Chemical composition of acid rains in the Venezuelan savannah
                        region

Sanhueza, Eugenio; Arias, Manuel; Donoso, Loreto; Graterol, Nelson; Hermoso, Mariela; Ferrer, Ivet; Romero, Johnny; Rondôn, Alberto; Santana, Magaly

doi:10.3402/tellusb.v44i1.15423

Cited by 38 publications

(15 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This is an unexpected result because in remote areas of the world the most typical result is a predominance of formic (F) over acetic (A) acid (Keene et al, 1983;Sanhueza et al, 1991Sanhueza et al, , 1992Chebbi and Carlier, 1996). The observed mean F:A ratio in this work was 0.23.…”

Section: Comparison Of Rainwater Chemistry In Centralmentioning

confidence: 41%

Aerosol and precipitation chemistry measurements in a remote site in Central Amazonia: the role of biogenic contribution

et al. 2012

View full text Add to dashboard Cite

Abstract. In this analysis a 3.5 years data set of aerosol and precipitation chemistry, obtained in a remote site in Central Amazonia (Balbina, (1 • 55 S, 59 • 29 W, 174 m a.s.l.), about 200 km north of Manaus) is discussed. Aerosols were sampled using stacked filter units (SFU), which separate fine (d < 2.5 µm) and coarse mode (2.5 µm < d < 10.0 µm) aerosol particles. Filters were analyzed for particulate mass (PM), Equivalent Black Carbon (BC E ) and elemental composition by Particle Induced X-Ray Emission (PIXE). Rainwater samples were collected using a wet-only sampler and samples were analyzed for pH and ionic composition, which was determined using ionic chromatography (IC). Natural sources dominated the aerosol mass during the wet season, when it was predominantly of natural biogenic origin mostly in the coarse mode, which comprised up to 81 % of PM 10 . Biogenic aerosol from both primary emissions and secondary organic aerosol dominates the fine mode in the wet season, with very low concentrations (average 2.2 µg m −3 ). Soil dust was responsible for a minor fraction of the aerosol mass (less than 17 %). Sudden increases in the concentration of elements as Al, Ti and Fe were also observed, both in fine and coarse mode (mostly during the April-may months), which we attribute to episodes of Saharan dust transport. During the dry periods, a significant contribution to the fine aerosols loading was observed, due to the large-scale transport of smoke from biomass burning in other portions of the Amazon basin. This contribution is associated with the enhancement of the concentration of S, K, Zn and BC E . Chlorine, which is commonly associated to sea salt and also to biomass burning emissions, presented higher concentration not only during the dry season but also for the April-June months, due to the establishment of more favorable meteorological conditions to the transport of Atlantic air masses to Central Amazonia. The chemical composition of rainwater was similar to those ones observed in other remote sites in tropical forests. The volume-weighted mean (VWM) pH was 4.90. The most important contribution to acidity was from weak organic acids. The organic acidity was predominantly associated with the presence of acetic acid instead of formic acid, which is more often observed in pristine tropical areas. Wet deposition rates for major species did not differ significantly between dry and wet season, except for NH + 4 , citrate and acetate, which had smaller deposition rates during dry season. While biomass burning emissions were clearly identified in the aerosol component, it did not present a clear signature in rainwater. The biogenic component and the long-range transport of sea salt were observed both in aerosols and rainwater composition. The results shown here indicate that in Central Amazonia it is still possible to observe quite pristine atmospheric conditions, relatively free of anthropogenic influences.

show abstract

Section: Comparison Of Rainwater Chemistry In Centralmentioning

confidence: 41%

Aerosol and precipitation chemistry measurements in a remote site in Central Amazonia: the role of biogenic contribution

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Both the ion balance and electric conductivity suggested the presence of unmeasured anions. In tropical savanna, organic acid anions derived from volatile organic carbons (VOCs) such as isoprene emitted by vegetation (Sanhueza et al, 1989) and biomass burning (Sanhueza et al, 1992) may contribute to ion balance of rainwater. The similar positive ion balance errors can be seen in the EANET sites in tropical countries, including Nakhon Ratchasima site near Sakaerat site (EANET, 2011).…”

Section: Quality Assurancementioning

confidence: 99%

Deposition Process of Sulfate and Elemental Carbon in Japanese and Thai Forests

Sase¹,

Matsuda²,

Visaratana³

et al. 2012

Asian J. Atmos. Environ

View full text Add to dashboard Cite

“…E-mail address: mzunckel@csir.co.za (M. Zunckel). Andrea et al, (1988Andrea et al, ( , 1990) have studied precipitation chemistry over the central Amazon region in Brazil and Sanhueza et al (1992) have conducted similar studies over the Savannah region of Venezuela. Little other work however has been done on rainwater quality in Uruguay or elsewhere in South America.…”

Section: Introductionmentioning

confidence: 99%

Rainwater composition in northeast Uruguay

Zunckel

Saizar

Zarauz

2003

Atmospheric Environment

View full text Add to dashboard Cite

The chemical composition of rainfall in northeast Uruguay in 1999 and 2000 and the sources that contribute to the rainwater chemistry are assessed in this study, contributing to a limited knowledge base of rainwater quality in South America. Principal factor analysis and cluster analysis indicate that four main source groups influence the rainfall chemistry over a range of spatial scales. Terrigenous sources (e.g. rock, soil and dust) and agricultural sources (e.g. livestock and crop fertilization) contribute to rainwater chemistry on a local and sub-regional scale. Influx of marine air from the Atlantic Ocean has a regional-scale influence while biomass burning contributes at both a local and subregional scale (e.g. fuel wood, and agroindustries) and through long-range transport (forest fires and land clearing). As may be expected in this area dominated by agriculture, the concentrations of ions that are indicative of industrial emissions, NO 3 À and SO 4 2À , are typical of background measurements. The current data are limited, but provide an indication of rain quality and the sources that influence its chemistry in Uruguay. It may be inferred that large-scale biomass burning in the central parts of the continent influence rainwater chemistry on a scale far larger than indicated by the Uruguayan network. Similarly, but to lesser extent, the influx of marine air off the Atlantic Ocean has a greater regional-scale influence than suggested by these data. r

show abstract

Chemical composition of acid rains in the Venezuelan savannah region

Cited by 38 publications

References 18 publications

Aerosol and precipitation chemistry measurements in a remote site in Central Amazonia: the role of biogenic contribution

Aerosol and precipitation chemistry measurements in a remote site in Central Amazonia: the role of biogenic contribution

Deposition Process of Sulfate and Elemental Carbon in Japanese and Thai Forests

Rainwater composition in northeast Uruguay

Contact Info

Product

Resources

About