caa a22 4500 605471991 CHVBK 20210128100335.0 cr unu---uuuuu 210128e20150701xx s 000 0 eng 10.1007/s00382-015-2532-2 doi (NATIONALLICENCE)springer-10.1007/s00382-015-2532-2 Energetics of wave propagation leading to cold event in tropical latitudes of South America [Elektronische Daten] [Gabriela Müller, Manoel Gan, Everson Piva, Virginia Silveira] This paper presents a new vision on the cold and cool events that affect the tropical region of South America, considering the dynamics and the energetics of wave train propagation associated with these systems. Through a composite analysis of meridional winds at 300hPa for cold (T<0°C) and cool (0°C≤T≤2.5°C) air incursions affecting tropical latitudes and causing frost are studied. The cold events observed in tropical latitudes are associated with a single Rossby wave pattern propagating over the Pacific Ocean which drives the low level anticyclone from the southwest of the continent to low latitudes. This propagation involves a southern circulation due to the meridional wind penetration and consequently cold air advection causing temperatures to drop below 0°C. During cool events a subtropical wave train propagating through the Pacific Ocean is observed, which merges before the event with a wave coming from the subpolar latitudes of the South Atlantic Ocean. The zonal propagation leads to the entrance of the anticyclone from the west of the continent, and it is strengthened together with the meridionaly extended cyclone located upstream. This configuration causes southerly wind advection over central-southeastern Brazil and consequently causes the temperature decrease. The energetics shows that the cold events kinetic energy maxima are more intense than those of cool events. For the cold events three maxima are observed, the first (K1) and the third (K3) maxima are developed by baroclinic conversion and ageostrophic flux convergence and the second one (K2) by ageostrophic flux convergence. For the cool events two maxima are found, the first maximum (K4) developed by baroclinic conversion and the second one by ageostrophic flux convergence. Springer-Verlag Berlin Heidelberg, 2015 Energetics nationallicence Wave propagation nationallicence Frost events nationallicence South America nationallicence Müller Gabriela Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción (CICYTTP/CONICET), Materi y España, s/n, CP 3105, Diamante, Entre Ríos, Argentina aut Gan Manoel Centro de Previsão de Tempo e Estudo Climáticos, Instituto Nacional de Pesquisas Espaciais (CPTEC/INPE), São José dos Campos, SP, Brazil aut Piva Everson Departamento de Física, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil aut Silveira Virginia Centro de Previsão de Tempo e Estudo Climáticos, Instituto Nacional de Pesquisas Espaciais (CPTEC/INPE), São José dos Campos, SP, Brazil aut Climate Dynamics Springer Berlin Heidelberg 45/1-2(2015-07-01), 1-20 0930-7575 45:1-2<1 2015 45 382 https://doi.org/10.1007/s00382-015-2532-2 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-015-2532-2 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Müller Gabriela Centro de Investigaciones Científicas y Transferencia de Tecnología a la Producción (CICYTTP/CONICET), Materi y España, s/n, CP 3105, Diamante, Entre Ríos, Argentina aut NATIONALLICENCE 700 1- Gan Manoel Centro de Previsão de Tempo e Estudo Climáticos, Instituto Nacional de Pesquisas Espaciais (CPTEC/INPE), São José dos Campos, SP, Brazil aut NATIONALLICENCE 700 1- Piva Everson Departamento de Física, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil aut NATIONALLICENCE 700 1- Silveira Virginia Centro de Previsão de Tempo e Estudo Climáticos, Instituto Nacional de Pesquisas Espaciais (CPTEC/INPE), São José dos Campos, SP, Brazil aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 45/1-2(2015-07-01), 1-20 0930-7575 45:1-2<1 2015 45 382