بررسی اقلیمی مه در فرودگاه مشهد

نوع مقاله : مقاله پژوهشی

نویسندگان

1 کارشناس پژوهشی/پژوهشگاه هواشناسی و علوم جو

2 دانشیار، پژوهشگاه هواشناسی و علوم جو، تهران، ایران

3 استادیار، پژوهشگاه هواشناسی و علوم جو، تهران، ایران

چکیده

کاهش دید ناشی از رخداد مه می‌تواند بر ترافیک هوایی تأثیر بگذارد و در برخی موارد علت اصلی سوانح هوایی است. مه وضعیتی است که در آن قطرات آب یا بلورهای یخ در لایه هوای نزدیک سطح زمین، دید افقی را به کمتر از 1000 متر کاهش می‌دهند. پدیده مه در فرودگاه مشهد به طور مکرر باعث تأخیر یا لغو پروازها شده است. بنابراین بررسی اقلیمی رخداد مه در این فرودگاه به شناخت بهتر این پدیده و بهبود پیش‌بینی آن کمک می‌کند. برای این منظور انواع رخدادهای مه با استفاده از داده‌های دیدبانی ساعتی متار طی دوره آماری 2001 تا 2020 و بر اساس الگوریتم تردیف و راسموسن (2007) شناسایی شدند و مورد بررسی قرار گرفتند. بر اساس نتایج به دست آمده، رایج‌ترین نوع مه در طول دوره‌ی مطالعه در این فرودگاه مه CBL بود. در بررسی غلظت مه مشاهده شد که در طول دوره مورد مطالعه، کمینه دید افقی مربوط به مه تابشی و CBL بود. همچنین مه بارشی دارای بیشترین کمینه دید و در نتیجه کم‌ترین غلظت بود. همپنین در همه ماه‌های سال، فراوانی رخدادهای مه شبه غلیظ با کمینه دید 100 تا 500 متر بیشتر از انواع دیگر مه بود و رخدادهای مه با کمینه دید 100 متر دارای بیشترین فراوانی در بین کمینه دیدهای 100 تا 500 متر بودند. با توجه به این‌که مه غلیظ نشست و برخاست هواپیما را دچار مشکل می‌کند، اهمیت رخداد مه در این فرودگاه از نظر ترافیک هوایی مشخص می‌شود. در طول سالهای مورد مطالعه در ساعات نیمه شب و قبل از طلوع آفتاب، بیش‌ترین گزارش رخداد مه ثبت شده بود.

کلیدواژه‌ها

عنوان مقاله [English]

Climatology study of fog at Mashhad airport

نویسندگان [English]

  • Razieh Pahlavan 1
  • Mohammad Moradi 2
  • sahar tajbakhsh 3
  • Majid Azadi 2
  • mehdi rahnama 3
1 Research Expert/ ASMERC
2 Associate Prof. of Atmospheric Science and Meteorological Research (ASMERC), Tehran
3 faculty member
چکیده [English]

Climatology study of fog at Mashhad airport

Abstract



Low horizontal visibility caused by fog can affect air traffic and in some cases is the main cause of air accidents. Fog is a condition in which water droplets or ice crystals in the air layer near the Earth's surface reduce horizontal visibility to less than 1000 meters. Fog is one of the major causes of flight delays and accidents. In fact, fog is the second hazardous weather event affecting aviation activities (Gultepe et al., 2019). The effects of fog in the aviation industry can cost hundreds of millions of dollars due to flight delays and cancelations (Gultepe et al., 2017). Fog event at Mashhad airport has repeatedly delayed or canceled flights. Therefore, study the climatology of the fog event at this airport helps to better understand this phenomenon and improve fog forecasting.

For this purpose, all types of fog events were detected and analyzed using the hourly observation data of METAR during the statistical period from 2001 to 2020 and based on Tardif and Rasmussen (2007) algorithm. Then the fog climate was studied during the period. The results showed that CBL fog is the most common type of fog in terms of frequency with 43.94% of all fog occurrences at Mashhad Airport. Precipitation fog is also the rarest type of fog among fog types with 22.72% of all fog occurrences. Advection fog, which is formed under the influence of the marine environment, was not observed at this airport. Given that radiation fog usually forms at night and usually dissipates after sunrise, this type of fog has been the longest-lasting type of fog at the airport during 16 years of study. Also, the duration of CBL fog was the shortest one compared to other types of fog events.

