in this study, a new array of meteorological elements and a synoptic climatologic classification to produce abaseline climate and to derive meteorological factors that are effective on air pollution in tehran, which is located in a semi-enclosed basin was developed. the data set includes daily sea-level pressure and 500mb geopotential height fields from ncep-ncar and tehran upper air sounding d...

An intriguing manifestation of the underlying nonlinear fluid dynamic character of the atmosphere is found in a simple quasi-geostrophic model of the troposphere. For identical forcing and dissipation, the model’s climate is found to depend sensitively upon the choice of initial conditions, tending either toward a state resembling the current Northern Hemisphere wintertime circulation, characte...

Diagnosing the climate of New Zealand from low-resolution General Circulation Models (GCMs) is notoriously difficult due to the interaction of the complex topography and the Southern Hemisphere (SH) mid-latitude westerly winds. Therefore, methods of downscaling synoptic scale model data for New Zealand are useful to help understand past climate. New Zealand also has a wealth of palaeoclimate-pr...

Stratus clouds are important in the regulation of the earth’s radiation budget and so play an important role in climate over both the land and ocean. Therefore, it is necessary that adequate observational databases exist for both continental and maritime boundary layer clouds. Stratus cloud and environmental properties may vary as a function of the large-scale synoptic regime. These differences...

extended abstract 1. introduction climate change refers to the increase or decrease in the average climatic factors over a long period of time (i.e. more than 30 years). today, climate change has become a human concern and the scientific community are already aware of this fact. global temperature has followed an unprecedented increase over the last hundred years. based on synoptic climatology,...

Cold air drainage and pooling occur in many mountain valleys, especially at night and during winter. Local climate regimes associated with frequent cold air pooling have substantial impacts on species phenology, distribution and diversity. However, little is known about how the degree and frequency of cold air drainage and pooling will respond to a changing climate. Evidence suggests that, beca...