Sulfate annual variation

N. Bourgougnon, M. Lahaye, B. Quemener, J.-C. Chermann, M. Rimbert, M. Cormaci, G. Funari, and J.-M. Komprobst, Annual variation in composition and in vitro anti-HIV-1 activity of the sulfated glucuronogalactan from Schizymenia dubyi (Rhodophyta, Gigartinales), J. Appl. Phycol., 8 (1996) 155-161. 

It is well known that, after its absorption, NOz forms nitric acid and nitrous acid in water. There is some indication that nitrite produced in this way is oxidized by dissolved 03 (Penkett, 1972). If neutralizing agents (ammonia, calcium carbonate etc.) are present, some nitrate salt is finally formed. It follows from this discussion that both S02 and N02 are oxidized in cloud water by atmospheric ozone. If this speculation is true a correlation should be found between the concentration of sulfate and nitrate ions in precipitation waters. Such a correlation was found in precipitation samples by Gambell and Fisher (1964) among others. However, correlations between any two species in rainwater must be considered with caution because the level of all ions is affected in a similar way by the precipitation intensity or quantity (see Subsection 5.4.1). Nevertheless the identical annual variations of the two ions in precipitation water (see Subsection 5.4.5) suggests that the two species are formed by some similar processes. 

Annual variation of sulfate concentration in precipitation at Chicago-Airport (Lodge et al., 1968). (By courtesy of the National Center for Atmospheric Research)... 

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