Papers by Marcelo Seluchi
International Journal of Climatology, 2000
The objective of the present paper is to analyse the possible impact of ENSO events on the spatia... more The objective of the present paper is to analyse the possible impact of ENSO events on the spatial and the temporal distribution of frost occurrences, within the central region of Argentina. Therefore, the minimum temperature series have been studied for 41 meteorological stations within the Pampa Hú meda region and, for a period of 30 years from 1961 to 1990, exploring possible relationships with El Niñ o (EN)/La Niñ a (LN) events and the changes in the Southern Oscillation. It can be concluded that part of the frost frequency variability within this region is explained by the ENSO cycle. Results indicate that, for at least 1 of the 2 years in which the EN event takes place, the mean number of frost occurrences drops below the climatological value. The low phase of the Southern Oscillation Index (SOI) also coincides with those years for which the number of frost events remained below the total annual mean in all cases, with the year 1965 as an exception. Conversely, during the high phase of the SOI, this number was above the total annual mean for four of the six classified cases. In the particular case of seasonal frost occurrence, it is related to the warm event development state, exhibiting a greater impact during the autumn and winter months, for which the cold event also seems to have influence.
Geofísica Internacional
Una de las regiones más ciclogenéticas del Hemisferio Sur está comprendida entre los 20°S y 35°S ... more Una de las regiones más ciclogenéticas del Hemisferio Sur está comprendida entre los 20°S y 35°S sobre el este del continente americano y el Océano Atlántico adyacente. Las depresiones que allí se generan están usualmente asociadas a intensas precipitaciones y fuertes vientos del sudeste sobre el estuario del Río de la Plata, causando frecuentemente su desborde. El objetivo del presente trabajo es estudiar Ia situación sinóptica típica conducente a desarrollos de ciclones sobre el Este de Sudamérica y obtener métodos objetivos para su pronóstico. A partir de 54 casos, se obtuvieron los campos medios de altura geopotencial en los niveles de 1000 y 500 hPa y de espesor 500/1000 hPa, desde cinco días antes del evento. Los mapas medios muestran que la perturbación responsable puede ser detectada cinco días antes de la formación del ciclón. Dicha perturbación se desplaza lentamente, más al norte que lo habitual, se intensifica con la altura y está asociada a un núcleo frio en el mapa de ...
Weather and Climate Extremes
Revista Brasileira de Geografia Física, 2022
A atuação de um ciclone explosivo próximo da costa sudoeste da América do Sul entre junho/julho d... more A atuação de um ciclone explosivo próximo da costa sudoeste da América do Sul entre junho/julho de 2020 trouxe grandes prejuízos socioeconômicos para essa região. A previsibilidade limitada devido ao rápido aprofundamento da pressão em superfície, motivou o desenvolvimento deste trabalho, que tem como objetivo contribuir com informações que possam ser utilizadas para os setores de tomadas de decisão. A descrição sinótica foi feita através de dados de reanálise do European Centre for Mediun Range Weather Forecasts, as respostas observacionais de variáveis meteorológicas foram obtidas a partir das estações meteorológicas do Instituto Nacional de Meteorologia e imagens de satélite do GOES-16. A ciclogenêse foi observada as 11UTC do dia 29 de junho de 2020 e apresentou uma queda de pressão de 35hPa nas primeiras 16 horas, com taxa de decaimento de 2,2 hPa/h, chegando ao valor de 969 hPa no centro do ciclone. Nas horas seguintes, foi observado um aumento no valor da pressão em 3 hPa, che...
Atmosfera, 2007
The objective of this paper is the study of the conditions observed before and during the develop... more The objective of this paper is the study of the conditions observed before and during the development of the convective storm recorded the last hours of January 1, 2000, that affected an area located north of the city of Mendoza, including the International Airport. The work also attempts to determine the behavior of the dynamic and thermodynamic variables that triggered off this case of severe convection. The hourly surface data and daily radiosoundings of Meteorological Station Mendoza Aero, identified as SAME, were analyzed for the period December 30, 1999 to January 2, 2000. The synoptic scale analysis was done with information of National Center for Enviromental Prediction and National Center for Atmospheric Research (NCEP/NCAR), USA, and the results from Centro de Previsao de Tempo e Estudos Climaticos (CPTEC), Brazil. Mesoscale precipitation information was obtained from Instituto Nacional del Agua (INA) network, Argentina. During one hour of the storm the record in SAME was ...
