abstractâ in this study, for spatial-temporal analyzing of cyclones in 1376, the spatial range of 30 to 80 degrees of east longitude and 0 to 80 degrees of north latitude and geo potential data with 2/ 5* 2 / 5 degrees of networking in arc levels of 1000, 925, 850, 700, 600 and 500 hpa have been used. these data are extracted for six hours (00, 06, 12, 18 zulu) database (ncep / ncar). so that, ...

abstractâ iran country due to laying in the desert belt on the northern hemisphere, are dry and desert climate of many parts of it predominate. due to the same location in the atmospheric loss of human life and animal life and it has an important role. and according to the moisture sources in the country and located outside of the atmospheric loss from year to year fluctuations have other roles...

in this study, frequency and location of frontogenesis related to heavy rainfall have been analyzed using environmental to circulation approach. based on the threshold of upper 99 percent, we selected 125 days of the super and overall heavy rainfall from irimo data base (included 1437 synoptic, climatic and rain gage stations from 21/3/1961 up to 31/12/2004). frontogenesis frequency and their l...

Within this study we present a robust method for generating precipitation time series for the Anas catchment in North Western India. The method employs a multivariate stochastic simulation model that is driven by a time series of objectively classified circulation patterns (CPs). In a companion study (Zehe et al., 2006) it was already shown that CPs classified from the 500 or 700 Hpa levels are...

The meteorological conditions during the period of spring transition over the Middle East and the Persian Gulf and adjacent land area is investigated. Monthly and seasonal variations of large-scale atmospheric patterns and wind aloft features at different levels were drawn from data collected from the National Centers for Environmental Prediction and National Center for Atmospheric Researches. ...

Ahvaz can be regarded as one of the most polluted cities in the world in terms of air pollution. Successive years of drought and weather conditions in recent years have resulted in particulate matter (PM10) concentration in Ahvaz. In this study, using probability distribution techniques, an appropriate threshold to identify the PM10 maximum extreme concentrations (MEC) has been detected. Based ...

introduction climate change is an important environmental hazard that has been discussed in recent years. increasing the number or frequency of extreme climatic events such as severe droughts, floods, storms, heat and cold waves and heavy rains are the evidences of climate change. any of these events, due to the severity and persistence and their spread are a natural hazard that adverse effects...

Ahvaz can be regarded as one of the most polluted cities in the world in terms of air pollution. Successive years of drought and weather conditions in recent years have resulted in particulate matter (PM10) concentration in Ahvaz. In this study, using probability distribution techniques, an appropriate threshold to identify the PM10 maximum extreme concentrations (MEC) has been detected. Based ...