http://www.adv-sci-res.net/Advances in Science and Research Latest Articleshttp://www.adv-sci-res.net/4/99/2010/<b>Describing the possible climate changes in France and some examples of their effects on main crops used in livestock systems</b><br /><br />Advances in Science and Research, 4, 99-104, 2010<br /><br />Author(s): F. Ruget, J.-C. Moreau, M. Ferrand, S. Poisson, P. Gate, B. Lacroix, J. Lorgeou, E. Cloppet, and F. Souverain<br /><br />The effects of climate change on forage and crop production are an important question for the farmers and more largely for the food security in the world. Estimating the effect of climate change on agricultural production needs the use of two types of tools: a model to estimate changes in national or local climates and an other model using climatic data to estimate the effects on vegetation. In this paper, we will mainly present the effects of climate change on climatic features, the variability of criteria influencing crop production in various regions of France and some possible effects on crops.2010-08-02T00:00:00+02:00http://www.adv-sci-res.net/4/89/2010/<b>Evaluating multi-scale precipitation forecasts using high resolution analysis</b><br /><br />Advances in Science and Research, 4, 89-98, 2010<br /><br />Author(s): C. Wittmann, T. Haiden, and A. Kann<br /><br />The SAL (Structure, Amplitude, Location) method is used for verification of precipitation forecasts at horizontal grid spacings ranging from 2.5 km to 25 km, using a high-resolution 1 km precipitation analysis as a reference. The verification focuses on a summertime period with predominantly convective precipitation. The verification domain contains lowland as well as alpine areas. Evaluation of the individual SAL components shows that with regard to area mean values (<i>A</i>) the benefit of high resolutions models becomes apparent only in high impact weather situations. For the summertime period studied, the subjective impression of better structured precipitation fields (<i>S</i>) in higher resolution models can generally be confirmed. The most significant improvement appears to be associated with explicit simulation of deep convection.2010-07-15T00:00:00+02:00http://www.adv-sci-res.net/4/83/2010/<b>WRF model and ASAR-retrieved 10 m wind field comparison in a case study over Eastern Mediterranean Sea</b><br /><br />Advances in Science and Research, 4, 83-88, 2010<br /><br />Author(s): M. M. Miglietta, S. Zecchetto, and F. De Biasio<br /><br />In Synthetic Aperture Radar (SAR) imagery, signatures of coherent atmospheric structures, due to sea surface roughness modulation by surface winds, are usually well detected. In the present study, the wind field derived from the Envisat Advanced SAR (ASAR) sensor has been analyzed and compared with those simulated with a regional atmospheric model in a case study over an area located in the eastern Mediterranean Sea, extending southward and eastward of Crete island. This is a region subject to complex wind patterns, due to the interaction of the almost steady northerly Etesian wind with the orography of the islands in the region. <br><br> The ASAR Wide Swath Mode images provide datasets at resolutions exceptionally high compared to model data, appropriate for investigating the mesoscale phenomena on the marine atmospheric boundary layer and to retrieve the surface wind field. The latter has been obtained with a methodology based on the 2-D Continuous Wavelet Transform, suitable to isolate the backscatter patterns on the base of energy and scale considerations. <br><br> Numerical simulations with the Weather Research and Forecasting (WRF) model have been performed using three 2-way nested domains, the inner one covering the area of interest with a resolution of 1 km. Several simulations, using different diffusion and boundary layer parameterization schemes, have been performed in a case study corresponding to mountain lee waves detected in the ASAR image. The 10 m winds resulting from the numerical experiments have been compared to those retrieved from the ASAR, both quantitatively and qualitatively, in order to analyze the correspondence of observed and simulated wind structures.2010-07-01T00:00:00+02:00http://www.adv-sci-res.net/4/77/2010/<b>Tornado-type stationary vortex with nonlinear term due to moisture transport</b><br /><br />Advances in Science and Research, 4, 77-82, 2010<br /><br />Author(s): P. B. Rutkevich and P. P. Rutkevych<br /><br />Tornado vortex is believed to be essentially nonlinear phenomenon; and the puzzle to choose the nonlinear term(s) responsible for its formation is still unresolved. In the present work we consider the nonlinear term associated with atmosphere humidity, by introducing variable temperature gradient depending on the vertical velocity of the fluid. Such term is able to yield energy to the system and is very suitable for such a problem. Other nonlinear terms are neglected, assuming slow rotation, or in other words a "weak" tornado approximation. We consider one-dimensional radial boundary problem, and use a modificaiton of shooting method to satisfy boundary conditions at large radii. Obtained numerical solutions of the nonlinear differential equation qualitatively agree with the observed atmosphere vortices (tornados, tropical cyclones). The obtained results show general possibility of existence of unstable motion even in convectively stable atmosphere stratification.2010-06-14T00:00:00+02:00