[A-CC26] Glaciology

[ACC26-P10] Verification experiment of an ultrasonic snow depth sensor mounted on the AWSs deployed in Antarctica: Report 2

*Naohiko Hirasawa^1,2, Nuerasimuguli Alimasi¹, Keisuke Saito² (1.National Institute of Polar Research, 2.Graduate University for Advanced Studies (SOKENDAI))

Keywords:Ultrasonic snow depth sensor, Field experiment, Blowing snow, Automatic Weather Station

Four AWSs deployed on the Antarctic ice sheet were equipped with an ultrasonic snow depth sensor (SR50A, Campbell Scientific, Inc., UAS). The main purpose of the observation was to obtain surface level fluctuations at high frequency time intervals and to determine the mechanism of increase or decrease in accumulation. These data show stepwise fluctuations in snow surface level and pulse-like fluctuations (Hirasawa, 2021). The stepwise variation contributes significantly to the annual increase in snow level, while the pulse-like variation contributes little to the annual variation. The causes of pulse-like fluctuations have not been fully explored in many studies. However, the fact that pulse-like fluctuations are often accompanied by stepwise fluctuations and that the frequency of pulse-like fluctuations tends to be higher during cold season may reflect some natural phenomena. This study assumes that relatively large-amplitude pulse-like variations may be produced by blowing snow, and reproduces these pulse-like variations by creating artificial pseudo blowing snow events in a field experiment in Rikubetsu, Hokkaido, Japan. This presentation is the second report following last year's report, and discusses the results of the experiment for the winter of 2024. This study was supported by JAXA-EORA3.

1. Hirasawa, et al. (2021): Seppyo 83, 67-77. (In Japanese)