Dust signatures observed in atmospheric aerosols and related to radiative transfer algorithms

The Natural Sources of pollutants, such as Sahara desert dust outbreaks or ashes from vulcanoes, in many cases, could grow the bad air quality forecast and PM limits values measured could exeed the European Law recomendations, in that case the country have to pay to the Community if an evidence of that is a Natural Pollutant is not brought to the European Court. The goal to control air quality could be reached studying the pollution sources, the dispersion with atmospheric model, the chemical reactions occurring and also the study of air depositions. Exeedences of air quality limit value represent breaches of Community law which can have significant legal consequences for the European Member States. For some existing limit values, such as those in the directive 1999/30/EC (first daughter Directive), an exeedence which is caused by particular natural sources can be ignored for the purpose of ensuring compliance with Community law; article 2.15 of the first daughter directive defines “natural events” as volcanic eruptions, seismic activities, geothermal activities, wild-land fires, high wind events or the atmospheric resuspension or transport of natural particles from dry regions. The next air quality directive will likely extend this principle to natural (i.e. Non anthropogenic) sources of pollution generally so long as the “natural contribution” can be quantified and documented. Particle Matters (PM) emissions sources are sea-spray, soil moved by wind, biogenic aerosols, volcanic emissions, forest fires, and anthropogenic sources. The EU legislation give limits for mobile emission, there are many like the Euro X limitation for private cars (gasoline and diesel). To control the road transport emissions there is a common trend of modification of the engines technology, the reduction of traffic in big city centre, the use of Pb and S free fuel, the promotion of the use of renewable energy and the use of alternative fuel. A cure strategy is post combustion treatment. The aim of this PhD work is to present a new way to approach radiative tranfer on air when dust episodes occurs, and to start a study/work group able to inform, with quality and quantity data, on natural sources of air pollution, capable to discuss with other governative and regional organizations such as ARPAS (with monitoring in site stations or mobile devices), and POLARIS 's entrerprises, which main topic is dealing with Environmental Science and Air quality. It is globally achieved that dust is part of natural aerosols quantity in air, with dimension from 1 to 10 microns, and could affect both human health, for breath disease, and local climate system, or global as well. Dust could reach Mediterranean and South European countries because of the local meteorology, the source points are often in the Sahara desert. Using Satellites Spectroradiometry we could detect and visualise dust over land and oceans. We used three Modis combination bands into the multispectral data analysis toolkit HYDRA (HYperspectral data viewer for Development if Research Application): a simple algorithm is showed with the help of HYDRA software, that help scientists to see dust easly without any other processed data. A case study is showed over the South West Mediterranean Area, near Tunisia and Lybia, but could be used for any other case and area of the world.