Ellipsoidal Correction in GRACE Surface Mass Change Estimation

doi:10.1002/2017JB014033

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	Ellipsoidal Correction in GRACE Surface Mass Change Estimation
	Li, Jin 1,2; Chen, Jianli 3; Li, Ziang 1,2; Wang, Song-Yun 1,2; Hu, Xiaogong 2
刊名	JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
	2017-11-01
卷号	122 期号:11 页码:9437-9460
关键词	Grace Mass Inversion Polar Ice Loss Ellipsoidal Correction Spherical Harmonics Ellipsoidal Harmonics
ISSN号	2169-9313
DOI	10.1002/2017JB014033
英文摘要	The Earth's shape is much closer to an ellipsoid than a sphere. The commonly used spherical approximation in mass change inversion is expected to cause bias by the spherical harmonic (SH) solutions from Gravity Recovery and Climate Experiment (GRACE), especially in high-latitude regions where significant present-day ice losses occur. This bias, or ellipsoidal correction, reaches up to 8% from the evaluation by simulations based on synthetic mass change rate models. Further evaluation using 14 plus years of GRACE monthly SH solutions (from April 2002 to December 2016) indicates that the ellipsoidal correction is also noticeable in the total mass change time series over polar regions. Before and after the ellipsoidal correction, the estimated linear rates from mass change time series differ by 4.3%, 4.7%, 5.2%, 5.7%, and 6.6% for five selected regions over Greenland, Antarctic Peninsula, Amundsen Sea Embayment, Alaska glacier, and Svalbard Islands, respectively. Although with amplitudes likely below the current GRACE's uncertainty level, these differences are consistently negative over the five regions. This indicates that the spherical approximation leads to systematic underestimation for polar mass change rates. Thus, the ellipsoidal correction needs to be considered for more precise mass recovery with GRACE SH solutions. It also depends on spatial scales of mass change signals (the smaller the spatial scale, the larger the correction). To more reliably estimate high-latitude surface mass changes by GRACE SH solutions, the ellipsoidal correction is recommended, especially for ice-loss signals over polar regions.
WOS研究方向	Geochemistry & Geophysics
语种	英语
出版者	AMER GEOPHYSICAL UNION
WOS记录号	WOS:000419102700045
内容类型	期刊论文
源URL	[http://119.78.226.72/handle/331011/32521]
专题	中国科学院上海天文台
通讯作者	Li, Jin
作者单位	1.Univ Chinese Acad Sci, Sch Astron & Space Sci, Beijing, Peoples R China 2.Chinese Acad Sci, Shanghai Astron Observ, Shanghai, Peoples R China 3.Univ Texas Austin, Ctr Space Res, Austin, TX 78712 USA
推荐引用方式 GB/T 7714	Li, Jin,Chen, Jianli,Li, Ziang,et al. Ellipsoidal Correction in GRACE Surface Mass Change Estimation[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,2017,122(11):9437-9460.
APA	Li, Jin,Chen, Jianli,Li, Ziang,Wang, Song-Yun,&Hu, Xiaogong.(2017).Ellipsoidal Correction in GRACE Surface Mass Change Estimation.JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH,122(11),9437-9460.
MLA	Li, Jin,et al."Ellipsoidal Correction in GRACE Surface Mass Change Estimation".JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 122.11(2017):9437-9460.