based on spi and rdi indices, changes in droughts in the semi-arid areas of west golestan province was assessed in the gis environment by incorporating data from hashemabad synoptic station and 11 climatic stations. after evaluating the ability of lars-wg5 in the simulation period (1984-2010), downscaling of hadcm3, ipcm, and gfc models was done as a group under scenarios of a1b, a2 and b1 to e...

abstract in this study we have used the monthly data resulted from the calculation of temperature and precipitation for a 52-year period (1951-2003). the doubling effect of carbon dioxide ( ) on temperature and precipitation was modeled as the most important climatic parameters. the resulting hythergraph and ambrothermic models for tabriz indicate monthly increases of temperature and precipitat...

A novel strategy is proposed for the efficient simulation of geochemical tracers in ocean models. The method captures the tracer advection and diffusion in a general circulation model (GCM) without any alteration (or even knowledge) of the GCM code. In comparison with offline tracer models, the proposed method is considerably more efficient and automatically includes all parameterizations of un...

[1] Spectrally resolved outgoing radiance is a potentially powerful tool for testing climate models. To show how it can be used to evaluate the simulation of cloud variability, which is the principal uncertainty in current climate models, we apply spectral empirical orthogonal function (EOF) analysis to satellite radiance spectra and synthetic spectra derived from a general circulation model (G...

because of low spatial resolution and simplifications in meteorological processes in global circulation models, they cannot sufficiently simulate the weather, comparing to the regional models; then, spatial and temporal downscaling of the gcm outputs are needed for decreasing errors of the global circulation models. there are two methods of downscaling: statistical and dynamic. weather generato...

Using General Circulation Models (GCMs) for tropical cyclone studies is difficult due to the relatively small size of the storms, the intense convection and multitudes of large-scale small-scale interactions. These are mostly unresolved at typical GCM resolutions of about 50-100 km, and still challenged at high resolutions between 12-30 km. Nevertheless, high-resolution GCMs are becoming a tool...

introduction numerous studies have demonstrated the relationship between the amount of co2 in the atmosphere and climate change. in this respect, developed countries have an undeniable role and cause serious damage to earth environment throughout the world. ipcc’ forth evaluation report implies that adding greenhouse gases to the atmosphere during recent decades prevents the heat rays to emit w...

The principal tools used to model future climate change are General Circulation Models which are deterministic high resolution bottom-up models of the global atmosphere-ocean system that require large amounts of supercomputer time to generate results. But are these models a cost-effective way of predicting future climate change at the global level? In this paper we use modern econometric techni...