HR: 11:50h
AN: A32C-07    [Abstracts]
TI: Mechanisms for the Acceleration of the Brewer-Dobson Circulation in a Climate Change Scenario
AU: * Calvo, N
EM: calvo@ucar.edu, nataliac@fis.ucm.es
AF: Universidad Complutense de Madrid, Fac.CC.Fisicas Dpto.Fisica Tierra II Avda/Complutense sn, Madrid, 28916, Spain
AU: * Calvo, N
EM: calvo@ucar.edu, nataliac@fis.ucm.es
AF: National Center for Atmospheric Research, P.O.Box.3000, Boulder, CO 80305, United States
AU: Garcia, R R
EM: rgarcia@ucar.edu
AF: National Center for Atmospheric Research, P.O.Box.3000, Boulder, CO 80305, United States
AB: The evolution of the Berwer-Dobson circulation as a result of climate change has been analyzed using the NCAR's Whole Atmosphere Community Climate Model (WACCM3). Two experiments, one with fixed greenhouse gas concentrations from 2000 onwards and the other with concentrations that follow the A1B scenario have been compared for the period 2000-2050. In both experiments, the sea surface temperatures are specified from existing runs of NCAR's coupled atmosphere-ocean model that follow the same scenarios. The comparison shows that the Brewer-Dobson circulation in the tropical lower stratosphere strengthens when the greenhouse gases increase. This acceleration is due to changes in the Eliassen-Palm (EP) flux divergence in the subtropical lower stratosphere. In this work, we will show the waves responsible for the changes in the EP flux divergence and the mechanisms whereby these changes take place.
DE: 3305 Climate change and variability (1616, 1635, 3309, 4215, 4513)
DE: 3334 Middle atmosphere dynamics (0341, 0342)
DE: 3337 Global climate models (1626, 4928)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting