The paper presents the nature of variation of refractive index of atmospheric medium before the onset of squall over kolkata (22 34′N 88 22′E), India. The variation of the refractive index with surface temperature and relative humidity during squall is also presented. It is concluded that sharp decrease of the refractivity may be taken as a possible method of forecasting squall. This kind of study is very much helpful from the standpoint of aviation hazards and communication. Possible explanation for the observed results is also presented. © 2013 Indian Association for the Cultivation of Science.

SUBRATA MIDYA

Atmospheric Science

D GHOSH

G K DAS

H SARKAR

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

Indian Journal of Physics

The paper presents the nature of annual cycles of tropospheric ozone, cloud occurrences, NO2, rainfall, SO2, SPM, CO, non-methane hydrocarbon and surface solar radiation for the period October 2004 to June 2009 over Alipore (22.52°N, 88.33°E), India. Annual cycle of low-level cloud occurrences depicts that the low-level cloud over Alipore had been noticed to occur for many days and nights, particularly from June to September. The low-level cloud occurrences were found in winter months and post-monsoon period. The effect of cloud occurrences on tropospheric ozone concentration has been critically analysed and explained. It has been observed that the concentration of ozone is oscillatory with cloud occurrences and has a slight linear decreasing trend with the increase of cloud occurrences and vice versa. The concentration of tropospheric ozone attained higher value at moderate cloud occurrences and comparatively lower value at both of the lower and higher cloud occurrences. The related possible chemical and physical explanation for role of cloud occurrences on tropospheric ozone has been offered. © Indian Academy of Sciences.

Fulltext

Journal of Earth System Science

Effect of cloud occurrences on tropospheric ozone over, Alipore (22.52Â°N, 88.33Â°E), India

The paper presents the nature of the variation of refractive index of atmospheric medium with time and altitude before, during and after the onset of thunderstorms over Gangetic West Bengal during the pre-monsoon period. A critical analysis shows that sharp depletion of the refractive index takes place before the onset of Nor'westers and possible explanations are also offered for the said occurrence. © 2011 Springer-Verlag.

Meteorology and Atmospheric Physics

Sharp depletion of atmospheric refractive index associated with Nor'wester over Gangetic West Bengal: A possible method of forecasting Nor'wester

The sharp depletion of attenuation of 22.235 GHz signal before the onset of Nor'wester over Kolkata, India is observed and possible explanation of such type of variation is presented. It is concluded that this may be taken as one possible method of forecasting severe thunderstorm associated with Nor'wester. Physical explanations based on the formation and dissipation mechanisms of thunderstorm are also presented. © 2010 IACS.

Sharp depletion of attenuation of 22.235 GHz associated with Nor'wester over Kolkata, India and possible method of forecasting Nor'wester

A genetic algorithm (GA) is introduced to fix ranges of parameters, in a quantitative manner, pertaining to forecasting the genesis of severe thunderstorms in the pre-monsoon season over Calcutta (22°32′, 88°20′) in the northeastern part of India (20°-24°N latitude, 85°-93°E longitude). The results depict that definite quantitative ranges of parameters can be made available before as well as after the occurrence of severe thunderstorms using a GA. Thus, a suitable combination of these ranges of parameters before the onset can represent a possible predictor of thunderstorm genesis. © World Scientific Publishing Company.

Advances in Complex Systems

Prediction of severe thunderstorms with minimal a priori information

CYTOLOGIA

Karyomorphology in Nine Species of Jute (Corchorus L., Tiliaceae)

Quarterly Journal of the Royal Meteorological Society

On instability from water vapour

Study of atmospheric refractivity prior to squall onset and its strong association with surface temperature and relative humidity over Kolkata (22 34â€²N, 88 22â€²E)

Journal	Indian Journal of Physics
Publisher	-
ISSN	0973-1458
Open Access	No