INVESTIGATION OF SAHARAN DUST TRANSPORT ON THE BASIS OF AEROLOGICAL MEASUREMENTS
R. TÓTH, L. NYITRAI
ABSTRACT. – Investigation of Saharan dust transport on the basis of aerological measurements. The Sahara Desert is the largest dust source on Earth. Its dust is frequently emitted into the Mediterranean atmosphere and transported by the winds sometimes as far north as Central Europe. The accumulated particles contribute to soil forming processes, while the atmospheric mineral dust has an impact on the radiation budget, cloud forming processes, the pH of precipitation and biogeochemical cycles of marine ecosystems. The PM (particulate matter) in ambient air does not contain only primary particles but secondary particles formed in the atmosphere from precursor gases as well. Especially these latter ones have significant negative impacts to human health.
There are in average four-five Saharan dust episodes annually in Hungary, sometimes in form of colour precipitation (brown rainfall, red snow). There are several possibilities for providing evidence for the Saharan origin of the dust observed in our country: back-trajectories using NOAA HYSPLIT model, TOMS satellite maps of NASA, maps of aerosol index of Ozone Monitoring Instrument, observations of spectral aerosol optical depth of Aerosol Robotic Network, satellite maps of EUMETSAT, elemental analysis of dust samples.
In this study we try to reveal the suitability of the upper-air wind fields in detection of Saharan dust episodes in Central Europe. We deployed the global upper-air data base of the last 41 years that is available by courtesy of College of Engineering and Applied Sciences at University of Wyoming. We apply this method also for tracking air pollution of vegetation fires.
Keywords: upper-air, aerological measurement, Saharan dust transport, back-trajectories.