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Dust mobilization and transport in the northern Sahara during SAMUM 2006 – a meteorological overview |
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| Authors: | By PETER KNIPPERTZ ALBERT ANSMANN DIETRICH ALTHAUSEN DETLEF MÜLLER MATTHIAS TESCHE EIKE BIERWIRTH TILMAN DINTER THOMAS MÜLLER WOLFGANG VON HOYNINGEN-HUENE KERSTIN SCHEPANSKI MANFRED WENDISCH BERND HEINOLD KONRAD KANDLER REAS PETZOLD LOTHAR SCHÜTZ INA TEGEN |
| Institution: | Institute for Atmospheric Physics, Johannes Gutenberg University Mainz, D-55099 Mainz, Germany;Leibniz Institute for Tropospheric Research, Leipzig, Germany;Institute of Environmental Physics, University of Bremen, Bremen, Germany;Leibniz-Institute for Marine Sciences, IfM-Geomar, Kiel, Germany;Institute for Applied Geosciences, Darmstadt University of Technology, Darmstadt, Germany;Institute for Atmospheric Physics, German Aerospace Center, Oberpfaffenhofen, Germany |
| Abstract: | The SAMUM field campaign in southern Morocco in May/June 2006 provides valuable data to study the emission, and the horizontal and vertical transports of mineral dust in the Northern Sahara. Radiosonde and lidar observations show differential advection of air masses with different characteristics during stable nighttime conditions and up to 5-km deep vertical mixing in the strongly convective boundary layer during the day. Lagrangian and synoptic analyses of selected dust periods point to a topographic channel from western Tunisia to central Algeria as a dust source region. Significant emission events are related to cold surges from the Mediterranean in association with eastward passing upper-level waves and lee cyclogeneses south of the Atlas Mountains. Other relevant events are local emissions under a distinct cut-off low over northwestern Africa and gust fronts associated with dry thunderstorms over the Malian and Algerian Sahara. The latter are badly represented in analyses from the European Centre for Medium–Range Weather Forecasts and in a regional dust model, most likely due to problems with moist convective dynamics and a lack of observations in this region. This aspect needs further study. The meteorological source identification is consistent with estimates of optical and mineralogical properties of dust samples. |
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