ارزيابي اثر ناهنجاري هاي كره زمين بر دماهاي متوسط ماهانه و فصلي ايران

The Assessments of Global land-Oceans Mean Temperature Index on Monthly and Seasonal Mean Temperatures in Iran

اگر چه وجود يا عدم وجود تغيير اقليم جاي بحث دارد، اما تقريباً همه اقليم شناسان گرمايش جهاني را به عنوان يك معضل و مخاطره اقليمي قبول دارند. به دليل اهميت اين موضوع، پژوهش پيش رو جهت ارزيابي ميزان تاثير گرمايش جهاني بر روي دماهاي متوسط، به صورت ماهانه و دوره اي (سرد و گرم) انجام گرفته است. براي انجام اين پژوهش از دو دسته داده، داده هاي دماي 17 ايستگاه سينوپتيك كشور و مقادير متناظر آن، داده هاي شاخص ناهنجاري هاي متوسط دمايي خشكي ها و اقيانوس هاي كره زمين طي بازه زماني 60 ساله (2010-1951) ميلادي استفاده شده است. جهت انجام اين پژوهش از روش همبستگي پيرسون براي محاسبه ارتباط بين داده ها، از روش روند خطي جهت تحليل مولفه روند سري زماني داده ها، براي نشان دادن پراكندگي مكاني همبستگي بين داده هاي دماي ايستگاه ها با گرمايش جهاني در سطح كشور از مدل زمين آمار و در نهايت جهت تشخيص معناداري روند تغيير دماها از آزمون ناپارامتري من – كندال استفاده گرديده است. با توجه به نتايج بدست آمده همه ايستگاه هاي مطالعاتي به غير از اروميه و خرم آباد روندي افزايشي در دماي متوسط را تجربه مي كنند. بيش ترين تاثير گرمايش جهاني از ماه آوريل تا اكتبر مشاهده مي گردد كه در اين بين ماه هاي تابستان نسبت به ساير ماه ها از ضريب همبستگي بالاتري برخوردار بوده و نشان از افزايش دماي متوسط تابستانه دارد. فرآيند ذكرشده در بررسي هاي تحليل سري زماني و تغيير روند دمايي صورت گرفته نيز كاملاً مشهود بوده و تغير روند صورت گرفته در بيشتر ماه ها كاملاً معني دار بوده و تغير در روند دماي متوسط صورت گرفته را تصديق مي كند. نتايج حاصل از تحليل هاي رابطه دماي متوسط دوره هاي سرد و گرم با شاخص ناهنجاري هاي متوسط دمايي خشكي ها و اقيانوس هاي كره زمين گوياي رابطه معنادار قوي دوره گرمايي نسبت به دوره سرد است. تغير روند دمايي صورت گرفته در هر دو دوره مطالعاتي براساس نتايج حاصله كاملاً معنادار مي باشند.

Although it is questionable whether there is climate change, but almost all climatologists agree that global warming is a problem and that climate hazard. In history before the Industrial Revolution, Earth's climate changed due to natural causes not related to human activity. Most often, global climate has changed because of variations in sunlight. Tiny wobbles in Earth's orbit altered when and where sunlight falls on Earth's surface. Variations in the Sun itself have alternately increased and decreased the amount of solar energy reaching Earth. Volcanic eruptions have generated particles that reflect sunlight, brightening the planet and cooling the climate. Volcanic activity has also, in the deep past, increased greenhouse gases over millions of years, contributing to episodes of global warming. "Global warming" refers to the global-average temperature increase that has been observed over the last one hundred years or more. But to many politicians and the public, the term carries the implication that mankind is responsible for that warming. Global warming occurs when water vapors and other greenhouse gasses collect in the atmosphere and absorb sunlight and solar radiation that have bounced off the earth's surface. Normally, this radiation would escape into space-but these pollutants, which can last for years to centuries in the atmosphere, trap the heat and cause the planet to get hotter. That's what's known as the greenhouse effect. The impacts of global warming are being felt across the globe. Extreme heat waves have caused tens of thousands of deaths around the world in recent years. And in an alarming sign of events to come, Antarctica has been losing about 134 billion metric tons of ice per year since 2002. Over the past 50 years, the average global temperature has increased at the fastest rate in recorded history. And experts see the trend is accelerating: All but one of the 16 hottest years in NASA's 134-year record have occurred since 2000. Each year, scientists learn more about the consequences of global warming, and many agree that environmental, economic, and health consequences are likely to occur if current trends continue. Here's just a smattering of what we can look forward to: - Melting glaciers, early snowmelt, and severe droughts will cause more dramatic water shortages and increase the risk of wildfires in the American West. - Rising sea levels will lead to coastal flooding on the Eastern Seaboard, especially in Florida, and in other areas such as the Gulf of Mexico. - Forests, farms, and cities will face troublesome new pests, heat waves, heavy downpours, and increased flooding. All those factors will damage or destroy agriculture and fisheries. - Disruption of habitats such as coral reefs and Alpine meadows could drive many plant and animal species to extinction. -Allergies, asthma, and infectious disease outbreaks will become more common due to increased growth of pollen-producing ragweed, higher levels of air pollution, and the spread of conditions favorable to pathogens and mosquitoes. Air temperature is the most sensitive meteorological element to global warming. Because of this, the research ahead is done for the detection of global warming on average temperatures in monthly and periodic (hot and cold) time scales. - Data Methods For this study, two groups of data, monthly average temperatures data of 17 synoptic stations and corresponding amounts of data in global land and oceans temperature anomalies were figured out over 60 years period of time (1951 to 2010}. Goals, the Pearson correlation method for detecting relationships between data's, and linear trend for trend analysis time series data, To illustrate the correlation between the spatial distribution of temperature data with global warming stations nationwide Geostatistical model Finally, non-parametric test for detecting significant temperature changes Man - Kendall method were used. Discussion and Conclusion According to the results, all studies stations apart from Urmia and Khorramabad experience increasing trend in the average of temperature. The most influence over global warming observed from April to October is the month of the summer than other months of the relationship that has a significant high than the average summer temperature is going up. This process in the analysis of time-series and temperature trends has been quite evident. Change in trend occurred been a significant in most months and changes in the average temperature trend has been confirmed. The results obtained from the analysis period (hot and cold) temperatures average, indicating a strong relation to the hot period than the cold periods. The change in temperature trend occurred in both studies period, According to the results obtained are quite significant. Conclusions This study investigated the statistical characteristics and spatiotemporal distribution and trends of average temperatures events and its relationships to global land ocean anomalies in Iran. According to obtained results in summer months and hot period relationships between average temperatures of stations and global land ocean anomalies are significant than other seasons and months. Therefore global warming is affected on average monthly temperatures of Iran.