Atmospheric rivers as an indicator of circulation variability: between the Atlantic and the Black Sea region
DOI:
https://doi.org/10.26565/2410-7360-2026-64-23Keywords:
atmospheric rivers, circulation indices, correlation analysis, moisture transport, atmospheric precipitation, seasonal variability, Eastern Europe, Atlantic-European sector, reanalysisAbstract
Introduction. Atmospheric rivers (ARs) are a key mechanism of water vapour transport in the mid-latitudes, shaping precipitation regimes in many coastal regions of the world. Their impact on Western Europe is well studied; however, the role of ARs in Eastern Europe and their relationship with large-scale circulation regimes remain insufficiently explored.
The purpose of the study. The aim of this study is to identify statistical relationships between the frequency of atmospheric rivers in the Atlantic–European sector and the main circulation indices, as well as to analyse the potential responses of these phenomena in Eastern Europe.
The research methodology. The methodology is based on the use of the AR Reanalysis Databases V3.0 (Guan, 2021), where the identification of atmospheric rivers was carried out following the approach of Guan & Waliser (2019), taking into account integrated water vapour transport (IVT). For the correlation analysis, the ERA-Interim–based dataset (1.5° × 1.5°) was employed; circulation indices (NAO, PE, EA/WR, SCAND) were obtained from CPC; and monthly precipitation totals were taken from the ClimUAd database (0.1° × 0.1°). These data were used to calculate correlation relationships and to construct maps.
Research results. Atmospheric rivers (ARs) in the Atlantic–European sector exhibit a distinct seasonality: their frequency peaks in winter and reaches a minimum in summer, with a pronounced impact on precipitation in Eastern Europe, particularly in the Carpathians and the Black Sea region. Statistically significant correlations between AR frequency and circulation indices (NAO, SCAND, EA/WR, PE) confirm the role of large-scale atmospheric dynamics in shaping AR trajectories.
The novelty of the developments. This study proposes to consider atmospheric rivers as manifestations of large-scale atmospheric circulation dynamics. Unlike most research that focuses on the direct AR effects in Western Europe, this work is the first to highlight the potential responses of atmospheric rivers in Eastern Europe, particularly along the northern coast of the Black Sea. For the first time, a correlation analysis between AR frequency and circulation indices (NAO, EA/WR, PE, SCAND) is conducted, along with an assessment of their influence on the region’s monthly precipitation.
Practical significance. The results of this study can be applied to improve the understanding of atmospheric circulation as a driver of regional hydrometeorological anomalies. Identifying the potential impact of ARs on precipitation and cloudiness in Eastern Europe will enhance methods for long-term forecasting of the water balance and extreme weather events. This is of particular value for regions sensitive to precipitation deficits or sudden heavy rainfall, especially in the contexts of agriculture, water resource management, and risk management.
References
Barnston, A.G. & Livezey, R.E. (1987). Classifications, Seasonality, and Persistence of Low-Frequency Atmospheric Circulation Patterns. Monthly Weather Review, 115, 1083–1126. https://doi.org/10.1175/1520-0493(1987)115%3C1083:CSAPOL%3E2.0.CO;2
2. Benedict, I., Ødemark, K., Nipen, T., & Moore, R. (2019). Large-Scale Flow Patterns Associated with Extreme Precipitation and Atmospheric Rivers over Norway. Monthly Weather Review, 147(4), 1415–1428. https://doi.org/10.1175/MWR-D-18-0362.1
3. Dacre, H. F., & Clark, P. A. (2025). A kinematic analysis of extratropical cyclones, warm conveyor belts and atmospheric rivers. Npj Climate and Atmospheric Science, 8(1), 97. https://doi.org/10.1038/s41612-025-00942-z
4. Espinoza, V., Waliser, D. E., Guan, B., Lavers, D. A., & Ralph, F. M. (2018). Global Analysis of Climate Change Projection Effects on Atmospheric Rivers. Geophysical Research Letters, 45(9), 4299–4308. https://doi.org/10.1029/2017GL076968
5. Francis, D., Fonseca, R., Bozkurt, D., Nelli, N., & Guan, B. (2024). Atmospheric River Rapids and Their Role in the Extreme Rainfall Event of April 2023 in the Middle East. Geophysical Research Letters, 51(12), e2024GL109446. https://doi.org/10.1029/2024GL109446
