1. introduction heavy snow hazards, although have less frequency in comparison with extreme weather events such as freezing, but are major hazards in midlatitudes (smith, 2009, 196). heavy snow damages manmade structures, crops, casualties, even between urban and rural ways of blocking.(briant. 69, 2005. ohara et al, 2009, 1611). various definitions have been offered for heavy snow, those are c...

A strong link exists between stratospheric variability and anomalousweather patterns at the earth’s surface. Specifically, during extreme variability of the Arctic polar vortex termed a ‘‘weak vortex event,’’ anomalies can descend from the upper stratosphere to the surface on time scales of weeks. Subsequently the outbreak of cold-air events have been noted in high northern latitudes, as well a...

The impacts of climate change on tropospheric transport, diagnosed from a carbon monoxide (CO)-like tracer 15 species emitted from global CO sources, are evaluated from an ensemble of four chemistry-climate model (CCMs) contributing to the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). Model time-slice simulations for present-day and end of the 21 century conditions w...

[1] A significant correlation between the annual cosmic ray flux and the amount of low clouds has recently been found for the past 20 years. However, of the physical explanations suggested, none has been quantitatively verified in the atmosphere by a combination of modelling and experiment. Here we study the relation between the global distributions of the observed low cloud amount and the calc...

The spectrum of Uranus has been recorded in Oct.–Nov. 2002, between 4.6 and 5.0 μm, using the ISAAC imaging spectrometer at the VLT-UT1 (ANTU) 8-m telescope of ESO. The spectral resolving power was 1500. In addition to a few strong H3 emission lines, the spectrum of Uranus distinctly shows the emission lines of the CO(1–0) band from R7 to P8. The relative intensity distribution of the observed ...

dust storms are destructive climate phenomenon which damage farm, installations,roads,traffic and etc indemnifiable. this phenomena at dry and pertaining regions of the country as environmental perils, is effected by particular atmospheric condition.if the origin and extention of this phenomenon be recognized the damages can be decreased or counteracted.the studied about dust storm show thirtee...

Net vertical air mass export by thermally driven flows from the atmospheric boundary layer (ABL) to the free troposphere (FT) above deep Alpine valleys was investigated. The vertical export of pollutants above mountainous terrain is presently poorly represented in global chemistry transport models (GCTMs) and needs to be quantified. Air mass budgets were calculated using aircraft observations o...