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Freeboard height and snow depth observed by floating GPS on land-fast sea ice in Nella Fjord, Antarctica
- Source :
- Annals of Glaciology, Vol 61, Pp 227-239 (2020)
- Publication Year :
- 2020
- Publisher :
- Cambridge University Press, 2020.
-
Abstract
- Although altimeters have been widely used to monitor the spatiotemporal variation of sea-ice thickness, they are unable to separate sea-ice freeboard from snow depth. We use a floating GPS deployed on sea ice to derive the freeboard and snow depth near China's Zhongshan Station. Our results show that the standalone floating GPS can monitor freeboard with a precision of 4.2 cm. If time-varying dynamic ocean topography provided by, for example, a bottom pressure gauge is available, then the precision of GPS-derived freeboard can improve to 1.3 cm. The daily snow depth inverted by GPS interferometric reflectometry captures three precipitation events during our experiment, showing that the floating GPS can monitor the variation in snow depth and observe the freeboard variation at the same time. By studying the relationship between freeboard, snow depth and sea-ice thickness, we find that sea-ice thickness will be greatly underestimated by the negative single-point freeboard under the assumption of hydrostatic equilibrium. As a supplement to existing technologies, the GPS-derived freeboard and snow depth can be used both to evaluate the altimeter observations directly and to improve our understanding of the real-time variation of freeboard and snow depth in the experimental area.
- Subjects :
- GPS
sea-ice freeboard
sea-ice thickness
snow depth
Meteorology. Climatology
QC851-999
Subjects
Details
- Language :
- English
- ISSN :
- 02603055 and 17275644
- Volume :
- 61
- Database :
- Directory of Open Access Journals
- Journal :
- Annals of Glaciology
- Publication Type :
- Academic Journal
- Accession number :
- edsdoj.f16ccb2d3b34499eb3ce235b686b8d70
- Document Type :
- article
- Full Text :
- https://doi.org/10.1017/aog.2020.41