PI Sophie Nowicki


Brian Beckley, Michael Croteau, Beata Csatho, Richard Cullather, Denis Felikson, Manuela Girotto, Bryant Loomis, Richard Ray, Terence Sabaka, Anton Schenk, Randal Koster, Scott Luthcke, Brooke Medley


The overarching aim of this research is to understand and characterize relevant mechanisms and underlying processes that are key in current and future sea level change. Our goal necessitates an integrated approach which uses available the current and projected sea level change using NASA’s multi-satellite observations, modeling and climate system assimilation capabilities. Our interdisciplinary team consists of modelers and remote sensing experts in the fields of ocean, atmosphere, hydrology and cryosphere sciences, that is uniquely suited to contribute to this important question and the sea level change team.

Expected Significance

Our work builds on previous research efforts sponsored by NASA (including past N-SLCTs) and are primarily based on NASA observations and models, yet our research will benefit the larger sea level and climate research communities. The work also addresses the broader needs of stakeholders and others affected by sea level by investigating prognostic forecasts on seasonal and 21st century timescales.

Our team provides datasets to the N-SLCT portal; for example, the global sea level dataset from altimetry, which we can immediately revise and update without waiting for external groups to address reprocessing issues on their time frame. This strength applies to all the observational or modeling datasets that we will share with the N-SLCT, and given the importance of these dataset or models for sea level research, it is important that the N-SLCT has members cognizant of any issues that require special attention when dataset are used, assimilated or interpreted.


The objectives of the proposed work are to:

  1. Provide observation evidence of global and regional sea level change with improved spatio-temporal accuracy from multi-satellite observations of sea level and ice sheets.
  2. Quantify the contribution of underlying physical mechanisms of sea level variability with atmospheric reanalysis and land hydrology data assimilation from the Goddard Earth Observing System (GEOS) and ice sheet studies.
  3. Project sea level change on near-term timescales using the seasonal forecasting system of GEOS and 21st Century contribution of ice sheet mass using the Ice Sheet System Model (ISSM).
  4. Contribute with our knowledge and expertise to the NASA Sea Level Change Team (N- SLCT), and deliver products on the N-SLCT portal that can be used towards a common product.


  • Improved observational evidence of sea level change and global mean sea level budget closure from altimetry (for example, T/P-Jason mean sea level time series revised in light of TOPEX corrections and extended with validated Jason-CS data) and gravimetry (for example, GSFC mascon)

  • Greenland Ice Sheet elevation reconstruction for: the 1980s (from aerial photogrammetry DEMs (marginal zone) and extrapolated laser altimetry trend (central), 2007 (from SPOT and ASTER DEMs), and 2017 (from DigitalGlobe DEMs, corrected and adjusted to laser altimetry time series).

  • High spatiotemporal resolution reconstruction of Greenland and Antarctic ice sheet changes from altimetry and GRACE (monthly on a 1 km grid for Greenland and 5 km for Antarctica) partitioned into changes due to ice dynamics and surface processes (surface mass balance, firn densification)

  • Calibrated projections for the Greenland and Antarctic ice sheet up to 2100.

  • GEOS-5 derived land hydrology datasets and seasonal sea level forecasts.


Felikson, D., Catania, G. A., Bartholomaus, T. C., Morlighem, M., & Noël, B. P. Y. (2020). Steep glacier bed knickpoints mitigate inland thinning in Greenland. Geophysical Research Letters, 48, e2020GL090112. https://doi.org/10.1029/2020GL090112
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