Arctic Sea Level Change From a Reprocessed 2 Decade Altimetric Sea Level Record

Tuesday, 16 December 2014
Ole Baltazar Andersen, Per Knudsen and Yongcun Cheng, Technical University of Denmark - Space, Kongens Lyngby, Denmark
For ocean and climate research it is essential to get as accurate long-term altimetric sea level data as possible. However, the accuracy of the altimetric data is frequently degraded in the interior of the Arctic Ocean due to the presence of seasonal or permanent sea ice. We have reprocessed ERS-1/2/Envisat satellite altimetry to develop an improved 20-year sea level dataset for the Arctic Ocean adding in recent retracked Cryosat-2 to bring the record up to 2014 . We have developed both an along-track dataset and 3-day gridded sea level anomaly (SLA) maps from September 1992 to April 2014. A major improvement in data coverage was gained by tailoring the standard altimetric editing criteria to Arctic conditions. The new reprocessed data has significant increased data coverage with between 4 and 10 times the amount of data in regions like the Beaufort Gyre region compared with AVISO and RADS datasets. This allows for a more accurate estimation of sea level changes from satellite altimetry in the Arctic Ocean.

The reprocessed dataset exhibit a mean sea level trend of 2.1±1.3 mm/year (without Glacial Isostatic Adjustment correction) covering the Arctic Ocean between 66°N and 82°N with significant higher trend in the Beaufort Gyre region showing an increase in sea level trend at the cm level up to 2011.