GNSS-IR Measurements of Inter Annual Sea Level Variations in Thule, Greenland from 2008–2019

Dahl-Jensen, Trine S.; Andersen, Ole B.; Williams, Simon D. P. ORCID: https://orcid.org/0000-0003-4123-4973; Helm, Veit; Khan, Shfaqat A.. 2021 GNSS-IR Measurements of Inter Annual Sea Level Variations in Thule, Greenland from 2008–2019. Remote Sensing, 13 (24). 5077. https://doi.org/10.3390/rs13245077

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Official URL: http://dx.doi.org/10.3390/rs13245077

Abstract/Summary

Studies of global sea level often exclude Tide Gauges (TGs) in glaciated regions due to vertical land movement. Recent studies show that geodetic GNSS stations can be used to estimate sea level by taking advantage of the reflections from the ocean surface using GNSS Interferometric Reflectometry (GNSS-IR). This method has the immediate benefit that one can directly correct for bedrock movements as measured by the GNSS station. Here we test whether GNSS-IR can be used for measurements of inter annual sea level variations in Thule, Greenland, which is affected by sea ice and icebergs during much of the year. We do this by comparing annual average sea level variations using the two methods from 2008–2019. Comparing the individual sea level measurements over short timescales we find a root mean square deviation (RMSD) of 13 cm, which is similar to other studies using spectral methods. The RMSD for the annual average sea level variations between TG and GNSS-IR is large (18 mm) compared to the estimated uncertainties concerning the measurements. We expect that this is in part due to the TG not being datum controlled. We find sea level trends from GNSS-IR and TG of −4 and −7 mm/year, respectively. The negative trend can be partly explained by a gravimetric decrease in sea level as a result of ice mass changes. We model the gravimetric sea level from 2008–2017 and find a trend of −3 mm/year.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.3390/rs13245077
ISSN:	2072-4292
Date made live:	22 Mar 2022 14:15 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/531793

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.3390/rs13245077

ISSN:

2072-4292

Date made live:

22 Mar 2022 14:15 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/531793