- 1Leipzig Institute for Meteorology, Leipzig University, Leipzig, Germany (maximilian.maahn@uni-leipzig.de)
- 2DIATI , Politecnico of Torino, Turin, Italy
- 3School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, USA
- 4Department of Atmospheric and Oceanic Sciences, McGill University, Montreal, QC Canada
- 5Department of Earth & Environmental Sciences, KU Leuven, Leuven, Belgium
- 6Department of Geoscience and Remote Sensing, TU Delft, Delft, Netherlands
- 7Institute of Atmospheric Science and Climate (CNR-ISAC), National Research Council of Italy, Rome, Italy
- 8Department of Meteorology, University of Reading, Reading, United Kingdom
Snowfall is an important indicator of climate change, affecting surface albedo, glaciers, sea ice, freshwater storage, cloud lifetime, and ecosystems. Accurate measurements of snowfall at high latitudes are particularly important for estimating the mass balance of ice sheets; however, snowfall is difficult to quantify from both in situ and remotely sensed measurements.
Today, global snowfall products are mostly based on space-borne cloud radar observations such as CloudSat and now EarthCARE. However, these products suffer from systematic and random errors due to poor spatio-temporal sampling, the inability to observe snowfall near the surface due to ground clutter, and retrieval uncertainties due to insufficient information content of the observations.
WIVERN (WInd VElocity Radar Nephoscope) is one of the two remaining ESA Earth Explorer 11 candidate missions, with the final selection in July 2025. It is equipped with a 94 GHz conical scanning polarimetric Doppler radar and a 94 GHz passive radiometer. The main objective of the mission is to measure global horizontal winds in clouds, but it will also quantify cloud water content and precipitation rate.
Here we analyze WIVERN's potential to improve global snowfall products through the mission's unique design. Compared to CloudSat, WIVERN's 800 km swath provides 70 times better coverage including sampling closer to the poles and its 42 off-zenith angle significantly reduces the radar blind zone near the surface (especially over the ocean). In addition, WIVERN's radar includes polarimetric measurements and is accompanied by a radiometric mode, which can further improve the estimation of snowfall rates. Our results show that the WIVERN sampling strategy significantly reduces the uncertainty in polar snowfall estimates, making it a valuable product for climate model evaluation and as an input to surface mass balance models of the major ice sheets at the regional and seasonal spatio-temporal scales.
How to cite: Maahn, M., Battaglia, A., Coppola, M., Hörnig, S., Kollias, P., Lhermitte, S., Maherndl, N., Montopoli, M., Scarsi, F., Tridon, F., and Illingworth, A.: How can global snowfall estimates be improved by ESA's proposed Earth Explorer 11 WIVERN mission?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15261, https://doi.org/10.5194/egusphere-egu25-15261, 2025.
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