New geoid of Greenland: A case study of terrain and ice effects, GOCE and use of local sea level data

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review

Abstract

Making an accurate geoid model of Greenland has always been a challenge due to the ice sheet and glaciers, and the rough topography and deep fjords in the ice free parts. Terrestrial gravity coverage has for the same reasons been relatively sparse, with an older airborne survey of the interior being the only gravity field data over the interior, and terrain and ice thickness models being insufficient both in terms of resolution and accuracy. This data situation has in the later years changed substantially, first of all due to GOCE, but also new airborne gravity and ice thickness data from the NASA IceBridge mission, and new terrain models from ASTER, SPOT-5 and digital photogrammetry. In the paper we use all available data to make a new geoid of Greenland and surrounding ocean regions, using remove-restore techniques for ice and topography, spherical FFT techniques and downward continuation by least squares collocation. The impact of GOCE and the new terrestrial data yielded a much improved geoid, as evidenced by comparison to GPS measurements along fjords, which serves as a proxy for GPS leveling data, and comparisons to new GPS leveling data in Iceland. The comparisons show significant improvements over EGM08 and older geoid models, and also highlight the problems of global sea level models, especially in sea ice covered regions, and the definition of a new consistent vertical datum of Greenland.
Original languageEnglish
Title of host publicationProceedings of the 3rd International Gravity Field Service (IGFS), Shanghai, China, June 30 - July 6, 2014
EditorsShuanggen Jin , Riccardo Barzaghi
Number of pages7
Volume144
PublisherSpringer
Publication date2015
Pages153-159
ISBN (Print)978-3-319-39819-8
ISBN (Electronic)978-3-319-39820-4
DOIs
Publication statusPublished - 2015
Event3rd International Gravity Field Service, IGFS 2014 - Shanghai, China
Duration: 30 Jun 20146 Jul 2014

Conference

Conference3rd International Gravity Field Service, IGFS 2014
CountryChina
CityShanghai
Period30/06/201406/07/2014
SeriesInternational Association of Geodesy Symposia
ISSN0939-9585

Keywords

  • Geoid
  • Gravity
  • Greenland

Cite this

Forsberg, R., & Jensen, T. E. (2015). New geoid of Greenland: A case study of terrain and ice effects, GOCE and use of local sea level data. In S. J., & R. B. (Eds.), Proceedings of the 3rd International Gravity Field Service (IGFS), Shanghai, China, June 30 - July 6, 2014 (Vol. 144, pp. 153-159). Springer. International Association of Geodesy Symposia https://doi.org/10.1007/1345_2015_50