Dynamics of "internal” interannual variability of the Indian summer monsoon in a GCM

The poor predictability of the Indian summer monsoon (ISM) appears to be due to the fact that a large fraction of interannual variability (IAV) is governed by unpredictable "internal” low frequency variations. Mechanisms responsible for the internal IAV of the monsoon have not been clearly identified. Here, an attempt has been made to gain insight regarding the origin of internal IAV of the seasonal (June-September, JJAS) mean rainfall from "internal” IAV of the ISM simulated by an atmospheric general circulation model (AGCM) driven by fixed annual cycle of sea surface temperature (SST). The underlying hypothesis that monsoon ISOs are responsible for internal IAV of the ISM is tested. The spatial and temporal characteristics of simulated summer intraseasonal oscillations (ISOs) are found to be in good agreement with those observed. A long integration with the AGCM forced with observed SST, shows that ISO activity over the Asian monsoon region is not modulated by the observed SST variations. The internal IAV of ISM, therefore, appears to be decoupled from external IAV. Hence, insight gained from this study may be useful in understanding the observed internal IAV of ISM. The spatial structure of the ISOs has a significant projection on the spatial structure of the seasonal mean and a common spatial mode governs both intraseasonal and interannual variability. Statistical average of ISO anomalies over the season (seasonal ISO bias) strengthens or weakens the seasonal mean. It is shown that interannual anomalies of seasonal mean are closely related to the seasonal mean of intraseasonal anomalies and explain about 50% of the IAV of the seasonal mean. The seasonal mean ISO bias arises partly due to the broad-band nature of the ISO spectrum allowing the time series to be aperiodic over the season and partly due to a non-linear process where the amplitude of ISO activity is proportional to the seasonal bias of ISO anomalies. The later relation is a manifestation of the binomial character of rainfall time series. The remaining 50% of the IAV may arise due to land-surface processes, interaction between high frequency variability and ISOs, etc

Potential predictability and extended range prediction of Indian summer monsoon breaks

Extended range prediction (two to three weeks in advance) of Indian summer monsoon active (rainy) and break (dry) phases are of great importance for agricultural planning and water management. Using daily rainfall and circulation data for 23 years, a fundamental property of the monsoon intraseasonal oscillations (ISO's) is discovered and shown that the potential predictability limit (~20 days) of monsoon breaks is significantly higher than that for active conditions (~10 days). An empirical model for prediction of monsoon ISO's is then constructed and feasibility of useful prediction of monsoon breaks up to 18 days in advance is demonstrated

ENSO control on the south Asian monsoon through the length of the rainy season

Being an integral effect of sub-seasonal rain spells over the season, the seasonal mean south Asian monsoon (SAM) rainfall could be affected by change in the length of the rainy season (LRS). An objective definition of the duration of the SAM season has, however, been lacking. Here we show that the meridional gradient of tropospheric temperature (ΔTT) over the SAM region controls the LRS and defines the SAM season. It is further shown that ENSO induces decreased SAM rainfall by regulating the LRS. The atmospheric response to tropical sea surface temperature (SST) over the tropical Pacific during an evolving El Nino reduces ΔTT over the SAM region and shortens LRS by delaying the onset and advancing the withdrawal. The strong negative correlation between LRS and ENSO related SST has remained steady and provides basis for improved prediction of seasonal mean SAM rainfall variability

Clustering of synoptic activity by Indian summer monsoon intraseasonal oscillations

Active and break phases of the Indian summer monsoon are characterized by enhancement and decrease of precipitation over the monsoon trough region. Using genesis data of monsoon low pressure systems (LPS) and circulation data for the period 1954 to 1993, it is shown that the frequency of occurrence of LPS is nearly 3.5 times higher in the active phase of monsoon as compared to the break phase. In addition, the tracks of these synoptic systems are also strongly spatially clustered along the monsoon trough during the active phase of the monsoon. The enhanced (decreased) frequency of occurrence of LPS during active (break) phases is due to modulation of meridional shear of zonal winds and cyclonic vorticity along the monsoon trough by the intraseasonal oscillations (ISO)

