Uncertainties of TWS Time Series for Arbitrary Regions - Modelled vs. Formal Covariances

Eva Boergens, Andreas Kvas, Henryk Dobslaw, Annette Eicker, Christoph Dahle, Frank Flechtner

Research output: Contribution to conferencePaper


Knowledge of the variances and covariances of gridded terrestrial water storage anomalies (TWS) as observed with GRACE and GRACE-FO is crucial for many applications thereof. For example, data assimilation into different models, trend estimations, or combinations with other data set require reliable estimations of the variances and covariances. Today, the Level-2 Stokes coefficients are provided with formal variance-covariance matrices which can yield variance-covariance matrices of the gridded data after a labourious variance propagation through all post-processing steps, including filtering and spherical harmonic synthesis. Unfortunately, this is beyond the capabilities of many, if not most, users.

This is why, we developed a spatial covariance model for gridded TWS data. The covariance model results in non-homogeneous, non-stationary, and anisotropic covariances. This model also accommodates a wave-like behaviour in latitudinal-directed correlations caused by residual striping errors. The model is applied to both VDK3 filtered GFZ RL06 and ITSG-Grace2018 TWS data.
Original languageEnglish
Publication statusPublished - 30 Apr 2021
EventEGU General Assembly 2021 - Virtuell
Duration: 19 Apr 202130 Apr 2021


ConferenceEGU General Assembly 2021
Abbreviated titlevEGU21
Internet address


  • uncertainty
  • covariance model

ASJC Scopus subject areas

  • Earth and Planetary Sciences(all)

Fields of Expertise

  • Sustainable Systems


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