The month-to-month and year-to-year variability of the lower atmosphere appears in a set of recurrent patterns, denoted teleconnections. Teleconnections mediate the seasonal climate: heat and cold waves; seasonal droughts and periods of flooding. Feldstein will investigate the dynamical mechanisms that set the structures of these patterns and determine their behavior over time. Five specific questions will be addressed: 1. What dynamical processes determine how teleconnections vary over time? 2. How does the stratosphere influence the leading high-latitude patterns, which organize weather throughout the extratropics? 3. Do teleconnection patterns represent distinct regimes or continua of states? 4. The zonal-mean jet exhibits periods when it propagates poleward. Can such periods be predicted? If so, what are the implications for forecasting the weather? 5. How do storms lead to the development of the leading teleconnection patterns over the North Atlantic and North Pacific Oceans?
These questions will be answered by analyzing existing atmospheric data sets together with an extensive set of simulations using an idealized numerical model. The model simulations will include runs with topography and with a resolved stratosphere.
A broader impact of the research will be to make available, to the community, the output of the extensive set of model simulations. A graduate student will be trained, and research opportunities will be provided for undergraduate honors students. These studies may ultimately lead to improvements in intraseasonal prediction.
