a) is filtered by 300 km Gaussian filter; (c) Coseismic gravity signals of CSR products with spherical harmonic coefficients ( Zhang et al., 2020)
图 13 GRACE恢复的三个较小地震的同震重力变化. (a)2013年5月24日鄂霍次克海深海地震(MW8.3);(b)2007年9月12日明古鲁地震(MW8.5);(c)2012年4月11日苏门答腊/印度洋双震(MW8.6+MW8.2). 左列为Mascon产品,右列为球谐系数产品(SH),并做300 km的高斯滤波和去相关滤波,单位为µGal(修改自Zhang et al., 2020)
Figure 13. Co-seismic gravity changes derived from GRACE data. (a) the 2013 Okahotsk event (MW8.3); (b) 2007 Benkulu event (MW8.5); (c) 2012 Sumatra/Indian Ocean event (MW8.6+MW8.2). The left column is Mascon product, and the right column is spherical harmonic product and applying a Gassian filter with radius of 300 km and a P4M6 filter, the unit is µGal (modified from Zhang et al., 2020)
表 1 三家官方机构最新版本的Mascon产品参数对比
Table 1. The parameters of the latest Mascon products of three official organizations
JPL CSR GSFC 格网大小 0.5°×0.5° 0.25°×0.25° 1°×1° 时间采样 1个月 1个月 10天 格网形状 圆盘形 正六边形 正方形 原始分辨率 3°×3° 1°×1° 1°×1° 总格网数 4551 41000 41168 基于数据 L1b级星间距和GPS数据 L2级球谐系数数据 L1b级星间距和GPS数据 有无外部物理模型
先验约束有 无 有 关键技术 基于先验信息的白噪声建模;
连续卡尔曼滤波Tikhonov正则化方法;
L曲线法迭代求解;
自协方差矩阵的正则化 -
[1] Alexander P M, Tedesco M, Schlegel N-J, et al. 2016. Greenland ice sheet seasonal and spatial mass variability from model simulations and GRACE (2003-2012)[J]. Cryosphere, 10: 1259-1277. doi: 10.5194/tc-10-1259-2016 [2] Andrews S B, Moore P, King M A. 2015. Mass change from GRACE: a simulated comparison of Level-1B analysis techniques[J].Geophysical Journal International, 200: 503-518. [3] Arendt A, Luthcke S, Gardner A, et al. 2013. Analysis of a GRACE global mascon solution for Gulf of Alaska glaciers[J]. Journal of Glaciology, 59: 913-924. doi: 10.3189/2013JoG12J197 [4] Arendt A A, Luthcke S B, Larsen C F, et al. 2008. Validation of high-resolution GRACE mascon estimates of glacier mass changes in the St Elias Mountains, Alaska, USA, using aircraft laser altimetry[J]. Journal of Glaciology, 54: 778-787. doi: 10.3189/002214308787780067 [5] Awange J L, Fleming K M, Kuhn M, et al. 2011. On the suitability of the 4 degrees×4 degrees GRACE mascon solutions for remote sensing Australian hydrology[J]. Remote Sensing of Environment, 115: 864-875. doi: 10.1016/j.rse.2010.11.014 [6] Bhanja S N, Mukherjee A, Saha D, et al. 2016. Validation of GRACE based groundwater storage anomaly using in-situ groundwater level measurements in India[J]. Journal of Hydrology, 543: 729-738. doi: 10.1016/j.jhydrol.2016.10.042 [7] Bhanja S N, Zhang X K, Wang J Y. 2018. Estimating long-term groundwater storage and its controlling factors in Alberta, Canada[J]. Hydrology and Earth System Sciences, 22: 6241-6255. doi: 10.5194/hess-22-6241-2018 [8] Bonsor H, Shamsudduha M, Marchant B, et al. 2018. Seasonal and Decadal Groundwater Changes in African Sedimentary Aquifers Estimated Using GRACE Products and LSMs, Remote Sensing, 10, 904. doi: 10.3390/rs10060904 [9] Cambiotti G, Sabadini R. 2012. A source model for the great 2011 Tohoku earthquake (MW=9.1) from inversion of GRACE gravity data[J]. Earth and Planetary Science Letters, 335: 72-79. [10] Chen J L, Wilson C R, Tapley B D, et al. 2017. Long-term and seasonal Caspian Sea level change from satellite gravity and altimeter measurements[J]. Journal of Geophysical Research: Solid Earth, 122: 2274-2290. [11] Chen T Y, Shen Y Z, Chen