Co-leads: Marilyn Raphael (UCLA, USA) and Gareth Marshall (British Antarctic Survey, UK)

The goal of this theme is to improve understanding of atmospheric circulation and its role on climate variability and climate change in the Southern Hemisphere. Many of the current pressing scientific questions involve the response of the atmospheric circulation to ozone depletion/recovery and greenhouse-gas increases, and how this impacts surface climate, ocean circulation, sea ice, and ice shelves. These interactions have implications for carbon and heat uptake and the stability of ice sheets. We need to understand the observed relationships and how they are represented in models, in order to improve decadal prediction and longer term projections of Antarctic climate. Recent studies suggest that the zonal and non-zonal circulation influence the climate system of the high latitude Southern Hemisphere. This influence may be reflected in the variability in Antarctic sea ice extent as well as the climate over the Antarctic continent. Activities associated with this theme could examine the coupling between the larger scale atmospheric circulation and the climate system of the Southern Hemisphere, especially with regard to how the southern jets and the non-zonal circulation couple to the rest of the system (ocean, sea ice and land ice). These activities may include but are not limited to, theoretical, observational and modeling studies on the vertically coupled processes.

Next steps

1.    Contact possible interested parties to gauge interest in this theme over the next few months.  

2.    Host a workshop (perhaps 2 days long) with a small group of scientists who are working on research relevant to Theme 6.  This will be some subset of the people who have responded to our earlier contact, A potential location for this Workshop is UCLA (Marilyn will make local arrangements) and we could time this to precede or follow the AGU Fall Meeting. It might even be possible to have this Workshop at the AGU. We will have to look into this.  The idea is to leverage the travel that people will already be making to the AGU.  

3.    Host session at the AGU Fall Meeting, which should appeal to people interested and working in the area of interest. Target scientists identified in the first step (above) to have them contribute to this session.  The outcomes of this workshop would determine what would be done over the year following the AGU Meeting.  In that year (2014) we expect to meet at scientific meetings that we would have individually intended to attend and use some of the available monies to support extra days of stay etc.

4.    Host a second workshop that brings together the work that has been accomplished over the preceding year could be held in association with the 11th ICSHMO conference in 2015.

Some other thoughts not yet included in the rough timeline given above: One idea for a Workshop is the Amundsen-Bellingshausen Sea Low. The workshop would explore why the Low is where it is, its variability, its effect on Antarctic climate, etc. The outcome of a workshop like this could be written up for an outlet like Reviews of Geophysics.  If we decide that this is a useful way to go this activity can be added to the tentative proposed timeline.