Impact of different assimilated satellite geometries on tropospheric ozone simulations
Palmira Messina(1), Federico Fierli(1), Massimo D'Isidoro(1) and Alberto Maurizi(1)
(1) Italian National Research Council (CNR), Via Gobetti 101, Bologna, 40129, Italy
The aim of this work is to determine which is the more suitable satellite geometry for improving, through a data assimilation procedure, the models simulations of gaseous pollutants such as ozone, nitrogen dioxide, and carbon monoxide.
This study is carried out using both BOLCHEM and CHIMERE model. BOLCHEM (BOLam + CHEMistry) is based on the meteorological hydrostatic mesoscale model BOLAM (Bologna Limited Area Model) and the photochemical mechanism SAPRC90; the meteorology is coupled online (one way) with the chemistry. CHIMERE is a three-dimensional Eulerian chemistry-transport model; the gas fase chemical mechanism is MELCHIOR2 and the meteorological fields come from BOLAM.
The models include a sequential Optimal Interpolation (O.I.) routine for gaseous pollutants data assimilation.
We focus first on the assimilation of observed tropospheric columns from satellite observations of NO2 from SCIAMACHY, on-board ENVISAT ESA satellite, and OMI, on-board EOS Aura satellite, to evaluate the impact of data assimilation on the distribution of pollutants during two photochemical pollution events.
The second step is to use the Observing System Simulation Experiment (OSSE) to define a priori the geometry and the frequency of simulated observations to evaluate the impact of different geometries and coverages on the improvement due to the assimilation.
The work is part of the Pilot Project QUITSAT, funded by the Italian Space Agency (ASI), contract I/035/06/0 – http://www.quitsat.it.