A model intercomparison of changes in the Atlantic thermohaline circulation in response to increasing atmospheric CO2 concentration

As part of the Coupled Model Intercomparison Project, integrations with a common design have been undertaken with eleven different climate models to compare the response of the Atlantic thermohaline circulation ( THC) to time-dependent climate change caused by increasing atmospheric CO2 concentration. Over 140 years, during which the CO2 concentration quadruples, the circulation strength declines gradually in all models, by between 10 and 50%. No model shows a rapid or complete collapse, despite the fairly rapid increase and high final concentration of CO2. The models having the strongest overturning in the control climate tend to show the largest THC reductions. In all models, the THC weakening is caused more by changes in surface heat flux than by changes in surface water flux. No model shows a cooling anywhere, because the greenhouse warming is dominant.

Dynamic sea level changes following changes in the thermohaline circulation

Using the coupled climate model CLIMBER-3α, we investigate changes in sea surface elevation due to a weakening of the thermohaline circulation (THC). In addition to a global sea level rise due to a warming of the deep sea, this leads to a regional dynamic sea level change which follows quasi-instantaneously any change in the ocean circulation. We show that the magnitude of this dynamic effect can locally reach up to ~1m, depending on the initial THC strength. In some regions the rate of change can be up to 20-25 mm/yr. The emerging patterns are discussed with respect to the oceanic circulation changes. Most prominent is a south-north gradient reflecting the changes in geostrophic surface currents. Our results suggest that an analysis of observed sea level change patterns could be useful for monitoring the THC strength.

Climate simulation for 125 kyr BP with a coupled ocean-atmosphere general circulation model

The ECHAM-1 T21/LSG coupled ocean-atmosphere general circulation model (GCM) is used to simulate climatic conditions at the last interglacial maximum (Eemian. 125 kyr BP). The results reflect thc expected surface temperature changes (with respect to the control run) due to the amplification (reduction) of the seasonal cycle of insolation in the Northern (Southern) Hemisphere. A number of simulated features agree with previous results from atmospheric GCM simulations e.g. intensified summer southwest monsoons) except in the Northern Hemisphere poleward of 30 degrees N. where dynamical feedback, in the North Atlantic and North Pacific increase zonal temperatures about 1 degrees C above what would be predicted from simple energy balance considerations. As this is the same area where most of the terrestrial geological data originate, this result suggests that previous estimates of Eemian global average temperature might have been biased by sample distribution. This conclusion is supported by the fact that the estimated global temperature increase of only 0.3 degrees C greater than the control run ha, been previously shown to be consistent a with CLIMAP sea surface temperature estimates. Although the Northern Hemisphere summer monsoon is intensified. globally averaged precipitation over land is within about 1% of the present, contravening some geological inferences bur not the deep-sea delta(13)C estimates of terrestrial carbon storage changes. Winter circulation changes in the northern Arabian Sea. driven by strong cooling on land, are as large as summer circulation changes that are the usual focus of interest, suggesting that interpreting variations in the Arabian Sea. sedimentary record solely in terms of the summer monsoon response could sometimes lead to errors. A small monsoonal response over northern South America suggests that interglacial paleotrends in this region were not just due to El Nino variations.

La circulation de monnaie carolingienne dans la péninsule ibérique. À propos d’un denier de l’atelier de Roda

Les trouvailles de monnaies carolingiennes dans la péninsule ibérique sont peu abondantes, surtout pour les pièces frappées dans la Marche d’Espagne. Cet article présente l’état des connaissances sur cette question à propos d’un fragment de denier carolingien trouvé dans les fouilles archéologiques du site d’El Tolmo de Minateda (Hellín, Albacete, Espagne). Il s’agit d’une émission de Charlemagne de l’atelier de Roda, situé dans la Marche d’Espagne, atelier dont on ne connaissait jusqu’à maintenant qu’une seule pièce pour ce souverain franc. Le contexte stratigraphique de ce denier apporte une donnée intéressante sur le moment de son utilisation et en fait un des plus anciens exemples de la circulation de monnaies carolingiennes dans la Péninsule ibérique.

Terapêutica na insuficiência cardíaca aguda

Trabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2014

La justification des atteintes aux libertés de circulation : cadre méthodologique et spécificités matérielles = Justification of attacks on freedom of movement: methodological framework and specific hardware. Research Paper in Law 01/2013

No abstract.

La consécration du critère de l’« accès au marché » au sein de la libre circulation des marchandises: mythe ou réalité? = Consecration of the criterion of "market access" in the free movement of goods: myth or reality? Research Papers in Law, 04/2011

No abstract.