HR: 1340h
AN: A13A-0900    [Abstracts]
TI: Solar cycle modulation of the Southern Annular mode -Simulation with the MRI-chemistry-climate model-
AU: * Kuroda, Y
EM: kuroda@mri-jma.go.jp
AF: Meteorological Research Institute, 1-1, Nagamine, Tsukuba, 305-0052 Japan
AU: Shibata, K
EM: kshibata@mri-jma.go.jp
AF: Meteorological Research Institute, 1-1, Nagamine, Tsukuba, 305-0052 Japan
AB: Observation indicates that the 11-year solar cycle modulates the characteristics of the October/November mean Southern Annular Mode (SAM) [Kuroda and Kodera, 2005]. In fact, signal of the SAM tends to extend toward the upper stratosphere during late winter and the activity below lower stratosphere lasts until following summer in the high solar (HS) years. However accumulation and accuracy of observation is not good enough to examine the mechanism. To overcome this difficulty, we had examined this effect through simulation of the Meteorological-Research-Institute (MRI) chemistry climate model. 20-year integrations of the model was performed for an enhanced ultraviolet (UV) radiation corresponding to the HS years and moderate UV corresponding to the low solar (LS) years, respectively. Larger extension of the signal toward the upper stratosphere and longer duration of the signal was found in a HS experiment, whereas there was not in LS one. Analysis shows that the longer duration of signal in HS run was originated from lower stratospheric ozone which was transported from upper stratosphere through higher-extended wave driving toward the upper stratosphere. These results were almost consistent with that observed.
DE: 1620 Climate dynamics (0429, 3309)
DE: 3309 Climatology (1616, 1620, 3305, 4215, 8408)
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3362 Stratosphere/troposphere interactions
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005