Intraseasonal Variability of the Zonal-Mean Extratropical Tropopause: The Role of Changes in Polar Vortex Strength and Upper-Troposphere Wave Breaking

Barroso, Jesús Á.; Zurita‐Gotor, Pablo

doi:10.1175/jas-d-15-0177.1

Cited by 4 publications

(9 citation statements)

References 63 publications

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“…Conversely, a reduction in tropopause pressure is accompanied by a decrease in stratospheric temperature and UTLS static stability, and a strengthening of stratospheric westerlies. This relationship is similar to the results in other studies (Ambaum and Hoskins 2002;Barroso and Zurita-Gotor 2016;Tomassini et al 2012;Jucker 2016;Wong and Wang 2003;Zängl and Hoinka 2001).…”

Section: Evolution In the Arctic Stratosphere And Troposphere And Itssupporting

confidence: 92%

“…It can be said, therefore, that the mid-latitude tropopause anomalies are more closely linked to tropospheric wind anomalies than the Arctic tropopause anomalies. This relationship with the tropospheric jet also appears in the zonal mean sense, which explains the wavy deformation of tropopause anomalies to the north and south of the zonal wind anomalies through meridional flux of quasigeostrophic PV at the tropopause level (Barroso and Zurita-Gotor 2016).…”

Section: Mid-latitude Tropospheric Jet Fluctuation and Its Linkage Tomentioning

confidence: 77%

“…S10). In this study, the normalized PCH index is used as a proxy for the Northern Annular Mode (NAM) index, which describes variation of the polar vortex strength (Baldwin and Dunkerton 2001; Baldwin and Thompson 2009). If a local extremum of the 10-hPa NAM index is greater than +1.5 , a weak vortex event is assumed to have occurred, and a strong vortex event is assumed to have occurred if it is less than −1.5 .…”

Section: Role Of the Two Modes In The Extreme Stratospheric Vortex Evmentioning

confidence: 99%

“…To investigate the fundamental characteristics of tropopause variation, Barroso and Zurita-Gotor (2016) and Wong and Wang (2003) analyzed the principal component of the zonal mean tropopause variability. In both studies, change in stratospheric polar vortex plays an important role in the major modes of tropopause fluctuations.…”

Section: Introductionmentioning

confidence: 99%

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The leading modes of NH extratropical tropopause variability and their connection with stratosphere-troposphere variability

Kim

2021

Clim Dyn

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The leading modes of Northern Hemisphere tropopause variability for November–April (1979/1980–2018/2019) and the associated stratosphere-troposphere variability were analyzed based on the NCEP and ERA interim reanalysis products. For this, cyclostationary empirical orthogonal function technique is employed. The first two modes feature the intraseasonal evolution of tropopause pressure anomalies over the Arctic, which respond directly to stratospheric temperature fluctuations in association with stratospheric polar vortex variations. These two modes reflect the link between stratospheric polar vortex strength and high-latitude tropospheric circulation. The first mode represents a single-phase fluctuation of the stratospheric polar vortex from winter to early spring. The second mode describes a two-phase fluctuation of the stratospheric vortex with opposite signs in winter and in spring. Tropopause pressure anomalies near the mid-latitude tropospheric jet regions exhibit significant zonal variation. In the first mode, in particular, these mid-latitude tropopause anomalies are linked to asymmetric jet variations in the Atlantic and the Pacific regions. In regard to the Northern Annular mode, distinct vertical evolution structures of the two modes are practically related to the varying evolutionary structure of extreme vortex events with relatively long persistence.

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Section: Evolution In the Arctic Stratosphere And Troposphere And Itssupporting

confidence: 92%

Section: Mid-latitude Tropospheric Jet Fluctuation and Its Linkage Tomentioning

confidence: 77%

Section: Role Of the Two Modes In The Extreme Stratospheric Vortex Evmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The leading modes of NH extratropical tropopause variability and their connection with stratosphere-troposphere variability

Kim

2021

Clim Dyn

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“…22, 25-31), and stratospheric dynamics (e.g., refs. 19,[32][33][34][35]. It is frequently viewed in the context of a radiative constraint and a dynamic constraint (22,23,30).…”

Section: Discussionmentioning

confidence: 99%

Thermodynamic constraint on the depth of the global tropospheric circulation

Thompson

Bony

2017

Proc. Natl. Acad. Sci. U.S.A.

