Two students successfully defended Climate Dynamics Doctoral Dissertations in Spring 2019. For full abstracts, see AOES Seminar Pages.
Akiko Elders, working with AOES faculty member Kathy Pegion, investigated the relationship between weather and Arctic sea ice decline. The Arctic is warming faster than other regions of Earth, resulting in a dramatic decline in sea ice. Sea ice decline may be linked to extreme winter whether in mid-latitude regions such as the United States. Elders used a state-of-the-art climate model to separate the impacts on mid-latitude weather of global warming and sea ice decline.
Liang Yu, whose advisor was AOES faculty member Bohua Huang, studied components of Atlantic Multidecadal Variability (AMV). AMV is the tendency of the North Atlantic to be colder or warmer than average for decades at a time, causing large-scale changes in climate during these periods. The phenomenon is poorly understood but thought to be related to interactions between ocean currents and the atmosphere. The atmosphere can drive ocean variability through the exchange of momentum (by wind pushing on the sea surface), heat (cooling and heating the sea), and freshwater (evaporation and precipitation). In a coupled atmosphere-ocean climate model, all three exchanges vary simultaneously. Yu studied the separate effect of each influence by conducting experiments with an ocean circulation model in which each forcing (wind, heat, and water) from the coupled model was applied separately.