Skip to main content
Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1973 Feb;70(2):357–360. doi: 10.1073/pnas.70.2.357

Downwind and Upwind Effects in the Arizona Cloud-Seeding Experiment

Jerzy Neyman 1, Elizabeth L Scott 1, Marcella A Wells 1
PMCID: PMC433258  PMID: 16592056

Abstract

The principal subject of this report is a comparison of precipitation on days with seeding with that without seeding, averaged over those rain gauges that on each particular day were “downwind,” “upwind,” or to the sides. Two estimates of relevant wind directions are used, based on successive radiosondes at Tucson that bracketed the scheduled time of seeding. By use of these radiosondes, the apparent effects of seeding on rain in downwind localities 90-180 miles (145-290 km) away from target were found to be an apparent 45% loss of rain (P = 0.002) and an apparent 34% loss of rain (P = 0.028), respectively. Other results indicate considerable geographic heterogeneity.

Keywords: moving grid method, randomization

Full text

PDF
357

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Lovasich J. L., Neyman J., Scott E. L., Wells M. A. Further studies of the whitetop cloud-seeding experiment. Proc Natl Acad Sci U S A. 1971 Jan;68(1):147–151. doi: 10.1073/pnas.68.1.147. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Neyman J., Osborn H. B. Evidence of widespread effects of cloud seeding at two Arizona experiments. Proc Natl Acad Sci U S A. 1971 Mar;68(3):649–652. doi: 10.1073/pnas.68.3.649. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Neyman J., Osborn H. B., Scott E. L., Wells M. A. Re-evaluation of the Arizona cloud-seeding experiment. Proc Natl Acad Sci U S A. 1972 Jun;69(6):1348–1352. doi: 10.1073/pnas.69.6.1348. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Proceedings of the National Academy of Sciences of the United States of America are provided here courtesy of National Academy of Sciences

RESOURCES