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Author Babu, C. A. ♦ Jayakrishnan, P. R. ♦ Sivaprasad, P.
Source CUSAT-Thesis
Content type Text
Publisher ELSEVIER
File Format PDF
Language English
Alternative Title Analysis using sonic anemometer data
Subject Domain (in DDC) Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Technology
Subject Keyword Annular solar eclipse ♦ Surface boundary layer ♦ Sonic anemometer
Abstract Atmospheric surface boundary layer parameters vary anomalously in response to the occurrence ofannular solar eclipse on 15th January 2010 over Cochin. It was the longest annular solar eclipseoccurred over South India with high intensity. As it occurred during the noon hours, it is considered tobe much more significant because of its effects in all the regions of atmosphere including ionosphere.Since the insolation is the main driving factor responsible for the anomalous changes occurred in thesurface layer due to annular solar eclipse, occurred on 15th January 2010, that played very importantrole in understanding dynamics of the atmosphere during the eclipse period because of its coincidencewith the noon time. The Sonic anemometer is able to give data of zonal, meridional and vertical wind aswell as the air temperature at a temporal resolution of 1 s. Different surface boundary layer parametersand turbulent fluxes were computed by the application of eddy correlation technique using the highresolution station data. The surface boundary layer parameters that are computed using the sonicanemometer data during the period are momentum flux, sensible heat flux, turbulent kinetic energy,frictional velocity (u*), variance of temperature, variances of u, v and w wind. In order to compare theresults, a control run has been done using the data of previous day as well as next day. It is noted thatover the specified time period of annular solar eclipse, all the above stated surface boundary layerparameters vary anomalously when compared with the control run. From the observations we couldnote that momentum flux was 0.1 Nm 2 instead of the mean value 0.2 Nm-2 when there was eclipse.Sensible heat flux anomalously decreases to 50 Nm 2 instead of the mean value 200 Nm 2 at the timeof solar eclipse. The turbulent kinetic energy decreases to 0.2 m2s 2 from the mean value 1 m2s 2. Thefrictional velocity value decreases to 0.05 ms 1 instead of the mean value 0.2 ms 1. The present studyaimed at understanding the dynamics of surface layer in response to the annular solar eclipse over atropical coastal station, occurred during the noon hours. Key words: annular solar eclipse, surfaceboundary layer, sonic anemometer
ISSN 13646826
Education Level UG and PG
Learning Resource Type Article