This paper qualifies the effect of different convection schemes and center-domains on the simulation of winter precipitation over Iran using RegCM3 numerical climate model. It is compressible, finite difference with hydrostatic equilibrium in sigma coordinate with a semi-implicit algorithm for reduction of horizontal diffusion. Iran experienced two dry and wet periods during winters of 1997 and...

The long-standing mainstay of support for C. T. R. Wilson’s global circuit hypothesis is the similarity between the diurnal variation of thunderstorm days in universal time and the Carnegie curve of electrical potential gradient. This rough agreement has sustained the widespread view that thunderstorms are the ‘‘batteries’’ for the global electrical circuit. This study utilizes 10 years of Trop...

An archive of land-based, surface-observed cloud reports has been updated and now spans 39 years from 1971 through 2009. Cloud-type information at weather stations is available in individual reports or in long-term, seasonal, and monthly averages. A shift to a new data source and the automation of cloud reporting in some countries has reduced the number of available stations; however this datas...

■ Abstract The influence of surface orography on patterns of precipitation gives rise to some of the most pronounced climate gradients on Earth, and plays a fundamental role in the interaction between the atmosphere and the rest of the Earth System on a wide variety of time scales. The physical mechanisms involved comprise a rich set of interactions encompassing fluid dynamics, thermodynamics, ...

so far several methods have been developed for mapping and interpolation of isohyets.one of the recently accepted methods is geographically weighting regression which is suitable for evaluation of spatial heterogeneity of dependent variable by using local regressions. in order to evaluate annually precipitation spatial variation, this study was conducted in gilan province which precipitation is...

[1] The focus of this study is on the role of precipitation uncertainty in the estimation of soil texture and soil hydraulic properties for application to land-atmosphere modeling systems. This work extends a recent study by Santanello et al. (2007) in which it was shown that soil texture and related physical parameters may be estimated using a combination of multitemporal microwave remote sens...

Climate change is one of the major global issues commonly concerned by international communities. Taking the Three Gorges Reservoir which is the largest water conservancy project in China as the object, this study attempts to clarify the current conditions of water resources and water environment especially the spatial distribution characteristics of water resources amount and main non-point so...