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The Southern Brazilian Continental Shelf (SBCS) is an area with great ecological and economic importance to Brazil. In this region can be observed the recurrent passage of frontal systems and extra-tropical cyclones, which are more frequent during the winter months of the southern hemisphere. These systems act on the ocean surface layers as direct driving forces, which may change the thermohaline structure of the water column and induce sea level perturbations. This study used the coupled ocean-atmosphere regional model (COAWST) to evaluate the effect of the passage of a frontal system associated with an extra-tropical cyclone. The ROMS oceanic model was configured with two nested grids, in order to solve the hydrodynamic processes at different scales. The parent (20–40° S/40–60° W) and child (25–29.3° S/46.3–50° W) grid comprise the coastal region, with a horizontal resolution of 1/9° and 1/27°, respectively, with 32 vertical levels. The initial conditions are the Global Analysis Forecast from CMEMS and forcing files used the Climate Forecast System v.2 (CFSv2) data, from NCEP. This event took place on the continental shelf of the State of Santa Catarina, in September of 2016. The model results were compared to remote sensing data and to the tide gauges from the City of Imbituba (State of Santa Catarina, Brazil). The comparison showed a correlation higher than 78 % between sea level rise data and the model results. The filtering of sea level data made it possible to identify the meteorological component in the model results. The comparison between the tidal-gauge and the model output presented values under 25 cm. The model was capable of representing the sea level anomalies propagation associated with the passage of the atmospheric frontal system. The model output showed the presence of a sea level anomaly propagating northward along the continental shelf at 480 km day−1, probably associated with the presence of a coastal-trapped wave.

DOI: não consta, por isso foi disponibilizado o link de acesso. Marine Isotope Stage 31 (MIS31, between 1085 and 1055 ka) was characterized by higher extratropical air temperatures and a substantial recession of polar glaciers compared to today. Paleoreconstructions and model simulations have increased the understanding of the MIS31 interval, but questions remain regarding the role of the Atlantic and Pacific oceans in modifying the climate associated with the variations in Earth's orbital parameters. Multi-century coupled climate simulations, with the astronomical configuration of the MIS31 and modified West Antarctic Ice Sheet (WAIS) topography, show an increase in the thermohaline flux and northward oceanic heat transport (OHT) in the Pacific Ocean. These oceanic changes are driven by anomalous atmospheric circulation and increased surface salinity in concert with a stronger meridional overturning circulation (MOC). The intensified northward OHT is responsible for up to 85 % of the global OHT anomalies and contributes to the overall reduction in sea ice in the Northern Hemisphere (NH) due to Earth's astronomical configuration. The relative contributions of the Atlantic Ocean to global OHT and MOC anomalies are minor compared to those of the Pacific. However, sea ice changes are remarkable, highlighted by decreased (increased) cover in the Ross (Weddell) Sea but widespread reductions in sea ice across the NH.

Made available in DSpace on 2022-04-28T19:11:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-01-01 Fundação de Amparo à Pesquisa do Estado de Minas Gerais (FAPEMIG) University of the Fraser Valley Extratropical cyclones and your preferred range of operation “storm tracks” play a key role in the global energy system, especially in regions of high latitudes. In this way, the current climatology of these systems are evaluated and its possible changes under situations of increased global temperature and CO2 concentrations are analysed from the global coupled climate model European Centre/Hamburg Model versão 5 / Max Planck Institute-Ocean Model (ECHAM-5-MPI-OM). So, with the intention of obtaining greater precision of intensity and spatial displacement of extratropical cyclones, evaluate important variables of climate energy component, as the flow of heat sensitive and dominant patterns of kinetic energy. To future conditions, the results obtained show that the trajectories of ST may suffer modifications in the distribution, moving South towards the pole. The results also indicate that variations in sea ice cover and sea surface temperature are fundamental in the distribution of the cyclonic activity in future climate conditions. Instituto Nacional de Pesquisas Espaciais Centro Regional Sul de Pesquisas Espaciais (CRS-INPE), Av. Roraima 1000, Bairro Camobi Universidade Federal do Rio Grande Instituto de Oceanografia, Av. Itália km 8 Universidade Federal de Viçosa Departamento de Engenharia Agrícola, P. H. Holfs S/N Universidade Estadual Paulista Faculdade de Ciências Centro de Meteorologia de Bauru, Av. Eng. Luiz Edmundo Carrijo Coube, 14-01 Universidade Estadual Paulista Faculdade de Ciências Centro de Meteorologia de Bauru, Av. Eng. Luiz Edmundo Carrijo Coube, 14-01

Observacoes em superficie da temperatura global sobre os continentes e oceanos indicaram um aumento no ultimo seculo como resposta a eventos cadas vez mais frequentes e intensos de anomalia da temperatura da superficie do mar. Desta forma, o objetivo deste estudo e apresentar as influencias exercidas pela Oscilacao Multidecadal do Atlântico (AMO) sobre as temperaturas da America do Sul, durante o periodo de verao austral, para o periodo de 1901 a 2012. Foi observado que a temperatura do ar apresentou tendencias positivas estatisticamente significativas para a regiao Sudeste e Sul do Brasil. Padrao semelhante foi observado para os extremos de temperatura para todo o periodo em analise. Ao dividir em periodos conforme a oscilacao da AMO, e removendo a tendencia, verifica-se que as anomalias das temperaturas do ar sao mais acentuadas durante a AMO-, e esperado um aumento (reducao) da temperatura do ar e seus extremos principalmente sobre a Bacia do Rio da Prata e Nordeste do Brasil (Centro-Oeste e Sudeste do Brasil). Estes padroes sao esperados pelo fato que durante a AMO+ ocorre um aumento da nebulosidade sobre a regiao correspondente a formacao da ZCAS, alem de um deslocamento mais para norte da ZCIT, fazendo com que a temperatura do ar fique com menores valores. Por outro lado, no extremo Sul da AS, as anomalias negativas da Tar e Tmin durante a AMO+ estao associadas com o transporte de umidade do Oceano Atlântico Sul pelo centro de alta pressao que se forma no litoral da Argentina. Decadal fluctuations in South American air temperature during the southern summer period and its relationship to the North Atlantic Ocean A B S T R A C T Surface observations of global temperature on continents and oceans have indicated an increase in the last century in response to increasingly frequent and intense sea surface temperature anomaly events. Thus, the aim of this study is to present the influences exerted by the Atlantic Multidecadal Oscillation (AMO) on South American temperatures during the austral summer period, from 1901 to 2012. It was observed that the air temperature presented statistically significant positive trends for the Southeast and South of Brazil. Similar pattern was observed for temperature extremes for the entire period under analysis. By dividing into periods as the AMO fluctuates, and removing the trend, it is found that anomalies in air temperatures are more pronounced during AMO-, an increase (decrease) in air temperature and its extremes is expected mainly over the Silver River Basin and Northeast Brazil (Midwest and Southeast Brazil). These patterns are expected due to the fact that during AMO + there is an increase in cloudiness over the region corresponding to the formation of ZCAS, as well as a further northward displacement of the ZCIT, making the air temperature lower. On the other hand, in the extreme south of AS, negative Tar and Tmin anomalies during AMO + are associated with the transport of moisture from the South Atlantic Ocean through the high pressure center that forms off the Argentine coast. Keywords: AMO, air temperature and teleconnection