Intercomparison of oceanic and atmospheric forced and coupled mesoscale simulations <br>Part I: Surface fluxes

International audienceA mesoscale non-hydrostatic atmospheric model has been coupled with a mesoscale oceanic model. The case study is a four-day simulation of a strong storm event observed during the SEMAPHORE experiment over a 500 × 500 km2 domain. This domain encompasses a thermohaline front associated with the Azores current. In order to analyze the effect of mesoscale coupling, three simulations are compared: the first one with the atmospheric model forced by realistic sea surface temperature analyses; the second one with the ocean model forced by atmospheric fields, derived from weather forecast re-analyses; the third one with the models being coupled. For these three simulations the surface fluxes were computed with the same bulk parametrization. All three simulations succeed well in representing the main oceanic or atmospheric features observed during the storm. Comparison of surface fields with in situ observations reveals that the winds of the fine mesh atmospheric model are more realistic than those of the weather forecast re-analyses. The low-level winds simulated with the atmospheric model in the forced and coupled simulations are appreciably stronger than the re-analyzed winds. They also generate stronger fluxes. The coupled simulation has the strongest surface heat fluxes: the difference in the net heat budget with the oceanic forced simulation reaches on average 50 Wm-2 over the simulation period. Sea surface-temperature cooling is too weak in both simulations, but is improved in the coupled run and matches better the cooling observed with drifters. The spatial distributions of sea surface-temperature cooling and surface fluxes are strongly inhomogeneous over the simulation domain. The amplitude of the flux variation is maximum in the coupled run. Moreover the weak correlation between the cooling and heat flux patterns indicates that the surface fluxes are not responsible for the whole cooling and suggests that the response of the ocean mixed layer to the atmosphere is highly non-local and enhanced in the coupled simulation

Performance e eficiência: qual a influência dos fatores ambientais e sociais?

Esta dissertação tem como objetivo analisar os fatores que influenciam a performance e eficiência das empresas, nomeadamente a influencia do fator social e ambiental. Para alcançar este objetivo foi analisada uma amostra de 16 empresas do PSI-20, durante o período de 2016 a 2020. Para testar as hipóteses formuladas de acordo com a revisão de literatura proposta, foi utilizada a metodologia de dados em painel, especificamente o método de estimação Generalized Method of Moments (GMM) system proposto por Arellano e Bond (1991) e aprimorado por Arellano e Bover (1995) e Blundell e Bond (1998), e o Value-Based DEA desenvolvido por Gouveia, Dias e Antunes (2008). Os resultados obtidos pelo modelo GMM mostram que o desempenho social apresenta uma relação negativa com a performance da empresa, sugerindo que tanto na ótica do gestor, como na ótica do acionista e na ótica do stakeholder externo à empresa e potenciais investidores o custo-benefício dos gastos sociais ainda não é entendido como vantajoso para a performance da empresa. Em contrapartida, na ótica de mercado, o desempenho ambiental influencia positivamente a performance da empresa, talvez por pressão da sociedade e da já tradição de divulgação de matérias ambientais. Os resultados do Value-Based DEA reforçam que na ótica do stakeholder externo à empresa e potenciais investidores, as empresas não eficientes devem aumentar o seu desempenho ambiental para se tornar eficientes, destacando o papel do desempenho ambiental na explicação da eficiência. Já no que diz respeito ao desempenho social é unânime que este ainda não é visto como alavanca de eficiência Esta dissertação apresenta duas grandes inovações, a primeira é a utilização de uma metodologia que combina o Generalized Method of Moments (GMM) proposto por Arellano e Bond (1991), Arellano e Bover (1995) e Blundell e Bond (1998), com o Value-Based DEA desenvolvido por Gouveia, Dias e Antunes (2008), para medir o impacto ambiental e social na performance e eficiência das empresas. A segunda inovação é a construção da variável de Desempenho Ambiental e da variável de Desempenho Social recorrendo à Análise de Componentes Principais (PCA)

Assessing ocean-model sensitivity to wind forcing uncertainties

International audienceIn this paper, we assess the short-term forecast error of a mesoscale primitive-equation open-ocean model, induced by uncertainties in wind forcing. Statistics calculated from an ensemble of ocean states show that temperature forecast error is strongest at the top of the ensemble-mean thermocline, as a consequence of vertical displacement of the mixed-layer base around its ensemble mean. Horizontal pattern of the temperature error in the mixed-layer is mainly explained by horizontal advection and surface heat flux fluctuations. These two mechanisms and entrainment through the mixed-layer bottom are presented as the three processes responsible for thermal forecast error growth in the modeled upper ocean

