Articles | Volume 21, issue 1
https://doi.org/10.5194/cp-21-67-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/cp-21-67-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
13 Jan 2025
Research article |
| 13 Jan 2025
| 13 Jan 2025
A stretched polar vortex increased mid-latitude climate variability during the Last Glacial Maximum
Yurui Zhang
CORRESPONDING AUTHOR
State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
Hans Renssen
Department of Natural Sciences and Environmental Health, University of South-Eastern Norway, Bø, Norway
Heikki Seppä
Department of Geosciences and Geography, University of Helsinki, Helsinki, Finland
Zhen Li
State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
Xingrui Li
State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Xiamen University, Xiamen, China
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Cited articles
Allen, R. J. and Zender, C. S.: Effects of continental-scale snow albedo anomalies on the wintertime Arctic oscillation, J. Geophys. Res.-Atmos., 115, D23105, https://doi.org/10.1029/2010jd014490, 2010.
Annan, J. D., Hargreaves, J. C., and Mauritsen, T.: A new global surface temperature reconstruction for the Last Glacial Maximum, Clim. Past, 18, 1883–1896, https://doi.org/10.5194/cp-18-1883-2022, 2022.
Baldwin, M. P. and Dunkerton, T. J.: Stratospheric Harbingers of Anomalous Weather Regimes, Science, 294, 581–584, https://doi.org/10.1126/science.1063315, 2001.
Baldwin, M. P. and Thompson, D. W. J.: A critical comparison of stratosphere–troposphere coupling indices, Q. J. Roy. Meteorol. Soc., 135, 1661–1672, https://doi.org/10.1002/qj.479, 2009.
Baldwin, M. P., Thompson, D. W., Shuckburgh, E. F., Norton, W. A., and Gillett, N. P.: Atmospheric science. Weather from the stratosphere?, Science, 301, 317–319, https://doi.org/10.1126/science.1085688, 2003.
Bereiter, B., Eggleston, S., Schmitt, J., Nehrbass-Ahles, C., Stocker, T. F., Fischer, H., Kipfstuhl, S., and Chappellaz, J.: Revision of the EPICA Dome C CO2 record from 800 to 600 kyr before present, Geophys. Res. Lett., 42, 542–549, https://doi.org/10.1002/2014gl061957, 2015.
Braconnot, P. and Kageyama, M.: Shortwave forcing and feedbacks in Last Glacial Maximum and Mid-Holocene PMIP3 simulations, Philos. T. Roy. Soc. A, 373, 20140424, https://doi.org/10.1098/rsta.2014.0424, 2015.
Braconnot, P., Harrison, S. P., Kageyama, M., Bartlein, P. J., Masson-Delmotte, V., Abe-Ouchi, A., Otto-Bliesner, B., and Zhao, Y.: Evaluation of climate models using palaeoclimatic data, Nat. Clim. Change, 2, 417–424, https://doi.org/10.1038/nclimate1456, 2012.
Cai, D., Lohmann, G., Chen, X., and Ionita, M.: The linkage between autumn Barents-Kara sea ice and European cold winter extremes, Front. Climate, 6, 1345763, https://doi.org/10.3389/fclim.2024.1345763, 2024.
Charney, J. G. and Drazin, P. G.: Propagation of planetary-scale disturbances from the lower into the upper atmosphere, J. Geophys. Res., 66, 83–109, https://doi.org/10.1029/JZ066i001p00083, 1961.
Clark, P. U. and Mix, A. C.: Ice sheets and sea level of the Last Glacial Maximum, Quaternary Sci. Rev., 21, 1–7, https://doi.org/10.1016/S0277-3791(01)00118-4, 2002.
Cleator, S. F., Harrison, S. P., Nichols, N. K., Prentice, I. C., and Roulstone, I.: A new multivariable benchmark for Last Glacial Maximum climate simulations, Clim. Past, 16, 699–712, https://doi.org/10.5194/cp-16-699-2020, 2020.
Cohen, J. and Jones, J.: Tropospheric Precursors and Stratospheric Warmings, J. Climate, 24, 6562–6572, https://doi.org/10.1175/2011jcli4160.1, 2011.
Cohen, J., Barlow, M., Kushner, P., and Saito, K.: Stratosphere-Troposphere coupling and links with Eurasian Land-Surface Variability, J. Climate, 20, 5335–5343, https://doi.org/10.1175/2007JCLI1725.1, 2007.
