Toward a Satellite-Derived Climatology of Blowing Snow Over Antarctica

Satellite lidar remote sensing of the atmosphere has been ongoing for more than a decade providing the opportunity to study atmospheric processes in great detail. Here we use 12 years of Cloud-Aerosol Lidar with Orthogonal Polarization measurements to derive a climatology of blowing snow layer height, optical depth, and frequency over Antarctica for the period 2006–2017. Limited to the vertical resolution of the Cloud-Aerosol Lidar with Orthogonal Polarization data, our climatology includes all blowing snow layers greater than about 30 m in thickness for clear or optically thin cloud regions. Our results show that blowing snow occurs over 50% of the time over large regions with frequencies often exceeding 70%. The overall pattern of blowing snow frequency is fairly consistent from year to year, but there are regional differences. We examined the data for temporal trends in blowing snow properties and found significant trends only in blowing snow frequency. A small area of East Antarctica with generally low blowing snow frequency shows a statistically significant increase in blowing snow frequency ranging from 10% to 100% per decade. No significant trends in frequency were found in regions of high (>50%) blowing snow frequency, and only isolated small areas exhibited a decrease in frequency through the study period. Plain Language Summary During the last decade a new satellite remote sensing tool has become available for atmospheric research. The technique, called lidar (light ranging and detection), uses short (laser) pulses of visible light to probe the vertical structure of the atmosphere. The Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations mission launched in 2006 has greatly increased our knowledge of atmospheric structure over the polar region. One of the important discoveries made by this satellite is the ubiquitous nature of blowing snow episodes over Antarctica. Blowing snow occurs when the surface wind exceeds a threshold value (about 5–7 m/s) and snow is carried aloft and transported downwind. Once aloft, the snow particles can be carried great distances and even blown off the continent. In this paper we use Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation data to detect the occurrence of blowing snow over Antarctica and construct a 12-year climatology of its frequency of occurrence, layer depth, and particle density. We have discovered that many regions of Antarctica experience blowing snow over 70% of the time and that blowing snow storms can last for days, cover areas as large as the state of Texas, and reach heights of 400 m or more.