Q J. 2016. Mass flux solution in the Tibetan Plateau using Mascon modeling[J]. Remote Sensing, 8(5): 439. doi: 10.3390/rs8050439 [12] Feng W, Shum C K, Zhong M, Pan Y. 2018. Groundwater storage changes in China from satellite gravity: An overview[J]. Remote Sensing, 10(5): 674. doi: 10.3390/rs10050674 [13] Ferreira V G, Yong B, Tourian M J, et al. 2020. Characterization of the hydro-geological regime of Yangtze River basin using remotely-sensed and modeled products[J]. Science of the Total Environment, 718: 137354. doi: 10.1016/j.scitotenv.2020.137354 [14] Ghobadi-Far K, Sprlak M, Han S-C. 2019. Determination of ellipsoidal surface mass change from GRACE time-variable gravity data[J]. Geophysical Journal International, 219: 248-259. doi: 10.1093/gji/ggz292 [15] Ghobadi-Far K, Han S C, Allgeyer S, et al. 2020. GRACE gravitational measurements of tsunamis after the 2004, 2010, and 2011 great earthquakes[J]. Journal of Geodesy, 94: 65. doi: 10.1007/s00190-020-01395-3 [16] Gu Y C, Fan D M, You W. 2017. Comparison of observed and modeled seasonal crustal vertical displacements derived from multi-institution GPS and GRACE solutions[J]. Geophysical Research Letters, 44: 7219-7227. doi: 10.1002/2017GL074264 [17] 郭飞霄, 肖云, 汪菲菲. 2014. 利用GRACE星间距离变率数据反演地球表层质量变化的Mascon方法[J]. 地球物理学进展, 29(6): 2494-2497. doi: 10.6038/pg20140602Guo F X, Xiao Y, Wang F F. 2014. Mascon inversion method of Earth surface mass anomaly using Grace range rate data[J]. Progress in Geophysics, 29 (6) : 2494-2497(in Chinese). doi: 10.6038/pg20140602. [18] Han S-C, Shum C K, Bevis M, et al. 2006. Crustal dilatation observed by GRACE after the 2004 Sumatra-Andaman earthquake[J]. Science, 313: 658-662. doi: 10.1126/science.1128661 [19] Han S-C, Sauber J, Luthcke S. 2010. Regional gravity decrease after the 2010 Maule (Chile) earthquake indicates large-scale mass redistribution[J]. Geophysical Research Letters, 37: L23307. [20] Han S-C, Sauber J, Riva R. 2011. Contribution of satellite gravimetry to understanding seismic source processes of the 2011 Tohoku-Oki earthquake[J]. Geophysical Research Letters, 38: L24312. [21] Han S-C, Riva R, Sauber J, Okal E. 2013. Source parameter inversion for recent great earthquakes from a decade-long observation of global gravity fields[J]. Journal of Geophysical Research: Solid Earth, 118: 1240-1267. doi: 10.1002/jgrb.50116 [22] Hardy R A, Nerem R S, Wiese D N. 2017. The impact of atmospheric modeling errors on GRACE estimates of mass loss in Greenland and Antarctica[J]. Journal of Geophysical Research: Solid Earth, 122: 10440-10458. doi: 10.1002/2017JB014556 [23] Heki K, Matsuo K. 2010. Coseismic gravity changes of the 2010 earthquake in central Chile from satellite gravimetry[J]. Geophysical Research Letters, 37: L24306. [24] Hill E M, Davis J L, Tamisiea M E, et al. 2011. Using a spatially realistic load model to assess impacts of Alaskan glacier ice loss on sea level[J]. Journal of Geophysical Research: Solid Earth, 116: B10407. doi: 10.1029/2011JB008339 [25] Hu Y, Mei J, Luo J. 2019. TianQin project and international collaboration[J]. Chinese Science Bulletin, 64: 2475-2483. doi: 10.1360/N972019-00046 [26] Ivins E R, James T S, Wahr J, et al. 2013. Antarctic contribution to sea level rise observed by GRACE with improved GIA correction[J]. Journal