Frontiers in Water, 2021
The Pantanal region in South America is one of the world's largest wetlands. Since 2019, the ... more The Pantanal region in South America is one of the world's largest wetlands. Since 2019, the Pantanal has suffered a prolonged drought that has spelled disaster for the region, and subsequent fires have engulfed hundreds of thousands of hectares. The lack of rainfall during the summers of 2019 and 2020 was caused by reduced transport of warm and humid summer air from Amazonia into the Pantanal. Instead, a predominance of warmer and drier air masses from subtropical latitudes contributed to a scarcity of summer rainfall at the peak of the monsoon season. This led to prolonged extreme drought conditions across the region. This drought had severe impacts on the hydrology of the Pantanal. Hydrometric levels fell all along the Paraguay River. In 2020, river levels reached extremely low values, and in some sections of this river, transportation had to be restricted. Very low river levels affected the mobility of people and shipping of soybeans and minerals to the Atlantic Ocean by the...
International Journal of Climatology, 2018
This study presents a 9‐year climatology and composite analysis of quasi‐linear convective system... more This study presents a 9‐year climatology and composite analysis of quasi‐linear convective systems (QLCSs) in southern Brazil (SB). QLCSs are identified using radar imagery and defined as a 100‐km long, 40‐dBZ convective line that lasts for at least 1 hr. QLCS cases associated with at least three severe wind reports are classified as severe. Composites of the synoptic‐scale environments and severe convective weather parameters are constructed for severe and non‐severe cases of three synoptic patterns found as the most recurrent in QLCS cases. QLCSs are more frequent and more likely to be severe during spring, while very few cases occur during winter. Most cases occur during late night and morning, corroborating previous research of mesoscale convective systems in this area, but the percentages of severe cases are higher in late afternoon and early night. Faster QLCSs, particularly those with velocities greater than 50 km/hr, have higher probability of being severe in comparison to s...
Revista Brasileira …, 2001
Este trabalho analisa um caso de ciclogênese no costa oriental da América do Sul, ocorrida nos di... more Este trabalho analisa um caso de ciclogênese no costa oriental da América do Sul, ocorrida nos dias 15 e 16 de maio de 2000. O intenso ciclone causou precipitações intensas, ventos fortes e provocou prejuízos na população do litoral do Rio da Prata. A situação sinótica caracterizou-se pelo deslocamento de um cavado nos altos níveis que atravessou a Cordilheira dos Andes e interagiu com um sistema frontal em superfície localizado entre o centro da Argentina e Rio Grande do Sul (Brasil). A previsão do Eta/CPTEC foi avaliada comparando os campos do modelo com as análises do NCEP e com dados observados sobre algumas estações meteorológicas. O modelo mostrou um nível de acerto muito alto, pois previu a intensificação do ciclone com uma antecipação de 48 horas. Alem disso foi utilizado para pesquisar os processos físicos envolvidos no desenvolvimento do sistema. A equação das tendências conseguiu mostrar que a intensificação de ciclone deveu-se à variação da altura geopotencial do nível de 500 hPa, causada pelo deslocamento de uma intensa perturbação de onda curta.
Revista Brasileira de Meteorologia, 2020
The present study gives evidence of the occurrence of foehn-like wind on the eastern slopes of th... more The present study gives evidence of the occurrence of foehn-like wind on the eastern slopes of the mountains at Southeastern Brazil. A particular case was detected based on observational evidence on 4 July 2015 near the city of Cruzeiro, state of Sao Paulo, on the Serra da Mantiqueira mountains. Results obtained from numerical simulations are consistent with the foehn wind occurrence deducted from the analysis of regional patterns and time series of selected meteorological parameters.
