Possíveis relações entre a variabilidade interanual do gelo marinho antártico e a precipitação na América do Sul

Investigamos as diferenças na circulação atmosférica do Hemisfério Sul em extremos interanuais de retração e expansão de gelo marinho antártico e as possíveis relações com a precipitação na América do Sul. Os resultados mostram que, com a retração de gelo marinho no mar de Weddell e Bellingshausen-Amundsen (mar de Ross), houve uma redução (aumento) de precipitação no Nordeste do Brasil. Na região Sul, houve um aumento associado aos mares de Bellingshausen-Amundsen. Estas relações não foram tão evidentes através das células de circulação meridional, mas através de padrões de teleconexão barotrópico equivalente de latitudes extratropicaisTrabalho publicado em: Ciência e Natura, Santa Maria, v. esp., p. 72-74, dez. 2013

Trabalhos Destacados no V Simpósio Internacional de Climatologia (v sic)

http://dx.doi.org/10.5902/2179460X17164 The International Symposium of Climatology promoted by the Brazilian Society of Meteorology  - SBMET - is intended to bring together the scientific and professional community from Brazil and abroad to present and discuss issues related to climatology and related fields. These events began to be held in 2005 and happen biannually.Os Simpósios Internacionais de Climatologia promovidos pela Sociedade Brasileira de Meteorologia SBMET têm como finalidade reunir a comunidade científica e profissional do Brasil e do exterior para apresentar e discutir temas associados à climatologia e áreas correlatas. Estes eventos começaram a ser realizados em 2005 e tem periodicidade bianual

A global and hemispherical analysis of the Lorenz energetics based on the representative concentration pathways used in CMIP5

So far, only a few studies have evaluated the impact of greenhouse gases emissions on the global and limited area energetics. Furthermore, all of them have concentrated on the increasing of CO2. As new climate projections are now available froma number of climate models under the MPI-ESR-MR experiment, the present study analyses the global and hemispherical energetics under the increase of greenhouse gas forcings that follow Representative Concentration Pathways (RCP26, RCP45, and RCP85). The results have shown a reduction in the LEC intensity as the concentration of greenhouse gases increases, with the RCP85 scenario generating the strongest decrease. For both global and hemispherical domains, zonal kinetic energy is the only energy reservoir which increases in awarmer environment,whereas the conversion between eddy kinetic energy and zonal kinetic energy (\u1d436����������������\u1d43e����������������) is the only energy flux also experiencing an increase. Aquantitative analysis of the inner processes involved in the conversion terms shows important changes in the horizontal and vertical eddy-transport of momentum and sensible heat. In the case of \u1d436����������������\u1d43e���������������� both vertical and horizontal eddy-transports of momentum play an important role in the increase of zonal kinetic energy for the global domain.CNPq - 150356/2011-0FAPESP - 08/58101-9CLARIS LPBINCLINE/US

Tropospheric pathways of the late-winter ENSO teleconnection to Europe

The late-winter signal associated with the El Niño-Southern Oscillation (ENSO) over the European continent is unsettled. Two main anomalous patterns of sea-level pressure (SLP) can be identified: a "wave-like" pattern with two opposite-signed anomalies over Europe, and a pattern showing a single anomaly ("semi-isolated"). In this work, potential paths of the tropospheric ENSO teleconnection to Europe and their role in favoring a more wave-like or semi-isolated pattern are explored. Outputs from historical runs of two versions of the MPI-ESM coupled model, which simulate these two types of patterns, are examined. A novel ray-tracing approach that accounts for zonal asymmetries in the background flow is used to test potential propagation paths in these simulations and in observations; three source regions are considered: the tropical Pacific, the North America/North Atlantic, and the tropical Atlantic. The semi-isolated pattern is suggested to be related to the well-known Rossby wave train emanating from the tropical Pacific, either via a split over northern North America or via reflection due to inhomogeneities in the background flow. The wave-like pattern, in turn, appears to be related to a secondary wave train emerging from the tropical Atlantic. The competition between these two pathways contributes to determining the actual surface response

