Abstract
Automatic Weather Stations (AWSs) with ultrasonic snow depth sensors were newly installed at four sites. The installation was started in January 2016 and completed in October 2019. The sites are H128 in the coastal region, MD78 in the continental slope region with the katabatic wind, NRP in the inland high region on the upside of the continental slope, and NDF on the summit of the ice sheet. The purpose of this AWS system is to clarify the temporal variations of accumulations affected by synoptic-scale disturbances and diurnal variations while reflecting the regional characteristics over a wide area of the Antarctic ice sheet. This paper investigates the temporal variations of surface height observed at these four sites. The results are as follows: 1) The temporal changes of surface height include stepwise fluctuations and pulse-like fluctuations, and the rise in surface height is mainly caused by stepwise rises, rather than pulse-like fluctuations. 2) A comparison between H128 and NRP showed four cases in which surface height fluctuations appeared simultaneously over a wide area. The NOAA infrared image reveals that the cloud area associated with a synoptic-scale disturbance formed over the ice sheet. 3) The surface height is less likely to rise largely between different sites on the same day. 4) At the three sites other than NRP, a slow decline in surface height was observed during the warm season.
