EGU22-2586, updated on 20 Feb 2024
https://doi.org/10.5194/egusphere-egu22-2586
EGU General Assembly 2022
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

Contributions of ocean bottom pressure and density changes to regional sea level change in the East Indian Ocean from GRACE, altimetry and Argo data

Alisa Yakhontova1, Roelof Rietbroek2, Jürgen Kusche1, Sophie Stolzenberger1, and Bernd Uebbing1
Alisa Yakhontova et al.
  • 1University of Bonn, Institude of Geodesy and and Geoinformation, APMG, Bonn, Germany (yakhontova@geod.uni-bonn.de)
  • 2ITC Faculty of Geo-information Science and Earth Observation,Department of Water Resources (WRS), Enschede, Netherlands

Understanding variations in the ocean heat content is tightly linked to understanding interactions of the global energy cycle with the regional water cycle. Mass, volume, temperature and density changes of  the ocean water column can be estimated with complimentary observations of sea surface height from radar altimetry, ocean bottom pressure from Gravity Recovery and Climate Experiment (GRACE), temperature and salinity from Argo floats. These three techniques have their specific deficiencies and advantages, which can be exploited in a joint inversion framework in order to improve temporal and spatial coverage of oceanic temperature and salinity estimates as well as regionally varying sea level contributions. Solving an inverse problem for temperature and salinity, forward operators are formulated linking the satellite observations to temperature and salinity at depth. This is done by (1) parametrization of temperature and salinity profiles over the full depth of the ocean with B-splines to reduce dimensionality while keeping complexity of the data intact and (2) linearization of the integrated density from parameterized T/S curves. We apply forward operators in the East Indian Ocean to resolve for sea surface height, ocean bottom pressure, temperature and salinity, and assess the regional importance of these factors. We explore the stability of a joint inversion using these forward operators in combination with along-track radar altimetry, GRACE and temperature and salinity by exploring a closed-loop inversion.

How to cite: Yakhontova, A., Rietbroek, R., Kusche, J., Stolzenberger, S., and Uebbing, B.: Contributions of ocean bottom pressure and density changes to regional sea level change in the East Indian Ocean from GRACE, altimetry and Argo data, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2586, https://doi.org/10.5194/egusphere-egu22-2586, 2022.