ارتباط شاخص‌های همرفتی و دورپیوندی در منطقه غرب آسیا

نوع مقاله : مقاله پژوهشی‌

نویسندگان

1 دانش‌آموخته کارشناسی ارشد، گروه فیزیک فضا، موسسه ژئوفیزیک دانشگاه تهران، ایران

2 استادیار، گروه فیزیک فضا، موسسه ژئوفیزیک دانشگاه تهران، ایران

3 استاد، گروه فیزیک فضا، موسسه ژئوفیزیک دانشگاه تهران، ایران

چکیده

نوسانات بزرگ­مقیاس دورپیوندی می­توانند تأثیر بسزایی بر ظرفیت تشکیل سامانه­های همرفتی در جوّ داشته باشند. در این مطالعه توزیع اقلیم­شناختی برخی شاخص­های پایداری ایستایی جوّ (شاخص­های همرفتی) و ارتباط آن با برخی نوسانات دورپیوندی در منطقه غرب آسیا بررسی می­شود.
در این پژوهش، ابتدا با استفاده از داده­های بازتحلیل JRA55با تفکیک افقی 25/1×25/1 درجه، چهار شاخص پایداری جوّ شامل انرژی پتانسیل دسترس­پذیر همرفتی (CAPE)، شاخص بالابری (LI)، شاخص کا (KI) و شاخص مجموع مجموع­ها (TTI) طی دوره 1958 تا 2018 محاسبه شد. سپس توزیع میانگین فصلی این شاخص­ها در منطقه غرب آسیا در بخش اول این مطالعه ارائه شد. در بخش دوم، با تعیین فازهای بحرانی چهار شاخص دورپیوندی شامل نوسان اطلس شمالی (NAO)، شرق اطلس/ غرب روسیه (EA/WR)، دوقطبی اقیانوس هند (IOD) و نوسان مادن- جولیان (MJO)، اختلاف توزیع میانگین شاخص­های پایداری مذکور برای ماه­های بحرانی مثبت و منفی این شاخص­های دورپیوندی در فصل بهار طی دوره مطالعاتی در منطقه غرب آسیا بررسی شد.
نتایج بخش اول این پژوهش نشان داد توزیع فصلی شاخص­های پایداری در منطقه مورد مطالعه، تحت تأثیر چرخه فصلی دما و رطوبت ناشی از جابه‌جایی ITCZ است. همچنین بیشترین مقادیر شاخص­های پایداری در فصل تابستان و در مناطق پست و کمترین آن طی فصل زمستان و در مناطق مرتفع قرار دارد. نتایج بخش دوم نشان داد اغلب فاز مثبت (منفی) دو شاخص NAO و EA/WR با کاهش (افزایش) و فاز مثبت (منفی) دو شاخص IOD و MJO با افزایش (کاهش) گستردگی مکانی توزیع مقادیر شاخص­های پایداری در بیشتر نواحی منطقه مورد مطالعه همراه است. بیشترین افزایش شاخص CAPE طی فاز منفی NAO (EAWR) نسبت به فاز مثبت آن در دریای عمان (شرق هند) به بیش از J/kg250 + (450+) و طی فاز مثبت IOD (MJO) نسبت به فاز منفی آن در غرب هند (دریای عمان) به بیش از J/kg 450 + (600+) می­رسد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

On the relationship between convective and teleconnection indices over the West Asia

نویسندگان [English]

  • Amir Tahmasebi Pasha 1
  • Mohammad Mirzaei 2
  • Alireza Mohebalhojeh 3
1 M.Sc. Graduate of Meteorology, Department of Space Physics, Institute of Geophysics, University of Tehran, Iran
2 Assistant Professor, Department of Space Physics, Institute of Geophysics, University of Tehran, Iran
3 Professor, Department of Space Physics, Institute of Geophysics, University of Tehran, Iran
چکیده [English]

