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Results of sun photometer-derived precipitable water content over a tropical Indian station

Raj, PE and Devara, PCS and Maheskumar, RS and Pandithurai, G and Dani, KK and Saha, SK and Sonbawne, SM and Tiwari, YK (2004) Results of sun photometer-derived precipitable water content over a tropical Indian station. Journal of Applied Meteorology, 43 (10). pp. 1452-1459.

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Abstract

A compact, hand-held multiband sun photometer (ozone monitor) has been used to measure total precipitable water content (PWC) at the low-latitude tropical station in Pune, India (18°32′N, 73°51′E). Data collected in the daytime (0730–1800 LT) during the period from May 1998 to September 2001 have been used here. The daytime average PWC value at this station is 1.13 cm, and the average for only the clear-sky days is 0.75 cm. PWC values between 0.75 and 1.0 cm have the maximum frequency of occurrence. There is a large day-to-day variability due to varied sky and meteorological conditions. Mainly two types of diurnal variations in PWC are observed. The one occurs in the premonsoon summer months of April and May and shows that forenoon values are smaller than afternoon values. The other type occurs in November and December and shows a minimum around noontime. There is a diurnal asymmetry in PWC in which, on the majority of the days, the mean afternoon value is greater than the forenoon value. This asymmetry is more pronounced in the summer and southwest monsoon months (i.e., March–June). Monthly mean PWC is highest in September and lowest in December. The increase in PWC from the winter (December–February) to summer (March–May) seasons is about 50% and from the summer to southwest monsoon seasons (June–September) is almost 98%. Sun photometer–derived PWC shows a fairly good relationship with surface relative humidity and radiosonde-derived PWC, with a correlation coefficient as high as 0.80

Item Type: Article
Additional Information: Copyright of this article belongs to American Meteorological Society
Uncontrolled Keywords: Atmospheric humidity; Correlation methods; Meteorology; Photometers; Precipitation (chemical), Correlation coefficients; Meteorological conditions; Precipitable water content (PWC), Water, diurnal variation; photometer; precipitation assessment; tropical environment; water content, Asia; Eastern Hemisphere; Eurasia; India; Maharashtra; Pune; South Asia; World
Subjects: Meteorology and Climatology
Depositing User: IITM Library
Date Deposited: 18 Apr 2015 08:58
Last Modified: 18 Apr 2015 08:58
URI: http://moeseprints.incois.gov.in/id/eprint/1435

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