GACP Projects
A Time-Dependent Study of Aerosol-Ozone Interactions with a Low-Resolution Climate-Chemistry Coupled Model
Giovanni Pitari, PI
Vincenzo Rizi, Co-I
Eva Mancini,Co-I
Abstract: It is proposed to use a low-resolution climate-chemistry coupled model for studying the complex chemical-radiative-dynamical interactions of aerosols and ozone. A time-dependent numerical experiment will be designed covering the past 20 years of satellite aerosols measurements and future years, for investigating the effects on the ozone recovery rate of potentially increasing sulfate aerosols in the troposphere and lower-stratosphere. Future changes of sulfate aerosols will be calculated as a result of expected trends in surface emissions of sulfur precursors, aircraft emissions of sulfur dioxide and carbon soot particles, temperature and circulation changes due to growing emissions of greenhouse gases (carbon dioxide in particular).
The time-dependent aerosol radiative forcing will be calculated taking also into account the related ozone changes, looking in particular at the effects on climate and on the lower stratospheric circulation during the years of large volcanic perturbations of the stratospheric sulfate aerosol layer (i.e. after El Chichon and Pinatubo eruptions). A comparison of model calculated total ozone with TOMS data will help understand the role of aerosol induced circulation changes after these large volcanic perturbations. The chemical code of this model includes a fully interactive microphysics for sulfate aerosols, PSCs, carbon soot, sea-salt and soil dust particles. The presence of a simple scheme for deep convection lifting makes the model representation of tropospheric aerosols more realistic, which is important in addressing the future aerosol forcing on climate.
Desirable input:
lat/lon dependent surface fluxes of sea-salt and soil
dust particles and their size distributions.
Output:
time-dependent distribution of sulfate aerosols on the global
domain up to 40 Km altitude. Calculated values in the lower
stratosphere and upper troposphere may contribute to the creation
of a global aerosol climatology.
