To determine the role of past and possible future changes
in ozone in the climate system
Brief Description of the Research Project :
The project brings together observations, chemical
modelling, radiative transfer studies, and climate
modelling in a unified effort to understand the role of
in the climate system.
An analysis of the ozone anomalies and their evolution
will be produced and the analysis of ozone trends using
re-evaluated ground-based ozone-sonde and satellite data
will be updated. Using statistical models various quasi
periodic or aperiodic natural phenomena will be isolated
and filtered out.
Two 3-d chemical transport models will be used to study
the change in ozone in response to variations of ozone
precursors. The study includes present and pre-industrial
simulations as well as time-slice simulations for the
1960, 1970 and 1980 periods. The two models will be
intercompared and the time-slice simulations will be
compared to observations.
A number of numerical experiments intended to study the
sensitivity of stratospheric ozone to chemical and
dynamical processes will be performed with a low-resolution spectral circulation model and a chemical
transport model including a microphysics code for aerosol
formation and growth.
Radiative transfer codes will be used to compute the
radiative forcing due to both observed and modelled ozone
changes and the results will be intercompared. The models
include a standard Malkmus narrow band model and two
broad band models.
A simplified and a comprehensive general circulation
model will be used to calculate the climatic response to
the ozone changes and to test the concept of radiative
forcing as an indicator of climatic response. The
vertical sensitivity of radiative forcing and climate
response will be calculated. The ozone changes generated
by the chemical transport models will be imposed on the
simplified model and the climate response
A simplified chemistry package will be made using the
QSSA approach. An existing scheme including 51 species
will be used as a starting point. The goal is to reduce
the number to less than 20. The simplified chemical code
will be implemented in the
comprehensive general circulation model and tested.
Funding SchemeCSC - Cost-sharing contracts
RG6 2AU Reading / Silchester
67010 Coppito L'aquila