Variabilidade do perfil vertical de monóxido de carbono sobre a Região Metropolitana de Manaus e sua relação com a queima de biomassa

The present study analyzes the temporal variability of carbon monoxide (CO) over the Manaus Metropolitan Region (MMR) and its relations with nearby fires based on data obtained by the environmental satellite AQUA, for the 2003–2020 period. For this purpose, wavelet transform analyses and wavelet coherence analyses were used. The results show a well-defined seasonal behavior, with an increase and decrease in mean CO concentrations during dry and wet seasons, respectively. Semiannual and annual scales represent around 95 % of CO temporal variability in lower troposphere (500 to 1,000 hPa) and are associated with rains and fires dynamics in the region. In terms of interannual variability, multiple variability scales (1.2–2, 2.5–3 and 4.5–6 years) were observed, which explain around 10–15 % of concentration variability near surface. The results suggest that climatic variations, associated with the tropical Pacific and Atlantic sea surface temperature variations, on these different time scales, affect rain dynamics and, consequently, fires and CO concentration. Specifically, in 2015/16, the combined effect from different variability scales acted to prolong the dry period over the region, which contributed to increase fires and the CO to reach higher values compared to previous years. These results show a new aspect of the importance of evaluating the combined effect of different climate variability scales on CO concentrations in the atmosphere.O presente estudo analisa a variabilidade temporal do gás monóxido de carbono (CO) sobre a Região Metropolitana de Manaus (RMM) e sua relação com as queimadas com base em informações obtidas pelo satélite ambiental AQUA, para o período entre 2003 e 2020. Para tal, foram realizadas análises de transformada de ondeleta e análises de coerência e fase da ondeleta. Os resultados apontam para um comportamento sazonal bem definido, com aumento das concentrações médias de CO durante a estação seca e redução na estação chuvosa. As escalas semianual e anual representam cerca de 95% da variabilidade temporal do CO na baixa troposfera (500 a 1.000 hPa) e estão associadas à dinâmica das chuvas e queimadas na região. Com relação à variabilidade interanual, observaram-se múltiplas escalas de variabilidade (1,2–2, 2,5–3 e 4,5–6 anos), que explicam juntas em torno de 10–15 % da variabilidade das concentrações próximas à superfície. Os resultados sugerem que variações climáticas, associadas às variações da temperatura da superfície do mar nos oceanos Pacífico e Atlântico tropicais, nessas diferentes escalas de tempo, afetam a dinâmica das chuvas e, consequentemente, as queimadas e a concentração de CO. Especificamente em 2015/16, o efeito combinado das diferentes escalas de variabilidade atuou para prolongar o período seco sobre a região, o que contribuiu para o aumento das queimadas e para que o CO alcançasse maiores valores em relação aos anos anteriores. Tais resultados mostram um aspecto novo sobre a importância de avaliar o efeito combinado de diferentes escalas de variabilidade climática nas concentrações de CO na atmosfera, particularmente em anos extremos

Spatio-temporal analysis of the droughts in Cali, Colombia and their primary relationships with the El Nino-Southern Oscillation (ENSO) between 1971 and 2011

This paper analyzed the spatio-temporal variability of droughts in Cali, Colombia and their primary relations to the El Nino Southern Oscillation (ENSO). The Standardized Precipitation Index (SPI) was used to detect drought events from monthly rainfall data of 24 stations well spread over Cali during 1971-2011. The SPI provided the drought intensity, magnitude, frequency, and the minimum rainfall thresholds, mainly on an annual scale (SPI-12). Eighty percent of the stations reported four events with dry conditions in Cali: 1976-1977, 1983-1984, 1990-1992 and 2009-2010. The ENSO influence was evaluated using the correlation and wavelet transform analyses. Significant (non-significant) negative correlations between SPI-12 in the northern (southern) part of Cali, the multivariate ENSO Index (MEI), and Sea Surface Temperature (SST) Nino 3.4 and Nino 4 indices were observed. The wavelet coherence analysis showed significant coherencies between ENSO and SPI-12: at interannual scale (4-6 years), the phase difference of-135o generates a lag of 6-9 months between the minimum peak of the SPI-12 and the maximum peak of the indices. On the quasi-biennial scale (2-3 years), the phase difference of-180o suggests that the maximum wet (dry) conditions coincide with the mature stage of the La Nina (El Nino) event; and on the decadal scale (8-16 years), the decreases (increases) in rainfall precede the El Nino (La Nina) mature stage by approximately 10-18 months. These results are relevant for seasonal forecasting, since changes in SST in the equatorial Pacific may take place 6-18 months ahead of the dry conditions in Cali. © 2020 Universidad Nacional Autonoma de Mexico

