Synoptic patterns of atmospheric rivers leading to heavy rains in the west and northwest of Iran

Document Type : Research Paper

Authors

1 PHD student in Tabriz university

2 The University of Tabriz

3 Assistant Professor of Climatology, University of Tabriz, Iran

4 Professor, Department of Physical Geography, School of Earth Science, The University of Shahid Beheshti (SBU), Tehran, Iran

10.22034/gp.2024.57342.3165

Abstract

Heavy rainfall is considered one of the climatic features of precipitation that can occur in any climate, but its occurrence in arid and semi-arid climates, due to the lack of adequate and appropriate infrastructure, is associated with greater damage. These rains occur under different synoptic conditions. In this study, the role of atmospheric rivers in the formation of heavy rainfall has been investigated. For this purpose, heavy rainfall data from stations in the west and northwest of the country were extracted for a 33-year period. Then, precipitation systems were separated in conjunction with atmospheric rivers. In the next step, using weather maps and the troposphere's underlying layer levels, synoptic patterns that lead to the formation of atmospheric rivers were identified. The results showed that atmospheric rivers were responsible for heavy rainfall in the study area, following three general patterns. The Sudanese low-pressure pattern and the combined pattern of Sudanese low-pressure and Mediterranean cyclone were responsible for the most significant role in the formation of atmospheric rivers leading to heavy rainfall, respectively. In the Sudanese low-pressure pattern, two to three days earlier, a broad tongue of Siberian high pressure spreads over the warm waters of the Oman, Arabian, and Aden seas, passing through Afghanistan, Pakistan, and the eastern part of Iran. This tongue, with the rotation of moisture, escapes from the Sudanese system. The Mediterranean trough deepens over western Asia and northeast Africa, and this moisture is strengthened along the southern currents and, by passing over the mountains,leads to the formation of atmospheric rivers. In the combined pattern, with the expansion of the Sudanese low-pressure tongue to the eastern Mediterranean and western Asia, the southern warm waters' moisture is released onto this region with the transport of moisture from the Mediterranean, it is strengthened, leading to the formation of atmospheric rivers.

Keywords

Main Subjects

Full Text

بارش‌های سنگین یکی از ویژگی اقلیمی عنصر بارش محسوب می‌شوند که در هر اقلیمی ممکن است اتفاق بیافتند. ولی رخداد آن ها در اقلیم‌های خشک و نیمه خشک به دلیل فقدان زیرساخت‌های کافی و مناسب همراه با خسارت بیشتری هستند. این بارش‌ها در شرایط همدیدی مختلفی رخ می‌دهند. در این پژوهش نقش رودخانه‌های جوی در شکل‌گیری بارش‌های سنگین مطالعه شده است. برای این منظور ابتدا بارش‌های سنگین ایستگاه‌های غرب و شمال غرب کشور دریک دوره 33 ساله استخراج گردید. سپس سامانه‌های بارشی همراه با رودخانه جوی تفکیک شد. در گام بعد با استفاده از نقشه‌های جوی تراز‌های لایه زیرین تروپوسفر الگو‌های همدیدی منجر به ایجاد رودخانه‌های جوی شناسایی شد. نتایج بررسی نشان دادند که رودخانه‌های جوی منجر به بارش‌های سنگین در منطقه مورد مطالعه از سه الگوی کلی تبعیت می‌کنند. دو الگوی کم فشار سودانی و الگوی ترکیبی کم فشار سودان و سیکلون مدیترانه‌ای به ترتیب بیشترین نقش را در ایجاد روخانه‌های جوی منجر با بارش سنگین بر عهده داشته‌اند. در الگوی همدیدی کم فشار سودان از دو تا سه روز قبل، زبانه گسترده‌ای از پرفشار سیبری در لایه زیرین تروپوسفر با عبور از کشور‌های افغانستان و پاکستان و بخش شرقی ایران بر روی آب‌های گرم دریا‌های عمان، عرب و خلیج عدن گسترش می‌یابد. این زبانه با گردش واچرخندی رطوبت این دریا‌ها را به درون سامانه سودانی فرارفت می‌کند. با تعمیق ناوه مدیترانه‌ای بر روی غرب آسیا و شمال شرق آفریقا این رطوبت در امتداد جریانات جنوبی جلوی ناوه و با عبور از روی آب‌های دریای سرخ تقویت شده و رودخانه جوی شکل می‌گیرد. در الگوی ادغامی با گسترش زبانه کم فشار سودان به بخش شرقی مدیترانه و غرب آسیا رطوبت دریا‌های گرم جنوبی بر روی این منطقه فرارفت شده و با رطوبت انتقالی از روی مدیترانه تقویت گردیده و رودخانه جوی شکل می‌گیرد.

