A JET-STREAM ASSOCIATED HEAVY DUST STORM IN THE WESTERN MEDITERRANEAN

Examination of the dynamical structure of a heavy dust storm event ove r the western Mediterranean revealed an almost exact coincidence of th e western boundary of the dust plume with a cold front and a significa nt jet stream. A confrontation was found between the dry desert air ma ss associated with a notable downward flowing jet stream and the moist er Mediterranean air mass. Vertical cross sections across and along th e dust plume indicated that the high mountain Ahaggar region over the Sahara was probably the source of dust, which was transported northwar d more than 2400 km and washed out by heavy rainfall.