The Effect of Climate Change on the Variability of the Northern Hemisphere Stratospheric Polar Vortex by Mitchell, D, Osprey, S, Gray, L, Butchart, N, Hardiman, S, Ciarlton-Perez, A, Watson, P

Multi-model analysis of Northern Hemisphere winter blocking: Model biases and the role of resolution by Anstey, J, Davini, P, Gray, L, Woollings, T, Butchart, N, Cagnazzo, C, Christiansen, B, Hardiman, S, Osprey, S, Yang, S

“…Blocking of the tropospheric jet stream during Northern Hemisphere winter (December-January-February) is examined in a multi-model ensemble of coupled atmosphere-ocean general circulation models (GCMs) obtained from the Coupled Model Intercomparison Project Phase 5 (CMIP5). …”

Multi-model analysis of Northern Hemisphere winter blocking: Model biases and the role of resolution by Anstey, J, Davini, P, Gray, L, Woollings, T, Butchart, N, Cagnazzo, C, Christiansen, B, Hardiman, S, Osprey, S, Yang, S

The effect of climate changes on the variability of the Northern Hemisphere stratospheric polar vortex (vol 69, pg 2608, 2012) by Mitchell, D, Osprey, S, Gray, L, Butchart, N, Hardiman, S, Charlton-Perez, A, Watson, P

Teleconnections of the Quasi-Biennial Oscillation in a multi-model ensemble of QBO-resolving models by Anstey, JA, Simpson, IR, Richter, JH, Naoe, H, Taguchi, M, Serva, F, Gray, LJ, Butchart, N, Hamilton, K, Osprey, S, Bellprat, O, Braesicke, P, Bushell, AC, Cagnazzo, C, Chen, C, Chun, H, Garcia, RR, Holt, L, Kawatani, Y, Kerzenmacher, T, Kim, Y, Lott, F, McLandress, C, Scinocca, J, Stockdale, TN, Versick, S, Watanabe, S, Yoshida, K, Yukimoto, S

“…The models do not show clear evidence of a QBO teleconnection to the Northern Hemisphere Pacific‐sector subtropical jet. …”

Extreme weather events in early summer 2018 connected by a recurrent hemispheric wave-7 pattern by Kornhuber, K, Osprey, S, Coumou, D, Petri, S, Petoukhov, V, Rahmstorf, S, Gray, L

“…We show that this pattern constitutes an important teleconnection in Northern Hemisphere summer associated with prolonged and above-normal temperatures in North America, Western Europe and the Caspian Sea region. …”

An unexpected disruption of the atmospheric quasi-biennial oscillation by Osprey, S, Butchart, N, Knight, J, Scaife, A, Hamilton, K, Anstey, J, Schenzinger, V, Zhang, C

“…Instead the primary cause was waves transporting momentum from the Northern Hemisphere. Seasonal forecasts did not predict the disruption but analogous QBO disruptions are seen very occasionally in some climate simulations. …”

Prospect of increased disruption to the QBO in a changing climate by Anstey, JA, Banyard, TP, Butchart, N, Coy, L, Newman, PA, Osprey, S, Wright, CJ

“…The quasi-biennial oscillation (QBO) of tropical stratospheric winds was disrupted during the 2019/20 Northern Hemisphere winter. We show that this latest disruption to the regular QBO cycling was similar in many respects to that seen in 2016, but initiated by horizontal momentum transport from the Southern Hemisphere. …”

The Climatology of the Middle Atmosphere in a Vertically Extended Version of the Met Office's Climate Model. Part I: Mean State by Hardiman, S, Butchart, N, Osprey, S, Gray, L, Bushell, A, Hinton, T

“…The time of final warming of the winter polar vortex is found to descend monotonically in the Southern Hemisphere, as would be expected for purely radiative forcing. In the Northern Hemisphere, however, the time of final warming is driven largely by dynamical effects in the lower stratosphere and radiative effects in the upper stratosphere, leading to the earliest transition to westward winds being seen in the midstratosphere. …”

Stratospheric Variability in Twentieth-Century CMIP5 Simulations of the Met Office Climate Model: High Top versus Low Top by Osprey, S, Gray, L, Hardiman, S, Butchart, N, Hinton, T

“…A reduction in the westerly bias in the Northern Hemisphere polar night jet is found in the high-top model. …”

Interactions between the stratospheric polar vortex and Atlantic circulation on seasonal to multi-decadal timescales by Dimdore-Miles, O, Gray, L, Osprey, S, Robson, J, Sutton, R, Sinha, B

“…Variations in the strength of the Northern Hemisphere winter polar stratospheric vortex can influence surface variability in the Atlantic sector. …”

Multimodel climate and variability of the stratosphere by Butchart, N, Charlton-Perez, A, Cionni, I, Hardiman, S, Haynes, P, Krueger, K, Kushner, P, Newman, P, Osprey, S, Perlwitz, J, Sigmond, M, Wang, L, Akiyoshi, H, Austin, J, Bekki, S, Baumgaertner, A, Braesicke, P, Bruehl, C, Chipperfield, M, Dameris, M, Dhomse, S, Eyring, V, Garcia, R, Garny, H, Joeckel, P

“…Quantitatively, "metrics" indicate a wide spread in model performance for most diagnostics with systematic biases in many, and poorer performance in the SH than in the Northern Hemisphere (NH). Correlations were found in the SH between errors in the final warming, polar temperatures, the leading mode of variability, and jet strength, and in the NH between errors in polar temperatures, frequency of major SSWs, and jet strength. …”

Uncertainty in the response of sudden stratospheric warmings and stratosphere‐troposphere coupling to quadrupled CO2 concentrations in CMIP6 models by Ayarzagüena, B, Charlton-Perez, AJ, Butler, AH, Hitchcock, P, Simpson, IR, Polvani, LM, Butchart, N, Gerber, EP, Gray, L, Hassler, B, Lin, P, Lott, F, Manzini, E, Mizuta, R, Orbe, C, Osprey, S, Saint-Martin, D, Sigmond, M, Taguchi, M, Volodin, EM, Watanabe, S

“…However, up to now, there is not a clear consensus on which projected changes to the polar vortex are robust, particularly in the Northern Hemisphere, possibly due to short data record or relatively moderate CO2 forcing. …”

Prediction of the quasi‐biennial oscillation with a multi‐model ensemble of QBO‐resolving models by Stockdale, TN, Kim, Y, Anstey, JA, Palmeiro, FM, Butchart, N, Scaife, AA, Andrews, M, Bushell, AC, Dobrynin, M, Garcia‐Serrano, J, Hamilton, K, Kawatani, Y, Lott, F, McLandress, C, Naoe, H, Osprey, S, Pohlmann, H, Scinocca, J, Watanabe, S, Yoshida, K, Yukimoto, S

“…Teleconnections from the QBO to Northern Hemisphere winter circulation are also examined, and do not appear to be realistic beyond the first month. …”

Surface impacts of the quasi biennial oscillation by Gray, L, Anstey, J, Kawatani, Y, Lu, H, Osprey, S, Schenzinger, V

“…Teleconnections between the Quasi Biennial Oscillation (QBO) and the Northern Hemisphere zonally averaged zonal winds, mean sea level pressure (mslp) and tropical precipitation are explored. …”