Water
Trends in streamflow, rainfall and potential evapotranspiration (PET) time series, from 1970 to 2... more Trends in streamflow, rainfall and potential evapotranspiration (PET) time series, from 1970 to 2017, were assessed for five important hydrological basins in Southeastern Brazil. The concept of elasticity was also used to assess the streamflow sensitivity to changes in climate variables, for annual data and 5-, 10- and 20-year moving averages. Significant negative trends in streamflow and rainfall and significant increasing trend in PET were detected. For annual analysis, elasticity revealed that 1% decrease in rainfall resulted in 1.21–2.19% decrease in streamflow, while 1% increase in PET induced different reductions percentages in streamflow, ranging from 2.45% to 9.67%. When both PET and rainfall were computed to calculate the elasticity, results were positive for some basins. Elasticity analysis considering 20-year moving averages revealed that impacts on the streamflow were cumulative: 1% decrease in rainfall resulted in 1.83–4.75% decrease in streamflow, while 1% increase in ...
On February 15, 2022, the city of Petrópolis in Rio de Janeiro, Brazil, received an unusually hig... more On February 15, 2022, the city of Petrópolis in Rio de Janeiro, Brazil, received an unusually high volume of rain within three hours (258 mm). It resulted in flash floods and subsequent landslides that caused 231 fatalities, the deadliest landslide disaster recorded in Petrópolis. In this paper, we analyzed the root cause and the key triggering factors of this landslide disaster by assessing the spatial relationship of landslide occurrence with various environmental factors. Rainfall data were retrieved from 1977 to 2022, while other remote sensing data from 1985 to 2020, were utilized to map the landslide scars, soil moisture, terrain attributes, line-of-sight displacement (land surface deformation), and urban sprawling .. to. The results showed that the average rainfall for February 2022 was 200 mm, the heaviest recorded in Petrópolis since 1932. From the rainfall spatial distribution, heavy rainfall was also recorded mostly in regions where the landslide occurred. As for terrain, 23% of slopes between 45-60° had landslide occurrences and east-facing slopes appeared to be the most conducive for landslides as they recorded landslide occurrences of about 9 to 11%. Regarding the soil moisture, higher variability was found in the lower altitude (842 m) where the residential area is concentrated. From our land deformation assessment, the area is geologically stable, and the landslide occurred only in the thin layer at the surface of the 1,700 buildings found in the region of interest, 1,021 are on the slope between 20 to 45° and about 60 houses were directly affected by the landslides. As such, we conclude that the heavy rainfall was not the only cause responsible for the catastrophic event of February 15, 2022; a
This report was prepared with the contributions of the members of the LPB Implementation Steering... more This report was prepared with the contributions of the members of the LPB Implementation Steering Group, and the additional contributions of Heitor Coutinho, Nelson Luís
International Journal of Disaster Risk Reduction, 2020
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Hydrological Processes, 2018
Southeastern Brazil is characterized by seasonal rainfall variability. This can have a great soci... more Southeastern Brazil is characterized by seasonal rainfall variability. This can have a great social, economic, and environmental impact due to both excessive and deficient water availability. During 2014 and 2015, the region experienced one of the most severe droughts since 1960. The resulting water crisis has seriously affected water supply to the metropolitan region of São Paulo and hydroelectric power generation throughout the entire country. This research considered the upstream basins of the southeastern Brazilian reservoirs Cantareira (2,279 km 2 ; water supply) and Emborcação (29,076 km 2), Três Marias (51,576 km 2), Furnas (52,197 km 2), and Mascarenhas (71,649 km 2 ; hydropower) for hydrological modelling. It made the first attempt at configuring a season-based probability-distributed model (PDM-CEMADEN) for simulating different hydrological processes during wet and dry seasons. The model successfully reproduced the intra-annual and interannual variability of the upstream inflows during 1985-2015. The performance of the model was very satisfactory not only during the wet, dry, and transitional seasons separately but also during the whole period. The best performance was obtained for the upstream basin of Furnas, as it had the highest quality daily precipitation and potential evapotranspiration data. The Nash-Sutcliffe efficiency and logarithmic Nash-Sutcliffe efficiency were 0.92 and 0.93 for the calibration period 1984-2001, 0.87 and 0.88 for the validation period 2001-2010, and 0.93 and 0.90 for the validation period 2010-2015, respectively. Results indicated that during the wet season, the upstream basins have a larger capacity and variation of soil water storage, a larger soil water conductivity, and quicker surface water flow than during the dry season. The added complexity of configuring a season-based PDM-CEMADEN relative to the traditional model is well justified by its capacity to better reproduce initial conditions for hydrological forecasting and prediction. The PDM-CEMADEN is a simple, efficient, and easy-touse model, and it will facilitate early decision making and implement adaptation measures relating to disaster prevention for reservoirs with large-sized upstream basins.
