Stratospheric Chemistry Models
The JHU atmospheric sciences group is involved with several different
activities using multi-dimensional coupled chemical - physical models to
understand past changes and predict future changes in stratospheric composition
and global climate.
NASA GSFC Coupled Chemistry Climate Model
We are collaborating with scientists at NASA Goddard Space Flight Center (GSFC)
on a ``Chemistry-Climate Studies Using General Circulation Models"
project. This project involves the development and assessment of an integrated
chemistry-climate model (CCM), and the use of this CCM to investigate the
interactions between atmospheric composition and climate dynamics. The
specific scientific goals of this proposal are to quantify the impact of
dynamics on stratospheric ozone recovery, the role of stratospheric and
tropospheric ozone in climate change, and the overall influence of atmospheric
chemistry and aerosols on climate change.
For more detail see NASA GSFC
web page .
Early versions of the GSFC models have been used to examine several different
issues relevant to the above project. For example, a multi-decadal simulations
was used to examine the role of extratropical wave driving in Interannual variability of stratospheric trace
CCM Validation Activity (CCMVal)
CCM Validation Activity for SPARC (CCMVal) is an international project
aimed at process-oriented validation of coupled chemistry-climate models
The initial stages of this project have involved the identification of the key
chemical, dynamical, transport, and radiative processes in the
troposphere-stratosphere system, and development of observationally-based
diagnostics of these processes. These diagnostics are being applied to a
large number of CCMs from around the world to assess how well these processes
are simulated. The majority of these CCMs are performing simulations of the
past and future evolution of stratospheric ozone that are being used in the
WMO/UNEP 2006 Ozone Assessment.
For more information see the
CCMVal web site .
Stratospheric Age of Air
Correctly simulating the transport within the atmosphere is a critical for
accurate simulations of ozone and other trace gases. An important aspect of
the transport are the distributions of transit times ("age spectra"). A major
research focus in recent years has been to quantify these transport times from
measurements of trace gases and to use these observations to assess the
transport models. More details are here.