of Geophysical Research: Solid Earth, 118: 3126-3141. doi: 10.1002/jgrb.50208 [27] Jacob T, Wahr J, Pfeffer W T, Swenson S. 2012. Recent contributions of glaciers and ice caps to sea level rise[J]. Nature, 482: 514-518. doi: 10.1038/nature10847 [28] Jing W L, Zhang P Y, Zhao X D. 2019. A comparison of different GRACE solutions in terrestrial water storage trend estimation over Tibetan Plateau[J]. Scientific Reports, 9: 1765. doi: 10.1038/s41598-018-38337-1 [29] Johnson C W, Fu Y N, Burgmann R. 2020. Hydrospheric modulation of stress and seismicity on shallow faults in southern Alaska[J]. Earth and Planetary Science Letters, 530(15): 115904. [30] Killett B, Wahr J, Desai S, et al. 2011. Arctic Ocean tides from GRACE satellite accelerations[J]. Journal of Geophysical Research: Oceans, 116: C11005. doi: 10.1029/2011JC007111 [31] Klosko S, Rowlands D, Luthcke S, et al. 2009. Evaluation and validation of mascon recovery using GRACE KBRR data with independent mass flux estimates in the Mississippi Basin[J]. Journal of Geodesy, 83: 817-827. doi: 10.1007/s00190-009-0301-x [32] Lemoine F G, Luthcke S B, Rowlands D D, et al. 2007. The Use of Mascons to Resolve Time-Variable Gravity from GRACE[M]//Tregoning P, Rizos C. Dynamic Planet: Monitoring and Understanding a Dynamic Planet with Geodetic and Oceanographic Tools. Springer Berlin Heidelberg, 231-236. [33] 李琼. 2014. 地表物质迁移的时变重力场反演方法及其应用研究[D]. 武汉: 武汉大学.Li Q. 2014. Earth’s surface mass transport recovered from temporal gravity field and its applications[D]. Wuhan: Wuhan University (in Chinese). [34] Long D, Pan Y, Zhou J, et al. 2017. Global analysis of spatiotemporal variability in merged total water storage changes using multiple GRACE products and global hydrological models[J]. Remote Sensing of Environment, 192: 198-216. doi: 10.1016/j.rse.2017.02.011 [35] Loomis B D, Luthcke S B. 2017. Mass evolution of Mediterranean, Black, Red, and Caspian Seas from GRACE and altimetry: Accuracy assessment and solution calibration[J]. Journal of Geodesy, 91: 195-206. doi: 10.1007/s00190-016-0952-3 [36] Loomis B D, Richey A S, Arendt A A, et al. 2019. Water storage trends in high mountain Asia[J]. Frontiers in Earth Science, 7: 235. doi: 10.3389/feart.2019.00235 [37] Luthcke S B, Arendt A A, Rowlands D D, et al. 2008. Recent glacier mass changes in the Gulf of Alaska region from GRACE mascon solutions[J]. Journal of Glaciology, 54: 767-777. doi: 10.3189/002214308787779933 [38] Luthcke S B, Sabaka T J, Loomis B D, et al. 2013. Antarctica, Greenland and Gulf of Alaska land-ice evolution from an iterated GRACE global mascon solution[J]. Journal of Glaciology, 59: 613-631. doi: 10.3189/2013JoG12J147 [39] Matsuo K, Heki K. 2011. Coseismic gravity changes of the 2011 Tohoku-Oki earthquake from satellite gravimetry[J]. Geophysical Research Letters, 38: L17312. [40] Morgan B, Awange J L, Saleem A, Kexiang H. 2020. Understanding vegetation variability and their "hotspots" within Lake Victoria Basin (LVB: 2003-2018)[J]. Applied Geography, 122: 102238. doi: 10.1016/j.apgeog.2020.102238 [41] Mu D, Xu T, Xu G. 2020. An investigation of mass changes in the Bohai Sea observed by GRACE[J]. Journal of Geodesy, 94: 79. doi: 10.1007/s00190-020-01408-1 [42] Muller P M, Sjogren W L. 1968. Mascons: Lunar mass concentrations [J]. Science, 161: 680-684. doi: 10.1126/science.161.3842.680 [43] Nerem R S, Beckley B D, Fasullo J T, et al. 2018. Climate-change-driven accelerated sea-level rise detected in the altimeter era[J]. Proceedings of the National Academy of Sciences of the United States of America, 115: 2022-2025. doi: 10.1073/pnas.1717312115 [44] Nie W S, Zaitchik B F, Rodell M, et al. 2018. Groundwater withdrawals under drought: Reconciling GRACE and land surface models in the United States high plains aquifer[J]. Water Resources Research, 54: 5282-5299. doi: 10.1029/2017WR022178 [45] 宁津生, 罗志才, 陈永奇, 2002. 卫星重力梯度数据用于精化地球重力场的研究, 中国工程科学, 4(7): 23-28. doi: 10.3969/j.issn.1009-1742.2002.07.005Ning J S, Luo Z C, Chen Y Q.2002. Application of satellite gravity gradiometry data to the refinement of the Earth' s gravity field[J]. Engineering Science, 4(7): 23-28 (in Chinese). doi: 10.3969/j.issn.1009-1742.2002.07.005 [46] Paulson A, Zhong S, Wahr J. 2007. Inference of mantle viscosity from GRACE and relative sea level data[J]. Geophysical Journal International, 171: 497-508. doi: 10.1111/j.1365-246X.2007.03556.x [47] Peltier W R. 2004. Global glacial isostasy and the surface of the ice-age earth: The ice-5G (VM2) model and grace[J]. Annual Review of Earth and Planetary Sciences, 32: 111-149. doi: 10.1146/annurev.earth.32.082503.144359 [48] Ran J, Ditmar P, Klees R, Farahani H H. 2017. Statistically optimal estimation of Greenland Ice Sheet mass variations from GRACE monthly solutions using an improved mascon approach[J]. Journal of Geodesy, 92: 299-319. [49] Ran J, Ditmar P, Klees R. 2018. Optimal mascon geometry in estimating mass anomalies within Greenland from GRACE[J]. Geophysical Journal International, 214: 2133-2150. doi: 10.1093/gji/ggy242 [50] Rowlands D D, Luthcke S B, Klosko S M, et al. 2005. Resolving mass flux at high spatial and temporal resolution using GRACE intersatellite measurements[J]. Geophysical Research Letters, 32: L04310. [51] Rowlands D D, Luthcke S B, McCarthy J J, et al. 2010. Global mass flux solutions from GRACE: A comparison of parameter estimation strategies—Mass concentrations versus Stokes coefficients[J]. Journal of Geophysical Research, 115: B01403. [52] Sabaka T J, Rowlands D D, Luthcke S B, Boy J-P. 2010. Improving global mass flux solutions from Gravity Recovery and Climate Experiment (GRACE) through forward modeling and continuous time correlation[J]. Journal of Geophysical Research: Solid Earth, 115: B11403. doi: 10.1029/2010JB007533 [53] Save H, Bettadpur S, Tapley B D. 2016. High-resolution CSR GRACE RL05 mascons[J]. Journal of Geophysical Research: Solid Earth, 121: 7547-7569. doi: 10.1002/2016JB013007 [54] Scanlon B R, Zhang Z, Save H, et al. 2016. Global evaluation of new GRACE mascon products for hydrologic applications[J]. Water Resources Research, 52: 9412-9429. doi: 10.1002/2016WR019494 [55] Scanlon B R, Zhang Z, Save H, et al. 2018. Global models underestimate large decadal declining and rising water storage trends relative to GRACE satellite data[J]. Proceedings of the National Academy of Sciences of the United States of America, 115: E1080-E1089. doi: 10.1073/pnas.1704665115 [56] Schlegel N-J, Wiese D N, Larour E Y, et al. 2016. Application of GRACE to the assessment of model-based estimates of monthly Greenland Ice