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Adriana Gioda Olga L. Mayol-Bracero Gabriel J. Reyes-Rodriguez Gilmarie Santos-Figueroa Jeffrey L. Collett Jr. 《Journal of Atmospheric Chemistry》2008,61(2):85-99
Chemical characterization was performed on cloud and rainwater samples collected as part of the Rain In Cumulus over the Ocean Experiment (RICO). This experiment took place at a mountaintop site (East Peak) in Puerto Rico from December 2004 to March 2007 in order
to determine water-soluble organic and nitrogen fractions in a marine background environment. For cloud water, similar average
concentrations of 1.0 (±0.3) mg/L were found for total organic carbon (TOC) and total nitrogen (TN) and an average concentration
of 0.8 (±0.2) mg/L was found for dissolved organic carbon (DOC). In rainwater, these concentrations were lower, ranging from
0.3 to 0.5 (±0.1) mg/L. Changes in the concentrations of these species were observed in periods under the influence of anthropogenic,
African dust, and volcanic ash air masses. In these periods the concentrations of TOC, DOC, and TN were 2 to 4 times higher
than in periods under the influence of trade winds. The insoluble organic material arriving during African dust events showed
total carbon (TC) concentrations on averaging 1.5 mg/L for cloud water. The TC was composed mainly of organic carbon with
polar compounds from low to high molecular weight (MW). The polar compounds with high MW were probably associated with pollution
(e.g., fossil fuel combustion) from other regions. Crustal species (Al and Fe) dominated particles associated with dust episodes,
confirming the soil origin. Our results suggested that a fraction (40–80%) of TOC and (<100%) of TN in Puerto Rican cloud/rainwater
could be originated from long-range transport of dust, ash and/or pollution. 相似文献
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