Start Date/Time: Monday, September 24, 2012, 3:30 PM
Ending Date/Time: Monday, September 24, 2012, 4:20 PM
Location: ATG 310C
Speaker: Roger Davies, Professor, Physics Department, The University of Auckland, Auckland, New Zealand
Coordinator: Prof. Qiang Fu (email@example.com)
Abstract: Clouds are a major problem when it comes to assessing future climate change. Despite a consistent satellite data record that is not yet long enough to be definitive, it is very tempting to see what hints are emerging from the global observations. Analysis of high resolution MISR data for the last 12 years shows apparently significant downward trends in both effective height and TOA albedo. The height trend suggests negative feedback to global warming, whereas the albedo trend suggests positive feedback. The zonal differences in these trends indicate that they are not simply due to changes in total cloud fraction. To explore the relative significance of such cloud effects on equilibrium surface temperature, Iíve been working on a new radiative-convective equilibrium model, and will show some results from this too.