A new 25 years Arctic Sea level record from ESA satellites

• Main Authors: Andersen, Ole Baltazar, Cheng, Yongcun, Knudsen, Per
• Format: Conference Object
• Language: English
• Published: 2016
• Subjects: Arctic; Arctic Ocean; Sea ice
• Online Access: https://orbit.dtu.dk/en/publications/cddde37f-5ada-46ea-b027-a5bb2442b484; http://lps16.esa.int/page_session185.php#1587p

The Arctic is an extremely challenging region for the use of remote sensing for ocean studies. One is the fact that despite 25 years of altimetry only very limited sea level observations exists in the interior of the Arctic Ocean. However, with Cryosat-2 SAR altimetry the situation is changing and through development of tailored retrackers dealing with presence of sea ice within the radar footprint, we can now develop sea surface height and its variation in most of the Arctic Ocean. We have processed 5 years of Cryosat-2 data quantified as either Lead or Ocean data within the Cryosat-2 SAR mask in the Arctic Ocean. By carefully reprocessing and reedited conventional altimetry from ERS-1/ERS-2 and Envisat we have now been able to derive a 25 year time series (1991-2016) using far more remote sensing data in the interior of the Arctic Ocean than ever before.Along with gradiometer observations from the ESA GOCE mission we are now able to derive a mean dynamic topography of the Arctic Ocean with unprecedented accuracy to constrain the ocean circulation. We present both a new estimation of the mean ocean circulation and new estimates of large scale sea level changes based on satellite data and perform an estimation of the freshwater storage increase over the last decade using temporal gravity changes from the GRACE satellite.