Ma_.(1982),33, 3, 317-324

581.505.8(267)" 1979"

A study of performance of different types of radiosondesused oyer Indian sea areas durit g Monex-79

N. SESHADRIMeteorological Office. New Delhi

( Received 12 No vember 1981)

m:-~'~i j(I. mil"~· 1 9 i <'\mm ~llrf.r'l"flAm:"~.r..l "" "",",,~\'I'I'

fuA' ""l oil ",",·,f oilllfil i<fom~ "" 'l"l'Tol "" moil.rd "'""' 'lOT ~ I~~ oil~:mrl ~ lr~liR'l rm 'IlrniPr~ """'""~ lr t,",".wm m .m '"!"" u~ ~""i'"'" ~lr "'fuitymi!.oU rm om~.m"'"'" oil~mil ~~ il'l"if 'lit 'fro! • ifa",~ lr 'IlrniPr~ liR ~...n lr fil;n OR"'""' "'""' 'lOT ~ I fiIfiA ll'6T< i .r..l "\'I'I'i\. ""T1t 'Ill .• ..~~ \{'f'lT 'iii <' tr{ ~ I 'IlrniPr ~m .m m.n .mflfrur.. .;I~ oil <ffilfu; 'f'RT .. qfumff .,ft 'iii~ "'""' 'lOTt I

Ill'l"l'Tol 'I.m lll{it mil ~~ "''! m-m. o6~~Jroi\1t~ IfP. "" J.1fU l'ITful u",) m.~~ oilIllq.m >ti 'f'RT ~ 'l~rn "" 'fOm!l'll" 'OW ~l """"liRI~)"m if 'IlrniPr ~ lIR if ""'"" "ll11! 'Ill ,"","".m:",t<rr 'f'RT rim "" ..-ni. l;lrtt l'ITful ll"lf <rn 'lit<Mm '6T'!IT f....""'''d' rof4<1f .m: p oillI<fu!r 'OW ~ I qfumff >ti~ 'J'I'II if >m<iTll m lr f~ 'Ill 'I'f'l 06 illR'l~ <illi'lT liR li'~ 'Ill .mflfr'l'R oil il'f'l 't'"~ lr ""'1ft fll"Rf~~ 'Ill i I

ABSTRACf. :An attemp t has been made to stud and evaluate the compatibility of the upperair thermodynamic data recorded using different types of Radiosondes during Monex-79 from thevarious platforms over Indian sea areas. The observatiqns .recorded over the Arabian Sea and , ayof Bengal areas using Russian Radiosondes from USS~ research vessels, Vaisa1a Omegasonde fromIndian Monu ships, and American dropsonde from the US research aircraft together with the IndianRadiosonde observations from coastal Indian land stations have been studied. The essential informationon the sensor!' used in the different types of sondes is also given. The results of intercomparison betweenthe Indian Radiosonde and Vaisala Omegasonde data has also been presented.

This study provides an opportunity to evaluate the c mparative performance of tbe Indian Radio-­sonde with that of other established radiosonde techniq es in the field of upper air sounding overJand and sea areas. The performance or the temperatu~ and humidity sensors used in the Indianradiosonde have showed a very high degree of reliability. ptability and compatibility in respect of datarecorded by the other established systems. The wind observations taken by the Indian sonde have alsoshown very close agreement with the Omega winds of aisala Omegasonde 8.. brought out by theresults of inter-comparison.

I. Introducdoa Bay of Bengal. The fourth ship INS Betwa filledwith only a data acquisition modu le of Navaid

Du ring the Global Weather Experimenl and Sou ding System was posilioned in the Bay ofMonex-79, four Indian ships were deployed in Ben al during Monex-79 . The data generatedthe Arabian Sea and the Bay of Bengal. Two of were processed in delayed mode. The US re-these ships, INS Darshak and INS Deepak, search airc raft and USSR ships deployed overequip ped wilh complete FGGE Navaid Sound ing the Ind ian sea areas had real time da ta process-Systems capable of producing real time upper ing facilities on board . The Indi an land stationsair data were deployed initially over the Arabian also 'p roduced real lime data using semi auto-Sea during SOP-II (1 May to 30 June 1979). At mated techniques. An atlempt has been made 10the end of the Arabian Sea phase, lhese Iwo evaluate the compatibility of upper air thermody-ships along with RV Gaveshani (with ao indi- narnid data recorded by the FGGE Navaidgenous omegasonde equipment) moved into the Sounding Systems on board Indi an Monex ships,

(317)