Articles | Volume 11, issue 6
https://doi.org/10.5194/tc-11-2555-2017
https://doi.org/10.5194/tc-11-2555-2017
Research article
 | 
10 Nov 2017
Research article |  | 10 Nov 2017

Blowing snow sublimation and transport over Antarctica from 11 years of CALIPSO observations

Stephen P. Palm, Vinay Kayetha, Yuekui Yang, and Rebecca Pauly

Abstract. Blowing snow processes commonly occur over the earth's ice sheets when the 10 m wind speed exceeds a threshold value. These processes play a key role in the sublimation and redistribution of snow thereby influencing the surface mass balance. Prior field studies and modeling results have shown the importance of blowing snow sublimation and transport on the surface mass budget and hydrological cycle of high-latitude regions. For the first time, we present continent-wide estimates of blowing snow sublimation and transport over Antarctica for the period 2006–2016 based on direct observation of blowing snow events. We use an improved version of the blowing snow detection algorithm developed for previous work that uses atmospheric backscatter measurements obtained from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) lidar aboard the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) satellite. The blowing snow events identified by CALIPSO and meteorological fields from MERRA-2 are used to compute the blowing snow sublimation and transport rates. Our results show that maximum sublimation occurs along and slightly inland of the coastline. This is contrary to the observed maximum blowing snow frequency which occurs over the interior. The associated temperature and moisture reanalysis fields likely contribute to the spatial distribution of the maximum sublimation values. However, the spatial pattern of the sublimation rate over Antarctica is consistent with modeling studies and precipitation estimates. Overall, our results show that the 2006–2016 Antarctica average integrated blowing snow sublimation is about 393 ± 196 Gt yr−1, which is considerably larger than previous model-derived estimates. We find maximum blowing snow transport amount of 5 Mt km−1 yr−1 over parts of East Antarctica and estimate that the average snow transport from continent to ocean is about 3.7 Gt yr−1. These continent-wide estimates are the first of their kind and can be used to help model and constrain the surface mass budget over Antarctica.

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Short summary
Blowing snow processes are an important component of ice sheet mass balance and also the atmospheric hydrological cycle. This paper presents the first satellite-derived estimates of continent-wide sublimation and transport of blowing snow over Antarctica. We find larger sublimation values than previously reported in the literature which were based on model parameterizations. We also compute an estimate of the amount of snow transported from continent to ocean and find this to be significant.