The scientist word Since the beginning of last century emitted aerosols has increased dramatically, contributing in a large manner to the Climate change. Anthropogenic pollution sources have also a large impact on human health. In particular very fine particles, under PM2.5, provoke large health problems on the urban population and particularly to children, senior people, or people suffering from asthma or other heart or lung disease.

Some efforts have already been conducted in the main megacities in order to reduce their emissions (e.g. traffic regulations, shift from coal to natural gas for domestic uses ). Anyhow there is still a strong need for air quality forecasting improvement. This will be handled by a better description and understanding of the processes controlling the vertical distribution of aerosols.

The ALS and WLS lidar remote sensors from LEOSPHERE are offering the best solution to tackle these challenges by providing the dynamical structure of the atmosphere along any line of sight. As a result, the ALS can therefore retrieve automatically and continuously the height of the planetary boundary layer which is controlling the dilution of pollutants. But It can also detect any plume around up to several kms away, and track it. Individual sources of pollution will be then highlighted. Hence, adding some information about the type of aerosols emitted, the ALS will be able to get the information on the mass concentration.

The WLS provides the profile of wind speed and direction, turbulence and vertical winds, which are of key interest to forecast the formation, transformation and dissipation of pollutants.

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Transcontinental pollution

Aerosols may have a greater impact on patterns of overall rainfall and future climate change than previously thought. In example, the extensive pollution haze emanating from Asia may be re-shaping rainfall patterns in northern Australia. Recent climate modelling shows that there may be important effects on southern hemisphere climate due to aerosol pollution from the Northern Hemisphere. These include an increase of rainfall certain areas, and an increase of air pressure over others, which may have contributed to less rainfall there. The ALS can measure and detect different aerosol layers and through the backscattering trajectories it is possible to identify the original pollution source causing major climate changes.

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Regional and Urban Pollution

What's the contribution of the regional pollution to the concentrations of particulate matter recorded locally? Regional-to-local transfer of pollutants is indeed a growing concern expressed by air quality managers. Monitoring the vertical structure of the urban and regional atmosphere, while identifying the primary nature of aerosols (anthropogenic from mineral dust for example) brings an innovative contribution to the challenge that is supported by the ALS 300 and its ability to monitor continuously the evolution of the mixing layer above, as well as to discriminate the rough shape of the particles. 

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Indoor air quality Bigger strongly urbanized cities in the world are often exposed to atmospheric pollution events. Both the train and the subway are basic components of public transportation in order to limit the pollution and the greenhouse emission.  Hence, the limitation of aerosol pollution in public indoor areas is of crucial importance.  ALS performed measurements in underground station to test the potential interest of active remote sensing to follow the spatiotemporal evolution of aerosol content inside a confined microenvironment. Read More »

Industrial pollution Monitoring emissions of atmospheric pollutants now comes up as a pressing duty on industrial and public environnmental managers. The ALS feature, "Aerosol Plume Tracker", detects through horizontal scans the temporal evolution of emitted plumes. Some measurement tests were performed in the Champs Elysées (Paris), an area with an intense traffic. Short time horizontal and vertical scans put in evidence  variable dispersion patterns of car exhausts depending on traffic lights. Other two measurement campaigns took place in Dunkerque, France and in Port Headland, Australia. The first one detected the evolution of the plumes over a highly industrialized area. High frequency temporal scans show spatial evolution and intensity of the plumes. In the second one, the scans reconstructed the 3-D plumes evolution thanks to the fast speed velocity with a spatial resolution of 1.5 m. Read More »