Environmental Engineering Reference
In-Depth Information
5.6 Impact of Saharan Dust on Precipitation Chemistry
in Croatia
Kornelija Špoler Čanić
1
, Iva Kavčič
2
, and Zvjezdana Bencetić Klaić
2
1
Meteorological and Hydrological Service, Zagreb, Croatia
2
Department of Geophysics, Faculty of Science, University of Zagreb, Zagreb, Croatia
Abstract
The aim of this research was to examine Saharan dust transport over the
Mediterranean towards Croatia. We analyzed several episodes of mud rain during
the period 2001-2005 on two mountainous, background sites. The mud rains
related to Saharan dust outbreaks were identified using Earth Probe/Total Ozone
Mapping Spectrometer (TOMS) aerosol index (AI) data and backwards trajectories.
The mud rains were characterized by higher calcium concentrations and pH values.
In addition, we investigated the contribution of mud rains to the annual total
calcium deposition.
Keywords
Aerosol index, TOMS, trajectories, calcium, pH
1. Introduction
The Sahara is the world's largest source of aeolian desert dust (Middleton and
Goudie, 2001). The dust can be entrained over large areas in dust storms, transported
over thousands of kilometers and then deposited downwind. Saharan dust has a
major influence on soil characteristics, oceanic productivity and air chemistry. Thus,
Saharan dust is the subject of considerable scientific interest (e.g. Goudie, 2009).
Saharan dust can be removed from the atmosphere by dry or wet deposition.
The latter is also known as the mud rain, and such events we examined in this
work. Mud rains are frequent over southern Europe and they have been reported
since ancient times. However, few investigations have dealt with this phenomenon
in Croatia. The most comprehensive one is the work of Lisac (1973), where
meteorological, chemical and mineralogical aspects of one mud rain event were
analyzed.
In this work we tried to determine the frequency of mud rains over Croatia
during the period 2001-2005 and their influence on precipitation chemistry. In
order to detect mud rain events we used AI, backwards trajectories and precipitation
chemistry analysis.
