JWG C10. Tailored Parameterization Strategies for ClimateApplications of Satellite Gravimetry

Chair: Marius Schlaak (Germany)
Vice chair: João de Teixeira da Encarnação (Netherlands)
Affiliations: Commission 2, ICCT, GGOS, IGFS

Introduction

Satellite gravity measurements have successfully observed changes in the Earth system for more than two decades and deliver critical information on mass changes linked to climate change. To ensure continuity, the Mass-change And Geoscience International Constellation (MAGIC) is planned to be launched in the next decade, increasing the resolution of mass-change observations. Especially the long-term observation of Terrestrial Water Storage (TWS) and ocean mass are important climate indicators. TWS consists of all water storage over the continents in liquid and frozen states and has recently been declared a new Essential Climate Variable (ECV) in the implementation plan 2022 of the Global Climate Observing System (GCOS). Changes in ocean mass directly impact sea-level changes, and their measurement allows for quantifying Earth’s Energy imbalance, essentially driving climate change. The importance of increased resolution and long-term sustained observing systems for TWS is underlined in the IUGG resolution no. 2 in 2023, expressing the chance to enable new science and applications of enormous societal benefit. By ensuring a long-term sustainable operation of satellite gravity missions, applications in the hydrosphere, cryosphere, and ocean can profit from tailored processing products of the long-term data record, trading spatial and temporal resolution for an optimal outcome for the respective cases.This working group focuses on identifying and implementing spatiotemporally tailored parameterization strategies for satellite gravimetry observations designed for different climate applications. Building up from the simulation environments implemented in previous working groups, parameter models can be evaluated concerning their capabilities to represent climate-related mass transport signals and their feasibility in real data applications. To envision the possibilities that will arise with upcoming satellite gravity missions, improvements expected from MAGIC and future mission concepts shall be investigated next to current single-pair satellite GRACE-type missions. The parameter models shall be defined in close interaction with the respective applications to identify the main criteria to allow new science to emerge from the advanced parameterization strategies.

Objectives

• Create a modeled mass transport series of 30 years for different applications.
• Define temporal-tailored parameter models for specific climate applications in cooperation with the users.
• Compare the impact of local base functions, e.g., Spherical harmonics, Mascon,Slepians, etc., on specific regions and applications.
• Identify frequencies in the interannual variability and evaluate the impact on the long-term trend assessment if they are (not) considered
  

Program of Activities

• Meetings within the working group to plan collaboration and share scientific results.
• Specialized subgroup meetings for different climate applications.
• Contribute actively to ICCC Geodesy for Climate Workshops and organize sessions.
• Participation in and contribution to conferences such as GSTM, GGHS, and EGU.
• Organizing splinter meetings at said conferences.
  

Members

• Alejandro Blazquez (France)
• Bert Wouters (Netherlands)
• Changqing Wang (China)
• David Wiese (USA)
• Erik Ivins (USA)
• Ingo Sasgen (Germany)
• Julia Pfeffer (France)
• Klara Middendorf (Germany)
• Laurent Longuevergne (France)
• Lijing Cheng (China)
• Linus Shihora (Germany)
• Martin Horwath (Germany)
• Matthias Willen (Netherlands)
• Özge Günes (Turkey)
• Roland Pail (Germany)
• Thorben Döhne (Germany)
• Vincent Humphrey (Switzerland)
• Wei Feng (China)