Document Type : Research Paper

Author

Ph.D. in Natural Geography - Climatology

Abstract

This article was conducted in order to gain more knowledge about thermal differences (Thermal Island) between Tehran and Karaj based on a five-year statistical period (1993-1997). The element of temperature as the most important climatic element has been obtained as daily minimum and maximum from the Meteorological Organization of Iran. In the study of thermal island, stations of Dushan Tappeh in the east, Aqdasieh in the north and Mehrabad in west of Tehran, as the most important study area and Karaj station in west of Tehran as complementary area, have been selected.
Based on the investigations carried out on the average temperatures of three stations in Tehran and Karaj station, it was observed that Dushan Tappeh as the most important thermal region in Tehran has the highest temperature values ​​for both minimum and maximum annual temperatures with temperatures 13.33 and 22.49 ° C, respectively. Next, Mehrabad station has been determined as the second thermal zone in Tehran with the minimum annual temperature of 12.88 ° C and 12.29 ° C at maximum temperatures. Third, Aqdasieh station, with a mountainous character and higher elevation than the rest, acts as a relatively weak thermal zone, the average annual minimum temperature at this station being 10.33 and the maximum temperature 19.9 ° C.
Generally, the mean annual temperatures of all three stations in Tehran have higher temperature values ​​at both minimum and maximum temperatures than Karaj station, so that Tehran has a temperature difference of more than 0.75 ° C in the mean annual maximum temperature and a temperature difference of 3.37 ° C at the average annual minimum temperature with Karaj, and so has been recognized as the warmer region.

Keywords

1- افشار، مژگان، 1379، بررسى و شناخت جزیره حرارتى شهر تهران، پایان ‏نامه کارشناسى ارشد، دانشگاه آزاد اسلامى، واحد تهران مرکزى.
2- پاک، رجبعلى، 1377، بررسى تفاوت هاى عناصر اقلیمى شرق و غرب تهران، پایان‏ نامه کارشناسى ارشد، دانشگاه آزاد اسلامى واحد تهران مرکزى، ص 3.
3- جهانبخش، سعید، 1371، بررسى فاکتورهاى میکروکلیمایى مؤثر در حرارت شهر، فصلنامه تحقیقات جغرافیایى، شماره 26، ص 107.
4- خالدى، شهریار، 1374، آب وهواشناسى کاربردى، نشر قومس، 170.
5- ژیزل، اسکورو، شهریار خالدى، 1377، آب و هوا و شهر، انتشارات طبیعت، 251.
6- سازمان هواشناسى کشور، 1377، آمار درجه حرارت هاى حداقل و حداکثر روزانه، سال هاى 1997 - 1995.
7- سعیدى، مرضیه، 1377، بررسى و مقایسه دماى شهر تهران در روزهاى تعطیل و غیرتعطیل، پایان‏ نامه کارشناسى ارشد، دانشگاه آزاد اسلامى، ص 51 و 66.
8- سلطان ى‏نژاد، عبدالعظیم، 1376، اثرات زیست محیطى گازهاى آلاینده ناشى از وسائط نقلیه موتورى با تأکید بر هواى تهران بزرگ، فصلنامه محیط زیست، شماره 4، جلد نهم، ص 24.
9- محسنى، ذات‏ا...، 1366، تأثیر عوامل جوى بر روى آلودگى هواى تهران، پایان‏ نامه کارشناسى ارشد، موسسه ژئوفیزیک دانشگاه تهران، 44 ص.
10- David J. Sailor, 1994, Simulated Urban Climate Response to modification in surface albedo and vegetative cover; Journal of applied meteorology, 34, 1694-1695.
11- Kusaka.H. (2004). Thetmal effects of urban canyon structure on the nocturnalheat island: Numerical experiment using a mesoscale model coupled with an urban canopy model. Journal of appled meteorology, 43,1899-1909.
12- M.Shahgedanova, T.P.Burt and T.D.Davies, 1997, some aspects of the three dimensional heat island in moscow; internationaljornal of climatology, 17.1451-1465.
13- Patricia. figurola and nicolas A. Mazzeo, 1998, Urban-Rural temperature-differences in buenos aires; INT.J.Climatol18.1709-1723.
14- Roger, Barry and Richard J. Chorley, 1998, Atmosphere, Weather and Climate, 410.
15- S.B.Yoo and S.E.Moon, 1995, Detection of warming effects due to industrialization; An Accumulated intervention model with an application in POHAKG, Korea. Jornal Of Applied Meteorology1995, 34.
16- Turkes. M, summer. M . and demir.I.(2002). RE-evaluation of trends and chances in mean, maximum and minimum temperatures of turkey for the period 1929 - 1999.
International Journal o climatology, 22,947-977.