Carmen Galán and Herminia García Mozo, scientists at the University of Córdoba Department of Botany, Ecology and Plant Physiology, have been examining the effect of air masses from the Sahara on pollen transport in the south of the Iberian Peninsula, as part of a research project carried out jointly with María del Mar Trigo of the University of Málaga and Miguel Ángel Hernández Ceballos of the European Commission’s JointResearch Centre.
The high-altitude intrusion of African air masses is among the phenomena shaping wind dynamics in the Western Mediterranean during the spring, and especially between May and early July, coinciding with the olive flowering season, and plays a key role in olive-pollen transport and therefore in the incidence of pollen allergies.
However, the effect of this intrusion varies between geographical areas:pollen grains detected in Málaga have mostly been transported over long distances, from crops located to the north-east, in provinces such as Granada; by contrast, olive pollen recorded in Córdoba tends to come from more local sources, coinciding with olive flowering in central Andalusia, i.e. in the provinces of Jaén and Córdoba.
These research findings also highlight the major role of sea-land breezes in Málaga city, and the importance of the location of the Córdoba spore-trap in the Guadalquivir river plain.
This joint research involved the combined analysis of airborne pollen counts,air masses at 3,000 metres above ground level which include African intrusions, and surface wind dynamics (at 300 metres above ground),which are shaped by the behaviour of air masses at higher levels.
The study, carried out in Málaga and Córdoba between 2010 and 2015,revealed that African air masses, on reaching the Iberian Peninsula,are affected by a series of oscillations and turbulences which favour the transport of pollen from distant locations. Though not representative of the pollen counts detected in Andalusia,the pollen levels associated with African air masses remain high rather than subsequently declining, as might be expected.
These data will enable more accurate forecasting both of olive harvests and of allergy incidence both by place and by season.
The study is part of broader research into innovations in olive-growing, backed by the University of Córdoba and the Spanish Olive Oil Interprofessional Association.
Wind dynamics' influence on south Spain airborne olive-pollen during African intrusions. García-Mozo, H; Hernández-Ceballos, MA; Trigo, MM; Galán, C. SCIENCE OF THE TOTAL ENVIRONMENT Volume 609, 31 December 2017, Pages 1340-1348 DOI: 10.1016/j.scitotenv.2017.08.005