Six years ago, we compared the climate sensitivity of 19 atmospheric general circulation models and found a roughly threefold variation among the models; most of this variation was attributed to differences in the models' depictions of cloud feedback. In an update of this comparison, current models showed considerably smaller differences in net cloud feedback, with most producing modest values. There are, however, substantial differences in the feedback components, indicating that the models still have physical disagreements

Many motion detection and tracking algorithms rely on the process of background subtraction, a technique which detects changes from a model of the background scene. We present a new algorithm for the purpose of background model initialization. The algorithm takes as input a video sequence in which moving objects are present, and outputs a statistical background model describing the static parts of the scene. Multiple hypotheses of the background value at each pixel are generated by locating periods of stable intensity in the sequence. The likelihood of each hypothesis is then evaluated using optical flow information from the neighborhood around the pixel, and the most likely hypothesis is chosen to represent the background. Our results are compared with those of several standard background modeling techniques using surveillance video of humans in indoor environments.

Shoulder dystocia may be anticipated in cases involving short women and discrepancy between maternal height or weight and infant weight.

No abstract

No abstract

To cite this article: Emmanuelle Cohen-Solal & Hervà Le Treut (1997) Rôle of the oceanic heat transport in climate dynamics A sensitivity study with an atmospheric general circulation model, Tellus A: Dynamic Meteorology and Oceanography, 49:3, 371-387, ABSTRACTEstimating meridional ocean heat transport from the present generation of atmospheric general circulation models, assuming energetic equilibrium, leads to a large variety of results, depending on the model. The current uncertainty on such an important process may cause significant errors in coupled atmosphere/ocean models. To determine the possible nature of these errors, we investigate how the prescription of the oceanic heat transport can affect the results of a coupled surface ocean/atmosphere model where the ocean is limited to thermodynamics and turbulent fluxes but sea-ice is included. In particular, we study the response of the surface fluxes and atmospheric transport to a reduction of the ocean transport. We focus on the initial phase, where these feedback effects begin to develop while the model is still realistic. The model response is strongly dependent on a combination of features: changes in the Hadley cell circulation, the atmospheric heat transport, the radiative and turbulent fluxes at the surface, changes of the radiative fluxes at the top of the atmosphere. In this study, we examine the partitioning between these different effects. It is shown that the atmosphere partly takes up the missing ocean transport, but that this leads to a change in the cloud/radiative equilibrium of the ITCZ region.

No abstract

No abstract