Causes and impacts of anomalous warming in the Prydz Bay, East Antarctica during austral summer 2016-17

Abstract

Understanding of the coastal waters of Antarctica is crucial in determining the ocean-ice system response to climate change. In this study, using hydrography data we have provided the observational evidence of anomalous warming (>1 °C) in the Prydz Bay during austral summer. Even though the warming was centred at 68°S, 74°E, the presence of warmer waters were also noticed close to the Amery Ice Shelf. The study further explored the causes and impact of this anomalous warming using satellite and re-analysis data. It was suggested that the advection of warmer waters towards the shelf region of the Prydz Bay between 72°E and 75°E was the main driver for the mixed layer warming. The surface heat flux played a weak role in the observed warming. The warm water advection and surface circulation during the observation period were anomalous compared to the normal pattern. The analysis further confirmed that warming caused a drastic reduction in sea-ice and chlorophyll in the Prydz Bay region. The study ascertains that regional oceanographic processes have significant implications on the sea-ice and biological productivity of the coastal waters of Antarctica.