Tropospheric pathways of the late-winter ENSO teleconnection to Europe

The late-winter signal associated with the El Niño-Southern Oscillation (ENSO) over the European continent is unsettled. Two main anomalous patterns of sea-level pressure (SLP) can be identified: a “wave-like” pattern with two opposite-signed anomalies over Europe, and a pattern showing a single anomaly (“semi-isolated”). In this work, potential paths of the tropospheric ENSO teleconnection to Europe and their role in favoring a more wave-like or semi-isolated pattern are explored. Outputs from historical runs of two versions of the MPI-ESM coupled model, which simulate these two types of patterns, are examined. A novel ray-tracing approach that accounts for zonal asymmetries in the background flow is used to test potential propagation paths in these simulations and in observations; three source regions are considered: the tropical Pacific, the North America/North Atlantic, and the tropical Atlantic. The semi-isolated pattern is suggested to be related to the well-known Rossby wave train emanating from the tropical Pacific, either via a split over northern North America or via reflection due to inhomogeneities in the background flow. The wave-like pattern, in turn, appears to be related to a secondary wave train emerging from the tropical Atlantic. The competition between these two pathways contributes to determining the actual surface response.B.M. and J.G.-S. were supported by the “Contratos Predoctorales para la Formación de Doctores” (BES-2016-076431) and “Ramón y Cajal” (RYC-2016-21181) programmes, respectively. Tercio Ambrizzi was supported by the National Institute of Science and Technology for Climate Change Phase 2 under CNPq Grant 465501/2014-1, 301397/2019-8; FAPESP Grants 2014/50848-9 and 2017/09659-6. This study also received funding from the Spanish ATLANTE project (PID2019-110234RB-C21). We acknowledge the World Climate research Programme’s Working Group on Coupled Modelling, which is responsible for CMIP. Technical support at BSC (Computational Earth Sciences group) is sincerely acknowledged. We also thank the two anonymous reviewers for their valuable insights.Peer ReviewedPostprint (published version

A new climatology for Southern Hemisphere blockings in the winter and the combined effect of ENSO and SAM phases

This study presents 53-year climatology of Southern Hemisphere (SH) blockings in the winter using\ud daily 500-hPa geopotential height data from NCEP–NCAR reanalysis. The variability of SH blocking events and their\ud relationships with combined phases of El Ni˜no/southern oscillation (ENSO) and the southern annular mode (SAM) are\ud examined. Conventional indices were revised and a slightly modified index is proposed to detect latitudinal variations of\ud SH blockings. The South Pacific region is examined in detail. There is no statistically significant long-term trend in the SH\ud blockings. During moderate El Ni˜no, the preferred location SH blocking is observed over East Pacific, and we show that\ud the blocking frequency increases during negative SAM phases. During moderate La Ni˜na the SH blockings are significantly\ud suppressed over Central Pacific, with lower blocking frequency during positive SAM phases. These results indicate that\ud the daily variability of SH blocking is strongly modulated by both ENSO and SAM phases.NOAA/OAR/ESRL PSD, Boulder, Colorado, USACAPESCNPqNOAA Office of Global Programs (NA10OAR4310170)FAPESP - 08/58101-9INCTMC/CNP

Avaliação da Climatologia na Região Amazônica nos Modelos da Família Higem

This study analyzed the high resolution coupled and atmospheric global models of HiGEM/UJCC project (version 1.2) with different horizontal resolutions over Amazon region (South America). The purpose of this study was to understand the impact of the horizontal resolution of coupled models in simulating atmospheric patterns and processes of interaction between spatial scales over Amazon region. Therefore, we used simulations from HadGEM, HiGEM (coupled), HadGAM, HiGEM (uncoupled), and also observed data from different reanalyzes, with different spatial horizontal resolution (CMAP, CRU, GPCP, NCEP, CPC, ERA-Interim). The precipitation and temperature seasonal patterns and annual cycles were compared with observed data, and some measures of dispersion for the annual cycles were analyzed. To study the annual cycle we considered two subdomains in this region: AMN (North Amazon) and AMN (Amazon). The results indicated that the grid refinement and ocean-atmosphere coupling contributes to a better representation of seasonal patterns, both precipitation and temperature, on the Amazon region. Besides, the climatic models analyzed represent better than other models (regional and global) the climatic characteristics of this region. This indicates a breakthrough in the development of high resolution climate models.Neste trabalho foram analisados os modelos globais acoplados e atmosféricos de alta resolução do projeto HiGEM/UJCC (versão 1.2) com diferentes resoluções horizontais sobre a região da Amazônia (América do Sul). O objetivo é compreender o impacto da resolução horizontal dos modelos acoplados de alta resolução nos padrões atmosféricos e em seus processos de interação entre escalas espaciais sobre a região da Amazônia. Para tanto, foram utilizados além das simulações HadGEM, HiGEM (acopladas), HadGAM e HIGAM (atmosféricas), dados observados de diferentes reanalises, com diferentes resoluções espaciais (CMAP, CRU, GPCP, NCEP, CPC, ERA-Interim). Os padrões sazonais e o ciclo anual da precipitação e da temperatura foram comparados aos dados observados, bem como foram analisadas algumas medidas de dispersão para o ciclo anual. Na análise do ciclo anual foram considerados dois subdomínios nesta região: AMN (Amazônia Norte) e AMZ (Amazônia). Os resultados indicam que, o refinamento da grade e acoplamento oceano-atmosfera contribui para a melhor representação dos padrões, tanto de precipitação como de temperatura, sobre a região da Amazônia. Além disso, os modelos climáticos analisados representaram melhor do que outros modelos (regionais e globais) as características climáticas desta região, indicando um avanço no desenvolvimento de modelos climáticos de alta resolução

