Weak pressure gradient over the Iberian Península and African dust outbreaks: a new dust long transport scenario

Abstract

African dust outbreaks over the Iberian Peninsula have been related to four synoptic patterns responsible for the advection of dust: 1. A North African high located at surface level. 2. An Atlantic depression centered over northwestern Africa, western Iberia or the southwest of the Portuguese coast with an associated high or ridge over the Mediterranean Sea. 3. A North African depression. 4. A North African high located at upper levels. Consequently, particulate matter (PM) levels in Iberia are expected to rise when any of these atmospheric synoptic scenarios prevail. Nevertheless, PM levels might not increase due to wet deposition, as Spain receives the most African-derived dust rain events of any European country. In this study, a meteorological scenario different than the above situations is evaluated.