6. Guan, B. (2021). AR Reanalysis Database [Dataset] Retrieved from: https://ucla.box.com/ARcatalog
7. Guan, B., Molotch, N. P., Waliser, D. E., Fetzer, E. J., & Neiman, P. J. (2013). The 2010/2011 snow season in California’s Sierra Nevada: Role of atmospheric rivers and modes of large-scale variability: Atmospheric Rivers and Modes of Large-Scale Variability. Water Resources Research, 49(10), 6731–6743. https://doi.org/10.1002/wrcr.20537
8. Guan, B., & Waliser, D. E. (2015). Detection of atmospheric rivers: Evaluation and application of an algorithm for global studies. Journal of Geophysical Research: Atmospheres, 120(24), 12514–12535. https://doi.org/10.1002/2015JD024257
9. Guan, B., & Waliser, D. E. (2019). Tracking Atmospheric Rivers Globally: Spatial Distributions and Temporal Evolution of Life Cycle Characteristics. Journal of Geophysical Research: Atmospheres, 124(23), 12523–12552. https://doi.org/10.1029/2019JD031205
10. Henny, L., & Kim, K.-M. (2025). The Changing Nature of Atmospheric Rivers. Journal of Climate, 38(6), 1435–1456. https://doi.org/10.1175/JCLI-D-24-0234.1
11. Hurrell, J. W. (1995). Decadal Trends in the North Atlantic Oscillation: Regional Temperatures and Precipitation. Science, 269(5224), 676–679. https://doi.org/10.1126/science.269.5224.676
12. Indices CPC_Indices Northern Hemisphere Teleconnection Indices. [Dataset]. https://iridl.ldeo.columbia.edu/SOURCES/.Indices/.CPC_Indices/.NHTI/
13. Ionita, M., Nagavciuc, V., & Guan, B. (2020). Rivers in the sky, flooding on the ground: The role of atmospheric rivers in inland flooding in central Europe. Hydrology and Earth System Sciences, 24(11), 5125–5147. https://doi.org/10.5194/hess-24-5125-2020
14. Kwon, Y., & Son, S.-W. (2025). Future projection of East Asian atmospheric rivers in high-resolution climate models. Weather and Climate Extremes, 48, 100776. https://doi.org/10.1016/j.wace.2025.100776
15. 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. https://doi.org/10.1016/j.jhydrol.2014.12.010
16. Liberato, M. L. R., Ramos, A. M., Trigo, R. M., Trigo, I. F., Durán-Quesada, A. M., Nieto, R., & Gimeno, L. (2012). Moisture sources and large-scale dynamics associated with a flash flood event. In J. Lin, D. Brunner, C. Gerbig, A. Stohl, A. Luhar, & P. Webley (Eds.), Lagrangian Modeling of the Atmosphere (pp. 111–126). American Geophysical Union. https://doi.org/10.1029/2012GM001244
17. Maclennan, M. L., Winters, A. C., Shields, C. A., Thaker, R., Barthelemy, L., Codron, F., & Wille, J. D. (2025). Rising atmospheric moisture escalates the future impact of atmospheric rivers in the Antarctic climate system. Communications Earth & Environment, 6(1), 369. https://doi.org/10.1038/s43247-025-02333-x
18. Massoud, E. C., Espinoza, V., Guan, B., & Waliser, D. E. (2019). Global Climate Model Ensemble Approaches for Future Projections of Atmospheric Rivers. Earth’s Future, 7(10), 1136–1151. https://doi.org/10.1029/2019EF001249
19. Michel, C., Sorteberg, A., Eckhardt, S., Weijenborg, C., Stohl, A., & Cassiani, M. (2021). Characterization of the atmospheric environment during extreme precipitation events associated with atmospheric rivers in Norway–Seasonal and regional aspects. Weather and Climate Extremes, 34, 100370. https://doi.org/10.1016/j.wace.2021.100370
20. Mundhenk, B. D., Barnes, E. A., & Maloney, E. D. (2016). All-Season Climatology and Variability of Atmospheric River Frequencies over the North Pacific. Journal of Climate, 29(13), 4885–4903. https://doi.org/10.1175/JCLI-D-15-0655.1
21. Osadchyi, V., Skrynyk, O., Sidenko, V., Aguilar, E., Guijarro, J., Szentimrey, T., Skrynyk, O., Bihari, Z., Palamarchuk, L., Oshurok, D., Kravchenko, I., & Pinchuk, D. (2025). ClimUAd: Observation‐Based Gridded Daily Climate Data for Ukraine, 1946–2020. Geoscience Data Journal, 12(2), e70000. https://doi.org/10.1002/gdj3.70000
22. Paltan, H., Waliser, D., Lim, W. H., Guan, B., Yamazaki, D., Pant, R., & Dadson, S. (2017). Global Floods and Water Availability Driven by Atmospheric Rivers. Geophysical Research Letters, 44(20). https://doi.org/10.1002/2017GL074882
