تحلیل فضایی مخاطرات محیطی

تحلیل فضایی مخاطرات محیطی

پیشبینی کاهش دید ناشی از مه و بارش در منطقه تهران با استفاده از مدل WRF

نویسندگان
دانشگاه تهران
چکیده
دید افقی از مهم­ترین ویژگی­های نوری جوّ به‌شمار می­رود و پیش‌بینی آن از جنبه­های گوناگون اهمیت دارد. هدف از مقاله حاضر، پیشبینی کاهش دید ناشی از مه و بارش با استفاده از مدل WRF در منطقه تهران است. دو مطالعه موردی در 7 مارس 2013 و در11 ژانویه 2014 با کاهش دید افقی به دلیل رخداد بارش برف و مه برای بررسی انتخاب شده‌اند. برای پیش‌بینی دید از چهار روش پارامترسازی SW99، FSL، AFWA و UPP1 استفاده شده‌است این چهار روش پس از کدنویسی، در مدل پیش­بینی عددی WRF پیاده سازی می­شوند و مقادیر پیش­بینی شده در نهایت با دید مشاهداتی مقایسه می­شوند. نتایج نشان می­دهند که تمام روش‌ها، رخداد کاهش دید را پیش‌بینی می­کنند، اما به نظر می‌رسد کارآیی روش به نوع پدیده مورد مطالعه بستگی دارد؛ به طوری­که پیش‌بینی دید در هنگام رخداد برف نسبت به رخداد مه از دقت بیشتری برخوردار است. نتایج بررسی عوامل ایجاد خطا نشان می­دهد که در پیش‌بینی‌ مربوط به دما و دمای نقطه شبنم فرابرآورد وجود دارد. هم­چنین خطا در تخمین رطوبت نسبی در بسیاری از موارد مثبت است که متعاقباً منجر به ایجاد خطا در پیش­بینی دید، به­ویژه در هنگام رخداد مه، می­شود.

کلیدواژه‌ها

عنوان مقاله English

Visibility prediction during fog and precipitation using the WRF model over Tehran

نویسندگان English

Parisa Jaberi
Samaneh Sabetghadam
Sarmad Ghader
MA, Department of Space Physics, Institute of Geophysics, University of Tehran.
چکیده English

Visibility is one of the most important optical characteristics of the atmosphere. Prediction of visibility is essential for air pollution, air traffic, flight safety, road traffic and shipping. Visibility reduction may be caused by different reasons. Fog is one of the most common reasons of visibility reduction, i.e. the droplets of water suspended in the atmosphere reduce the visibility to less than 1 km. Precipitation may also reduce visibility. Prediction of visibility in NWP models is usually accomplished by using the relationship between visibility and liquid water content, temperature, relative humidity. Purpose of the present work is to predict visibility during fog and precipitation over Tehran area in January 11th, 2014 and March 7th, 2013. Different algorithms including UPP1, AFWA, FSL and SW99 have been experimented to predict visibility.. Predicted visibility has been compared to observations, including Synoptic and METAR data in Imam Khomeini and Mehrabad airport. The WRF version 3.8.1 has been used to simulate precipitation and fog. In this simulation model configuration defined in Lambert uniform space. The model consist three nested domains. First domain was a 27-km grid model (83×65), surrounding a 9-km grid model (112×94) which was surrounding a 3-km grid model (112×97). Center of all domains was at longitude 51° and 44' and latitude 36° and 5' which is located almost at center of Tehran. All domains had 40 vertical layers and model top was located at 100hPa. The out puts of 3-km domain is used for visibility estimation. Initial and boundary conditions were set by using FNL data which is 1°×1° degree grid data. This data is available every 6 hours. Simulations were in 36 hours and first 12 hours was the spin up time. Results show that most of these algorithms can partly predict visibility reduction. The FSL algorithm works better than the other methods in fog situation and SW99 works better in snow situation. Comparing results shows that the visibility reduction during snow is more reliable than during fog. There were some errors in model predictions some of them were due to visibility algorithms, because the coefficients of these algorithms were driven in other parts of earth. The other errors were systematic errors of WRF. Predictions of temperature had warm bias and also there were positive bias in prediction of relative humidity.

