HR: 14:25h
AN: A53F-04    [Abstracts]
TI: Tracer Transport by Deep Convection: Implications of the Connection Between Convective Mass Fluxes and Large-Scale Circulations
AU: * Lawrence, M G
EM: lawrence@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Department of Atmospheric Chemistry, Postfach 3060, Mainz, 55020, Germany
AU: Salzmann, M
EM: salzmann@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Department of Atmospheric Chemistry, Postfach 3060, Mainz, 55020, Germany
AU: Tost, H
EM: tost@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Department of Atmospheric Chemistry, Postfach 3060, Mainz, 55020, Germany
AU: Joeckel, P
EM: joeckel@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Department of Atmospheric Chemistry, Postfach 3060, Mainz, 55020, Germany
AU: Lelieveld, J
EM: lelieveld@mpch-mainz.mpg.de
AF: Max Planck Institute for Chemistry, Department of Atmospheric Chemistry, Postfach 3060, Mainz, 55020, Germany
AB: Global chemistry-transport models (CTMs) generally simulate vertical tracer transport by deep convection separately from the advective transport due to large-scale mean winds, even though a component of the large-scale transport, for instance in the Hadley and Walker cells, occurs in deep convective updrafts. This split treatment of vertical transport can have several significant implications for CTM simulations, such as numerical diffusion, misinterpretation of the transport characteristics in convectively active regions, and underestimation of the effects of convective tracer transport on ozone and other gases. Here we show that there is a significant overlap between the convective and large-scale advective vertical transport fluxes in the CTM MATCH, and discuss the main implications for tracer transport studies which can be expected due to this. We also give an outlook to the next step of this study, in which we are examining the connection between diagnosed convective mass fluxes and the vertical fluxes in the tropical Hadley and Walker Cells using the ECHAM5/MESSy GCM, which is set up with a flexible framework allowing the use of several different convection parameterizations. From the direct comparison of multiple deep convection parameterizations within the same model we expect to gain a better sense of the relationship between parameterized deep convection and large-scale circulations, as well as of the present uncertainty due to differences in convection parameterizations. This work is anticipated to contribute to the objectives of Activity 2 (vertical tracer distributions) of AC&C.
DE: 0320 Cloud physics and chemistry
DE: 0368 Troposphere: constituent transport and chemistry
DE: 3314 Convective processes
DE: 3319 General circulation (1223)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting