Cyrille Flamant

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The Paris area is strongly urbanized and is exposed to atmospheric pollution events. To understand the chemical and physical processes that are taking place in this area it is necessary to describe correctly the atmospheric boundary-layer (ABL) dynamics and the ABL height evolution. During the winter of 1994-1995, within the framework of the Etude de la(More)
We have developed a new airborne UV lidar for the forest canopy and deployed it in the Landes forest (France). It is the first one that: (i) operates at 355 nm for emitting energetic pulses of 16 mJ at 20 Hz while fulfilling eye-safety regulations and (ii) is flown onboard an ultra-light airplane for enhanced flight flexibility. Laser footprints at ground(More)
[1] The Bodélé Depression, Chad is the planet's largest single source of dust. Deflation from the Bodélé could be seen as a simple coincidence of two key prerequisites: strong surface winds and a large source of suitable sediment. But here we hypothesise that long term links between topography, winds, deflation and dust ensure the maintenance of the dust(More)
An overview of advances in the observation, modelling, forecasting, and understanding of flows through gaps achieved in the Mesoscale Alpine Programme is given. Gaps are lateral constrictions of topography (level gaps) often combined with vertical terrain changes (passes). Of the possible flow configurations, only an asymmetric one (relatively deep and slow(More)
A large body of work has shown that year-to-year variations in North African dust emission are inversely proportional to previous-year monsoon rainfall in the Sahel, implying that African dust emission is highly sensitive to vegetation changes in this narrow transitional zone. However, such a theory is not supported by field observations or modeling(More)
African dust emission and transport exhibits variability on diurnal to decadal timescales and is known to influence processes such as Amazon productivity, Atlantic climate modes, regional atmospheric composition and radiative balance and precipitation in the Sahel. To elucidate the role of African dust in the climate system, it is necessary to understand(More)
Origin: Cold downdrafts from moist convection. Typical meteorological conditions associated with dusty gust fronts: Wind speed: 5-15 m s-1 Visibility conditions: 0-1 km. Surface temperature drop: 0-20°C Surface pressure increase: ~ 9 hPa. Typical meteorological conditions associated with dusty gust fronts: Wind speed: 5-15 m s-1 Visibility conditions: 0-1(More)
Three-dimensional nested tracer simulations of a pollution plume originating from the Indian sub-continent over the Indian Ocean in the framework of the Indian Ocean Experiment (INDOEX) between 5 and 9 March 1999 were performed with the Regional Atmospheric Modeling System (RAMS) to provide insight into the transport patterns of 5 the pollutants as well as(More)
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