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@MastersThesis{Silva:2005:InVóCi,
               author = "Silva, L{\'{\i}}gia Alves da",
                title = "A influ{\^e}ncia do v{\'o}rtice cicl{\^o}nico de altos 
                         n{\'{\i}}veis (VCAN) sobre a precipita{\c{c}}{\~a}o do 
                         nordeste do Brasil (NEB) e as caracter{\'{\i}}sticas 
                         associadas",
               school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                 year = "2005",
              address = "S{\~a}o Jos{\'e} dos Campos",
                month = "2005-08-29",
             keywords = "v{\'o}rtice cicl{\^o}nico de altos n{\'{\i}}veis, c{\^o}vados 
                         de altos n{\'{\i}}veis, precipita{\c{c}}{\~a}o, regi{\~a}o 
                         Nordeste (Brasil), sistemas cicl{\^o}nicos, high levelss vortex 
                         cyclonic, high levels depression, precipition, Northwest region 
                         (Brasil), cyclonic systems.",
             abstract = "Os sistemas cicl{\^o}nicos de altos n{\'{\i}}veis, V{\'o}rtice 
                         Cicl{\^o}nico de Altos n{\'{\i}}veis e Cavados de Altos 
                         N{\'{\i}}veis (VCAN/CAN) sobre o Nordeste do Brasil (NEB) e 
                         oceano adjacente exercem grande influ{\^e}ncia na 
                         precipita{\c{c}}{\~a}o de diferentes sub-regi{\~o}es do NEB no 
                         per{\'{\i}}odo de ver{\~a}o austral. S{\~a}o analisadas as 
                         caracter{\'{\i}}sticas e ocorr{\^e}ncia dos VCAN/ CAN sobre e 
                         pr{\'o}ximo ao NEB para 7 ver{\~o}es de 1994 2001. S{\~a}o 
                         estudadas as influ{\^e}ncias dos VCAN/CAN sobre tr{\^e}s 
                         sub-regi{\~o}es distintas e importantes do NEB (noroeste do NEB e 
                         interior do estado da Bahia e do semi-{\'a}rido), focalizando o 
                         estudo em tr{\^e}s {\'a}reas alvo dentro destas 
                         sub-regi{\~o}es. Os VCAN/CAN apresentam alta variabilidade 
                         interanual na frequ{\^e}ncia de ocorr{\^e}ncia e intensidade. 
                         Estes sistemas t{\^e}m intensidade m{\'e}dia de -5x10-5s-1 e 
                         extens{\~a}o horizontal de 2.000.000 km2 vistos atrav{\'e}s das 
                         cartas de vorticidade (\ζ < -2,5x10-5s-1) em 200 hPa. As 
                         tr{\^e}s sub-regi{\~o}es consideradas s{\~a}o influenciadas 
                         pelos VCAN/CAN, apresentando redu{\c{c}}{\~a}o de 
                         precipita{\c{c}}{\~a}o di{\'a}ria quando est{\~a}o diretamente 
                         sobre a sub-regi{\~a}o em quest{\~a}o, conforme o resultado de 
                         Kousky e Gan (1981), a subsid{\^e}ncia no centro dos VCAN/CAN 
                         posicionada sobre regi{\~o}es inibe a precipita{\c{c}}{\~a}o. 
                         Quando os VCAN/CAN est{\~a}o distantes da sub-regi{\~a}o entre 
                         1000 km 2000 km, nos setores nordeste, leste e sudeste em 
                         rela{\c{c}}{\~a}o {\`a} sub-regi{\~a}o em quest{\~a}o, a 
                         frequ{\^e}ncia de chuva forte aumenta substancialmente devido o 
                         efeito da banda de nebulosidade convectiva na borda, posicionar-se 
                         a oeste do sistema. Quando a dist{\^a}ncia {\'e} menor que 1000 
                         km o efeito da banda convectiva {\'e} marginal e quando {\'e} 
                         maior que 2000 km o efeito dos VCAN/CAN tamb{\'e}m {\'e} 
                         reduzido. Os balan{\c{c}}os de vorticidade nos tr{\^e}s casos de 
                         VCAN revelam que o termo de diverg{\^e}ncia {\'e} dominante nos 
                         est{\'a}gios de intensifica{\c{c}}{\~a}o e dacaimento. Como 
                         esperado, o efeito \β {\'e} significativo e a 
                         advec{\c{c}}{\~a}o de \ζ mostra um papel importante nos 
                         lados leste e oeste dos v{\'o}rtices. Os VCAN/CAN tem 
                         dura{\c{c}}{\~a}o de aproximadamente 10 dias e se deslocam 
                         principalmente do Atl{\^a}ntico para noroeste. ABSTRACT: The 
                         Upper Tropospheric Cyclonic circulation Systems (UTCS) over the 
                         Northeast Brazil (NEB) and the adjoing ocean in the austral summer 
                         have a strong influence on the rainfall over different subregions 
                         of NEB. The occurrence and the characteristics of the UTCS over 
                         and near NEB in the 7 summers from 1994-2001 are examined. The 
                         influence of the UTCS over the three important and distinct 
                         subregions of NEB namely, the northwestern part of NEB, northern 
                         part of Bahia state and the semiarid interior of the Northest, are 
                         studied (by focusing the study on three target areas within the 
                         subregions). The interanual variability is quite high in the 
                         frequency and the intensity of the UTCS. The UTCS on the average, 
                         have an intensity of -5x10-5 s-1 and horizontal extent of 
                         2.000.000 km2 as seen from the vorticity (\ζ< -2.5x10-5 s-1) 
                         charts at 200 hPa. The three subregions considered are influenced 
                         by the UTCS with reduction of daily precipitation when the UTCS is 
                         directly over the subregion considered, confirming the result of 
                         Kousky and Gan (1981) that the subsidence in the center of UTCS 
                         over these regions inhibits precipitation. When the UTCS is far 
                         from the subregion in the northeastern, eastern and southeastern 
                         sectors in relation to the subregion within 1000 and 2000 km 
                         distance, the frequency of mode rate to intense rainfall increases 
                         substantially due to the effect of the convective cloud band near 
                         the border of the system in its western sector. When the distance 
                         is less than 1000 km the effect of the convective band is marginal 
                         and when the distance is greater than 2000 km the effect of the 
                         UTCS is reduced. The vorticity balance for three cases of UTCS 
                         revealed that divergence term is dominant, both in the formative 
                         stage and the dissipative stage. As is expected, for larger UTCS 
                         the effect of \β is significant and the advection of 
                         \ζ plays an important role on the western and eastern sides 
                         of the vortex. The life of UTCS has duration of about 10 days and 
                         they mostely move to northweast from the Atlantic.",
            committee = "Gan, Manoel Alonso (presidente) and Satyamurty, Prakki 
                         (orientador) and Cavalcanti, Iracema Fonseca de Albuquerque and 
                         Gandu, Adilson Wagner",
           copyholder = "SID/SCD",
         englishtitle = "The influence of upper tropospheric cyclonic vortex (UTCV) on the 
                         rainfall over the Northeast Brazil (NEB) and the caracteristics 
                         associates",
             language = "pt",
                pages = "134",
                  ibi = "6qtX3pFwXQZGivnJSY/HTbGp",
                  url = "http://urlib.net/rep/6qtX3pFwXQZGivnJSY/HTbGp",
           targetfile = "paginadeacesso.html",
        urlaccessdate = "28 jan. 2021"
}


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