References

Sapandar, Nesa; Omidvar, Kamal. (2011). Analysis of the relationship between heavy rainfall in southern and southwestern Iran and atmospheric rivers (ARs). Journal of Applied Research in Geographical Sciences, No. 295-314.
Salimi, Saadoon; Saliki, Mohammad. (2016). The impact of atmospheric rivers (ARs) on the climate of Iran. Physical Geography Research. No. 48, 247-264.
Shadmani, Nahid; Nasra-Esfahani, Mohammad Ali; Ghasemi, Ahmad Reza. (2018). Identification of moisture supply sources and the precise path of movement of moist air masses affecting torrential rainfall in western and southern Iran (Case study: floods of November 20 and 21, 2015). Iranian Journal of Geophysics, No. 12, 50-63.
Lashkari, Hassan; Esfandiari, Neda. (2011). Synoptic and thermodynamic patterns of atmospheric rivers leading to heavy precipitation during the cold period in Iran. Natural Environmental Hazards, No. 10, 125-144.
Lashkari, Hassan; Esfandiari, Neda. (2019). Identification and synoptic analysis of the highest precipitation associated with atmospheric rivers in Iran. Spatial Analysis of Environmental Hazards, No. 2, 187-206.
Akbary, M., Salimi, S., Hosseini, S. A., & Hosseini, M. (2019). Spatio‐temporal changes of atmospheric rivers in the Middle East and North Africa region. International Journal of Climatology, 39(10), 3976-3986.
Debbage, N., Miller, P., Poore, S., Morano, K., Mote, T., & Marshall Shepherd, J. (2017). A climatology of atmospheric river interactions with the southeastern United States coastline. International Journal of Climatology, 37(11), 4077-4091.
Dettinger, M. D., & Ralph, F. M. (2011). Tapash Das, Paul J. Neiman, and Daniel R. Cayan, 445-78.
Eckhardt, S., Stohl, A., Wernli, H., James, P., Forster, C., & Spichtinger, N. (2004). A 15-year climatology of warm conveyor belts. Journal of climate, 17(1), 218-237.
Gimeno, L., Nieto, R., Vázquez, M., & Lavers, D. A. (2014). Atmospheric rivers: A mini-review. Frontiers in Earth Science, 2, 2.
Kaspi, Y., & Schneider, T. (2013). The role of stationary eddies in shaping midlatitude storm tracks. Journal of the atmospheric sciences, 70(8), 2596-2613.
Kim, J., Moon, H., Guan, B., Waliser, D. E., Choi, J., Gu, T. Y., & Byun, Y. H. (2021). Precipitation characteristics related to atmospheric rivers in East Asia. International Journal of Climatology, 41, E2244-E2257.
Lakshmi, D. D., & Satyanarayana, A. N. V. (2019). Influence of atmospheric rivers in the occurrence of devastating flood associated with extreme precipitation events over Chennai using different reanalysis data sets. Atmospheric Research, 215, 12-36.
Lashkari, H., & Esfandiari, N. (2020). Identification and synoptic analysis of the highest precipitation linked to ARs in Iran. Journal of Spatial Analysis Environmental hazarts, 7(2), 187-206[In Parsin].
Lashkari, H., & Esfandiari, N. (2021). Synoptic and thermodynamic patterns of atmospheric rivers associated to heavy precipitation in the cold period of Iran. Journal of Natural Environmental Hazards, 10(29), 125-144[In Parsin].
Lashkari, H., Matkan, A., Azadi, M., & Mohamadi, Z. (2018). Synoptic patterns lead to premature precipitation in the South and South West of Iran during the period (1979-2015). Geography and Planning, 22(64), 247-266[In Parsin].
Lashkari, H., & Mohammadi, Z. (2015). The effect of the location of the Arabian subtropical high pressure on the precipitation systems in the south and southwest of Iran. Researches of Natural Geography, 47(1), 73-90[In Parsin].
Lavers, D. A., & Villarini, G. (2015). The contribution of atmospheric rivers to precipitation in Europe and the United States. Journal of Hydrology, 522, 382-390.
Lavers, D. A., Allan, R. P., Wood, E. F., Villarini, G., Brayshaw, D. J., & Wade, A. J. (2011). Winter floods in Britain are connected to atmospheric rivers. Geophysical Research Letters, 38(23).
Liang, J., & Yong, Y. (2021). Climatology of atmospheric rivers in the Asian monsoon region. International Journal of Climatology, 41, E801-E818.
Mahoney, K., Jackson, D. L., Neiman, P., Hughes, M., Darby, L., Wick, G., ... & Cifelli, R. (2016). Understanding the role of atmospheric rivers in heavy precipitation in the southeast United States. Monthly Weather Review, 144(4), 1617-1632.
Miller, D. K., Hotz, D., Winton, J., & Stewart, L. (2018). Investigation of atmospheric rivers impacting the Pigeon River basin of the southern Appalachian Mountains. Weather and Forecasting, 33(1), 283-299.
Nayak, M. A., Villarini, G., & Bradley, A. A. (2016). Atmospheric rivers and rainfall during NASA’s Iowa Flood Studies (IFloodS) campaign. Journal of Hydrometeorology, 17(1), 257-271.
Neiman, P. J., Ralph, F. M., White, A. B., Kingsmill, D. E., & Persson, P. O. G. (2002). The statistical relationship between upslope flow and rainfall in California's coastal mountains: Observations during CALJET. Monthly Weather Review, 130(6), 1468-1492.
Newell, R. E., Newell, N. E., Zhu, Y., & Scott, C. (1992). Tropospheric rivers?–A pilot study. Geophysical research letters, 19(24), 2401-2404.
Newman, M., Kiladis, G. N., Weickmann, K. M., Ralph, F. M., & Sardeshmukh, P. D. (2012). Relative contributions of synoptic and low-frequency eddies to time-mean atmospheric moisture transport, including the role of atmospheric rivers. Journal of climate, 25(21), 7341-7361.
Park, C., Son, S. W., & Kim, H. (2021). Distinct features of atmospheric rivers in the early versus late East Asian summer monsoon and their impacts on monsoon rainfall. Journal of Geophysical Research: Atmospheres, 126(7), e2020JD033537.
Ralph, F. M., Neiman, P. J., & Rotunno, R. (2005). Dropsonde observations in low-level jets over the northeastern Pacific Ocean from CALJET-1998 and PACJET-2001: Mean vertical-profile and atmospheric-river characteristics. Monthly weather review, 133(4), 889-910.
Ralph, F. M., Neiman, P. J., & Wick, G. A. (2004). Satellite and CALJET aircraft observations of atmospheric rivers over the eastern North Pacific Ocean during the winter of 1997/98. Monthly weather review, 132(7), 1721-1745.
Ramos, A. M., Trigo, R. M., Tomé, R., & Liberato, M. L. (2018). Impacts of atmospheric rivers in extreme precipitation on the European Macaronesian Islands. Atmosphere, 9(8), 325.
Salimi, S., & Saligheh, M. (2016). The effects of Atmospheric Rivers on Iran climate. Physical Geography Research Quarterly, 48(2), 247-264[In Parsin].
Sepandar, N., & Omidvar, K. (2021). Investigation of the Relation between South and Southwest Iran's Heavy Rainfall with Atmospheric Rivers (ARs). Jgs, 21 (61), 295-314[In Parsin].
Sodemann, H., & Stohl, A. (2013). Moisture origin and meridional transport in atmospheric rivers and their association with multiple cyclones. Monthly Weather Review, 141(8), 2850-2868.
Stohl, A., Forster, C., & Sodemann, H. (2008). Remote sources of water vapor forming precipitation on the Norwegian west coast at 60 N–a tale of hurricanes and an atmospheric river. Journal of Geophysical Research: Atmospheres, 113(D5).
Zhu, Y., & Newell, R. E. (1994). Atmospheric rivers and bombs. Geophysical Research Letters, 21(18), 1999-2002.
 

Files

Share

How to cite

Statistics