Skip to Main Content
Time dependence of the pH of rainAuthor(s): John A. Kadlecek; Volkar A. Mohnen
Source: In: Dochinger, L. S.; Seliga, T. A., eds. Proceedings of the first international symposium on acid precipitation and the forest ecosystem; Gen. Tech. Rep. NE-23. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. p.207
Publication Series: General Technical Report (GTR)
Station: Northeastern Research Station
PDF: Download Publication (39.46 KB)
DescriptionStandard procedures for determining the pH of rain samples usually involve substantial delays from the time of rainfall to the time of analysis. This assumes that no change in pH occurs during the storage period. We have found that this is not always true. We have determined that individual rain water samples possess a time dependent pH which can be correlated with the surface wind trajectories terminating at our sampling location (Schenectady, New York). Our preliminary investigations have identified four characteristic time dependent behaviors: 1) if the trajectories generally proceeded from the west along the Mohawk Valley the pH gradually increased by about 1/3 in 2 to 4 days; 2) if the trajectories were from the south up the Hudson Valley the pH remained constant; 3) if they came from the east across southern Massachusetts the pH gradually increased by about 1/6; and 4) if they came from the north and west across the southern Adirondack Mountains the pH increased by about 1/5 in a few hours. After these changes occurred, the pH remained constant. No correlations occurred between pH and either surface winds at the time of precipitation or the 500 mb trajectories. This data suggests that for rain water, a time dependent behavior, the [H+] is understated by as much as an order of magnitude.
- Check the Northern Research Station web site to request a printed copy of this publication.
- Our on-line publications are scanned and captured using Adobe Acrobat.
- During the capture process some typographical errors may occur.
- Please contact Sharon Hobrla, email@example.com if you notice any errors which make this publication unusable.
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationKadlecek, John A.; Mohnen, Volkar A. 1976. Time dependence of the pH of rain. In: Dochinger, L. S.; Seliga, T. A., eds. Proceedings of the first international symposium on acid precipitation and the forest ecosystem; Gen. Tech. Rep. NE-23. Upper Darby, PA: U.S. Department of Agriculture, Forest Service, Northeastern Forest Experiment Station. p.207
- Effect of sulphur dioxide on precipitation and on the sulphur content and acidity of soils in Alberta, Canada
- Effects of simulated rain acidified with sulfuric acid on host-parasite interactions
- Kinetics on cocondensation between phenol and urea through formaldehyde I.
XML: View XML