بررسي وردايي الگوهاي پيوند از دور و اثر آن‌ها بر بارش ايران

Study on Variation of Major Teleconnection Patterns (MTP) associated with Iran’s Precipitatio.

اين تحقيق با هدف درك تغييرات يا نوسان هاي شاخص هاي بارز پيوند از دور و اثرات آن ها روي بارش سالانه كشور ايران صورت كرفته است.داده‌هاي مورد استفاده بارش ماهانه بيست و چهار ايستگاه هواشناسي در سطح كشور از سازمان هواشناسي كشور و داده هاي ماهانه شاخص ها و الگوهاي بارز پيوند از دور از مركز اقيانوس شناسي و جوشناسي ملي نوآ (NOAA ) در دوره آماري 2005-1951 دريافت گرديد. در ادامه با استفاده از روش هاي آماري مانند همبستگي پيرسن و رگرسيون، تجزيه و تحليل داده ها انجام شد. يافته هاي تحقيق نشان دهنده تغيير الگوي بارشي كشور زير تاثير تغيير برخي از الگوهاي پيوند از دور مي باشد؛ به طوري كه تغيير در برخي شاخص ها نظير الگوهاي پيوند از دور در اقيانوس اطلس و اسكانديناوي سبب كاهش بارش و افزايش نمايه هاي اقيانوس آرام در جهت بهبود بارش ميانگين كشور شده است. به عنوان نتيجه مهم ديگر اين تحقيق، گرمايش جهاني به عنوان يكي از اصلي ترين عوامل كاهش و نوسان بارش كشور طي ده هاي جديد شناسايي شد.

Introduction: Climate in under influenced with some different complex phenomena. One of important parameters is Precipitation that has change from a year to other year. Teleconnection Patterns and Indices are remote controller of precipitation amount variation in Iran and the entire world. So in this paper on of main goal is relationship between teleconnection patterns and precipitation data in main meteorological station of IRAN that have long term data base. Material and Methods: By using Statistical analysis over Precipitation data via 25 Weather Station from 19512005 in whole Country and Teleconnection Indices from NOAA, we analysis and notice to archive component that have up most impact on Precipitation variation in Iran. Results and Discussion: According to the relationship between major teleconnection indices and Iran#039 s rainfall, we investigate to recognition of their effects and phenomena on climate of Iran. As a results the Sum of 24 stations, the precipitation of Iran have decrease trend. Eventually changes in some Teleconnection indices cause decreasing rainfall as SCAND index, GlobLandTA, NH ssta+Land, NH ta Land, NTA and EA in spite of intensifying of some indices that increasing rainfall as SST4, MEI, PDO, NOI. Conclusion: In resent decade, Global increasing temperature causes change over most atmospheric parameters in whole world and the other hand these atmospheric parameters themselves have impact as feedback over other branches of Climate and weather machine. One of important results in current paper is showing effect of Global Warming that cause decreasing in average of Iran#039 s precipitation by means of change in some teleconnection pattern in time series.