Formative Processes Governing Ross Sea Polynya Areal Variability

Abstract:

Of the 17 million km^2 of sea ice in the Southern Ocean, ~10% is generated through coastal polynyal systems. The largest and greatest contributor to sea ice formation in the Antarctic is the Ross Sea Polynya which exists in a region where sea ice trends are positive and significant. Understanding polynya areal dynamics and the contributing physical factors will give further insight into the future of Ross Sea ice production. Previous studies have established coastal winds and surface temperatures as key contributors to the development and maintenance of coastal polynyas. However, much that is understood is based on physically sound inference. While the influence of these variables have been studied separately, their concerted roles have not been quantified, neither has any indication of their variation with time been established. Automatic weather station data produced by the Antarctic Automatic Weather Station Program was acquired from the National Oceanic and Atmospheric Administration, and polynya area data was produced through the application of the Polynya Signature Simulation Method onto Special Sensor Microwave Imager input acquired from the National Snow and Ice Data Center. Wind speed, wind direction, sea surface temperature, near surface air temperature, oceanic temperature, and tidal fluctuations are examined as physically significant contributors to polynya areal variability and are considered in a multivariate regression model at a 95% confidence level. This study quantifies the degree to which each variable contributes to Ross Sea Polynya areal dynamics, and determines how their influences vary seasonally and in the long term.