Transportation of Saharan dust
Researcher: Yossi Barkan
Figure above shows the whole circular trajectory day after day marked by filled squares. The Azores High dominates the whole width of the Southern Atlantic between 20°N-40°N. It is clear that the dust cloud is driven by this synoptic system. Two Low centers to the north, one in Eastern Canada and the other around Iceland cause steep gradient and strong winds west and north of the AH. A well defined trough along the European coast turns the dust cloud southeastward toward Northern Africa.
An occurrence of transportation of Saharan dust from equatorial West African and back to Europe and Africa around the Atlantic Ocean was synoptically analyzed. The entire circle around the Atlantic took twelve days. The direction and speed of the dust cloud was governed by the position, the strength and the movement of the Center of Activity (COA) of the Azores High. This type of trajectory is quite rare. In the year 2009 (the year of the analyzed trajectory) it occurred only 8 times. We assume, that the interesting point in this type of trajectory is the possibility that in its long way, it collects from and deposits in, different types of aerosols at the American European and African continents and the Ocean between them.