|
|
Microphysics, Radiation and Surface Processes
in the Goddard Cumulus Ensemble (GCE) Model
Wei-Kuo Tao
NASA Goddard Space Flight Center
One of the most promising methods to test the representation of cloud
processes used in climate models is to use observations together with
Cloud Resolving Models (CRMs). The CRMs use more sophisticated and
realistic representations of cloud microphysical processes, and they can
reasonably well resolve the time evolution, structure, and life cycles of
clouds and cloud systems (size about 2-200 km). The CRMs also allow
explicit interaction between out-going longwave (cooling) and in-coming
solar (heating) radiation with clouds. Observations can provide the
initial conditions and validation for CRM results.
The Goddard Cumulus Ensemble (GCE) Model, a CRM, has been developed and
improved at NASA/Goddard Space Flight Center over the past two decades.
The GCE model has been used to understand the following: 1) water and
energy cycles and their roles in the tropical climate system; 2) the
vertical redistribution of ozone and trace constituents by individual
clouds and well organized convective systems over various spatial scales;
3) the relationship between the vertical distribution of latent heating
(phase change of water) and the large-scale (pre-storm) environment; 4)
the validity of assumptions used in the representation of cloud processes
in climate and global circulation models; and 5) the representation of
cloud microphysical processes and their interaction with radiative
forcing over tropical and midlatitude regions. Four-dimensional cloud and
latent heating fields simulated from the GCE model have been provided to
the TRMM Science Data and Information System (TSDIS) to develop and
improve algorithms for retrieving rainfall and latent heating rates for
TRMM and the NASA Earth Observing System (EOS). More than 90 referreed
papers using the GCE model have been published in the last two decades.
Also, more than 10 national and international universities are currently
using the GCE model for research and teaching.
In this talk, five specific major GCE improvements: (1) ice microphysics,
(2) longwave and shortwave radiative transfer processes, (3) land surface
processes, (4) ocean surface fluxes and (5) ocean mixed layer processes
are presented. The performance of these new GCE improvements will be
presented. Observations are used for model validation.
|
|