A condição das mulheres no contexto social contemporâneo

A violência contra as mulheres é a mais clara expressão histórica de desigualdade, estabelecida pela consequência direta da cultura patriarcal, um desrespeito aos direitos humanos que tende a ser cada vez mais debatida em todo o mundo, tanto no campo teórico como na prática. O objetivo deste artigo é buscar as vozes femininas atuais que ocupam o espaço público brasileiro, contextualizar o papel da mulher na construção da nação e literatura e estabelecer uma relação com a questão da violência contra as mulheres na esfera privada, tomando como objeto de análise uma reportagem da revista masculina ALFA (Editora Abril), de outubro de 2011. Pretende-se destacar o papel das mulheres na esfera pública, analisar suas recentes vozes e suas militâncias pela luta contra a violência feminina. Metodologicamente, trata-se de observar a importância evidente das mulheres na esfera pública e social, a situação contemporânea em que os homens cedem lugar as mulheres provedoras, independentes e competentes, mesmo em uma conjuntura ainda adversa e desigual, na qual ainda sofrem violência na esfera privada e com porcentagens alarmantes. Pesquisas recentes comprovam os efeitos da Lei Maria da Penha (11.340/06) mostram que o atendimento a mulheres vítimas de violência melhorou e o número de denúncias cresceu. Na busca por soluções, é consenso a opinião de que são necessárias manifestações e divulgações de ideias e atitudes políticas. Mudar a mentalidade da sociedade demanda tempo, porquanto se trata de um fenômeno social há muito enraizado, mas a violência não pode ser “trancada” no silêncio. A conclusão é que a revelação pública das violências conjugais é uma das principais estratégias de fortalecimento contra a violência feminina. Iniciativas e atitudes, como intervir junto as vítimas da violência doméstica, denunciar, propagar as leis e exigir do Estado investimentos nesta área, certamente contribuirá para a edificação de uma sociedade mais humana, justa e igualitária.Mesa: Mujeres que escriben (III).Centro de Estudios de Teoría y Crítica Literari

Vertical structure and diabatic processes of the Madden-Julian oscillation

The “Vertical Structure of Diabatic Processes of the Madden-Julian Oscillation” global-model evaluation project developed a novel experimental framework, which produces a complete characterization of models’ abilities to simulate the Madden-Julian oscillation (MJO). The three components of the project comprise 2-day and 20-day hindcasts and 20-year simulations; each obtained heating, moistening and momentum tendencies from the models’ sub-grid parameterizations. Thirty-five centers provided output for at least one component; nine centers provided data for all three. The models vary greatly in MJO fidelity in climate and hindcast experiments, yet fidelity in one was not correlated with fidelity in the other. In 20-year simulations, strong MJO models demonstrated heating, vertical-velocity and zonal-wind profiles that tilted westward with height, as in reanalysis data. The 20-day hindcasts showed no correspondence between the shape of the heating profile and hindcast skill. Low-to-mid-level moistening at moderate rain rates was a consistent feature of high-skill models and absent from low-skill models, suggesting a role for boundary-layer and congestus clouds in the MJO transition, which was confirmed by timestep data from the 2-day hindcasts. These hindcasts revealed a poor simulation of the MJO transition phase, even at short leads, with large mid-tropospheric dry biases and discrepancies in radiative-heating profiles

Sex-related variation in the vulnerability of wandering albatrosses to pelagic longline fleets

The population of wandering albatrosses Diomedea exulans at South Georgia is decreasing because of bycatch in longline fisheries. Until at least the early 1990s, the survival rate of females was lower than males, consistent with the adult female-biased bycatch reported for fisheries operating around the Brazil-Falklands Confluence (BFC). Here we use extensive tracking data (1990–2012) from breeding birds at South Georgia to investigate overlap with longline fishing effort reported to the International Commission for the Conservation of Atlantic Tunas (ICCAT). Using data from multiple years, we conclude that breeding females are at higher risk than males from all the main pelagic longline fleets in the south-west Atlantic. Our overlap index (based on fishing effort and bird distributions) correlated positively with numbers of ringed birds reported dead on longliners, indicating that the metric was a good proxy of bycatch risk. The consistent sex bias in overlap across years, and the likely resulting sex-biased mortality, could account for lower adult female survival rate at the colony. The risk from fisheries changed seasonally; both sexes overlapped with pelagic longline effort during incubation (January–March), and particularly during post-brood chick-rearing (May–December), whereas overlap was negligible during brooding (April). The highest percentage of overlap was with the Taiwanese fleet, then vessels flagged to Brazil, Uruguay, Spain, Japan and Portugal. Females were consistently at greatest risk in the BFC region, whereas males showed lower and more variable levels of overlap with fisheries from 35 to 45°S. Our results have important implications for management of ICCAT longline fisheries and conservation of this highly threatened albatross population

