Lightning and precipitation produced by severe weather systems over Belém, Brazil

Abstract

CG Lightning flashes events monitored by a LDN of the Amazon Protection System, which included 12 LPATS IV VAISALA sensors distributed over eastern Amazonia, were analyzed during four severe rainstorm occurrences in Belem-PA-Brazil, in the 2006-2007 period. These selected case studies referred to rainfall events, which produced more than 25 mm/hour, or more than 40 mm/ 2 hours of precipitation rate totals, registered by a tipping bucket automatic high-resolution rain gauge, located at 1° 47' 53'' S and 48° 30' 16" W. Centered at this location, a 30 ,10 and 5 km radius circles were drawn by means of a geographic information system, and the data from lightning occurrences within this larger area, were set apart for analysis. During these severe storms the CG lightning events, occurred almost randomly over the surrounding defined circle, previously covered by mesoscale convective systems, for all cases studied. This work also showed that the interaction between large-scale and mesoscale weather conditions have a major influence on the intensity of the storms studied cases. In addition to the enhancement of the lightning and precipitation rates, the electric activity within the larger circles can precede the rainfall at central point of the areas Keywords: Lightning, Storms, Amazonia. RESUMO: RELÂMPAGO E PRECIPITAÇÃO PRODUZIDOS POR SISTEMAS DE TEMPO SEVERO EM BELÉM, BRASILEventos de raios nuvem-solo registrados pela rede de detecção do SIPAM, integrada por 12 sensores VAISALA LPATS IV, distribuídos no leste da Amazônia, foram analisados durante 4 tempestades com ocorrência de precipitação intensa em Belém-PA-Brasil, em 2006-2007. Esses casos selecionados, correspondem a eventos de chuva com mais de 25 mm/hora ou 40 mm/ 2 horas, de precipitação registrada por um pluviômetro instalado em 1° 47' 53'' and 48° 30' 16" O. Com centro nessa localização, um círculos de 30, 10 e 5 km de raio foram traçados através de um sistema de informação geográfica e os dados de eventos de raios nessas áreas foram separados para analise. Durante essas tempestades, os eventos de raios ocorreram de maneira quase aleatória, sobre a área maior que já havia sido previamente coberta por sistemas convectivos de mesoescala, em todos os casos. Esse trabalho também mostrou a grande influencia dos sistemas de larga escala nas condições de tempo que levaram às tempestades severas estudadas. Adicionalmente, foi observado que, quando existe interação entre sistemas de larga e meso escalas, tanto a precipitação como o numero de relâmpagos aumentaram significativamente e a atividade elétrica nos círculos maiores pode anteceder a chuva no ponto central. Palavras-chave: raios, tempestades severas, Amazônia.

Thunderstorm Efficiency Regimes in South America as Observed by STARNET and TRMM

“…So, it is possible to conclude that thunderstorms from the continental‐maritime regime are found in regions that are affected by tropical monsoon or even green‐ocean regimes (Williams et al, ). Under such regimes, large rain volumes with weak electrical activity but spatially distributed are observed (Kodama et al, ; Liu et al, ; Petersen et al, ; Ribeiro et al, ; Williams et al, ; Xu & Zipser, ). Finally, thunderstorms from maritime regime show a predominance of warm over cold phases, which in turn decreases the efficiency of the charging mechanism.…”

Estudo de tempestades severas com a ocorrência de raios nas localidades de Santarém e Belém e suas consequências na sociedade (Lightning characteristics associated to severe storm cases which impacted the cities of Belem and Santarem, in Amazonia)

“…This severe rainstorm lasted until 05:00 of that day. This kind of time lag between lightning and rain storms is recurrently observed through similar methodology (Ribeiro et al, 2014) and may help on short time warnings of severe rainstorms. Next, the most intense storm in this case study will be analyzed.…”

“…In the past two decades a research group which includes the authors of this paper, developed several studies on lightning characteristics using data from two surface detection systems which cover the eastern Amazon Region (Ribeiro et al,2014;Almeida et al,2012;Dentel et al, 2014) and data from the Tropical Rainfall Measuring Mission (TRMM) satellite. Some environmental and local impacts associated to this atmospheric variable yielded the following results.…”

“…Their spatial distribution superposition was confirmed, as well as, their association with typical regional meteorological convective systems. Naturally, the appearance of these systems present a space and time seasonal behavior, characteristic of the regional climatology (Ribeiro et al, 2011a). The lightning occurrence densities in eastern Amazonia present a large increment between December and May and with a delay of a couple of weeks one observes the regional rainy season period (Ribeiro et al, 2011b).…”

Relação Entre o Total de Raios e os Raios Nuvem-Solo Sobre o Leste da Amazônia

“…A área selecionada para esta pesquisa é o leste da Amazônia, mais precisamente a região compreendida entre o sudeste do estado do Pará o centro-norte do estado do Maranhão, escolhida por apresentar alta variabilidade de incidência de raios NS (Ribeiro, 2014;Pompeu, 2017), bem como pelo fato de possuir diferentes características físicas, como o relevo acentuado, rica hidrografia, além de uma região costeira banhada pelo Oceano Atlântico equatorial (IBGE, 2017), que presumivelmente interferem na distribuição espacial de raios, sendo esta a hipótese da pesquisa. Tais regiões estão delimitadas entre as longitudes de 052°O e 044°O e as latitudes de 07°S e 02°S, subdividida em sete células de 2,5°x 2,5°, conforme descrito na Figura 1.…”