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The troposphere is the region of the atmosphere characterized by low static stability, vigorous diabatic mixing, and widespread condensational heating in clouds. Previous research has argued that in the tropics, the upper bound on tropospheric mixing and clouds is constrained by the rapid decrease with height of the saturation water vapor pressure and hence radiative cooling by water vapor in clear-sky regions. Here the authors contend that the same basic physics play a key role in constraining the vertical structure of tropospheric mixing, tropopause temperature, and cloud-top temperature throughout the globe. It is argued that radiative cooling by water vapor plays an important role in governing the depth and amplitude of large-scale dynamics at extratropical latitudes.climate dynamics | climate change | cloud feedbacks | extratropical dynamics | general circulation T he defining difference between the troposphere (the turning sphere) and the stratosphere (the layered sphere) is the amplitude of mixing within each region. The troposphere is marked by vigorous diabatic motions (i.e., motions that flux heat across isentropic surfaces); the stratosphere is characterized by relatively weak diabatic mixing.The top of the troposphere coincides closely to the level above which clouds rarely penetrate. In the tropics, the upper bound on tropospheric clouds is believed to be strongly constrained by the unique vertical structure of radiative cooling by water vapor. Saturation vapor pressure decreases rapidly with temperature in the tropical upper troposphere in accordance with the ClausiusClapeyron relationship. As the saturation vapor pressure decreases, so do water vapor concentrations, and hence so does the amplitude of the clear-sky radiative cooling (1, 2) and its associated downward mass flux (3). From continuity, the thermodynamic limit on sinking motion in clear-sky regions extends to rising motion in regions of deep convection (3). Because the rising motion in regions of deep convection is limited by saturation vapor pressures (and thus temperatures) in clear-sky regions and the static stabilities in clear-sky and cloudy regions of the tropics are comparable, it follows that cloud-top temperatures in the tropics are strongly constrained by the basic thermodynamics that govern clear-sky water vapor concentrations (3, 4).The physical linkages between clear-sky radiative cooling, the depth of tropospheric mixing, and clouds have been applied specifically to the case of tropical anvil clouds. Here we contend that the same physical linkages play an even broader role in the global atmosphere circulation. It is argued that clear-sky cooling by water vapor constrains the depth of tropospheric mixing, cloud-top temperatures, and the amplitude of large-scale atmospheric dynamics throughout the global atmosphere.A Thermodynamic Constraint on the Depth of the Troposphere At steady state, the thermodynamic energy equation can be expressed in pressure coordinates asWhere V · ∇ h T is the horizontal advection of temperature, ...

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A Diagnostic Equation for Tendency of Lapse-Rate-Tropopause Heights and Its Application

Kohma

Sato

2019

Journal of the Atmospheric Sciences

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The tropopause is the boundary between the troposphere and stratosphere and is normally defined by the temperature lapse rate. Previous studies have noted that synoptic-scale and planetary-scale disturbances bring about lapse-rate-tropopause (LRT) height fluctuations on time scales from several days to several years. In the present study, a diagnostic expression for the tendency of LRT height is derived by assuming that the LRT can be characterized as a discontinuity in the vertical gradient of the potential temperature. In addition, the contribution from each term in the thermodynamic equation to the LRT height is quantified. The derived equation is validated by examining the time variation of the LRT height associated with baroclinic waves in an idealized numerical calculation, that of the zonal-mean LRT height in GPS radio occultation data, and that of the LRT height in reanalysis data.

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Intraseasonal Variability of the Zonal-Mean Extratropical Tropopause: The Role of Changes in Polar Vortex Strength and Upper-Troposphere Wave Breaking

Cited by 4 publications

References 63 publications

The leading modes of NH extratropical tropopause variability and their connection with stratosphere-troposphere variability

The leading modes of NH extratropical tropopause variability and their connection with stratosphere-troposphere variability

Thermodynamic constraint on the depth of the global tropospheric circulation

A Diagnostic Equation for Tendency of Lapse-Rate-Tropopause Heights and Its Application

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