شناسایی و تحلیل سینوپتیکی امواج گرمایی غرب ایران (ایلام، خوزستان، لرستان، کرمانشاه)

امواج گرمایی یکی از بلایای طبیعی و آب‌و‌هوایی است که آثار زیانباری بر محیط زیست دارد. در این پژوهش سعی شد امواج گرمایی منطقه غرب ایران شامل چهار استان ایلام، خوزستان، لرستان و کرمانشاه با شاخص دمایی و شاخص رطوبت شناسایی شده و نیز دوره بازگشت این امواج با استفاده از تابع توزیع گمبل مشخص شود و در نهایت الگوهای همدیدی موثر در آن شناسایی شود. براساس نتایج، مجموع فراوانی امواج گرمایی استخراج‌شده در دوره آماری مورد مطالعه 143 موج است که از این تعداد، 70 موج در دوره گرم و 73 موج در دوره سرد سال رخ‌ داده است. بررسی ماهانه امواج گرمایی نشان می‌دهد که بیشترین میزان وقوع امواج در ماه فروردین بوده است. تحلیل سینوپتیک رخداد امواج گرم در طی فصول نشان می‌دهد که در فصل گرم، زبانه‌های کم‌فشار گنگ تا نواحی مرکزی ایران کشیده شده و حتی زبانه‌های آن تا شمال شرق ایران نفوذ کرده است. در زمان رخداد این امواج، در سطح زمین کم‌فشارهای حرارتی متعددی بر روی شاخ آفریقا، اروپا، عراق و عربستان بسته‌ شده و زبانه‌های کم‌فشار تشکیل‌شده روی عربستان قسمت‌های جنوب، جنوب غرب و بخش‌هایی از غرب ایران را تحت تاثیر قرار داده است. بررسی شرایط همدیدی امواج گرمایی دوره سرد نشان می‌دهد که منطقه تحقیق، جلوِ جبهه گرم قرار داشته و نفوذ هوای گرم به منطقه سبب افزایش دما در این هنگام از سال شده است.

Identification and Analysis of Synoptic of Heat Waves in West of Iran (Case Study: Ilam, Khouzestan, Lorestan, Kermanshah)

Heat wave has harmful effect on environment and human life. First of all, this research identifies the heat wave of four provinces of Ilam, Kermanshah, Lorestan, and Khuzestan, for the period between 2000 and 2010. This study uses the heat index, and the return period of this wave using the Gambel distribution function. According to obtained results, total redundancy of extracted heat waves was detected as 143,  which 70 waves of this amount have been in warm period and  73 waves in cold period of the years. Monthly process of thermal waves shows that the highest wave was occurred in the month of Farvardin. Process the maps of surface pressure of the earth during warm period of the year shows that low pressure tabs of Ganges had pulled near the central Iran, even its tabs in to north east of Iran and the center of Iran is lowpressure heat. In time of occurrence of this wave, there was pressure heat occurred in the earth surface from Horn of Africa, Europe, Iraq, and Saudi Arabia. Hence, the low pressure tab of Saudi Arabia has been affected southern, southwestern, and western parts of Iran. Synoptic Process of the heat wave condition shows that area is located in front of the hot air and the influence of hot air on the area has caused the temperature rise at this time of the year.1. IntroductionHeat wave is one of the most important natural disaster and weader conditions. That has harmful effect on environment and human life. heat wave is a warm period that is stable for several days to several weeks and maybe com with violent wet. Generally, increasing the temperature degree in extreme heat waves can cause the destruction of agriculture product and loss communities of the plant societies and ecosystems and also human death. Heat wave with Decrease the Photosynthesis measure in farm plants cause deacres the plants prrformance in measure product of the seed and fruit. One heat wave in could period of year  can have violent Damage on garden product from the way of hasty awaking in fruit tree and  deacres of Fertility of tree. according to the importance and effect of tempreture on inviromental  condition and also the roles on big and small  plans,  pattern modeling the Temperature  behavior, sience circle specially in the recent year had a great attenticn .2. Methodologyin this research first of all identify the  heat wave of  the west of iran area . that consist of four state ilam Kermanshah lorestan and Khuzestan  that we  identify  and return period of this wave with the using of Gambel distribution function and finally similar pattern    concentrated on area in  days who introuduce heat wave for this reason. Thereupon we recive the datas on surface  of earth from the Meteorological Organization for the period of time we ricive between 2000 to 2010 and then by this data and the using of  heat index and hum index (this tow index in order to using given apparent temperature is by Meteorological Service of Canada). identified heat wave In Excel spreadsheet software for this priod  of time is   and statistic Analysis is done  by Gambel distribution function that is suitable Distributive in order to study  Phenomena climate extremes. Then the Synoptic Analysis of wave of statistic we Analysis of the similar heat wave for this work were need a Representative days for per  period of heat wave that we choice this Representative days   at the middle of the wave Because is For each wave has a peak day that  after that  the temperature decreases again. Approximately 85% of this threshold or the peak temperature that day was the middle. after assiynmen  of  represent day  we astart make  the maps of dffernt level of the atmosphere by receive of the datas of the noa website. this maps consist of  geo potential height and moving tempreture.Index heat =  –42/379 + 2.04901523T + 10/14333127Rh – 0/22475541T a Rh – (6/83783 × 10 –3 T a2 ) – (5/481717 × 10 –2 Rh2 ) + (1/22874 × 10 –3 T a2 Rh) + (8/5282 × 10 –4 T a Rh2 ) – (1/99 × 10 –6 T a 2 Rh2 )(1)Humindex =Ta+HH =/05555(e10)e= 6/11 exp(5417/7530×(( )( )))(2)3. Results and discussionTotal heat waves extracted wave was detected in the study statiscic period 144  that this nummbers 70 in warm period and  73 waves in cold period of the years had happened. The durability of these waves  distincted wave two to 25 days. most occurrence waves of  tow, three, and  four allot of ten day wave with return period of 25 year with the average of apparent temperature of 55.5 C period return of the wave of 15 day and upper 50 year and more was calculated. Monthly process of therm waves shows that during of 11 year satistic(20002010). Highest of waves occurrence was in farvardin month and also in The event  heat waves in could period of year and more event is in winter season.  Plenty of waves in this season more is in day and esfand month. Process the maps of pressure of surface of the earth during the warm period of the year shows that Low pressure tabs of Ganges had pulled near the centeral iran, even its tabs in  to north east of iran and the center of iran is lowpressure heat. In time of occurence of this wave in the earth surface of the –pressure heat on the branch of the Africa, Europe. araq and saudi Arabia had been closed. That are from the kind of termal and showing the violent heat that is excit at the surface of the earth. Low pressure of Saudi Arabia one of the most important effective of wave occurrence of the heat That are from the kind of termal and showing the violent heat that is excit at the surface of the earth. Low pressure of Saudi Arabia one of the most important effective of wave occurrence of the heat That tabs effectet the south  southwest and  the parts from the west of iran. Synoptic Process of the heat wave condition shows that plan pattern pressure surface of the earth and height topografhy in the west of iran is ahighpressure pattern. Also, shows that area is located in front of the hot air and the influence of hot air on the area has caused the temperature rise at this time of the year.