Sheet mass balance (2003-2012)[J]. Cryosphere, 10: 1965-1989. doi: 10.5194/tc-10-1965-2016 [57] Schrama E J O, Wouters B, Rietbroek R. 2014. A mascon approach to assess ice sheet and glacier mass balances and their uncertainties from GRACE data[J]. Journal of Geophysical Research: Solid Earth, 119: 6048-6066. doi: 10.1002/2013JB010923 [58] Sun Z, Zhu X, Pan Y, et al. 2018. Drought evaluation using the GRACE terrestrial water storage deficit over the Yangtze River Basin, China[J]. Science of the Total Environment, 634: 727-738. doi: 10.1016/j.scitotenv.2018.03.292 [59] Sun Z, Long D, Yang W, et al. 2020. Reconstruction of GRACE data on changes in total water storage over the global land surface and 60 basins[J]. Water Resources Research, 56(4): e2019WR026250. [60] Tangdamrongsub N, Hwang C, Shum C K, Wang L. 2012. Regional surface mass anomalies from GRACE KBR measurements: Application of L-curve regularization and a priori hydrological knowledge[J]. Journal of Geophysical Research: Solid Earth, 117: B11406. [61] Tao D, Shi H, Gao C, et al. 2020. Water storage monitoring in the Aral Sea and its Endorheic Basin from multisatellite data and a hydrological model[J]. Remote Sensing, 12(5): 2408. [62] Uebbing B, Kusche J, Rietbroek R, Landerer F W. 2019. Processing choices affect ocean mass estimates from GRACE[J]. Journal of Geophysical Research: Oceans, 124: 1029-1044. doi: 10.1029/2018JC014341 [63] Velicogna I, Wahr J. 2006. Acceleration of Greenland ice mass loss in spring 2004[J]. Nature, 443: 329-331. doi: 10.1038/nature05168 [64] Velicogna I, Sutterley T C, van den Broeke M R. 2014. Regional acceleration in ice mass loss from Greenland and Antarctica using GRACE time-variable gravity data[J]. Geophysical Research Letters, 41: 8130-8137. doi: 10.1002/2014GL061052 [65] Wang L S, Chen C, Ma X, et al. 2020. Evaluation of GRACE mascon solutions using in-situ geodetic data: The case of hydrologic-induced crust displacement in the Yangtze River Basin[J]. Science of the Total Environment, 707: 135606. doi: 10.1016/j.scitotenv.2019.135606 [66] Wang S Y, Chen J L, Wilson C R, et al. 2018a. Reconciling GRACE and GPS estimates of long-term load deformation in southern Greenland[J]. Geophysical Journal International, 212: 1302-1313. doi: 10.1093/gji/ggx473 [67] Wang S Y, Chen J L, Wilson C R, et al. 2018b. Vertical motion at TEHN (Iran) from Caspian Sea and other environmental loads[J]. Journal of Geodynamics, 122: 17-24. doi: 10.1016/j.jog.2018.10.003 [68] Watkins M M, Wiese D N, Yuan D N, et al. 2015. Improved methods for observing Earth's time variable mass distribution with GRACE using spherical cap mascons[J]. Journal of Geophysical Research: Solid Earth, 120: 2648-2671. doi: 10.1002/2014JB011547 [69] Wiese D N, Landerer F W, Watkins M M. 2016. Quantifying and reducing leakage errors in the JPL RL05M GRACE mascon solution[J]. Water Resources Research, 52: 7490-7502. doi: 10.1002/2016WR019344 [70] Xiang L, Wang H, Steffen H, et al. 2016. Groundwater storage changes in the Tibetan Plateau and adjacent areas revealed from GRACE satellite gravity data[J]. Earth and Planetary Science Letters, 449: 228-239. doi: 10.1016/j.jpgl.2016.06.002 [71] Xie X W, Xu C J, Wen Y M, Li W. 2018. Monitoring groundwater storage changes in the Loess Plateau using GRACE