Sea Ice Observations

What is the point?

Passive microwave satellites provide sea-ice cover and extent data that is used by Polar going vessels, like the SA Agulhas II, to safely navigate the ice-covered polar regions. Due to the dynamic nature of the polar regions, it is necessary to validate the satellite data. To do this the satellite data are compared with in situ sea-ice observations.

From a scientific perspective, sea-ice observations allow us to monitor the evolution of the sea-ice cover as the vessel transects the Marginal Ice Zone and approaches the continent. Additionally, they allow us to track how the sea-ice cover and location changes year after year. Although satellites can provide uninterrupted observations, they are limited in what they can observe. However, observations using the Antarctic Sea Ice Processes and Climate (ASPeCt) protocol, which is an internationally accepted method of sea-ice observation, allow us to assess a broader spectrum of sea-ice characteristics.

The ASPeCt protocol looks at the sea-ice type, thickness, shape, edge properties, snow characteristics, and total concentration compared to open water to assess the sea-ice cover in the Polar region. Sea-ice features like leads, weathered ridges and types of rafting are also identified. Included in the ASPeCt protocol are meteorological observations that would influence the sea-ice cover in the area. Some of these include cloud cover, current weather conditions, wind speed and air temperature.

Sea-ice observations are being conducted from the bridge of the SA Agulhas II. These will be supported by a camera, mounted on the port side of the vessel, that is continuously recording wide angle time-lapse videos. 

Understanding how the sea-ice cover evolves as we move from the open ocean into the sea-ice dominated region is vital for navigational and scientific purposes. The WSE and the SA Agulhas II have provided us with the perfect opportunity and means to observe a relatively under-observed region of the Antarctic, the Weddell Sea.

Written by Riesna R Audh, an Oceanography Masters student at the University of Cape Town in South Africa. Her research is focused on the Antarctic Polar region, with specific interest in the dynamics and biogeochemistry of pancake ice in the Antarctic Marginal Ice Zone. She is fascinated by sea-ice and the implications of climate change on the Polar Regions. she intends on using her research to better inform our limited understanding of the Antarctic Polar region. She believes that science should be accessible and inclusive and that everyone has the potential to be a scientist.