Title: Detecting regional teleconnection patterns over North America, Asia, and Australia (slides)
Abstract: This talk combines two papers and some preliminary results on atmospheric teleconnections. One teleconnection is forced by extratropical waves that can be deflected from the Northern Hemisphere polar regions and travel southeastward over central Asia toward the western Pacific warm pool during northern winter. The wave pattern resembles the east Atlantic–west Russia pattern and influences the El Niño–Southern Oscillation (ENSO) region. It can be used as a predictor for the strength of emerging El Niños with the positve phase (low pressure over West Siberia) leading to east Pacific El Niños and the negative phase leading to central Pacific El Niños. This pattern also modifies the subtropical bridge between tropical eastern Pacific and subtropical North Atlantic suggesting a circumglobal wave train.
Another teleconnection occurs between the Tasman Sea and the Southern Ocean. It is related to El Niño–Southern Oscillation (ENSO), the Indian Ocean dipole (IOD), and the southern annular mode (SAM). This teleconnection is significantly correlated with SAM during austral summer, fall, and winter, with IOD during spring, and with ENSO in summer. It can thus be described as a hybrid between these modes. Strong amplitudes in this pattern can be related to the initial phase of long term droughts over Australia.
Some preliminary results include the attribution of temperature and precipitation changes over North America to combinations of teleconnections such as Pacific–North American pattern (PNA) and Northern Hemisphere annular mode (NAM) in addition to influences from ENSO and Atlantic Multidecadal Oscillation (AMO).
Biography
Stefan Liess received his M.Sc. and Ph.D. degrees in meteorology from the University of Hamburg in collaboration with the Max Planck Institute for Meteorology in 1997 and 2002, respectively.
He has held postdoctoral and research scientist positions at the School of Marine and Atmospheric Science (SoMAS) at Stony Brook University and is currently a researcher at the Department of Earth Sciences of the University of Minnesota. His research interests cover global and regional climate variability and climate change. He analyzes observational data and performs dynamical model simulations using high performance computing to focus on dynamical characteristics of the atmosphere, interactions between climate and vegetation, and interactions between the troposphere and the stratosphere. His other interests are studies of the hydrologic cycle, especially large-scale drought and flood events.
