List of Articles بندال

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  1 - Climatic Monitoring of Snow Days in Zahedan
  sayyed mohammad hosseini abdolreza kashki
  In this regard, the present study investigated the climatic of the Zahedan snow days since 1976 over a period of 40 years. To achieve this goal, two databases were used. First databases; the present weather codes are related to the snow phenomenon, which was collected d More

  In this regard, the present study investigated the climatic of the Zahedan snow days since 1976 over a period of 40 years. To achieve this goal, two databases were used. First databases; the present weather codes are related to the snow phenomenon, which was collected daily from the Meteorological Organization. The second database, relates to the daily data of sea level pressure and geopotential height in the troposphere from National Center for Environmental Prediction (NCEP). With Environmental to Circulation Technic and cluster analysis, weather patterns causing snow days, identified. The results of the analysis showed that, snowfall in Zahedan is concentrated in autumn and winter seasons (December, January, February and March). At sea level pressure, integration patterns of Siberian-Caspian high-pressure migrants with 32.5% and Siberian-Caucasian highs with 20%, play the most roles in snowfall event. Also in the middle troposphere, Turkmenistan's ridge and Blocks (cut-off high) account for 42.5% and the European omega block pattern accounts for 25% of the snowfall frequency. It seems that the simultaneous activity of atmospheric disturbances in the immigrant high pressure systems of the Siberian, European, Caucasian, Russian and Caspian, deep ridge polar latitudes and its extension to the lower latitudes, It will exacerbate showers and temperatures, cold weather and snowfall. Manuscript profile
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  2 - The study of two cases of severe flooding over the Eastern Azerbaijan Province from the synoptical and kinematic view and coincident of these events with GFS precipitation forecast (period on 2000-2010)
  Kh. Porjavad Asl F. Arkian
  Our statistical study showed that during period 2000-2010, Eastern Azerbaijan Province was threated by numerous severe floods. These occurred during spring with a frequency of 66% and summer with 28% and fall with 4% and winter with only 2% frequency. From damages viewp More

  Our statistical study showed that during period 2000-2010, Eastern Azerbaijan Province was threated by numerous severe floods. These occurred during spring with a frequency of 66% and summer with 28% and fall with 4% and winter with only 2% frequency. From damages viewpoint, we selected two of most severe floods of the province to work on. The first one was in Tabriz city, centre of Eastern Azerbaijan Province, on 14th of May 2007. The other one occurred in Mianeh city on 18th of June 2009. For studying the two severe floods, we analyzed synoptic charts at all standard levels for 13-15th of May 2007 and 17-19th of June 2009. We found an inverted thermal trough at the earth’s surface impacting with baroclinic short waves trough that moving fast from west to east over the region. The above features were induced by two blocking patterns. First one was a blocking high, located over north of Siberia, and second one was a Cut-off low, located over north of central Europe. The magnitude of upward mention over 700hpa level troughs,  was and magnitude of absolute vorticity over 500hpa, level troughs were in the range of  . the main pattern for the second flood, occurred in Mianeh, was also an inverted thermal trough at the earth’s surface, impacting a could cut-off low in middle and upper troposphere, located over Turkey for this case, we found that the magnitude of upward motion in the centre of cut-off low at 700hpa was  and magnitude of absolute vorticity in the center of cut-off low at 500hpa was  but at the same time absolute vorticity over the province was . The total daily amounts of precipitation forecast from GFS model was in a good harmony with recorded daily precipitation in the stations for the Mianeh flood but for Tabriz’s flood, the result was not appropriate. Manuscript profile
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  3 - Statistical and synoptical analyses of fog event in Rasht International Airport
  F. Arkian T. Saberi H. Ardakani M. T. Zamanian
  To better understand of fog events in the Rasht Airport, to improve the forecast accuracy, some statistical and synoptical analyses studied by 800m and less horizontal visibility during years 2000-2009. In this research, some parameters such as horizontal visibility, te More

  To better understand of fog events in the Rasht Airport, to improve the forecast accuracy, some statistical and synoptical analyses studied by 800m and less horizontal visibility during years 2000-2009. In this research, some parameters such as horizontal visibility, temperature, dew point deficit, relative moisture and winds speed on onset hour and in the duration of the event have been analyzed. Frequency percent of fog events was calculated for all month during 2000-2009. Frequency of occurrence increases in the colder months especially in February is about 24.64 .The occurrence frequency of long duration fog events  that begin between  1800 UTC to 2100 UTC hour  is more than 2100 UTC to 0300 UTC hour; and the most fog events terminate  nearby sunrise. The horizontal visibility at the onset time was lower (100m) for long duration fog events. In the most events, dew point deficit and relative humidity at the fog onset time were calculated zero and 80% respectively. Low wind speeds (0-0.2 ms-1) have long been known to favor fog development. Studied on Synoptic fog eventsshows that the most important  patterns in long duration fog events development are blocking pattern, Col region  and  inversion in cold season.  Manuscript profile