Marginal Ice Zone
The MIZ voyage aims to provide a multidisciplinary science platform to address key outstanding questions in the marginal ice zone. These include the physical characterisation of the marine cryosphere, including sea ice, snow on ice and wave-ice interactions. Other large work packages include sea-ice ecosystems and krill, trace metals and biogeochemistry. Atmospheric processes over the Southern Ocean and Antarctica have a profound influence on regional and global climate. However, state-of-the-art climate models exhibit large and persistent surface shortwave radiation biases in the region, largest in austral summer. These biases have been linked to our lack of understanding of aerosol and cloud formation processes in this region, and to what extent the biological productivity of the upper ocean drives aerosol formation. Recent experiments using RV Investigator and RSV Aurora Australis and long-term observations at Macquarie Island have highlighted the need to better understand the role of biological productivity in the ocean on aerosol formation and subsequent cloud and precipitation properties. This requires the collection of multidisciplinary datasets encompassing the whole process chain from phytoplankton characterization to the formation and release of gases to the atmospheric boundary layer precursor to aerosol formation, cloud and precipitation. From the few observations collected in 2018, this process chain also seems to be modulated by the release of precursor gases over the sea ice off the coast of Antarctica, but very few observations have been collected to date to investigate those processes in a robust way.
The goal of the MIZ experiment for the atmospheric team is to characterise the properties of aerosols, clouds, radiation, and precipitation near the marginal ice zone region of Antarctica and investigate how they are shaped by interactions between the atmosphere and biogeochemical cycles and biological productivity in the upper ocean. The observations and insights gained from the voyage will be used to develop, test, and implement new parameterisations for models used for weather forecasts and climate projections.
Platform: RSV Nuyina
Location: 140oE in the MIZ
Timing: October 2023
Contact: Simon Alexander (Simon.Alexander<@>awe.gov.au)