Streamflow Variability in Colombian Pacific Basins and Their Teleconnections with Climate Indices

[EN] Oceanic-atmospheric phenomena of different time scales concurrently might affect the streamflow in several basins around the world. The Atrato River Basin (ARB) and Pa-Ha River Basin (PRB) of the Colombian Pacific region are examples of such basins. Nevertheless, the relations between the streamflows in the ARB and PRB and the oceanic-atmospheric factors have not been examined considering different temporal scales. Hence, this article studies the relations of the climate indices and the variability of the streamflows in the ARB and PRB at interannual and decadal timescales. To this, the streamflow variability modes were obtained from the principal component analysis (PCA); furthermore, their linear dependence with indices of the El Nino/Southern Oscillation (ENSO), precipitation (PRP), the Choco low-level jet (CJ), and other indices were quantified through (a) Pearson and Kendall's tau correlations, and (b) wavelet transform. The PCA presented a single significant mode for each basin, with an explained variance of around 80%. The correlation analyses between the PC1s of the ARB and PRB, and the climate indices showed significant positive (negative) high correlations with PRP, CJ, and Southern Oscillation Index (SOI) (ENSO indices). The wavelet coherence analysis showed significant coherencies between ENSO and ARB: at interannual (2-7 years) and decadal scale (8-14), preferably with the sea surface temperature (SST) in the east and west Tropical Pacific Ocean (TPO). For PRB with the SST in the central and western regions of the TPO in the interannual (4-8 years) and decadal (8-14 years) scales, the decreases (increases) in streamflow precede the El Nino (La Nina) events. These results indicate multiscale relations between the basins' streamflow and climate phenomena not documented in previous works, relevant to forecast the extreme flow events in the Colombian Pacific rivers and for planning and implementing strategies for the sustainable use of water resources in the basins studied.The first author was supported by the Program for Strengthening Regional Capacities in Research, Technological Development and Innovation in the department of Naritio and the CEIBA foundation for doctoral studies. The second author was supported by the Doctoral Scholarship of the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior Brazil (CAPES) Finance Code 001 and Universidad del Valle (Cali-Colombia). The Conselho Nacional de Desenvolvimento Cientifico e TecnolOgico (CNPq) of Brazil partially supported the fifth and sixth authors under grants 305942/2015-8 and 302322/2017-5, respectively. This research was done partially during an internship of the first two authors at the Research Institute of Water and Environmental Engineering of the Universitat Politecnica de Valencia. This work was also supported by the Spanish Ministry of Science and Innovation through Project TETISCHANGE (RTI2018-093717-B-I00). We are thankful to the research groups IREHISA and PSI of the Universidad del Valle. The authors thank the anonymous reviewers for their useful suggestions.Canchala, T.; Cerón, WL.; Francés, F.; Carvajal-Escobar, Y.; Andreoli, RV.; Kayano, MT.; Alfonso-Morales, W.... (2020). Streamflow Variability in Colombian Pacific Basins and Their Teleconnections with Climate Indices. Water. 12(2):1-23. https://doi.org/10.3390/w12020526S12312

Streamflow Intensification Driven by the Atlantic Multidecadal Oscillation (AMO) in the Atrato River Basin, Northwestern Colombia

