Accueil > Actualités > Séminaires > Séminaire de Georgiy Stenchikov au LMD

Séminaire

Titre : Qantifying the impact of arabian dust storms
Nom du conférencier : Georgiy Stenchikov
Son affiliation : King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
Laboratoire organisateur : LMD
Date et heure : 16-10-2014 14h00
Lieu : Ecole Polytechnique, Palaiseau - LMD - salle de réunion du PMC au 2e étage
Résumé :

The Arabian Peninsula is one of the major sources of atmospheric dust. Frequent dust outbreaks and some 15 to 20 dust storms per year have profound effects on all aspects of human activity, natural processes, and air-quality in this region. To monitor dust impacts we have employed CIMEL Robotic Sunphotometer and established NASA AERONET site at KAUST campus. This instrument provides aerosol optical depth in eight wavelengths and allows retrieving aerosol column average size distribution. To further enhance the aerosol observing capability we have installed a micropulse YAG lidar system to provide the vertical distribution of aerosols in the boundary layer. This system is a part of NASA MPLNET and is collocated with the AERONET site at KAUST. To quantify the effect of severe dust events on radiation fluxes and regional climate characteristics, we simulated the storm that occurred on 18-20 March 2012 using a regional weather research forecast model fully coupled with the chemistry/aerosol module (WRF-Chem). This storm swept over a remarkably large area affecting the entire Middle East, North-Eastern Africa, Afghanistan and Pakistan. To estimate the dust radiative effects we have used a standalone column radiation transport model coupled with the Mie code. The calculations have been conducted for a wide range of optical depths. Comprehensive ground-based observations and satellite retrievals were used to estimate aerosol optical properties, validate calculations and carry out radiation closure.

Contact :

seminaires@lmd.polytechnique.fr