Cohen, J., Screen, J. A., Furtado, J. C., Barlow, M., Whittleston, D., Coumou, D., Francis, J., Dethloff, K., Entekhabi, D., Overland, J., and Jones, J.: Recent Arctic amplification and extreme mid-latitude weather, Nat. Geosci., 7, 627–637, https://doi.org/10.1038/ngeo2234, 2014.
Cohen, J., Agel, L., Barlow, M., Garfinkel, C. I., and White, I.: Linking Arctic variability and change with extreme winter weather in the United States, Science, 373, 1116–1121, https://doi.org/10.1126/science.abi9167, 2021.
Danabasoglu, G., Lamarque, J. F., Bacmeister, J., Bailey, D. A., DuVivier, A. K., Edwards, J., Emmons, L. K., Fasullo, J., Garcia, R., Gettelman, A., Hannay, C., Holland, M. M., Large, W. G., Lauritzen, P. H., Lawrence, D. M., Lenaerts, J. T. M., Lindsay, K., Lipscomb, W. H., Mills, M. J., Neale, R., Oleson, K. W., Otto-Bliesner, B., Phillips, A. S., Sacks, W., Tilmes, S., van Kampenhout, L., Vertenstein, M., Bertini, A., Dennis, J., Deser, C., Fischer, C., Fox-Kemper, B., Kay, J. E., Kinnison, D., Kushner, P. J., Larson, V. E., Long, M. C., Mickelson, S., Moore, J. K., Nienhouse, E., Polvani, L., Rasch, P. J., and Strand, W. G.: The Community Earth System Model Version 2 (CESM2), J. Adv. Model. Earth Syst., 12, e2019MS001916, https://doi.org/10.1029/2019ms001916, 2020.
ESGF: Coupled Model Intercomparison Project Phase 6 (CMIP6), https://esgf-node.llnl.gov/projects/esgf-llnl/ (last access: 15 July 2024), 2024.
Hajima, T., Watanabe, M., Yamamoto, A., Tatebe, H., Noguchi, M. A., Abe, M., Ohgaito, R., Ito, A., Yamazaki, D., Okajima, H., Ito, A., Takata, K., Ogochi, K., Watanabe, S., and Kawamiya, M.: Development of the MIROC-ES2L Earth system model and the evaluation of biogeochemical processes and feedbacks, Geosci. Model Dev., 13, 2197–2244, https://doi.org/10.5194/gmd-13-2197-2020, 2020.
Harrison, S. P., Bartlein, P. J., Izumi, K., Li, G., Annan, J., Hargreaves, J., Braconnot, P., and Kageyama, M.: Evaluation of CMIP5 palaeo-simulations to improve climate projections, Nat. Clim. Change, 5, 735–743, https://doi.org/10.1038/nclimate2649, 2015.
Jones, J. and Cohen, J.: Tropospheric Precursors and Stratospheric Warmings, J. Climate, 24, 6562–6572, https://doi.org/10.1175/2011jcli4160.1, 2011.
Kageyama, M., Albani, S., Braconnot, P., Harrison, S. P., Hopcroft, P. O., Ivanovic, R. F., Lambert, F., Marti, O., Peltier, W. R., Peterschmitt, J.-Y., Roche, D. M., Tarasov, L., Zhang, X., Brady, E. C., Haywood, A. M., LeGrande, A. N., Lunt, D. J., Mahowald, N. M., Mikolajewicz, U., Nisancioglu, K. H., Otto-Bliesner, B. L., Renssen, H., Tomas, R. A., Zhang, Q., Abe-Ouchi, A., Bartlein, P. J., Cao, J., Li, Q., Lohmann, G., Ohgaito, R., Shi, X., Volodin, E., Yoshida, K., Zhang, X., and Zheng, W.: The PMIP4 contribution to CMIP6 – Part 4: Scientific objectives and experimental design of the PMIP4-CMIP6 Last Glacial Maximum experiments and PMIP4 sensitivity experiments, Geosci. Model Dev., 10, 4035–4055, https://doi.org/10.5194/gmd-10-4035-2017, 2017.
Kageyama, M., Harrison, S. P., Kapsch, M.-L., Lofverstrom, M., Lora, J. M., Mikolajewicz, U., Sherriff-Tadano, S., Vadsaria, T., Abe-Ouchi, A., Bouttes, N., Chandan, D., Gregoire, L. J., Ivanovic, R. F., Izumi, K., LeGrande, A. N., Lhardy, F., Lohmann, G., Morozova, P. A., Ohgaito, R., Paul, A., Peltier, W. R., Poulsen, C. J., Quiquet, A., Roche, D. M., Shi, X., Tierney, J. E., Valdes, P. J., Volodin, E., and Zhu, J.: The PMIP4 Last Glacial Maximum experiments: preliminary results and comparison with the PMIP3 simulations, Clim. Past, 17, 1065–1089, https://doi.org/10.5194/cp-17-1065-2021, 2021.
