SODAR-based wind study at Jang Bogo Station, Antarctica, during the winter of 2017

Abstract

A Doppler Sonic Detection and Ranging (SODAR) wind-profiling system was deployed at Jang Bogo Station, Antarctica, during the summer of 2017. The parameters measured by the SODAR system were wind speed and direction averaged for 15 min from 30 m above the surface to 500 m aloft. Additionally, wind measurements obtained from the nearby walk-up tower and automatic weather station (AWS) were also used for additional data and comparison, respectively. The analysis and comparison used hourly average for consistency. The mean wind speed obtained from the SODAR measurement is highly correlated with those from the walk-up tower and the AWS measurements. All three measurements recorded westerlies during all strong wind events but varied during calm periods. The measurements also reveal that Jang Bogo Station experiences lower wind speeds compared to the nearest katabatic confluence region (Inexpressible Island), where the maximum airflow usually occurred. From the hourly averaged data, SODAR only detected a maximum wind speed of 18.1 m s-1. There were 238 occurrences of strong wind events equal to or above 10.8 m s-1 (Beaufort scale 6) from 10 May to 31 October 2017. These occurrences were recorded in 50 out of 175 days analysed in this study. From 10 to 12 June 2017, predominantly south-westerly-westerly winds were recorded at the surface and aloft during two strong wind events. Based on this case study, the boundary layer during calm and strong wind periods was also analysed.