Ma _. (1982) ,33, 3, 317-324 581.505.8(267)" 1979" A study of performance of different types of radiosondes used oyer Indian sea areas durit g Monex-79 N. SESHADRI Meteorological Office. New Delhi (Received 12 November 19 81) "" fuA' ""l oil "," ,·,f oilllfil i<fom "" 'l"l'Tol "" moil .rd "'""' 'lOT I oil lr 'IlrniPr """'"" lr t,",".wm m .m '"!"" "'fuitymi!. oU rm om "'"'" oil mil il'l"if 'lit 'fro! • ifa ", lr 'IlrniPr liR 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 "'""' 'lOT t I Ill'l"l'Tol 'I.m lll{it mil "''! m-m. IfP. "" J.1fU l'ITful u ",) oil Il lq.m >ti 'f'RT 'fOm!l'll " 'OW 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 oil lI<fu!r 'OW I qfumff >ti 'J'I'II if >m<iTll m lr '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 upper air thermodynamic data recorded using different types of Radiosondes during Monex-79 from the various platforms over Indian sea areas. The observat iqns .recorded over the Arabian Sea and , ay of Bengal areas using Russian Radiosondes from research vessels, Vaisa1a Omegasonde from Indian Monu ships, and American dropsonde from the US research aircraft together with the Indian Radiosonde observations from coastal Indian land stations have been studied. The essential information on the sensor!' used in the different types of sondes is also given. The results of intercomparison between the 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 over Jand and sea areas. The performance or the and humidity sensors used in the Indian radiosonde have showed a very high degree of reliability. ptability and compatibility in respect of data recorded by the other established systems. The wind observations taken by the Indian sonde have also shown very close agreement with the Omega winds of aisala Omegasonde 8.. brought out by the results of inter-comparison. I. Introducdoa Bay of Bengal. Th e fourth ship INS Betwa filled with only a data acquisition module of Navaid During the Global Weather Experimenl and Sou ding System was posilioned in the Bay of Monex-79, four Indian ships were deployed in Ben al during Monex-79 . The data generated the 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 aircraft and USSR ships deployed over equip ped wilh complete FGGE Navaid Sound ing the Indian sea areas had real time data process- Systems capable of producing real time upper ing facilities on board. Th e Indian land stations air data were deployed initially over the Arabian also 'produced real lime data using semi auto- Sea during SOP-II (1 May to 30 June 1979). At mated techniques. An atlempt has been made 10 the 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 Navaid genous omegasonde equipment) moved into the Sounding Systems on board Indian Monex ships, (317)