The minimum visibility of radiation and CBL fog events at this airport was lower than other types of fog. Also, precipitation fog had the lowest concentration compared to other types of fog events, which is consistent with the results of Tardif and Rasmussen (2007). The most reports of fog occurrence at Mashhad Airport during the studied years was at midnight and before sunrise, which could be due to the radiation cooling at night and before sunrise, which reaches its maximum (Hoch et al., 2011; Cséplő et al., 2019; Zouzoua et al., 2021; Wærsted et al., 2017). This result is consistent with the study of Cséplő et al. (2019) and Tardif and Rasmussen (2007). Tajbakhsh (2015) has also reported the maximum occurrence of fog at 21, 00 and 03 UTC using 20-years synoptic data at Mashhad Airport. Also, the frequency of fog occurrence decreases rapidly after 03 UTC.

The monthly distribution of fog types in Mashhad Airport showed that radiation fog events often occur in winter and CBL fog events often occur from late autumn to mid-spring. Boundary layer cooling is the most important process that causes fog event in spring, while winter fog occurrences can be related to large-scale atmospheric systems (Tardif and Rasmussen, 2007). The maximum monthly frequency of precipitation fog event at this airport is in the winter. The fog events in the autumn can also be related to these weather systems. Since precipitation fog events depend on large-scale factors (Tardif and Rasmussen, 2007), the maximum occurrence of this type of fog is observed in winter. In general, the frequency of fogs in December and January is higher than other months of the year. This result is consistent with Tajbakhsh (2015).

In terms of annual changes in fog occurrences, there was no significant trend in the number of fog hours during the studied years (2001-2020). In terms of fog concentration, in all months of the year, the number of semi-dense fog events with minimum visibility of 100 to 500 meters was more than other types. Also, the number of fog events with minimum visibility of 100 meters and then 200 meters had the highest number. It shows the importance of climate investigation and prediction of the fog event at this airport from the point of view of the aviation industry, because dense fog events cause difficulties in the landing and takeoff of airplanes.



Keywords: Fog climatology, Fog type, Radiation fog, Precipitation fog, CBL fog.

کلیدواژه‌ها [English]

  • Fog climatology
  • Fog type
  • Radiation fog
  • Precipitation fog
  • CBL fog