satellite gravity data, hydrological models and coal mining data[J]. Remote Sensing, 10(4): 605. [72] Xu Z, Schrama E, van der Wal W. 2015. Optimization of regional constraints for estimating the Greenland mass balance with GRACE level-2 data[J]. Geophysical Journal International, 202: 381-393. doi: 10.1093/gji/ggv146 [73] Yang X, Tian S, Feng W, et al. 2020. Spatio-temporal evaluation of water storage trends from hydrological models over Australia using GRACE mascon solutions[J]. Remote Sensing, 12: 3578. doi: 10.3390/rs12213578 [74] Yi S, Sun W. 2014. Evaluation of glacier changes in high-mountain Asia based on 10 year GRACE RL05 models[J]. Journal of Geophysical Research: Solid Earth, 119: 2504-2517. doi: 10.1002/2013JB010860 [75] Young J C, Arendt A, Hock R, Pettit E. 2018. The challenge of monitoring glaciers with extreme altitudinal range: mass-balance reconstruction for Kahiltna Glacier, Alaska[J]. Journal of Glaciology, 64: 75-88. doi: 10.1017/jog.2017.80 [76] Zhang B, Liu L, Khan S A, et al. 2019. Geodetic and model data reveal different spatio-temporal patterns of transient mass changes over Greenland from 2007 to 2017[J]. Earth and Planetary Science Letters, 515: 154-163. doi: 10.1016/j.jpgl.2019.03.028 [77] Zhang L, Yi S, Wang Q, et al. 2019. Evaluation of GRACE mascon solutions for small spatial scales and localized mass sources[J]. Geophysical Journal International, 218: 1307-1321. doi: 10.1093/gji/ggz198 [78] Zhang L, Tang H, Chang L, Sun W. 2020. Performance of GRACE mascon solutions in studying seismic deformations[J]. Journal of Geophysical Research: Solid Earth, 125: e2020JB019510. [79] Zhao Q, Zhang B, Yao Y, et al. 2019. Geodetic and hydrological measurements reveal the recent acceleration of groundwater depletion in North China Plain[J]. Journal of Hydrology, 575: 1065-1072. doi: 10.1016/j.jhydrol.2019.06.016 [80] Zheng W, Xu H, Zhong M, et al. 2014. Researches on future ultra-precision CSGM satellite gravity mission in China[J]. Journal of National University of Defense Technology, 36: 102-111. [81] Zheng W, Hsu H, Zhong M, Yun M. 2015. Requirements analysis for future satellite gravity mission improved-GRACE[J]. Surveys in Geophysics, 36: 87-109. doi: 10.1007/s10712-014-9306-y [82] Zhong Y, Zhong M, Feng W, et al. 2018. Groundwater depletion in the west Liaohe River Basin, China and its implications revealed by GRACE and in Situ measurements[J]. Remote Sensing, 10(4): 493. [83] Zhou X, Sun W, Zhao B, et al. 2012. Geodetic observations detecting coseismic displacements and gravity changes caused by the MW=9.0 Tohoku-Oki earthquake, J. Geophys. Res.-Solid Earth, 117: B05408. [84] 朱传东, 陆洋, 史红岭, 等. 2015. 高亚洲冰川质量变化趋势的卫星重力探测[J]. 地球物理学报, 58: 793-801. doi: 10.6038/cjg20150309Zhu C D, Lu Y, Shi H-L, et al. 2015. Trends of glacial mass changes in High Asia from satellite gravity observations[J]. Chinese Journal of Geophysics, 58: 793-801 (in Chinese). doi: 10.6038/cjg20150309 [85] 邹贤才, 金涛勇, 朱广彬. 2016. 卫星跟踪卫星技术反演局部地表物质迁移的MASCON方法研究[J]. 地球物理学报, 59: 4623-4632. doi: 10.6038/cjg20161223Zou X C, Jin T Y, Zhu G B. 2016. Research on the MASCON method for the determination of local surface mass flux with Satellite-Satellite Tracking technique[J]. Chinese Journal of Geophysics, 59: 4623-4632 (in Chinese). doi: 10.6038/cjg20161223 -