Revista USP, 2015
A “Carta de São Paulo” apresentou diagnósticos, análises e soluções para o problema da crise hídr... more A “Carta de São Paulo” apresentou diagnósticos, análises e soluções para o problema da crise hídrica no Sudeste. Mesmo após vários meses de sua publicação, ela ainda é atual e, por isso, é reproduzida na abertura deste Dossiê. Redução de demanda, mudanças no sistema de governança da água, uso intensivo de mais tecnologia para reúso, monitoramento intensivo da qualidade da água são algumas das principais recomendações dos especialistas que a elaboraram.
Http Digital Bl Fcen Uba Ar, 1993
Quiero expresar mi mds sincero y cdlido agrad&$mkento a1 Dr. Erich R. Lichtenstein, puesto que du... more Quiero expresar mi mds sincero y cdlido agrad&$mkento a1 Dr. Erich R. Lichtenstein, puesto que durante el tidpb que henos compartido he descubierto en 61 un brillante profesi'onal y una persona excelente. Gracias a sus invalorables C6mi2iPientos y disposicidn esta Tesis ha podido llegar a su concreeE6n. Deseo manifestar un agradecimiento muy especiak B la Dra. Susana A. Bischoff, quien ha aportado valiosas suget&kiW3 y me ha alentado continuamente en mi trabajo. Agradezco tambien a1 Dr. ~ario N. Ndfiez quieh me b Windado su estlmulo y, como Director del CIMA, la posibilidad 6% cairtar con el equipamiento y 10s medios necesarios pa-WaLizas mis investigaciones. Reconozco asimismo todo el apoyo ~fin~akto p.or mis compafieros del Departamento de Ciencias de la ~tm6gtdSl Y ael CIMA.
Revista Brasileira De Meteorologia, 2007
RESUMO Este trabalho analisa as condições meteorológicas que levaram à ocorrência de uma intensa ... more RESUMO Este trabalho analisa as condições meteorológicas que levaram à ocorrência de uma intensa onda de calor na região subtropical da América do Sul, com temperaturas máximas superiores aos 40°C imediatamente à leste dos Andes, na última semana de Janeiro de 2003. Para isso, os termos da Equação Termodinâmica foram avaliados a partir de simulações numéricas realizadas com o modelo regional Eta/CPTEC. O forte aumento da temperatura foi provocado pelo aquecimento por compressão adiabática, produto da subsidência, e pelo aquecimento superfi cial imediatamente a leste dos Andes. A análise da Equação Omega Quase-Geostrófi ca permitiu estabelecer que a subsidência de grande escala se deveu fundamentalmente ao avanço de uma crista de onda longa nos níveis meios da atmosfera. Além disso, as observações e as simulações numéricas apontam para a ocorrência de subsidência forçada (vento Zonda) a leste dos Andes, associada ao deslocamento de um cavado de onda curta imerso na crista de onda longa, à aproximação de uma frente fria e ao deslocamento para o sul da Baixa Termo-orográfi ca. Esse fato, muito pouco freqüente no verão, em combinação com os processos descritos anteriormente, explicaria a ocorrência de recordes históricos de temperatura no oeste da Argentina.
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Papers by Marcelo Seluchi