Spatiotemporal Patterns of Polar Low Activity Over the Southern Ocean

Abstract

AbstractPolar Lows (PLs) are intense maritime meso‐scale cyclones that form over cold ocean regions in high latitudes. They affect the weather and climate of Antarctica and the surrounding ocean by producing storms with near or above gale‐force winds and heavy precipitation. This study investigated PLs in the Southern Ocean (SO) between 60 and 85°S from 2000 to 2020, using a tracking algorithm applied to the ERA5, CCMP, and NCEP/NCAR data sets. The results showed that PLs are most frequent in winter (JJA) and least frequent in summer (DJF), with a maximum in 2018 and a minimum in 2014. The results also show that PLs are concentrated over the Antarctic Circumpolar Current (ACC) region, along the Ross Sea, the Amundsen Sea, and the Bellingshausen Sea from April to October. These regions have strong thermal gradients and orographic forcing that enhance cyclogenesis. Our research reveals that there were 1,073 occurrences of PLs during the study period, with an average 51 cases per year. The study also explored the influence of sea surface temperature anomalies, sea surface currents, and MCAOs Index on PL genesis. The Amundsen‐Bellingshausen Seas Low (ABSL) and Pacific Ocean currents have a considerable effect on PLs developing in the SO. This research provides valuable information on PLs in the SO, which are poorly observed and understood. However, more research is required to understand how these phenomena are evolving in the present, and how they will change in the future.