A comprehensive study on the chemical composition of precipitation, the influence
of peat fires and their relations with atmospheric circulation was conducted in the
year of 2012, in two intra-mountain basins, the Ciuc basin (CB) and the Giurgeu basin
(GB), Eastern Carpathians, Romania. Atmospheric circulation types showed the presence
of a westerly anticyclonic circulation, characterized by a strong development of the
Azores High to the northern Atlantic, contributing to the appearance of peat-fires.
Using ROCADA daily gridded climatic datasets, the maximum and minimum daily temperatures
were extracted, showing deviation from 2 degrees C to 6 degrees C in the studied year
against the multiannual mean for the 1981-2016 period. Rainwater samples were analyzed
for pH, major anions and cations; HCO3- concentrations were calculated based on the
empirical relationship between pH and HCO3-. The results showed that 45.16% and 54.55%
of precipitation had pH > 7.0 at CB and GB, respectively. NH3, NH4+ and Ca2+ are the
main neutralizing agents. The significant correlation between SO42- and NH4+ (r =
0.711 - CB; r = 0.736 - GB) indicated neutralization by NH3 in the forms of (NH4)(2)SO4
and NH4HSO4. Positive regression coefficient between the sum of (H+ + [NH4+] + [Ca2+])
and the sum of ([nss - SO42-] + [NO3-]) (r = 0.855 CB; r = 0.796 - GB), showed that
acid neutralization was primarily brought by NH4+ and/or CaCO3. Using Na as an indicator
of marine origin, the proportions of sea salt and non-sea-salt were estimated fromelemental
ratios. According to correlation analysis and PCA, main acidic ions (SO42- and NO3-)
and NH4+ were mainly derived from anthropogenic activities (biomass burning, peat
fires, fertilization), while Ca2+ and Mg2+ originated from terrestrial sources. The
behavior of gaseous pollutants and smoke distribution resulted from peat fires were
deciphered using the HYSPLIT model in a case study. (c) 2018 Elsevier B.V. All rights
reserved.
