The new record of drought and warmth in the Amazon in 2023 related to regional and global climatic features.

In 2023 Amazonia experienced both historical drought and warm conditions. On October 26th 2023 the water levels at the port of Manaus reached its lowest record since 1902 (12.70 m). In this region, October monthly maximum and minimum temperature anomalies also surpassed previous record values registered in 2015 (+ 3 °C above the normal considering the 1981-2020 average). Here we show that this historical dry and warm situation in Amazonia is associated with two main atmospheric mechanisms: (i) the November 2022-February 2023 southern anomaly of vertical integrated moisture flux (VIMF), related to VIMF divergence and extreme rainfall deficit over southwestern Amazonia, and (ii) the June-August 2023 downward motion over northern Amazonia related to extreme rainfall deficit and warm conditions over this region. Anomalies of both atmospheric mechanisms reached record values during this event. The first mechanism is significantly correlated to negative sea surface temperature (SST) anomalies in the equatorial Pacific (November-February La Niña events). The second mechanism is significantly correlated to positive SST anomalies in the equatorial Pacific, related to the impacts of June-September El Niño on the Walker Circulation. While previous extreme droughts were linked to El Niño (warmer North Tropical Atlantic SST) during the austral summer (winter and spring), the transition from La Niña 2022-23 to El Niño 2023 appears to be a key climatic driver in this record-breaking dry and warm situation, combined to a widespread anomalous warming over the worldwide ocean.

Current and Future Climate Extremes Over Latin America and Caribbean: Assessing Earth System Models from High Resolution Model Intercomparison Project (HighResMIP).

Extreme temperature and precipitation events are the primary triggers of hazards, such as heat waves, droughts, floods, and landslides, with localized impacts. In this sense, the finer grids of Earth System models (ESMs) could play an essential role in better estimating extreme climate events. The performance of High Resolution Model Intercomparison Project (HighResMIP) models is evaluated using the Expert Team on Climate Change Detection and Indices (ETCCDI) over the 1981-2014 period and future changes (2021-2050) under Shared Socioeconomic Pathway SSP5-8.5, over ten regions in Latin America and the Caribbean. The impact of increasing the horizontal resolution in estimating extreme climate variability on a regional scale is first compared against reference gridded datasets, including reanalysis, satellite, and merging products. We used three different groups based on the resolution of the model's grid (sg): (i) low (0.8° ≤ sg ≤ 1.87°), (ii) intermediate (0.5° ≤ sg ≤ 0.7°), and (iii) high (0.23° ≥ sg ≤ 0.35°). Our analysis indicates that there was no clear evidence to support the posit that increasing horizontal resolution improves model performance. The ECMWF-IFS family of models appears to be a plausible choice to represent climate extremes, followed by the ensemble mean of HighResMIP in their intermediate resolution. For future climate, the projections indicate a consensus of temperature and precipitation climate extremes increase across most of the ten regions. Despite the uncertainties presented in this study, climate models have been and will continue to be an important tool for assessing risk in the face of extreme events. Supplementary Information: The online version contains supplementary material available at 10.1007/s41748-022-00337-7.

Água e mudanças climáticas

O presente documento constitui uma revisão do estado da arte do conhecimento sobre mudanças de clima e água no Brasil e na América do Sul. Discutem-se alguns dos resultados dos estudos do Painel Intergovernamental de Mudanças Climáticas (IPCC) e do Relatório de Clima do Inpe em relação a estudos obervacionais de variabilidade de clima e projeções de clima e das componentes do ciclo hidrológico até finais do século XXI, para as principais bacias hidrográficas no continente. Um dos aspectos importantes discutidos neste informe refere-se aos aspectos econômico e gerencial do recurso água nas diferentes regiões do Brasil, e como isso pode mudar num cenário de mudanças de clima.

Apresentação de resultados dos relatórios de clima do IPCC e do INPE.

Apresentação que comenta os resultados dos relatórios de clima do Painel Intergovernamental de Mudanças Climáticas (IPCC), lançados em fevereiro, abril e maio de 2007, e do Instituto Nacional de Pesquisas Espaciais (INPE), lançado em março do mesmo ano. Alerta para o fato de que o homem já está sentindo os efeitos do aquecimento global, e que, as mudanças climáticas que ainda estão por vir afetarão todas as áreas da nossa vida. Destaca a emissão de gases antropogênicos (causadores do efeito estufa) nos últimos cinqüenta anos como uma das principais causas acelerativas do aquecimento global e como conseqüência, além do aumento da temperatura, a mudança no regime de precipitação das chuvas, que tende a aumentar em latitudes mais altas e diminuir em regiões subtropicais continentais. De acordo com o pesquisador, dentre os impactos do aumento da temperatura global sobre a saúde humana é possível destacar: Aumento do ônus decorrente da má nutrição, da diarréia e de doenças cardio-respiratórias e infecciosas, além do aumento da morbimortalidade causado por ondas de calor, secas e inundações, entre outras.