Convective systems are meso-scale atmospheric phenomena which their intensity of activity is determined by atmospheric static stability indices (convective indices). The effect of large-scale teleconnections on the increase or decrease in the potential for occurrence of convective systems in the atmosphere is of particular importance. Therefore, study of the climatological distribution of atmospheric stability indices along with teleconnections can be important in predicting convective systems. Given the lack of a comprehensive study of the relationship between the two phenomena, the purpose of this study is to investigate the climatological distribution of some atmospheric stability indices and their relationships with some teleconnections over the West Asia.
In this study, first using JRA55 reanalysis data with a horizontal resolution of 1.25×1.25 degree during the period 1958 to 2018, four atmospheric stability indices including Convective Available Potential Energy (CAPE), K Index (KI), Lifted Index (LI) and Total Totals Index (TTI) were calculated. Then, in the first part of this study, the average seasonal distribution of these indices on the West Asian region in the range of 0 to 60 degrees north and 10 to 90 degrees east are presented. Next, in the second part of this study, the relationship between atmospheric stability indices and teleconnections is examined. For this purpose, by determining the critical phases of the four teleconnections, including the North Atlantic Oscillation (NAO), East Atlantic/West Russia (EA/WR), Indian Ocean Dipole (IOD) and Madden–Julian Oscillation (MJO), the difference in distribution of the average atmospheric stability indices for the positive and negative critical months of these teleconnections is investigated in spring season during the study period on the West Asia.
The results of the first part of this study showed that the seasonal distribution of atmospheric stability indices on the study area is affected by the seasonal cycles of temperature and humidity associated with the ITCZ displacement. The results also showed that the maximum values of the stability indices occur in summer over lowland areas and the minimum ones in winter and highlands. The results of the second part showed that generally the area in which the atmospheric stability indices have significant values over the most parts of the study area decreases (increases) during the positive (negative) phases of the two northern indices of NAO and EA/WR, but increases (decreases) during the positive (negative) phases of the two southern indices IOD and MJO. The highest increase of CAPE index during the negative phase of NAO (EAWR) compared to its positive phase on the Oman Sea (East India) exceeds +250 (+450) J/kg and also during the positive phase of IOD (MJO) compared to its negative phase on Western India (Oman Sea) exceeds +450 (+600) J/kg.
 

کلیدواژه‌ها [English]

  • Convective available potential energy
  • K index
  • lifted index
  • total totals index
  • North Atlantic oscillatio
  • East Atlantic/West Russia
  • Indian Ocean dipole
  • Madden–Julian oscillation

مراجع

صمدیار، ب.، میرزائی، م.، محب‌الحجه، ع. ر.، طهماسبی پاشا، ا.، 1400، بررسی آماری- دینامیکی توفان­های همرفتی قوی در اهواز: مجله ژئوفیزیک ایران، پذیرفته‌شده.
Barnston, A. G., and Livezey, R. E., 1987, Classification, seasonality and persistence of low-frequency atmospheric circulation patterns: Monthly Weather Review, 115, 1083-1126.
Bolton, D., 1980, Computation of equivalent potential temperature: Monthly Weather Review, 108, 1046–1053.
Bryan, G. H., and Fritsch, J. M., 2004, A reevaluation of ice–liquid water potential temperature: Monthly Weather Review, 132, 2421–2431.
Campozano, L., Trachte, K., Célleri, R., Samaniego, E., Bendix, J., Albuja, C., and Mejia, J. F., 2018, Climatology and teleconnections of mesoscale convective systems in an Andean basin in Southern Ecuador: The case of the Paute basin: Advances in Meteorology, 2018, 1–13.
DeMott, C. A., and Randall, D. A., 2004, Observed variations of tropical convective available potential energy: Journal of Geophysical Research, 109, D02102.
Doswell, C. A., and Rasmussen, E. N., 1994, The effect of neglecting the virtual temperature correction on CAPE calculations: Weather Forecasting, 9, 625–629.
Firouzabadi, M., Mirzaei, M., and Mohebalhojeh, A. R., 2019, The climatology of severe convective storms in Tehran: Atmospheric Research, 221, 34-45.
Galway, J. G., 1956, The lifted index as a predictor of latent instability: Bulletin of the American Meteorological Society, 37, 528–529.
George, J. J., 1960, Weather Forecasting for
 
