ISSN:
1573-2932
Keywords:
ionic fluxes
;
acidic deposition
;
Saharan influence
;
particulate fluxes
;
scavenging ratio
Source:
Springer Online Journal Archives 1860-2000
Topics:
Energy, Environment Protection, Nuclear Power Engineering
Notes:
Abstract The ionic composition of 55 aerosol samples and 31 precipitation events collected in a coastal site in southern Sardinia (Capo Carbonara, 39°06′ N; 09°31′ E) were compared. The samples were collected during one year period (Oct'90/Oct'91) and showed high variability in composition according to meteorological conditions. Rain and soluble part of aerosol showed a strikingly similar ionic composition: most significant anions were chlorine and sulphate, and sodium is the principal cations, followed by magnesium and calcium. The acid events are associated with N-NW trajectories (anthropogenic influxes from N. Europe) with avg. pH=4.65, non sea salt (nss) Ca=60 μeq/l and NO3/nssSO4=0.6. Southern precipitations are influenced by Saharan dust alkaline effects, with avg. pH=6.75,nssCa=271 μeq/l and NO3/nssSO4=0.4. Na/Cl ratio in rain is similar to sea water (0.87), whilst in aerosols there is a Cl loss (Na/Cl=1.10), probably due to reaction with nitric acid. Total fluxes of Ca, Mg, NO3 and SO4 were 104, 9, 64 and 113 μg/cm2, and wet deposition exceeded (65–90%) dry deposition. Scavenging ratios (SR) as defined by the equation:SR=[(Ci)rain/(Ci)air] *d, (d=1200g/m3) were calculated, using geometric means (Ci) of precipitation and aerosols collected concurrently during the period (a total of 23 samples). The SR values are Ca=3400, Cl=2400, Na, K, SO4=1700, Mg=1000 and NO3=750. These numbers could be useful to infer total fluxes by using simply rainwater ionic composition in Mediterranean semi-arid sites like Sardinia.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01186140
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