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Wed, November 18, 2009
Title: Applying CloudSat/A-Train and ECMWF analysis data sets to constrain and evaluate cloud, convection and radiation parameterizations in numerical models
Speaker: Frank Li, JPL
Location: GSFC, B-33/C-206, Greenbelt, MD
Time: 11am
Host: Andrea Molod
Abstract:Clouds and convection play an important role in climate and weather related issues over various spatial and
time scales. Despite the efforts have been made, representing clouds, convections and their radiative and precipitating
processes in numerical weather and regional/global climate models remains a challenge. To help resolve these issues, a
CloudSat-centric, multi-parameter A-Train (e.g., CloudSat, Calipso, AIRS, AMSR, MODIS, CERES) and high-resolution ECMWF
analyses (INTRIM and YOTC) data set is being developed to characterize dynamical, macro-/microphysical, precipitating and
radiative processes associated with clouds and convection to evaluate and constraint the key relevant model physical
parameters/processes in numerical models. In this presentation, results from the comparisons between cloud, convection,
and precipitation statistics derived from using the above data set will be presented. The errors in the estimated radiative
fluxes and heating associated with ignoring convective/precipitating ice (something commonly done in GCMs) relative to the
standard CloudSat radiation product as well as results from a stand alone Fu-Liou radiative transfer model will also be
discussed.
Tue, December 1, 2009
Title: Estimates of the Water Vapor Climate Feedback during El Nino-Southern Oscillation
Speaker: Andrew Dessler, Dept of Atmospheric Sciences Texas A&M University
Location: GSFC, B-33/H-114, Greenbelt, MD
Time: 3:00 p.m.
Host: Michele Rienecker
Abstract:The water vapor feedback is the strongest positive feedback operating in the climate system, with the power to about double the direct warming from long-lived greenhouse gases. In our analysis, we estimate the strength of the water vapor feedback by analyzing the changes in tropospheric specific humidity during El Nino-Southern Oscillation (ENSO) cycles in climate models and in the MERRA and ERA40 reanalyses. We find a wide range in predicted feedback strengths among the models and between the models and the reanalyses, although they all predict a water vapor feedback that is strong and positive. The models and the reanalyses show a consistent relationship between the variations in the tropical surface temperature over an ENSO cycle and the radiative response to the associated changes in specific humidity. However, the feedback is defined as the ratio of the radiative response to the change in the global average temperature. Differences in extratropical temperature variations will therefore lead to different inferred feedbacks, and this is the root cause of large spread in feedbacks among the models and between the models and the reanalyses.
Thu, December 10, 2009 · GMAO Seminar Series
Thu, January 7, 2010 · GMAO Seminar Series
Thu, February 11, 2010 · GMAO Seminar Series
Thu, March 25, 2010
Title: TBD
Speaker: Clara Draper, Meteo France
Location: GSFC, B-33/A-128, Greenbelt, MD
Time: 1:30pm
Host: Rolf Reichle
Thu, May 6, 2010 · GMAO Seminar Series
Thu, July 1, 2010 · GMAO Seminar Series
Title: TBD
Speaker: Frederic Vitart, ECMWF
Location: GSFC, B-33/H-114, Greenbelt, MD
Time: 1:30pm
Host: Hailan Wang
Other seminars within GSFC:
Seminars outside of GSFC:
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