کلیدواژه‌ها English

visibility prediction
WRF
fog
Precipitation
اشرفی، خ.، 1383. پیش‌بینی عددی وضع هوا و بهینه‌سازی خروجی آن به روش MOS . پایان‌نامه کارشناسی ارشد. دانشگاه تهران. دانشکده فنی. گروه مهندسی مکانیک.
خضریان نژاد، ن.، حجام، س.،میرزایی، ا.، و مشکواتی، ا.ح.، 1392. پیش‌بینی رواناب حوضه آبریز تیره با استفاده از پیش‌بینی کمی بارش خروجی مدل WRF، پژوهش‌های اقلیم شناسی، 12: 63-75.
Aman, N., Manomaiphiboon, K., Pengchai, P., Suwanathada, P., Srichawana, J. and Assareh, N., 2019. Long-Term Observed Visibility in Eastern Thailand: Temporal Variation, Association with Air Pollutants and Meteorological Factors, and Trends. Atmosphere, 10(3), 122-146.
Bang, C.; Lee, J.W., and Hong, S.Y. 2009. Predictability experiments of fog and visibilityin local airports over Korea using the WRF model. Journal of Korean Society for Atmospheric Environment , 24: 92-101.
Bergot, T., Carrer, D., Noilhan, J., and Bougealt, F., 2005. Improved Site-Specific numerical prediction of fog and low clouds: a feasibility study. Weather Forecasting, 20, 627-646.
Benjamin, S.G., Dévényi, D., Weygandt, S.S., Brundage, K.J., Brown, J.M., Grell, G.A., Kim, D., Schwartz, B.E., Smirnova, T.G., Smith, T.L. and Manikin, G.S., 2004. An hourly assimilation–forecast cycle: The RUC. Monthly Weather Review, 132(2),495-518.
Boudala, F.S. and Isaac, G.A., 2009. Parameterization of visibility in snow: Application in numerical weather prediction models. Journal of Geophysical Research: Atmospheres, 114(D19).
Clark, P.A., Harcourt, S.A., Macpherson, B., Mathison, C.T., Cusack, S., and Naylor, M., 2008. Prediction of visibility and aerosol within the operational Met Office Unified Model. I:Model formulation and variational assimilation. Quarterly Journal of the Royal Meteorological Society, 134, 1801-1816.
Chung, Y.S., Kim, H.S. and Yoon, M.B., 1999. Observations of visibility and chemical compositions related to fog, mist and haze in south Korea. Water, Air, and Soil Pollution, 111,139-157.
Creighton, G., Kuchera, E., Adams-Selin, R., McCormick, J., Rentschler, S., and Wickard, B., 2014. AFWA Diagnostics in WRF.
Doran, J.A., Roohr, P.J., Beberwyk, D.J., Brooks, G.R., Gayno G.A., Williams, R.T., Lewis, J.M., and Lefevre, R.J. 1999. The MM5 at the AFWeather Agency-new products to support military operations. Preprints eighth conf. on Aviation, Range, Aerospace meteorology, Dallas, TX, Amer. Meteor. Soc., 115-119.
Glickman, T., 2000. Glossary of Meteorology. 2nd ed. American Meteorological Society, 855 pp.
Gultepe, I., and Milbrandt, J.A. 2010. Probabilistic parameterizations of visibility using observations of rain precipitation rate, relative humidity, and visibility. Journal of Applied Meteorology and Climatology, 49, 36–46.
Hong, S. Y., Noh, Y., & Dudhia, J. (2006). A new vertical diffusion package with an explicit treatment of entrainment processes. Monthly Weather Review, (134), 2318–2341.
Horvath, H. 1981. Atmospheric visibility. Atmospheric Environment, 15: 1785-1796.
Majewski, G., Rogula-Kozłowska, W., Czechowski, P., Badyda, A. and Brandyk, A., 2015. The impact of selected parameters on visibility: First results from a long-term campaign in Warsaw, Poland. Atmosphere, 6(8),1154-1174.
Malm, W.C., 1999. Introduction to Visibility. Air Resources Division, National Park Service, Cooperative Institute for Research in the Atmosphere (CIRA), NPS Visibility Program, Colorado State University, Fort Collins, CO.
Middleton, W., 1952. Vision through the Atmosphere, University of Toronto Press.
Payra, S., and Mohan, M., 2014: Multirule based diagnostic approach for the fog predictions using WRF modelling tool. Advances in Meteorology, 2014:1-11.
Reymann, M., Piasecki, J., Hosein, F., Larabee, S., Williams, G., Jimenez, M., and Chapdelaine, D., 1998. Meteorological Techniques. Air Force Weather Agency (AFWA), Offutt AFB IL AFWA/TN-90/002.
Ryerson, W.R., and Hacker, J.P., 2014. The potential for mesoscale visibility prediction with a multimodel ensemble. Weather and Forecasting, 29, 543-562.
Sabetghadam, S., Ahmadi-Givi, F. and Golestani, Y., 2012. Visibility trends in Tehran during 1958–2008. Atmospheric environment, 62,512-520.
Sabetghadam, S. and Ahmadi-Givi, F., 2014. Relationship of extinction coefficient, air pollution, and meteorological parameters in an urban area during 2007 to 2009. Environmental Science and Pollution Research, 21(1),538-547.
Singh, A., Bloss, W.J. and Pope, F.D., 2017. 60 years of UK visibility measurements: impact of meteorology and atmospheric pollutants on visibility. Atmospheric Chemistry and Physics, 17(3), 2085-2101.
Smirnova, T.G., Benjamin, S.G., and Brown, J.M., 2000. Case study verification of RUC/MAPS fog and visibility forecast. Preprints, Ninth, Conf. on Aviation, Range, and Aerospace Meteorology, Orlando, FL, Amer. Meteor. Soc., 2.3.
Smith, T.L., and Benjamin, S.G., 2002. Visibility forecast from the RUC20. Preprints, 10th , Conf. on Aviation, Range, and Aerospace Meteorology, Portland, OR, Amer. Meteor. Soc., JP1.27.
Stoelinga, M.T., and Warner, T.T., 1999. Nonhydrostatic, mesobeta-scale model simulation of cloud ceiling and visibility for an East Coast winter precipitation event. Journal of Applied Meteorology, 38: 385-404.
Wang, T., Jiang, F., Deng, J., Shen, Y., Fu, Q., Wang, Q., Fu, Y., Xu, J. and Zhang, D., 2012. Urban air quality and regional haze weather forecast for Yangtze River Delta region. Atmospheric Environment, 58,70-83.
Whiffen, B., 2001. Fog: Impact on aviation and goals for meteorological prediction. Second Conf. on Fog and Fog Collection, St. John’s, NL, Canada, Environment Canada and International Development Research Center (IDRC), 525–528.
Wilks, D. S., 2011. Statistical methods in atmospheric science, Second Edition, Academic presss., 100, 2-676.
Wu, D., Wu, X.J., Li, F., Tan, H.B., Chen, J., Chen, H.H., Cao, Z.Q. and Sun, X., 2011. Long-term variation of fog and mist in 1951-2005 in mainland China. Journal of Tropical Meteorology, 27, 145-151.