Objective
This proposal aims at improving our understanding of the evolution of ozone in the stratosphere, by preparing for the use of data from a new satellite instrument which will measure ozone with unprecedented long-term accuracy and vertical resolution. GOMOS will be launched on ESA's ENVISAT in 1999. GOMOS observes stellar occultations, and determines ozone, NO2 NO3 OC10 and aerosol from the ratio of two spectra, one outside the atmosphere, one through the atmosphere. This self-calibration is the basis for its excellent long-term accuracy, like the NASA instrument SAGE. Unlike SAGE, which observed a part of the Sun, so that the exact altitude of the tangent ray was uncertain, GOMOS will observe point sources whose location is precisely determined.
This preparation will be achieved by developing a system which couples the GOMOS data processing prototype to an evolutive 3D photochemical model. The coupling will be in both directions, so that the model will be used to create simulated GOMOS instrument data, which will then be assimilated in the model to produce three-dimensional time series of the distribution of ozone and other trace gases.
Model assimilation is particularly important for GOMOS because the field of stars is irregularly positioned in the sky, so that the sampling is not regular and depends on season as well as the choice of stars. It is important to ask the question: is the GOMOS sampling such that we can construct global averages of ozone for trend determination ? If not, can we quantify the bias a priory ? Finally, we wish to compare model output with and without assimilated data from NO2, NO3 and aerosol - This is the true test of model accuracy, and although it cannot be done until after launch all the preparations can be made by testing assimilation schemes in advance.
Some important software is already developed by a subset of the current proposers: the GOMOS System Simulator, which produces simulated GOMOS instrumental data with the exact orbit and star field; and the GOMOS Processing Prototype, which analyzes the GOMOS data and inverts them to produce vertical profiles.
Here we propose to develop, test, validate and exploit additional software: - modify the simulator to perform simulated measurements inside a 3-D field (the present version handles only spherically syrnmetric distributions);
- couple the retrieved output to a 3-D model (assimilation);
- provide tools to visualise 3-D fields and routines for averaging species by altitude and area;
- develop algorithms of aerosol size distribution and global climatology.
The final objective of the proposal is to enable us to produce reliable global latitudinallongitudinal-altitude maps of ozone using data similar to those of GOMOS, and to assess their accuracy for determination of trends. The proposal has been prepared for Theme 3, Area 3.1.2 of the Environment and Climate Prograrnme of the European Commission.
Fields of science (EuroSciVoc)
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
CORDIS classifies projects with EuroSciVoc, a multilingual taxonomy of fields of science, through a semi-automatic process based on NLP techniques.
- natural sciencescomputer and information sciencessoftware
- engineering and technologymechanical engineeringvehicle engineeringaerospace engineeringsatellite technology
- natural sciencesearth and related environmental sciencesenvironmental sciencesozone depletion
- natural sciencesearth and related environmental sciencesatmospheric sciencesclimatology
- natural sciencescomputer and information sciencesdata sciencedata processing
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Topic(s)
Call for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
06904 SOPHIA ANTIPOLIS
France