عنوان مقاله [English]
نویسندگان [English]چکیده [English]
One of the major factors that affect Iran’s climate, is its location in different geographical latitudes and variety of uneven lands on one hand, and entering of diverse synoptic systems during the year on the other hand. One of the main parameters that determinesthe climate of each region is temperature, especially degree-day (DD).
DD is the difference of the threshold temperature relative to the average daily temperature, and the temperature thresholds are also selected according to the objectives of the research. In this study, the sum of the average numbers of the country's annual and seasonal heating and cooling degree-day was calculated through the temperature thresholds of 25.11 and 25.14 respectively.The daily temperature data was extracted from the Asfazary database. The databases include the daily average temperature in 41 years from 1961 to 2002 on the 15x15 km. cells throughout the country. Thus, the average daily temperature in Asfazary database is an array of 15992x7187 dimensions in which the rows represent the time (day) and the columns represent the location (cells). The results of the research indicate that the highest cooling degree-day (CDD) is from the 11 degrees temperature threshold in the summer and is about 600-750 related to the coasts of Oman sea and the plain of Khuzistan, and the lowest is from the 25 degrees temperature threshold for the entire Iran in winter corresponding to a zero CDD. Regarding the amount of heating required, the highest is from the temperature threshold of 14 in the winter which is related to the Northwestern area and the heights with a CDD of 600-750 and the lowest is in the summer related to the whole country with a temperature threshold of 14 degrees corresponding to a zero CDD.