Effects of humidity and precipitation on VHF radar vertical beam echoes
Article first published online: 7 DEC 2012
Copyright 2000 by the American Geophysical Union.
Volume 35, Issue 6, pages 1389–1398, November-December 2000
How to Cite
2000), Effects of humidity and precipitation on VHF radar vertical beam echoes, Radio Sci., 35(6), 1389–1398, doi:10.1029/1999RS002260., and (
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Accepted: 21 JUN 2000
- Manuscript Received: 28 SEP 1999
We investigate in this paper the variation in power of VHF radar vertical echoes as a function of atmospheric humidity. We find that the echoes are greatest in air of moderate (30–70%) humidity, and least in very dry or near-saturated air. Compared to moderate humidities, the standard model for radar echoes, based on potential refractivity, overpredicts the echo power at high relative humidity by ∼10 dB. We propose that this is due to the effect of precipitation in suppressing small-scale humidity gradients. A model which assumes complete suppression underpredicts the observed power drastically, showing that precipitation can only remove a part of the small-scale structure in refractivity which is caused by fluctuations in humidity.