Cloudwater and Precipitation Chemistry at Popocatepetl Volcano: A High Elevation Site

• Published in: Journal of environmental quality 1997-01, Vol.26 (1), p.253-258
• Main Authors: Baez, A. P., Belmont, R.D., Azpra, E., Torres, M. B., Padilla, H. G.
• Format: Article
• Language: English
• Subjects: Crystalline rocks; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Geochemistry; Igneous and metamorphic rocks petrology, volcanic processes, magmas; Mineralogy; Pollution, environment geology; Silicates; Volcanoes; Water geochemistry
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq1997.00472425002600010035x

Cloud and rain water were collected at Tlamacas (3900 m above sea level), a site on the northern flanks of Popocatepetl volcano, 70 km southeast of Mexico City. Ten cloud events were sampled in September 1992 (five from 9–11 September, five from 29–30 September), eight from 19–21 July (1994) and three from 25–26 July (1995). During 9 to 11 September, cloud production was orographic, while during 29 to 30 September cloud production was associated with a cold front. On 19 to 21 July 1994 and 25 to 26 July 1995, cloud production was orographic. The results showed that cloudwater had a higher ionic concentration than rainwater, with two exceptions, in agreement with previous studies. The ionic concentrations in cloud and rain water seem to indicate a clear dependency on air mass origin and trajectories. Clouds in which back trajectories show passage over zones with little or no pollution produced cloudwater with low ionic concentrations (29 and 30 September). On 10 Sept. 1992, the winds had a strong easterly component, eliminating significant contamination from crater fumaroles. This meteorological situation yielded extremely clean rainwater.