      Aeronautics: Academic Press, 673 pp.
Groenemeijer, P. H., and Delden, A., 2007, Sounding-derived parameters associated with large hail and tornadoes in the Netherlands: Atmospheric Research, 83, 473–487.
Holley, D. M., Dorling, S. R., Steele, C. J., and Earl, N., 2014, A climatology of convective available potential energy in Great Britain:  International Journal of Climatology, 34, 3811–3824.
Jayakrishnan, P. R., and Babu, C. A., 2014, Assessment of convective activity using stability indices as inferred from radiosonde and MODIS data: Atmospheric and Climate Sciences, 4, 122-130.
Madden, R. A., and Julian, P. R., 1971, Detection of a 40–50 day oscillation in the zonal wind in the tropical Pacific: Journal of Atmospheric Sciences, 28, 702–708.
Meukaleuni, C., Lenouo, A. and Monkam, D., 2016, Climatology of convective available potential energy (CAPE) in ERA-Interim reanalysis over West Africa: Atmospheric Science Letters, 17, 65-70.
Miller, R. C., 1972, Notes on analysis and severe storm forecasting procedures of the Air Force Global Weather Central: Tech. Rept. 200(R), Headquarters, Air Weather Service, USAF, 190 pp.
Mo, K. C., and Livezey, R. E., 1986, Tropical–extratropical geopotential height teleconnection during the Northern Hemisphere winter: Monthly Weather Review, 114, 2488–2515.
Moncrieff, M. W., and Miller, M. J., 1976, The dynamics and simulation of tropical squall lines: Quarterly Journal of the Royal Meteorological Society, 102, 373–394.
Monkam, D., 2002, Convective available potential energy (CAPE) in Northern Africa and tropical Atlantic and study of its connections with rainfall in central and West Africa during summer 1985: Atmospheric Research, 62, 125–147.
Murugavel, P., Pawar, S. D., and Gopalakrishnan, V., 2012, Trends of convective available potential energy over the Indian region and its effect on rainfall: Internationl Journal of Climatology, 32, 1362–1372.
Nasr Esfahany, M. A., Mohebalhojeh, A. R., and Ahmadi Givi, F., 2017, Effects of different phases of Madden-Julian Oscillation on some tropospheric: Journal of the Earth and Space Physics, 43(3), 539-552.
Riemann-Campe, K., Fraedrich, K., and Lunkeit, F., 2009, Global climatology of Convective Available Potential Energy (CAPE) and Convective Inhibition (CIN) in ERA-40 reanalysis: Atmospheric Research, 93, 534–545.
Saji, N. H., Goswami, B. N., Vinayachandran, P. N., and Yamagata, T., 1999, A dipole mode in the tropical Indian Ocean: Nature, 401, 360–363.
Savvidou, K., Orphanou, A., Charalambous, D., Lingis, P., and Michaelides, S., 2010, A statistical analysis of sounding derived indices and parameters for extreme and non-extreme thunderstorms events over Cyprus: Advances in Geosciences, 23, 79–85.
Showalter, A. K., 1947, A stability index for forecasting thunderstorms: Bulletin of the American Meteorological Society, 34, 250-252.
Taszarek, M., Brooks, H. E., Czernecki, B., Szuster, P., and Fortuniak, K., 2018, Climatological aspects of convective parameters over Europe: A comparison of ERA-Interim and sounding data: Journal of Climate, 31, 4281–4308.
Walker, G. T., 1924, Correlation in seasonal variations of weather, IX: A further study of world weather: Memoirs of the Indian Meteorological Department, 24(Part 9), 275–332.
Wallace, J. M., and Gutzler, D. S., 1981, Teleconnections in the geopotential height field during the Northern Hemisphere winter: Monthly Weather Review, 109, 784–812.
Wieners, C. E., Dijkstra, H. A., and de Ruijter, W. P. M., 2017, The influence of atmospheric convection on the interaction between the Indian Ocean and ENSO: Journal of Climate, 30, 10155–10178.
Wilks, D. S., 2006, Statistical Methods in the Atmospheric Science: 2nd. Ed. Elsevierer, 627 pp.
Williams, E., and Renno, N., 1993, An analysis of the conditional instability of the tropical atmosphere: Monthly Weather Review, 121, 21–36.
Ziarani, M., Bookhagen, B., Schmidt, T., Wickert, J., de la Torre, A., and Hierro, R., 2019, Using convective available potential energy (CAPE) and dew-point temperature to characterize rainfall-extreme events in the south-central Andes: Atmosphere, 10, 379.
مجله ژئوفیزیک ایران
دوره 15، شماره 3
آذر 1400
صفحه 1-26

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