[EN] The impact of the Atlantic Multidecadal Oscillation (AMO) on the variations in the streamflow in the Atrato River Basin (ARB) during the 1965-2016 period was analyzed here by considering the cold (1965-1994) and warm (1995-2015) phases of this oscillation. The mean streamflow increased after 1994 (AMO phase change). This increase is related to the strengthening of the zonal gradients of the sea surface temperature (SST) and sea level pressure (SLP) between the tropical central Pacific and the tropical Atlantic after 1994 (warm AMO phase). These gradients contributed to strengthen the Walker cell related upward movement over northern and northwestern South America, in particular during November-December (ND). Consistently, the frequency (R20 mm) and intensity (SDII) of extreme daily rainfall events increased during the 1995-2015 period. Our results show a connection between the AMO and the increase in the streamflow in the ARB during the last five decades. These results contribute to the studies of resilience and climate adaptation in the region.The first author was supported by the Doctoral Scholarship of the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior-Brazil (CAPES), Finance Code 001 and Universidad del Valle (Cali-Colombia). The Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) of Brazil partially supported the second and third authors under grants 302322/2017-5 and 305942/2015-8, respectively. The fourth author was supported by the CAPES-Brazil and Universidade Federal de Vicosa for doctoral studies. The fifth author was supported by the Program for Strengthening Regional Capacities in Research, Technological Development and Innovation in the department of Narino and the CEIBA Foundation for doctoral studies. The seventh author was supported by the CAPES-Brazil. This research was done partially during an internship of the first and fifth author at the Research Institute of Water and Environmental Engineering of the Universitat Politecnica de Valencia. This work was also supported by the Spanish Ministry of Science and Innovation through Project TETISCHANGE (RTI2018-093717-B-I00).Cerón, WL.; Kayano, MT.; Andreoli, RV.; Avila, A.; Canchala, T.; Francés, F.; Rivera, IA.... (2020). Streamflow Intensification Driven by the Atlantic Multidecadal Oscillation (AMO) in the Atrato River Basin, Northwestern Colombia. Water. 12(1):1-23. https://doi.org/10.3390/w12010216S12312

Os últimos avanços na previsibilidade dos campos de umidade no sistema global de assimilação de dados e previsão numérica de tempo do CPTEC/INPE / Latest advances in the prediction of humidity fields in the data assimilation and numerical weather prediction global system from CPTEC/INPE

Nos últimos anos, duas importantes implementações foram feitas no sistema global de assimilação de dados e previsão de tempo do CPTEC/INPE, as quais têm uma relação direta com a previsibilidade dos campos de umidade. A primeira é a assimilação de valores do vapor d'água integrado na atmosfera (IWV-Integrated Water Vapor). A segunda é a utilização de uma versão melhorada do modelo de previsão de tempo, juntamente com o aumento da resolução da grade. O objetivo do presente estudo é caracterizar o impacto de tais implementações na melhoria da previsibilidade da umidade. Para isso, quatro experimentos foram realizados utilizando as versões T126L28 (sem as melhorias) e T213L42 (com a implementação das melhorias) do modelo global do CPTEC, com e sem a assimilação do IWV. Os resultados obtidos mostram que o impacto da assimilação de IWV é maior nas primeiras horas de previsão. Por outro lado, as melhorias implementadas no modelo geram bons resultados para as previsões de médio (após 60 horas) a longo prazo. Em consequência disso, o impacto combinado de ambas as implementações é significativo ao longo de todo o período de integração avaliado. Nessa circunstância, o intervalo das previsões do IWV consideradas estatisticamente válidas (coeficiente de correlação de anomalia acima de 0.6) é ampliado em 25 horas na região tropical e em 18 horas na América do Sul. ABSTRACT Two important implementations, directly related to the prediction of atmospheric humidity fields, have been introduced during in the recent years in the weather forecast model and its data assimilation system at CPTEC/INPE. The first is the inclusion of Integrated Water Vapor (IWV) data in the assimilation scheme. The second is the improvement of the weather forecast model along with an increase in the grid resolution. The goal of this paper is to characterize the impact of these implementations in the prediction of humidity fields. To achieve this goal four experiments were conducted using the T126L28 (without the improvement) and T213L42 (with the improvement) versions of the CPTEC's global model, with and without assimilation of IWV. The results show that the impact of IWV assimilation is larger in the first hours of forecast. On the other hand, the larger impacts produced by the improvements in the weather forecast model occur from the 60th h of forecast onward. Consequently the combined impact of both implementations represent an improvement throughout the integration period or the period at which predictions of IWV present an acceptable skill (above 60%) were extended in up to 25 hours over the global tropical regions and up to 18 hours over South America.Pages: 100