مراجع

  1. Błas, M., Sobik, M., Quiel, F., & Netzel, P. (2002). Temporal and spatial variations of fog in theWestern Sudety Mts., Poland. Atmos Res, 64:19– 28
  2. Cséplő, A., Sarkadi, N., & Horváth, Á., Schmeller, G., & Lemler, T. (2019). Fog climatology in Hungary. Quarterly Journal Of The Hungarian Meteorological Service, 123 (2), 241-264. http://doi.org/10.28974/idojaras.2019.2.7.
  3. Gultepe, I., Milbrandt, J. A., & Zhou, B. (2017). Marine fog: A review on microphysics and visibility prediction (Chap. 7). In D. Koracin & C. E. Dorman (Eds.), Marine fog: Challenges and advancements in observations, modeling and forecasting. New York: Springer.
  4. Gultepe, I., Sharman, R., Williams, P., Zhou, B., Ellrod, G., Minnis, P., Trier, S., Griffin, S., Yum, S., Gharabaghi, B., Feltz, W., Temimi, M., Dimri, A.P., Dietz, S., França, G., Almeida, M., Albuquerque, F., Pu, Z., Kneringer, P. & Thobois, L. (2019). A Review of High Impact Weather for Aviation Meteorology. Journal of Pure and Applied Geophysics. 176. 1869–1921. 10.1007/s00024-019-02168-6.
  5. Haeffelin, M., Bergot, T., Elias, T., Tardif, R., Carrer, D., Chazette, , Colomb, M., Drobinski, P., Dupont, E., Dupont, J. C., Gomes, L., Musson-Genon, L., Pietras, C., Plana-Fattori, A., Protat, A., Rangognio, J., Raut, J.-C., Rémy, S., Richard, D., Sciare, J., & Zhang, X. (2010). PARISFOG: shedding new light on fog physical processes. B. Am. Meteorol. Soc, 91, 767–783, https://doi.org/10.1175/2009BAMS2671.1.
  6. Hardwick, W.C. (1973). Monthly fog frequency in the continental United Mon. Weather Rev, 101 (10), 763–766.
  7. Hoch, SW., Whiteman, DC., & Mayer, B. (2011). A systematic study of longwave radiative heating and cooling within valleys and basins using a three-dimensional radiative transfer model. Journal of Applied Meteorology and Climatology, 50, 2473–2489, DOI: https://doi.org/10.1175/JAMC-D-11-083.1.
  8. Kloesel, K. A. (1992). Marine stratocumulus cloud clearing episodes observed during FIRE. Monthly Weather Review, 120, 565–578.
  9. Leipper, D. F. (1994). Fog on the U.S. west coast: A review. Bulletin of the American Meteorological Society, 75, 229–240
  10. Lester, P. (2007). Aviation weather, Jeppesen Pub. S.A.
  11. Meyer, M.B. & Lala, G.G. (1990). Climatological Aspects of Radiation Fog Occurrence at Albany. New York. J. Climate. 3, 577−586. https://doi.org/10.1175/1520-0442(1990)003<0577:CAORFO>2.0.CO;2fog with regional
  12. O’Brien, TA., Sloan, LC., Chuang, PY., Faloona, IC., & Johnstone, JA. (2012). Multidecadal simulation of coastal climate model. Clim Dyn. doi:10.1007/s00382-012-1486-x
  13. Peace, R.L. Jr. (1969). Heavy-Fog Regions In The Conterminous United States. Mon. Weather Rev, 97,116−123. https://doi.org/10.1175/1520-0493(1969)097<0116:HRITCU>2.3.CO;2
  14. Roach, W., Brown, R., Caughey, S. J., Garland, J. A., & Readings, C. J. (1976). The physics of radiation fog: I – A field study. Quarterly Journal of the Royal Meteorological Society, 102, 313–333.
  15. Tajbakhsh, S., 2017, Forecasting fog using some experimental methods (Tehran and Mashhad airports), Journal of Climate Research, 7(27-28), 43-56.
  16. Tajbakhsh, S., Rahnama, M., 2017, Monitoring and analyzing foggy events using ground and remote sensing data Case Study April 4, Nivar 42(100-101), 35-44.
  17. Tardif, R., & Rasmussen, R.M. (2007). Event-based climatology and typology of fog in the NewYork City region. J. Appl. Meteorol. Climatol, 46 (8), 1141–1168.
  18. Taylor, G. I., (1917). The formation of fog and mist. Quart. J. Roy. Meteor. Soc., 43, 241–268.
  19. Wærsted, E. G., Haeffelin, M., Dupont, J. C., Delanoë, J. & Dubuisson, P. (2017). Radiation in fog: quantification of the impact on fog liquid water based on ground-based remote sensing, Atmospheric Chemistry and Physics, 17, 10811–10835, https://doi.org/10.5194/acp-17-10811-2017.
  20. Willett, H. C. (1928). Fog and haze, their causes, distribution, and forecasting. Monthly Weather Review, 56, 435–468.
  21. Zouzoua, M., Lohou, F., Assamoi, P., Lothon, M., Yoboue, V., Dione, C., Kalthoff, N., Adler, B., Babić, K., Pedruzo-Bagazgoitia, X. & Derrien, S. (2021). Breakup of nocturnal low-level stratiform clouds during the southern West African monsoon season. Atmospheric Chemistry and Physics, 21, 2027–2051, https://doi.org/10.5194/acp-21-2027-2021
پژوهش های اقلیم شناسی
دوره 1401، شماره 52 - شماره پیاپی 52
سال سیزدهم | شماره پنجاه و دوم | زمستان 1401
اسفند 1401
صفحه 55-64

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