Professor Ghasem Azizi, , Leyla Sharifi,
Volume 17, Issue 47 (12-2017)
Abstract
Thunderstorms are major climatic events due to the significant effects and catastrophic consequences on humans and the natural environment. The researches have shown that the elevation and latitude factors are two variables that can affect the occurrence of this phenomenon. Therefore, the main aim of this study is to investigate the spatial analysis of the effects of lightning and its effects on the components such as elevation and geographic extent in Iran. Apart from this fact, firstly, the monthly data of thunderstorms occurrence in 118 synoptic stations of Iran, from 1991 to 2010 on a basis from the country's meteorological organization were obtained and GIS software was produced by the annual and seasonal maps of Iran. Then, for the spatial analysis of this climatic phenomenon, the method of landing statistics of the Kriging (Universal) method was to examine its seasonal and annual status. In order to better understand the effect of Thunder hurricanes from altitude and latitude using Curve Expert software, seasonal and annual charts, along with the correlation of each production, were analyzed. The results show that the highest annual thunderstorms occur in the northwest of Iran, and the least amount is consistent with the central and eastern parts of the country. In addition, according to seasonal analysis, although the station has the highest rate at 800 to 1,300 meters, the maximum occurrence of this phenomenon varies from 0 to 2200 meters in different seasons of the stations. The overall result shows that the factor of height is slightly correlated with the occurrence of the Thunder storm phenomenon and the highest correlation is due to the latitude factor.
Dr Batool Zeinali, Sima Khalili, Saideh Eiyni,
Volume 19, Issue 53 (6-2019)
Abstract
The aim of current research is atmospheric hazards climate zoning in Iran Northwest. So meteorological organization data were used in cases such as mean temperature , minimum temperature , maximum temperature, precipitation in monthly and daily scale for 13 synoptic stations in range of East Azerbaijan province, West Azerbaijan province) and Ardebil province during 26 years. (1990-2015) in this research , it was investigated 10 main atmospheric hazards such as famine or drought , hailstone,, heavy snow , thunder storm, severe precipitation, margin precipitation , blizzard , fogging , dust storm in range of Northwest bound. Then happening frequency maps were prepared with separating form for hazards by using Geographic information system. (GIS) Also spatial zoning maps were prepared for every class. Finally by combining all of hazards investigation; it was prepared Northwest region atmospheric hazards extensive map. Results show that, East, Southeast, center and West parts in Northwest region are located among most hazard zones based on happening frequency. But Northeast parts and zones have the least hazards. Also results express that blizzard and dust storm are main atmospheric hazards at Northwest regionThe highest hazard frequency in Northwest region relate to blizzard with 4148 hazards during 1990-2015 study period. The highest blizzard frequency in Ahar station is observed with 514 hazards. The second hazard in Northwest relate to dust phenomenon with 1948 cases. The highest frequency of mentioned case was observed in Maragheh station with 410 hazards. The third case in Northwest relate to thunder storm phenomenon with 1773 hazards. The sixth case relate to icing phenomenon with 1315 hazards meaning. The highest icing frequency is observed in Khalkhal station with 144 hazards. The seventh case relate to hailstone phenomenon at Northwest with 341 hazards. The highest of hailstone frequency is observed in Maragheh station with 56 hazards. The eighth case relate to fogging phenomenon with 333 hazards. The highest of fogging is observe in Ahar station with 135 hazards. The ninth case relate to famine or drought phenomenon at Northwest with 168 hazards. The highest of famine or drought frequency is observed in Urmia and Ardebil stations with 16 hazards totally. The highest margin precipitation is observed in Parsabad station with 19 hazards. The lowest frequency of margin precipitation relate to Makou and Khalkhal stations with 4 hazards totally.
Neamatallah Safarzaei, Alireza Entezari, Mokhtar Karami, Gholamali Khammar,
Volume 22, Issue 66 (9-2022)
Abstract
Today climate change cause increase in concentration of greenhouse gases has been cause increase extreme events and atmospheric hazards. goal of this research, analyze and review climate future is for atmospheric hazards in sistan region. In this study, to simulate minimum and maximum temperature data used from model data CanESM2 under three scenarios (RCP2.6, RCP4.5, RCP8.5) with SDSM statistical scrolling and to simulate rainfall data from the Hadcm3 model under scenarios (A1B, A2, B1) with statistical scrolling LARS-WG. For this purpose, after calibration, validation and data modeling at the selected station, the performance of the model from the viewpoint of the compliance of the base temperature data (1984-2005) and rainfall (1986-2015) with simulation values (2020-2039) evaluated at a significant level of confidence. To adapt base data to simulated data Used of the three criteria root mean square error (RMSE), coefficient of determination (R2) and mean squared error (MSE). According to simulated data were examined four important atmospheric hazard frost, heat waves, extreme precipitation and drought. The results showed that heat waves and drought in the future are serious threats in the region So that in 2021, under release scenario RCP 2.6, Predicted 32 heat waves and the study area will experience more than five heat waves in the year. In addition, most frequent drought forecast in 2020, under release scenario A1B. Extreme precipitation in some years under scenario B1 can be significant threat in the region. Intensity and abundance annual frost under release scenario RCP2.6 more than other scenarios and lower relative to investigated atmospheric threats.
