Presentation Information
[ACC45-P01]Relationship between visibility observed at Syowa station from 2020 to 2024 and the mass flux of blowing snow using the blowing snow scheme in the regional atmospheric climate model RACMO
*Soeta Shoki1, Konosuke Sugiura2 (1.Graduate School of Science and Engineering, University of Toyama, 2.Faculty of Sustainable Design, University of Toyama)
Keywords:
Antarctic,Syowa Station,blowing snow,visibility
It has been reported that significant snow drifts and severe degradation of visibility occur during blizzards in the ice sheet of Antarctica. Coastal areas, such as Syowa Station, are considered highly susceptible to the impacts of blowing snow on visibility. This is thought to be due to a combination of effects of inland from katabatic winds and lower latitudes from atmospheric disturbances. Although previous studies have investigated the visibility variation at Syowa Station, there remains scope for further research through long-term visibility statistical analysis and correlation studies with meteorological conditions. Consequently, this study calculates mass flux of blowing snow for Syowa Station using the regional atmospheric climate model RACMO blowing snow scheme with reanalysis data as input, thereby characterizing the relationship between the mass flux of blowing snow and visibility. Furthermore, this study evaluates the change of the estimated mass flux of blowing snow to variations in density of snow. To reproduce the blowing snow scheme for RACMO, European Center for Medium Range Weather Forecasts (ECMWF), ECMWF Reanalysis v5 (ERA5) was employed to calculate mass flux of blowing snow at 1-hour intervals. For the visibility data, Japan Meteorological Agency surface weather observation data at the Syowa Station was utilized. The visibility data have a temporal resolution of 3-hours. The analysis period for this study extends from 2020 to 2024. The results revealed a negative correlation between the mass flux of blowing snow and visibility across the entire study period. This finding is consistent with the results of previous studies. A comparison between cases of low density and high density revealed that the negative correlation between the mass flux of blowing snow and visibility strengthened during low density. This enhanced correlation is likely attributed to an increased frequency of blowing snow under low density, as well as the increasing of supply from the snow surface. Furthermore, the experimental formula described in previous studies exhibited behavior consistent with the lower limit value obtained in this analysis. These findings suggest that this experimental formula is applicable during degradation of visibility in Syowa Station. Subsequently, when entire study period was classified into season, a seasonal variation was observed between the mass flux of blowing snow and visibility. Even within the same mass flux of blowing snow, visibility was good in summer and poor in winter. This is likely attributable to differences in density of snow during the occurrence of blowing snow. In future research, we aim to elucidate the relationship between the mass flux of blowing snow and visibility by categorizing the causal factors of blowing snow, such as katabatic winds from inland and atmospheric disturbances from lower latitudes, while also identifying additional factors beyond density of snow that influence the relationship between the mass flux of blowing snow and visibility.