Research from 2013 had suggested these "troughs" might be caused by katabatic winds—winds that start off moving rapidly, causing erosion, and then quickly drop and slow down, resulting in deposits.
Blanken, Peter D. Williams, Mark W. Burns, Sean P. Monson, Russell K. Knowles, John Chowanski, Kurt and Ackerman, Todd 2009. A comparison of water and carbon dioxide ...
Hantel, M. and Steinheimer, M. 2006. A consistent vertical Bowen ratio profile in the planetary boundary layer. Quarterly Journal of the Royal Meteorological Society ...
Blowing snow can trick ultrasonic wind meters as well. In any case, Antarctica holds the Guinness World Record for the fastest katabatic wind (wind that travels down a slope), which was 168 mph ...