John, Thomas and Chopra, P. and Garg, S. C. (2009) Effect of photoelectric emission on blunt probe conductivity measurements in the stratosphere. Journal of Atmospheric and Solar-Terrestrial Physics , 71 (8-9). pp. 905-910. ISSN 1364-6826

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Abstract

Two identical planar blunt probes of stainless steel material, biased with a bipolar ramp voltage, are used to measure the stratospheric polar conductivities to altitudes of 34 km. One probe (DP) is mounted closer to the gondola, looking downwards and shielded from sunlight, while the other (SP) is mounted looking sideways, away from the gondola. The daytime observations of positive ions in the 29–34 km altitude range with SP, and of negative ions at 34 km with DP, show photoelectric contaminations induced by solar UV radiations in the 190–230 nm band. These contaminations are found to be due to photoemissions from the SP probe steel surface and from the carbon paint that coats the surface of the gondola, respectively. It is found that, a segment of the photocurrent contaminated I–V curve, recorded with SP at higher negative probe potentials, is linear, and it can give the ambient positive polar conductivity.

Item Type:	Article
Additional Information:	Copyright for this article belongs to M/s Elsevier B.V.
Uncontrolled Keywords:	Stratospheric polar conductivity; Photoelectric contamination; Blunt probe; Solar UV radiations
Subjects:	Geochemistry/ Geophysics Meteorology & Atmospheric Sciences
Divisions:	UNSPECIFIED
Depositing User:	Ms Neetu Chandra
Date Deposited:	24 Aug 2012 06:56
Last Modified:	24 Aug 2012 06:56
URI:	http://npl.csircentral.net/id/eprint/470

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