Kim, B. M., Son, S. W., Min, S. K., Jeong, J. H., Kim, S. J., Zhang, X., Shim, T., and Yoon, J. H.: Weakening of the stratospheric polar vortex by Arctic sea-ice loss, Nat. Commun., 5, 4646, https://doi.org/10.1038/ncomms5646, 2014.
Kim, J.-S., Kug, J.-S., Jeong, S., Yoon, J.-H., Zeng, N., Hong, J., Jeong, J.-H., Zhao, Y., Chen, X., Williams, M., Ichii, K., and Schaepman-Strub, G.: Arctic warming-induced cold damage to East Asian terrestrial ecosystems, Commun. Earth Environ., 3, 16, https://doi.org/10.1038/s43247-022-00343-7, 2022.
Kolstad, E. W., Breiteig, T., and Scaife, A. A.: The association between stratospheric weak polar vortex events and cold air outbreaks in the Northern Hemisphere, Q. J. Roy. Meteorol. Soc., 136, 886–893, https://doi.org/10.1002/qj.620, 2010.
Kretschmer, M., Cohen, J., Matthias, V., Runge, J., and Coumou, D.: The different stratospheric influence on cold-extremes in Eurasia and North America, npj Clim. Atmos. Sci., 1, 44, https://doi.org/10.1038/s41612-018-0054-4, 2018.
Kug, J.-S., Jeong, J.-H., Jang, Y.-S., Kim, B.-M., Folland, C. K., Min, S.-K., and Son, S.-W.: Two distinct influences of Arctic warming on cold winters over North America and East Asia, Nat. Geosci., 8, 759–762, https://doi.org/10.1038/ngeo2517, 2015.
Manzini, E., Cagnazzo, C., Fogli, P. G., Bellucci, A., and Müller, W. A.: Stratosphere-troposphere coupling at inter-decadal time scales: Implications for the North Atlantic Ocean, Geophys. Res. Lett., 39, L05801, https://doi.org/10.1029/2011gl050771, 2012.
Mauritsen, T., Bader, J., Becker, T., Behrens, J., Bittner, M., Brokopf, R., Brovkin, V., Claussen, M., Crueger, T., Esch, M., Fast, I., Fiedler, S., Fläschner, D., Gayler, V., Giorgetta, M., Goll, D. S., Haak, H., Hagemann, S., Hedemann, C., Hohenegger, C., Ilyina, T., Jahns, T., Jimenéz-de-la-Cuesta, D., Jungclaus, J., Kleinen, T., Kloster, S., Kracher, D., Kinne, S., Kleberg, D., Lasslop, G., Kornblueh, L., Marotzke, J., Matei, D., Meraner, K., Mikolajewicz, U., Modali, K., Möbis, B., Müller, W. A., Nabel, J. E. M. S., Nam, C. C. W., Notz, D., Nyawira, S. S., Paulsen, H., Peters, K., Pincus, R., Pohlmann, H., Pongratz, J., Popp, M., Raddatz, T. J., Rast, S., Redler, R., Reick, C. H., Rohrschneider, T., Schemann, V., Schmidt, H., Schnur, R., Schulzweida, U., Six, K. D., Stein, L., Stemmler, I., Stevens, B., von Storch, J. S., Tian, F., Voigt, A., Vrese, P., Wieners, K. H., Wilkenskjeld, S., Winkler, A., and Roeckner, E.: Developments in the MPI-M Earth System Model version 1.2 (MPI-ESM1.2) and Its Response to Increasing CO2, J. Adv. Model. Earth Syst., 11, 998–1038, https://doi.org/10.1029/2018ms001400, 2019.
McIntyre, M. E. and Palmer, T. N.: Breaking planetary waves in the stratosphere, Nature, 305, 593–600, https://doi.org/10.1038/305593a0, 1983.
NCAR: NCAR CESM2-FV2 model output prepared for CMIP6 PMIP lgm, NCAR [code], https://doi.org/10.22033/ESGF/CMIP6.17642, 2024.
Pan, Z. and Duan, A.: Influence of the Tibetan Plateau on the coupling of the North Pacific–North Atlantic pressure systems, Atmos. Res., 295, 107026, https://doi.org/10.1016/j.atmosres.2023.107026, 2023.
