No abstract

No abstract

No abstract

No abstract

Abstract. A rainwater chemistry study was carried out at a single site in Xalapa located at the eastern flanks of the Sierra Madre Oriental, Veracruz, Mexico, during the rainy and dry seasons under the influence of different meteorological conditions. Rain samples were analyzed for the most important ions. The statistical results indicated that there were significant differences at the 95% confidence level between the ionic concentration measured in samples collected in both seasons. The lower concentration values found during the rainy season could be attributed to dilution processes since in this season 79% of the annual precipitation occurs, compared to only 21% in the dry season. High and positive ion-pair correlations were found among the most important ions in both seasons. Although Xalapa is situated at less than 100 km from the coast, marine contribution of SO42-and Ca 2+ is negligible compared with the nonmarine contribution. In the rainy season, enrichment of SO42-, NH•-, and NO•-is due to upwind medium-and long-distance emission sources of Veracruz, as back trajectories of the predominant winds from the southeast indicate. On the other hand, in the dry season this enrichment is due to emission sources situated in Tampico, Madero, and Poza Rica and south-southeastern Texas, as indicated by the predominant winds from the northeast. Finally, wet deposition rates were, as expected, higher during the rainy season in spite of the dilution processes. [1978] reported that slow moving active frontal systems and anticyclones, characterized by the convergence of moist air and by light winds that prevail for several days, respectively, favor the occurrence of episodes of sulfate wet deposition. Singh and Noberr [1982] showed that precipitation acidity was inherently related to air masses in Quebec, Canada. Colin et al. [1989] reported that two main mechanisms are responsible for the enrichment of rain: the dissolution of gases and the impacting of particles that occur in the air column below the cloud base, when raindrops fall (a local phenomenon), and the incorporation of gases and aerosols to the 23,329

No abstract

No abstract

No abstract