بررسي پراكنش فصلي و روند بي هنجاري دماي سطح زمين روز و شب ايران با استفاده از داده هاي سنجندة MODIS

Investigation of seasonal distribution and abnormal trend of day and night surface temperature in Iran using MODIS sensor data

ﺑﯽ ﻫﻨﺠﺎري دﻣﺎي ﺳﻄﺢ زﻣﯿﻦ )LSTA( ﻣﺘﻐﯿﺮي ﮐﻠﯿﺪي در ﻣﻄﺎﻟﻌﺎت اﻗﻠﯿﻤﯽ، ﮐﺸﺎورزي، و ﻣﺪﯾﺮﯾﺖ ﻣﻨﺎﺑﻊ آب اﺳﺖ. ﻫﺪف از اﯾﻦ ﻣﻄﺎﻟﻌﻪ ﺑﺮرﺳﯽ ﺗﻐﯿﯿﺮات ﻓﺼﻠﯽ و روﻧﺪ ﺑﯽ ﻫﻨﺠﺎري دﻣﺎي ﺳﻄﺢ زﻣﯿﻦ روز و ﺷﺐ اﯾﺮان اﺳﺖ. ﺑﯽ ﻫﻨﺠﺎري دﻣﺎي ﺳﻄﺢ زﻣﯿﻦ ﺑﺮﮔﺮﻓﺘﻪ از ﺳﻨﺠﻨﺪة MODIS ﻣﺎﻫﻮارة Terra ﻃﯽ دو ﺑﺎزة زﻣﺎﻧﯽ روز و ﺷﺐ ﺑﺮاي دورة 2018-2001 ﺑﺮرﺳﯽ ﺷﺪه اﺳﺖ. ﺑﺮاي درﺳﺘﯽ ﺳﻨﺠﯽ داده ﻫﺎي دﻣﺎي ﺳﻄﺢ زﻣﯿﻦ از داده ﻫﺎي ﻫﺸﺖ اﯾﺴﺘﮕﺎه ﻫﻤﺪﯾﺪ ﺑﺎ روش رﮔﺮﺳﯿﻮن ﺧﻄﯽ اﺳﺘﻔﺎده ﺷﺪ ﮐﻪ ﻧﺘﺎﯾﺞ ﻧﺸﺎن از دﻗﺖ ﺑﺎﻻي اﯾﻦ داده ﻫﺎ در ﮐﺸﻮر را داﺷﺘﻪ اﺳﺖ. ﻧﺘﺎﯾﺞ ﻧﺸﺎن داد ﺑﯽ ﻫﻨﺠﺎري ﻣﻨﻔﯽ در ﻣﻨﺎﻃﻖ ﺧﺸﮏ ﮐﻢ ارﺗﻔﺎع و ﺑﯽ ﻫﻨﺠﺎري ﻣﺜﺒﺖ در ﻣﻨﺎﻃﻖ ﻣﺮﺗﻔﻊ و ﻋﺮض ﻫﺎي ﺟﻐﺮاﻓﯿﺎﯾﯽ ﺑﺎﻻ دﯾﺪه ﻣﯽ ﺷﻮد. ﺗﺤﻠﯿﻞ روﻧﺪ ﻧﺸﺎن داد ﺑﯽ ﻫﻨﺠﺎري دﻣﺎي ﺳﻄﺢ زﻣﯿﻦ روز و ﺷﺐ ﺑﺎ ﺳﺮﻋﺖ ﻣﺘﻮﺳﻂ 0/01 و 0/02 درﺟﮥ ﺳﻠﺴﯿﻮس ﺑﻪ ازاي ﻫﺮ ﺳﺎل در ﺣﺎل اﻓﺰاﯾﺶ اﺳﺖ. ﺑﯿﺸﯿﻨﮥ ﻧﻤﺮة Z آزﻣﻮن ﻣﻦ- ﮐﻨﺪال )روﻧﺪ ﻣﺜﺒﺖ( ﺑﺎ 3/80 در ﻓﺼﻞ ﺗﺎﺑﺴﺘﺎن ﺑﺮاي ﺷﺐ و روز اﺗﻔﺎق اﻓﺘﺎده اﺳﺖ. ﺑﺮﻋﮑﺲ، روﻧﺪ ﻣﻨﻔﯽ در ﺑﯽ ﻫﻨﺠﺎري ﻫﺎ ﺑﺮاي ﻣﻨﺎﻃﻖ ﺧﺸﮏ جنوب ﺷﺮﻗﯽ و داﺧﻠﯽ و ﮐﻮﻫﭙﺎﯾﻪ ﻫﺎي زاﮔﺮس و اﻟﺒﺮز ﺟﻨﻮﺑﯽ ﺑﻪ دﺳﺖ آﻣﺪه اﺳﺖ.

Introduction, Land surface temperature (LST) plays an important role in surface energy balance. A set of environmental parameters, such as temporal and geographical changes, thermal properties, biophysical properties, climatic parameters and subsurface conditions can cause heterogeneous spatio-temporal distribution of LST and its anomalies to be. LULCC-induced surface temperature anomalies have important implications for understanding the physical mechanisms associated with the surface to changes in various biophysical factors, including albido and surface roughness (also known as aerodynamic resistance). The purpose of this study is to evaluate the seasonal changes and abnormalities of daytime and nighttime land surface temperature in Iran based on LST derived from satellite data. Materials and methods, In this study, the following steps were performed: A study area: The whole country of Iran was wanted. To better reveal the behavior of surface temperature anomalies in Iran, the data has been converted to a seasonal scale and also for the first time in the country, surface temperature anomalies have been studied separately for night and day.