Peltier, W. R., Argus, D. F., and Drummond, R.: Space geodesy constrains ice age terminal deglaciation: The global ICE-6G_C (VM5a) model, J. Geophys. Res.-Solid, 120, 450–487, https://doi.org/10.1002/2014jb011176, 2015.
Plumb, R. A.: On the Three-Dimensional Propagation of Stationary Waves, J. Atmos. Sci., 42, 217–229, https://doi.org/10.1175/1520-0469(1985)042<0217:OTTDPO>2.0.CO;2, 1985.
Polvani, L. M. and Waugh, D. W.: Upward Wave Activity Flux as a Precursor to Extreme Stratospheric Events and Subsequent Anomalous Surface Weather Regimes, J. Climate, 17, 3548–3554, https://doi.org/10.1175/1520-0442(2004)017<3548:UWAFAA>2.0.CO;2, 2004.
Reichler, T., Kim, J., Manzini, E., and Kröger, J.: A stratospheric connection to Atlantic climate variability, Nat. Geosci., 5, 783–787, https://doi.org/10.1038/ngeo1586, 2012.
Renssen, H., Seppä, H., Heiri, O., Roche, D. M., Goosse, H., and Fichefet, T.: The spatial and temporal complexity of the Holocene thermal maximum, Nat. Geosci., 2, 411–414, https://doi.org/10.1038/ngeo513, 2009.
Shi, X., Yang, H., Danek, C., and Lohmann, G.: AWI AWI-ESM1.1LR model output prepared for CMIP6 PMIP midHolocene, Earth System Grid Federation [data set], https://doi.org/10.22033/ESGF/CMIP6.9332, 2020.
Takaya, K. and Nakamura, H.: A Formulation of a Phase-Independent Wave-Activity Flux for Stationary and Migratory Quasigeostrophic Eddies on a Zonally Varying Basic Flow, J. Atmos. Sci., 58, 608–627, https://doi.org/10.1175/1520-0469(2001)058<0608:AFOAPI>2.0.CO;2, 2001.
Tierney, J. E., Zhu, J., King, J., Malevich, S. B., Hakim, G. J., and Poulsen, C. J.: Glacial cooling and climate sensitivity revisited, Nature, 584, 569–573, https://doi.org/10.1038/s41586-020-2617-x, 2020.
White, R. H., Battisti, D. S., and Sheshadri, A.: Orography and the Boreal Winter Stratosphere: The Importance of the Mongolian Mountains, Geophys. Res. Lett., 45, 2088–2096, https://doi.org/10.1002/2018gl077098, 2018.
Yang, X.-Y., Yuan, X., and Ting, M.: Dynamical Link between the Barents–Kara Sea Ice and the Arctic Oscillation, J. Climate, 29, 5103–5122, https://doi.org/10.1175/jcli-d-15-0669.1, 2016.
Zhang, J., Tian, W., Chipperfield, M. P., Xie, F., and Huang, J.: Persistent shift of the Arctic polar vortex towards the Eurasian continent in recent decades, Nat. Clim. Change, 6, 1094–1099, https://doi.org/10.1038/nclimate3136, 2016.
Zhang, M., Yang, X. Y., and Huang, Y.: Impacts of Sudden Stratospheric Warming on Extreme Cold Events in Early 2021: An Ensemble-Based Sensitivity Analysis, Geophys. Res. Lett., 49, e2021GL096840, https://doi.org/10.1029/2021gl096840, 2022.
Zhang, Y., Renssen, H., and Seppä, H.: Effects of melting ice sheets and orbital forcing on the early Holocene warming in the extratropical Northern Hemisphere, Clim. Past, 12, 1119–1135, https://doi.org/10.5194/cp-12-1119-2016, 2016.
Zhu, J., Otto-Bliesner, B. L., Garcia, R., Brady, E. C., Mills, M., Kinnison, D., and Lamarque, J. F.: Small Impact of Stratospheric Dynamics and Chemistry on the Surface Temperature of the Last Glacial Maximum in CESM2 (WACCM6ma), Geophys. Res. Lett., 49, e2022GL099875, https://doi.org/10.1029/2022gl099875, 2022.
Short summary
The upper and lower atmospheres interact. The polar regions, with high-speed, cyclonically rotating winds, provide a window through which upper winds affect surface weather and climate variability. By analysing climate model results, we found that ice sheets induced anomalous upward wave propagation and stretched the rotating winds towards North America, increasing the likelihood of cold-air outbreaks at the mid-latitudes. This accounts for the enhanced winter cooling at these latitudes.
The upper and lower atmospheres interact. The polar regions, with high-speed, cyclonically...