Implementação em Portugal de um estudo de prevalência da demência e da depressão geriátrica: a metodologia do 10/66 Dementia Research Group

ResumoIntroduçãoA demência e a depressão têm um impacto social muito significativo. Em Portugal, escasseiam dados epidemiológicos em pessoas idosas na comunidade. Em países em desenvolvimento, o 10/66 Dementia Research Group (DRG) conduziu múltiplos estudos sobre a prevalência e a incidência destes quadros. Os protocolos de avaliação 10/66‐DRG foram validados extensivamente nesses países, havendo vantagens potenciais na aplicação em regiões europeias com populações idosas de baixa escolaridade. Neste estudo, fundamentamos e descrevemos a implementação em Portugal da metodologia 10/66‐DRG para estudo da prevalência da demência e da depressão geriátrica.Materiais e métodosO trabalho de campo desenrola‐se numa fase única, em áreas geográficas definidas, sendo avaliados detalhadamente e de forma sistemática todos os residentes de 65 anos ou mais. A informação é recolhida dos participantes e de informadores próximos (www.alz.co.uk/1066/).ResultadosSelecionámos e mapeámos uma área urbana (em Fernão Ferro) e outra rural (em Mora), definindo amostras finais de 702 e 779 pessoas, respetivamente. Os instrumentos de avaliação foram cuidadosamente traduzidos e adaptados ao contexto português. Teve lugar um treino rigoroso dos entrevistadores, assegurando a fiabilidade de cotação interobservadores.Discussão e conclusãoA aplicação dos protocolos 10/66‐DRG permitirá obter dados robustos de prevalência de demência e de depressão, com amostras comunitárias de pessoas idosas em Portugal. Dada a validade internacional da metodologia utilizada, estes resultados serão comparáveis com os de outros centros 10/66, à escala mundial.AbstractIntroductionDementia and depression have a huge social impact. In Portugal, epidemiological data is scarce regarding community dwelling elderly people with these conditions. In developing countries, the 10/66 Dementia Research Group‐DRG has conducted multiple studies on the corresponding prevalence and incidence. The 10/66‐DRG protocols for population‐based studies were extensively validated in those countries, and there is a rationale to apply them in low literacy elderly populations in Europe. We describe the implementation of the protocols related to the prevalence study (on dementia and geriatric depression) in Portuguese settings.Materials and methodsThis is a one‐phase survey, in which all people 65+ years living in defined catchment areas are comprehensively evaluated. Information is collected directly from participants and from a related informant (www.alz.co.uk/1066/).ResultsWe selected and mapped an urban area (in Fernão Ferro) and a rural one (in Mora). The final samples were n=702 and n=779 respectively. Questionnaires were carefully translated and culturally adapted. Rigorous training procedures took place to ensure inter‐rater reliability.Discussion and conclusionsThe implementation of the 10/66‐DRG protocols will lead to robust data on the prevalence of dementia and depression in community samples of elderly people in Portugal. Given the international validity of our methodology, these results will be comparable with those from other 10/66 centres around the world

Coupled versus uncoupled hindcast simulations of the Madden-Julian oscillation in the Year of Tropical Convection

This study investigates the impact of a full interactive ocean on daily initialised 15 day hindcasts of the Madden-Julian oscillation (MJO), measured against a Met Office Unified Model (MetUM) atmosphere control simulation (AGCM) during a 3 month period of the Year of Tropical Convection (YOTC). Results indicated that the coupled configuration (CGCM) extends MJO predictability over that of the AGCM, by up to 3-5 days. Propagation is improved in the CGCM, which we partly attribute to a more realistic phase relationship between sea surface temperature (SST) and convection. In addition, the CGCM demonstrates skill in representing downwelling oceanic Kelvin and Rossby waves which warm SSTs along their trajectory, with the potential to feed back on the atmosphere. These results imply that an ocean model capable of simulating internal ocean waves may be required to capture the full effect of air-sea coupling for the MJO