The role of the Amazon Basin moisture in the atmospheric branch\ud of the hydrological cycle: a Lagrangian analysis

We used a Lagrangian model (FLEXPART) together\ud with the 1979–2012 ERA-Interim reanalysis data to\ud investigate the role of the moisture in the Amazon Basin in\ud the regional hydrological budget over the course of the year.\ud FLEXPART computes budgets of evaporation minus precipitation\ud by calculating changes in the specific humidity along\ud forward and backward trajectories. The tropical Atlantic is\ud the most important remote moisture source for the Amazon\ud Basin. The tropical North Atlantic (NA) mainly contributed\ud during the austral summer, while the contribution of the tropical\ud South Atlantic (SA) prevailed for the remainder of the\ud year. At the same time, the moisture contribution from the\ud Amazon Basin itself is mainly for moisture supplying the\ud southeastern South America. The 33-year temporal domain\ud allowed the investigation of some aspects of the interannual\ud variability of the moisture transport over the basin, such as\ud the role of the El Niño Southern Oscillation (ENSO) and the\ud Atlantic Meridional Mode (AMM) on the hydrological budget.\ud During the peak of the Amazonian rainy season (from\ud February to May, FMAM) the AMM is associated more with\ud the interannual variations in the contribution from the tropical\ud Atlantic sources, while the transport from the basin towards\ud the subtropics responds more to the ENSO variability.\ud The moisture contribution prevailed from the SA (NA)\ud region in the years dominated by El Niño/positive AMM\ud (La Niña/negative AMM) conditions. The transport from the\ud Amazon towards the subtropics increased (reduced) during\ud El Niño (La Niña) years.Spanish GovernmentFEDER - project TRAMORede Clima - INCTCNPq - 573797/2008-0FAPESP - 2008/57719-9, 2008/58101-9, 2008/58161-1Go Amazon 2013/50538-

Climatologia da função frontogenética sobre a América do Sul em um cenário de clima presente e futuro

Os campos climatológicos da Função Frontogenética de Petterssen (FF) foram calculados com a partir do modelo global HadGEM2-ES para uma série 1975-2005. Os primeiros resultados mostram-se concordantes com aqueles obtidos anteriormente\ud por outros autores, indicando uma maior atividade de sistemas frontais durante o inverno e início da primavera. A partir destas constatações, a mesma metodologia pode ser utilizada com séries de clima futuro geradas pelo modelo.Trabalho publicado em: Ciência e Natura, Santa Maria, v. esp., p. 169-171, dez. 2013

Preliminary analysis on the global features of the NCEP CFSv2 seasonal hindcasts

The representation of the CFSv2 ocean-atmosphere ensemble hindcasts is investigated during Dec-Jan-Feb (DJF) and Jun-Jul-Aug\ud (JJA) from 1983 to 2010.The skill anomaly correlations showed that in some continents the forecasts do not have dependency with\ud changes in the initial conditions. Also, in both seasons the model has a higher skill at the 0-month lead time with the largest spatial\ud biases occurring over the North America, South America, and Oceania. Over the continents the largest biases in the nonlinearity\ud of El Ni˜no minus La Ni˜na events are found over the eastern South Africa, part of Oceania, and central-southeastern parts of South\ud America. During DJF the main biases are related to double-ITCZ, strengthening of SPCZ, and deepening of the Aleutian and\ud Icelandic low pressures.The simulation of a warmer SST on the eastern of most austral oceans, the strengthening (weakening) of\ud the Subtropical (Polar) Jet over the Southern Hemisphere, and the weakening of the zonal circulation near the Antarctic continent\ud are also found in both seasons. Over the central-eastern Equatorial Pacific a cooler bias in SST is found during JJA.These biases\ud are interpreted by analyses of the simulated global mean-state and their impact on the main patterns of variabilityFAPESP - 08/58101-9CNP