Abstract ATM-9416954 Chen, Tsing-Chang Iowa State University Title: Season-to-Interdecadal Climate Variability Several interesting problems concerning the climate variability of the atmospheric circulation with seasonal to decadal time scales emerged from our prior research project. In order to seek answers to these problems, the PI proposes the following research thrusts: a) the three-dimensional structure and maintenance mechanism of summertime stationary eddies and their interannual variation component; and b) the basic structure and time evolution of the interdecadal variation mode of the wintertime atmospheric circulation over the past five decades (1946-1994), and the possible mechanism inducing this interdecadal variation. The mechanisms responsible for the interannual variation of summertime stationary eddies and interdecadal variation of wintertime circulation, as suggested from diagnostic analyses, will be tested with the NCAR Community Climate Model, and the corresponding linearized version. Several data sources, including the OLR, COADS, NMC and ECMWF GDAS (1979-1994), NMC octagonal-grid (1946-1993) and 35-year reanalyzed NMC GDAS (1958-1993) data, will be used in the proposed research thrusts. Funds and time allowing, some further work will be done on seasonal and interannual variations of global relative atmospheric angular momentum, and the roles played by these variations in low-frequency climate variability. This research is important because it seeks to enhance knowledge about climate processes on seasonal-to-interdecadal time scales.