23. Patricola, C. M., Wehner, M. F., Bercos-Hickey, E., Maciel, F. V., May, C., Mak, M., Yip, O., Roche, A. M., & Leal, S. (2022). Future changes in extreme precipitation over the San Francisco Bay Area: Dependence on atmospheric river and extratropical cyclone events. Weather and Climate Extremes, 36, 100440. https://doi.org/10.1016/j.wace.2022.100440
24. Payne, A. E., Demory, M.-E., Leung, L. R., Ramos, A. M., Shields, C. A., Rutz, J. J., Siler, N., Villarini, G., Hall, A., & Ralph, F. M. (2020). Responses and impacts of atmospheric rivers to climate change. Nature Reviews Earth & Environment, 1(3), 143–157. https://doi.org/10.1038/s43017-020-0030-5
25. Pradhan, S., Wasko, C., & Peel, M. C. (2025). Atmospheric rivers and Australian precipitation: Impact of detection algorithm choice. Journal of Hydrology, 651, 132586. https://doi.org/10.1016/j.jhydrol.2024.132586
26. Ralph, F. M., Wick, G. A., Neiman, P. J., Moore, B. J., Spackman, J. R., Hughes, M., Yong, F., & Hock, T. (2012). Atmospheric rivers in reanalysis products: A six-event comparison with aircraft observations of water vapor transport. WCRP Reanalysis Conference, Silver Spring, MD. https://www.wcrp-climate.org/ICR4/posters/Hughes_Atmospheric_Rivers.pdf
27. Ralph, F. M., Iacobellis, S. F., Neiman, P. J., Cordeira, J. M., Spackman, J. R., Waliser, D. E., Wick, G. A., White, A. B., & Fairall, C. (2017). Dropsonde Observations of Total Integrated Water Vapor Transport within North Pacific Atmospheric Rivers. Journal of Hydrometeorology, 18(9), 2577–2596. https://doi.org/10.1175/JHM-D-17-0036.1
28. Ralph, F. M., Rutz, J. J., Cordeira, J. M., Dettinger, M., Anderson, M., Reynolds, D., Schick, L. J., & Smallcomb, C. (2019). A Scale to Characterize the Strength and Impacts of Atmospheric Rivers. Bulletin of the American Meteorological Society, 100(2), 269–289. https://doi.org/10.1175/BAMS-D-18-0023.1
29. Shchehlov, O., Shpyg, V., & Fomichev, N. (2022). Atmospheric rivers: Potential impact on atmospheric processes and meteorological phenomena on the territory of Ukraine. Meteorology. Hydrology. Environmental monitoring, 2(2), 4–10. https://doi.org/10.15407/Meteorology2022.02.004
30. Shchehlov, O., Shpyg, V., Povshyk, T., & Fomichev, N. (2024). Influence of atmospheric rivers on extreme precipitation in western Ukraine. Visnyk of V. N. Karazin Kharkiv National University. Series Geology. Geography. Ecology, 60, 292–304. https://doi.org/10.26565/2410-7360-2024-60-21
31. Shields, C. A., Li, H., Castruccio, F. S., Fu, D., Nardi, K., Liu, X., & Zarzycki, C. (2024). Response of the upper ocean to northeast Pacific atmospheric rivers under climate change. Communications Earth & Environment, 5(1), 603. https://doi.org/10.1038/s43247-024-01774-0
32. Shields, C. A., Payne, A. E., Shearer, E. J., Wehner, M. F., O’Brien, T. A., Rutz, J. J., Leung, L. R., Ralph, F. M., Marquardt Collow, A. B., Ullrich, P. A., Dong, Q., Gershunov, A., Griffith, H., Guan, B., Lora, J. M., Lu, M., McClenny, E., Nardi, K. M., Pan, M., … Zarzycki, C. (2023). Future Atmospheric Rivers and Impacts on Precipitation: Overview of the ARTMIP Tier 2 High‐Resolution Global Warming Experiment. Geophysical Research Letters, 50(6), e2022GL102091. https://doi.org/10.1029/2022GL102091
33. Vallejo-Bernal, S. M., Wolf, F., Boers, N., Traxl, D., Marwan, N., & Kurths, J. (2023). The role of atmospheric rivers in the distribution of heavy precipitation events over North America. Hydrology and Earth System Sciences, 27(14), 2645–2660. https://doi.org/10.5194/hess-27-2645-2023
34. Waliser, D., & Guan, B. (2017). Extreme winds and precipitation during landfall of atmospheric rivers. Nature Geoscience, 10(3), 179–183. https://doi.org/10.1038/ngeo2894
35. Wang, S., Ma, X., Zhou, S., Wu, L., Wang, H., Tang, Z., Xu, G., Jing, Z., Chen, Z., & Gan, B. (2023). Extreme atmospheric rivers in a warming climate. Nature Communications, 14(1), 3219. https://doi.org/10.1038/s41467-023-38980-x
36. Wang, Z., Ding, Q., Wu, R., Ballinger, T. J., Guan, B., Bozkurt, D., Nash, D., Baxter, I., Topál, D., Li, Z., Huang, G., Chen, W., Chen, S., Cao, X., & Chen, Z. (2024). Role of atmospheric rivers in shaping long term Arctic moisture variability. Nature Communications, 15(1), 5505. https://doi.org/10.1038/s41467-024-49857-y
37. Zhu, Y., & Newell, R. E. (1998). A Proposed Algorithm for Moisture Fluxes from Atmospheric Rivers. Monthly Weather Review, 126(3), 725–735. https://doi.org/10.1175/1520-0493(1998)126%3C0725:APAFMF%3E2.0.CO;2
