نوع مقاله : مقاله پژوهشی
نویسندگان
1 گروه جغرافیا، واحد نجف آباد، دانشگاه آزاد اسلامی، نجف‌آباد، ایران
2 گروه جغرافیا، واحد نجف آباد، دانشگاه آزاد اسلامی، نجف‌آباد، ایران، دانشیار گروه هواشناسی، دانشگاه
3 دانشیار دانشگاه پیام نور. تهران. ایران
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Introduction
Temperature is a factor feels by human body and body sense changes when the outside temperature changes for the reason of the heat transfer between body and the environment.
Wind chill is caused by the wind in lower temperature and the higher the wind speed and the lower the temperature, the wind chill and its effects on the creatures would increase. The WCT is important, since it’s an index which shows people how to dress up or to be optimum on energy consumption. When it feels cold due to the wind chill, it could contribute greatly to decision making in urban design and fair and optimum distribution of fuel. The main purpose of this paper is to study the effect of wind chill on reducing the temperature that body feels, also when this done, it could help decision makers in social, political issues as well as peoples clothing and etc based on the wind chill index.
Material and Methods
This research has been done about the determination of the temperature which our body feels based on the wind chill index in Isfahan.Isfahan with an area of about 105937 square kilometers has been placed between 30 degrees and 43 minutes to 34 degrees and 27 minutes of north latitude of equator and 49 degrees and 36 minutes to 55 degrees and 31 minutes of east longitude of Greenwich meridian. In this article we can calculate the wind chill index (WCT) from equation 1.
WCT=13.12+0.6215T-11.37V0.16+0.3965TV0.16 (1)
V: wind velocity in terms of km (hr) and T: air temperature in terms of °c
Results and discussion
From the studies we have done the table results indicated that the month of October is the beginning of the wind chill and the end of it would be in May. But since the frequency of occurrence of this phenomenon in these two months is much lower than other months, will not be discussed in this article. Therefore April, November, December, January and February and March were considered to study. The occurrence of wind chill at Knur Biabanak station was 228 times during 23 years (8395 days). The highest of the wind chill occurrence was 2257 times in February and its lowest was 39 times in May. The wind chill has occurred in Naein station 432 times in the month of February. And this number is the highest occurrence of wind chill in a month.
Conclusion
In this article, we have studied the effect of wind speed on the minimum temperature reduction in Isfahan province. Wind chill reduces the emotional temperature on the human body. The results of this research showed that the wind chill factor has been felt 2196 times at Isfahan airport station and 228 times at Khur station as the highest and the lowest numbers recorded, respectively. In the month of February we had 2257 times of wind chill occurrence in the statistical period that has been the most frequency of wind chill occurrence and the lowest number was 39 times in May. The minimum temperature and wind chill in the month of January respectively was -1.6 and -5.6 degrees Celsius. On average, wind blowing will cause the minimum temperature to reduce 4 degrees in this month. The zoning results of the minimum and the wind chill temperatures in Isfahan province indicate that the vulnerable areas of the wind chill in Isfahan are located in the center and western half (overlooking the mountains) of the province . In these regions some stations due to the topographic conditions are more vulnerable to the wind chill. These stations include Isfahan airport, Daran, Ardestan and Naien that they are the most vulnerable areas of the province against the wind chill. Also the month of February is considered as the most critical month in terms of wind chill effects on human body and the most widespread zone of wind chill happens in this month.
کلیدواژه‌ها [English]
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