On the assimilation of ice velocity and concentration data into large-scale sea ice models

Data assimilation into sea ice models designed for climate studies has started about 15 years ago. In most of the studies conducted so far, it is assumed that the improvement brought by the assimilation is straightforward. However, some studies suggest this might not be true. In order to elucidate this question and to find an appropriate way to further assimilate sea ice concentration and velocity observations into a global sea ice-ocean model, we analyze here results from a number of twin experiments (i.e. experiments in which the assimilated data are model outputs) carried out with a simplified model of the Arctic sea ice pack. Our objective is to determine to what degree the assimilation of ice velocity and/or concentration data improves the global performance of the model and, more specifically, reduces the error in the computed ice thickness. A simple optimal interpolation scheme is used, and outputs from a control run and from perturbed experiments without and with data assimilation are thoroughly compared. Our results indicate that, under certain conditions depending on the assimilation weights and the type of model error, the assimilation of ice velocity data enhances the model performance. The assimilation of ice concentration data can also help in improving the model behavior, but it has to be handled with care because of the strong connection between ice concentration and ice thickness. This study is first step towards real data assimilation into NEMO-LIM, a global sea ice-ocean model

Au large de Villefranche-sur-Mer – La rade

Tout au long de ce chantier organisé durant le mois de novembre 2015, nous avons travaillé dans des conditions météorologiques exceptionnelles. Du beau temps du début à la fin avec des eaux offrant une température de 20 à 18° fin novembre. Pas de courant, une eau limpide, aucune plongée annulée pour raison météo durant cette nouvelle prospection… Ces conditions météorologiques de fin d’été nous ont posé cependant un problème primordial pour nos fouilles. S’il est préférable de travailler dans..

Au large de Villefranche-sur-Mer – La Rade

Durant cette nouvelle prospection archéologique 2014, les découvertes effectuées lors des immersions ont été, une fois encore, à la hauteur de nos espérances. La météo défavorable à cette période de l’année a bien souvent des effets positifs pour notre prospection car les coups de mer dégagent totalement la partie supérieure du fond marin de la rade. Du coup, le bilan du mobilier sauvegardé lors de cette mission 2014 est exceptionnel. Sauvés des eaux, ces précieux témoignages du passé, minuti..

Alimentação e saúde oral

Dissertação para obtenção do grau de Mestre no Instituto Universitário Egas MonizPara ter boa saúde oral, a alimentação desempenha um papel importante. Terá um impacto definitivo na suscetibilidade pessoal de poder ser afetado por cáries ou erosão dentária. A influência dos alimentos cariogénicos na cavidade oral pode ser modificada ou diminuída pela ingestão de alimentos protetores ou pelo aumento do consumo de alimentos não-cariogénico, ou vitaminas e minerais. Vamos analisar os fatores de risco para cárie dentária e erosão e saber como preveni-los. Pessoas com distúrbios alimentares como anorexia nervosa e bulimia nervosa terão maior propensão para cáries e erosão dentária do que pessoas que não são afetadas. Isso deve se à frequência de ingestão de alimentos e aos tipos de alimentos ingeridos, muitas vezes má nutrição, rica em carboidratos, associados ou não a práticas compensatórias inadequadas, como vómitos ou uso de laxantes ou diuréticos.To have good oral health, nutrition plays an important role. It will have a significant impact on the personal susceptibility to caries or dental erosion. The influence of cariogenic foods on the oral cavity can be modified or decreased by eating protective foods or by increasing the consumption of non-cariogenic foods, or vitamins and minerals. We will look at the risk factors for tooth decay and erosion and how to prevent them. People with eating disorders such as anorexia nervosa and bulimia nervosa will have a higher propensity for tooth decay and erosion than people who do not have it. This is due to the frequency of food intakes and the types of foods ingested, which are often bad carbohydrate-rich diets, and may or may not be associated with inadequate compensatory practices, such as vomiting or the use of laxatives or diuretics