Some Eulerian and Lagrangian Diagnostics for a Model Stratospheric Warming

Dunkerton, Timothy J.; Hsu, Cheng-Wei; McIntyre, Michael E.

doi:10.1175/1520-0469(1981)038<0819:sealdf>2.0.co;2

Cited by 209 publications

(152 citation statements)

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“…11 of K1 since the northward and upward components of E-P flux are proportional to meridional and vertical gradient of phase multiplied by amplitude squared. The splitting of E-P flux into equatorward direction in low latitudes and upward direction in high latitudes prior to warming has been pointed out by several authors (Palmer, 1981a, b;O'Neill and Youngblut, 1982;Dunkerton et al, 1981).…”

Section: Figurementioning

confidence: 77%

“…Similar analyses were performed by Palmer (1981a, b) and O'Neill and Youngblut (1982) for the observed 1979 wavenumber 2 type warming and the 1980 wavenumber 1 warming, and for the 1977 wavenumber 1 type warming respectively. On the other hand, Dunkerton et al (1981) and Hsu (1981) made E-P flux diagnosis for the wavenumber 2 and 1 model warming respectively, by using the numerical model designed by Holton (1976). Recently, Bridger and Stevens (1982) investigated the sensitivity of the model warming to the assumed initial mean zonal wind distribution with use of the diagnostics of E-P flux and refractive index.…”

Section: Introductionmentioning

confidence: 99%

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Eliassen-Palm Flux Diagnostics and the Effect of the Mean Wind on Planetary Wave Propagation for an Observed Sudden Stratospheric Warming

Kanzawa

1982

Journal of the Meteorological Society of Japan

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Eliassen-Palm (E-P) flux whose direction is interpreted as that of planetary wave propagation in the meridional plane, is used for diagnosing planetary waves for the 1973 sudden stratospheric warming. E-P flux by zonal wavenumber 1 component was focused into the polar stratosphere prior to the circulation reversal. By the focusing there occurred the intense convergence of E-P flux which embodies the forcing of waves on mean flow. The convergence brought about the intense deceleration of mean zonal wind and the poleward residual mean meridional flow in the stratosphere.A discussion is made of the "refractive index" Q defined as mean quasi-geostrophic potential vorticity gradient divided by mean zonal wind. It is the maximum of Q which was situated in the polar stratosphere prior to the warming that is interpreted as a main factor which determines the switching of E-P flux from equatorward to poleward.After the easterly winds appeared in the polar stratosphere the convergence of E-P flux concentrated around the zero wind line, suggesting that the mechanism of critical layer absorption was driven.

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Section: Figurementioning

confidence: 77%

Section: Introductionmentioning

confidence: 99%

Eliassen-Palm Flux Diagnostics and the Effect of the Mean Wind on Planetary Wave Propagation for an Observed Sudden Stratospheric Warming

Kanzawa

1982

Journal of the Meteorological Society of Japan

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“…The bold dashed line signifies the tropopause height in the REF2000 simulation. Dunkerton et al (1981):…”

Section: Physical Mechanisms In the Stratospherementioning

confidence: 99%

The impact of polar stratospheric ozone loss on Southern Hemisphere stratospheric circulation and climate

et al. 2014

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Abstract. The impact of polar stratospheric ozone loss resulting from chlorine activation on polar stratospheric clouds is examined using a pair of model integrations run with the fully coupled chemistry climate model UM-UKCA. Suppressing chlorine activation through heterogeneous reactions is found to produce modelled ozone differences consistent with observed ozone differences between the present and pre-ozone hole period. Statistically significant high-latitude Southern Hemisphere (SH) ozone loss begins in August and peaks in October-November, with > 75 % of ozone destroyed at 50 hPa. Associated with this ozone destruction is a > 12 K decrease of the lower polar stratospheric temperatures and an increase of > 6 K in the upper stratosphere. The heating components of this temperature change are diagnosed and it is found that the temperature dipole is the result of decreased short-wave heating in the lower stratosphere and increased dynamical heating in the upper stratosphere. The cooling of the polar lower stratosphere leads, through thermal wind balance, to an acceleration of the polar vortex and delays its breakdown by ∼ 2 weeks. A link between lower stratospheric zonal wind speed, the vertical component of the Eliassen-Palm (EP) flux, F z and the residual mean vertical circulation, w * , is identified. In November and December, increased westerly winds and a delay in the breakup of the polar vortex lead to increases in F z , indicating increased wave activity entering the stratosphere and propagating to higher altitudes. The resulting increase in wave breaking, diagnosed by decreases to the EP flux divergence, drives enhanced downwelling over the polar cap. Many of the stratospheric signals modelled in this study propagate down to the troposphere, and lead to significant surface changes in December.

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“…7 shows the differences in eddy heat flux (v ′ T ′ ) between different runs. The eddy heat flux is proportional to the vertical flux of wave activity via the EP flux (Dunkerton et al, 1981, Weber et al, 2003. Figure 7 indicates enhancements in planetary wave activities in the high-latitude troposphere in E2, E3 and E4.…”

Section: Temperature and Circulation Responses Tomentioning

confidence: 99%

Effects of meridional sea surface temperature changes on stratospheric temperature and circulation

Tian

Xie

et al. 2014

Adv. Atmos. Sci.

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Article:Hu, D, Tian, W, Xie, F et al. (2 more authors) (2014) Effects of meridional sea surface temperature changes on stratospheric temperature and circulation. Advances in Atmospheric Sciences, 31 (4). 888 -900. ISSN 0256-1530 https://doi.org/10.1007/s00376-013-3152-6 eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. ABSTRACT Using a state-of-the-art chemistry-climate model, we analyzed the atmospheric responses to increases in sea surface temperature (SST). The results showed that increases in SST and the SST meridional gradient could intensify the subtropical westerly jets and significantly weaken the northern polar vortex. In the model runs, global uniform SST increases produced a more significant impact on the southern stratosphere than the northern stratosphere, while SST gradient increases produced a more significant impact on the northern stratosphere. The asymmetric responses of the northern and southern polar stratosphere to SST meridional gradient changes were found to be mainly due to different wave properties and transmissions in the northern and southern atmosphere. Although SST increases may give rise to stronger waves, the results showed that the effect of SST increases on the vertical propagation of tropospheric waves into the stratosphere will vary with height and latitude and be sensitive to SST meridional gradient changes. Both uniform and non-uniform SST increases accelerated the large-scale Brewer-Dobson circulation (BDC), but the gradient increases of SST between 60 • S and 60 • N resulted in younger mean age-of-air in the stratosphere and a larger increase in tropical upwelling, with a much higher tropopause than from a global uniform 1.0 K SST increase.

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Some Eulerian and Lagrangian Diagnostics for a Model Stratospheric Warming

Cited by 209 publications

References 0 publications

Eliassen-Palm Flux Diagnostics and the Effect of the Mean Wind on Planetary Wave Propagation for an Observed Sudden Stratospheric Warming

Eliassen-Palm Flux Diagnostics and the Effect of the Mean Wind on Planetary Wave Propagation for an Observed Sudden Stratospheric Warming

The impact of polar stratospheric ozone loss on Southern Hemisphere stratospheric circulation and climate

Effects of meridional sea surface temperature changes on stratospheric temperature and circulation

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