نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی دکتری اقلیم شناسی، دانشکده علوم جغرافیایی، دانشگاه خوارزمی، تهران، ایران
2 دانشیار گروه اقلیم شناسی، دانشکده علوم جغرافیایی، دانشگاه خوارزمی، تهران، ایران
3 استاد گروه اقلیم شناسی، دانشکده علوم جغرافیایی، دانشگاه خوارزمی، تهران، ایران
4 دکتری اقلیم شناسی، دانشکده علوم جغرافیایی، دانشگاه خوارزمی، تهران، ایران.
چکیده
کلیدواژه‌ها
عنوان مقاله [English]
نویسندگان [English]
Statistical analysis of temperature inversion and its types in Birjand city using by inversion intensity index
Introduction
The ambient air temperature in the troposphere usually decreases with increased altitude (per 1000 meters increases the height of 5 to 6 degrees Celsius), but sometimes with increased air temperature, which is called temperature or inversion inversion. Temperature inversion occurs when a layer of hot air is above cold air adjacent to the Earth. In this case, air stability is created and instead of increasing temperature height to a few hundred meters above Earth with increased height. We will increase temperature. The importance of temperature inversion phenomenon is doubled when examining the effects of temperature inversion phenomenon. The phenomenon of temperature inversion is important because it causes fumation. This phenomenon occurs when the sun's radiation is unstable in the vicinity of the surface for a short time after sunrise, then combined with the scattered material in the nightly layer, causing the scattered material to return to the surface. . As a result, the concentration of pollutants increases sharply and the phenomenon of fiomia is created.
Methodology
In this study, the daily data of the radio atmosphere above the Birjand Synoptic Station (Table 1) for 00 Greenwich (3.5 local) over the last 11 years (2010 to 2020) to 11 km high from Earth from Vioming University He got. Indicators used include thermodynamic indices such as SI, LI, KI and TT and potential temperature. Also of other data used in this study, radiosvand transmitted information including inversion height from ground to meter (ZBASE), inversion height from ground to meter (ZTOP), base temperature in base and inversion layer to degree Selicius (TBASE), the temperature difference between the base and the top of the inversion layer to the grade of silicius (DTINV) is the height difference between the base and the apex of inversion to meter (DZINV) and the pressure in the base (PBSE) and the inversion layer (PTOP) from Relationships (1 and 2) are calculated First calculated using the relationship (1) the potential of the ceiling and the floor of the inversion layer of the relationship (1)
Θ: Potential temperature to Kelvin grade
T: Temperature to Kelvin
P: Air pressure to hectopaskal
After calculating the potential temperature of the ceiling and floor of the inversion layer using the relationship (1), we have calculated the intensity of temperature inversion using relationship (2) on a monthly, seasonal and annual time scale. Relationship (2):
Δθ Difference of the temperature potential and the base of inversion to the grade of Kelvin
Δz thick layer of inversion to meter
Z station height to hectometry
Results and Discussion
The results showed that the average annual temperature inversion phenomenon at Birjand Station was about 90 cases per year, as it may not occur in different heights in some days, about 11.1 % of the radiation temperature inversion, front. A 12.4 %, and the other 76.5 % is related to temperature inversion of subsidence. Due to the air session underneath, the share of subsidence inversions is more than other types of inversion. The results showed that the highest average inversion layer in Birjand was formed in 2010 and 2015 at 9 ° C. The highest annual temperature of the inversion is related to the inversion of subsidence, which is due to the subsidence of the air subcutaneous air subcutaneous in the upper layers of the atmosphere and the high temperature on the ground. In terms of annual altitude, the highest height of the inversion layer occurred in 2019 with 4490 meters. In terms of thickness of the inversion, the inversion of the type of subsidence with 207 and the radiation with 145 meters form the thickest and the thinnest layer of inversion. Results of the average inversion layer pressure in Birjand showed that 2014 and 2015 were formed with about 870 miles and 2019 with 592 milligrams. Among the types of inversion, the most severe inversion of the front was 0.044 % and then subsidence with 0.030 %. In terms of the intensity of severe inversion with 0.7 % and poor inversions with 0.92 % were the lowest and the highest in Birjand. In fact, the inversions of the city of Birjand are poor because of their physiographical and geographical properties.
Conclusion
The correlation results also showed that there was a direct and significant relationship between the intensity of inversion and the inversion layer temperature at 99 %. That is, the higher the temperature of the inversion layer, the greater the inversion of inversion and vice versa. But there is a significant relationship between the inversion intensity and the height of the layer at 95 % probability level. This reverse relationship indicates that whenever the inversion layer occurred at the lower altitude, the inversion of inversion has also increased; But the relationship between the thickness and intensity of the inversion layer showed that with the increase in the thickness of the inversion layer, the inversion of inversion in Birjand also increased as the layer temperature was higher as the inversion was more severe. There is also a direct and significant relationship between the intensity and pressure of the inversion layer at 95 % so that with increased pressure, the inversion will increase. In general, the city of Birjand is under the tranquility of the tropical climate because of its specific location, which is also on the roads of 120 -day Sistan, so it will be weak if inversion occurs.
Keywords: temperature inversion, barley thickness, inversion intensity, barley pollution, Birjand
کلیدواژه‌ها [English]
)