Blowing Snow Sublimation and Transport over Antarctica
from 11 Years of CALIPSO Observations
Stephen P. Palm1, Vinay Kayetha1, Yuekui Yang2, and Rebecca Pauly11Science Systems Applications Inc., 10210 Greenbelt Road, Greenbelt, Maryland USA 20771 2NASA Goddard Space Flight Center, Greenbelt, Maryland USA 20771
Received: 22 Mar 2017 – Accepted for review: 29 Mar 2017 – Discussion started: 03 Apr 2017
Abstract. Blowing snow processes commonly occur over the earth's ice sheets when near surface wind speed exceeds a threshold value. These processes play a key role in the sublimation and re-distribution 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 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 lidar aboard the CALIPSO satellite. The blowing snow events identified by CALIPSO and meteorological fields from MERRA-2 are used to compute the 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 re-analysis 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 Antarctica average integrated blowing snow sublimation is about 393.4 ± 138 Gt yr−1 which is considerably larger than previous model-derived estimates. We find maximum blowing snow transport amount of 5 Megatons km−1 yr−1 over parts of East Antarctica and estimate that the average snow transport from continent to ocean is about 3.68 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.
Palm, S. P., Kayetha, V., Yang, Y., and Pauly, R.: Blowing Snow Sublimation and Transport over Antarctica
from 11 Years of CALIPSO Observations, The Cryosphere Discuss., doi:10.5194/tc-2017-45, in review, 2017.