MCR: modern colistin resistance

Recently, plasmid-mediated and, therefore, transferable bacterial polymyxin resistance was discovered in strains from both humans and animals. Such a trait may widely spread geographically, while simultaneously crossing microbial species barriers. This may ultimately render the “last resort” polymyxin antibiotics therapeutically useless. Colistin is currently used to treat infections caused by Gram-negative carbapenemase producers and colistin resistance may lead to practical pan-antibiotic resistance. We here analyzed the medical and diagnostic consequences of (emerging) colistin resistance and propose pathways toward adequate diagnostics for timely detection of both asymptomatic carriage and infection. Culture-based testing using chromogenic and selective media for screening clinical (and veterinary) specimens may constitute key tools for that purpose. Relevant molecular tests are also discussed

Equatorial upper-ocean dynamics and their interaction with the West African monsoon

Zonal wind anomalies in the western equatorial Atlantic during late boreal winter to early summer precondition boreal summer cold/warm events in the eastern equatorial Atlantic (EEA) that manifest in a strong interannual Atlantic cold tongue (ACT) variability. Local intraseasonal wind fluctuations, linked to the St. Helena anticyclone, contribute to the variability of cold tongue onset and strength, particularly during years with preconditioned shallow thermoclines. The impact of cold tongue sea surface temperature (SST) anomalies on the wind field in the Gulf of Guinea is assessed. It contributes to the northward migration of humidity and convection and possibly the West African monsoon (WAM) jump. Copyright @ 2010 Royal Meteorological Societ

Recent changes in the surface salinity of the North Atlantic subpolar gyre

Sea surface salinity (SSS) was measured since 1896 along 60°N between Greenland and the North Sea and since 1993 between Iceland and Newfoundland. Along 60°N away from the shelves, and north of 53°N, the amplitude of the seasonal cycle is comparable to or less than interannual variability. In these parts of the North Atlantic subpolar gyre, large-scale deviations from the seasonal cycle correlate from one season to the next. This suggests that in these regions, summer and autumn surface data are useful for monitoring changes in upper ocean salinity best diagnosed from less common winter surface data. Further south near the subarctic front, the Labrador Current or near shelves where seasonal variability is strong, this is not the case. Along 60°N, the multiannual low-frequency variability is well correlated across the basin and exhibits fresher surface water since the mid 1970s than in the late 1920s to 1960s. SSS in the Irminger Sea along 60°N lags by 1-year SSS farther east in the Iceland Basin. Variability between Iceland and Newfoundland within the Irminger Sea north of 54°N presents similar characteristics to what is observed along 60°N. Variability near the northwest corner of the North Atlantic Current (52°N/45°W) is larger and is not correlated to what is found further north. Maps of SSS were constructed for a few recent seasons between July 1996 and June 2000, which illustrate the fresh conditions found usually during that period across the whole North Atlantic subpolar gyre, although this includes an episode of higher salinity. The SSS anomaly maps have large uncertainties but suggest that the highest SSS occurred before the spring of 1998 in the Iceland Basin, and after that, in the Irminger Sea. This is followed by fresher conditions, first in the Labrador and Iceland Basin, reaching recently the Irminger Sea

Diagnostic and medical needs for therapeutic drug monitoring of antibiotics

Therapeutic drug monitoring (TDM) of antibiotics has been practiced for more than half a century, but it is still not widely applied for infected patients. It has a traditional focus on limiting toxicity of specific classes of antibiotics such as aminoglycosides and vancomycin. With more patients in critical care with higher levels of sickness severity and immunosuppression as well as an increasingly obese and ageing population, an increasing risk of suboptimal antibiotic exposure continues to escalate. As such, the value of TDM continues to expand, especially for beta-lactams which constitute the most frequently used antibiotic class. To date, the minimum inhibitory concentration (MIC) of infectious microbes rather than classification in terms of susceptible and resistant can be reported. In parallel, increasingly sophisticated TDM technology is becoming available ensuring that TDM is feasible and can deliver personalized antibiotic dosing schemes. There is an obvious need for extensive studies that will quantify the improvements in clinical outcome of individual TDM-guided dosing. We suggest that a broad diagnostic and medical investigation of the TDM arena, including marke

Processes leading to deep convection and sensitivity to sea-state representation during HyMeX IOP8 heavy precipitation event

International audienc