Relationships between Brewer-Dobson circulation, double tropopauses, ozone and stratospheric water vapour

Castanheira, J. M.; Peevey, Tanya R.; Marques, Carlos; Olsen, Mark A.

doi:10.5194/acp-12-10195-2012

Cited by 16 publications

(21 citation statements)

References 30 publications

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“…Intrusions of tropospheric air into MT regions also have been reported in START08 aircraft campaign data [e.g., Homeyer et al , ]. Castanheira et al [] present a statistical analysis of relationships between the upward branch of the Brewer‐Dobson circulation, the area covered by double tropopauses (DTs), and stratospheric O 3 and lower stratospheric H 2 O. While their statistical results cannot provide direct information on transport pathways, they show correlations between column O 3 , O 3 laminae, wave activity, and areas of DTs that are consistent with those expected from tropical to extratropical transport in the UTLS.…”

Section: Introductionmentioning

confidence: 92%

Climatology and variability of trace gases in extratropical double‐tropopause regions from MLS, HIRDLS, and ACE‐FTS measurements

et al. 2015

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Upper tropospheric and lower stratospheric measurements from the Aura Microwave Limb Sounder (MLS), the Aura High Resolution Dynamics Limb Sounder (HIRDLS), and the Atmospheric Chemistry Experiment-Fourier transform spectrometer (ACE-FTS) are used to present the first global climatological comparison of extratropical, nonpolar trace gas distributions in double-tropopause (DT) and single-tropopause (ST) regions. Stratospheric tracers, O 3 , HNO 3 , and HCl, have lower mixing ratios ∼2-8 km above the primary (lowermost) tropopause in DT than in ST regions in all seasons, with maximum Northern Hemisphere (NH) differences near 50% in winter and 30% in summer. Southern Hemisphere winter differences are somewhat smaller, but summer differences are similar in the two hemispheres. H 2 O in DT regions of both hemispheres shows strong negative anomalies in November through February and positive anomalies in July through October, reflecting the strong seasonal cycle in H 2 O near the tropical tropopause. CO and other tropospheric tracers examined have higher DT than ST values 2-7 km above the primary tropopause, with the largest differences in winter. Large DT-ST differences extend to high NH latitudes in fall and winter, with longitudinal maxima in regions associated with enhanced wave activity and subtropical jet variations. Results for O 3 and HNO 3 agree closely between MLS and HIRDLS, and differences from ACE-FTS are consistent with its sparse and irregular midlatitude sampling. Consistent signatures in climatological trace gas fields provide strong evidence that transport from the tropical upper troposphere into the layer between double tropopauses is an important pathway for stratosphere-troposphere exchange.

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Section: Introductionmentioning

confidence: 92%

Climatology and variability of trace gases in extratropical double‐tropopause regions from MLS, HIRDLS, and ACE‐FTS measurements

et al. 2015

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“…Castanheira et al [] found that as the baroclinicity in the UTLS increases, a potential outcome of climate change [e.g., Garcia and Randel , ; Randel et al , ], so does the DT frequency. Subsequent studies showed that the meridional extent of the DT is strongly correlated with baroclinic Rossby waves [ Castanheira and Gimeno , ] along with upwelling in the tropics and the frequency of low ozone lamina in the lower stratosphere [ Castanheira et al , ].…”

Section: Introductionmentioning

confidence: 99%

The double tropopause and its dynamical relationship to the tropopause inversion layer in storm track regions

et al. 2014

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Using High Resolution Dynamic Limb Sounder observations and ERA-Interim reanalysis this study demonstrates that the warm conveyor belt (WCB) is a mechanism responsible for the relationship between the double tropopause (DT) and the tropopause inversion layer (TIL), a relationship recently suggested in the literature based on idealized model simulations of baroclinic disturbances. Using these data sets, spatial and temporal characteristics of the DT-TIL relationship are examined over a 3 year period, [2005][2006][2007][2008]. In the extratropics, results from satellite data show that as the TIL increases in strength, so does the frequency of the DT, regardless of season or hemisphere. The inverse relationship is found in the tropics. Using only DT profiles, zonal composites of wind, relative vorticity, and temperature from reanalysis data show that as the TIL increases in strength, the upper tropospheric circulation switches from cyclonic to anticyclonic, and the upward vertical motion increases. This result suggests the WCB as a mechanism since it is on the anticyclonic side of the jet and is characterized by the movement of tropical air poleward and upward from the surface. To verify this relationship, the vertical and horizontal development of a synoptic-scale baroclinic system is analyzed over a 4 day period. Results show the equatorward extension of the polar tropopause, and thus the formation of the DT, due to the strengthening of the TIL in the region of vertical motion associated with the WCB. Moreover, this result suggests that air movement within the DT could originate from high latitudes when associated with a baroclinic disturbance.

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“…More recently, Peevey et al [] have documented similar results using 3 years (2005–2007) of high‐resolution dynamics limb sounder (HIRDLS) data. Although the formation and maintenance of multiple tropopause system are still not completely understood, increasing evidence points to Rossby wave dynamics as playing an important role in the occurrence of multiple tropopauses [ Pan et al , ; Castanheira and Gimeno , ; Castanheira et al , ; Peevey et al , ].…”

Section: Introductionmentioning

confidence: 99%

Characteristics of the subtropical tropopause region based on long‐term highly resolved sonde records over Tenerife

Rodriguez-Franco

Cuevas

2013

JGR Atmospheres

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[1] This study examines the structure of the subtropical tropopause region over Tenerife (the Canary Islands, Spain; 28 ı N, 16 ı W) based on a 20 year (1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011) ozonesonde data and European Center for Medium-Range Weather Forecasts ERA-Interim potential vorticity (PV) and zonal wind speed reanalysis. High-resolution vertical profiles allowed a detailed description of the subtropical tropopause break and the associated subtropical jet stream (STJ), where models fail to properly simulate the upper troposphere-lower stratosphere (UTLS). The subtropical UTLS is revealed as a complex atmospheric region with a thickness 8 km, which is examined through the analysis and evaluation of four different tropopause definitions: thermal (TT), cold point, ozone (OT), and dynamical (DT) tropopauses. A novel method to determine the DT based on the vertical gradient of Lait's modified PV is presented and the concept of a second DT has been introduced for the first time. Monthly climatologies of tropopause height and potential temperature are calculated for double and single tropopause events. The 14.3 km height level is used to differentiate between tropical and extratropical UTLS regimes, intimately linked to the position of the STJ. There is fairly good consistency between all the defined tropopauses under the double tropopause scheme, except in spring, when the OT is observed at lower levels due to frequent baroclinic instabilities in the upper troposphere. As concerns to single tropopause events, the same pattern is found from April to June, reflecting the influence of analogous processes during these months. In winter, altitude differences between OT, DT, and TT resulted from poleward STJ excursions forced by blocking systems over the North Atlantic. Analysis of the tropopause inversion layer showed distinctive features for tropical and midlatitude tropopauses.Citation: Rodriguez-Franco, J. J., and E. Cuevas (2013), Characteristics of the subtropical tropopause region based on long-term highly-resolved sonde records over Tenerife,

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Relationships between Brewer-Dobson circulation, double tropopauses, ozone and stratospheric water vapour

Cited by 16 publications

References 30 publications

Climatology and variability of trace gases in extratropical double‐tropopause regions from MLS, HIRDLS, and ACE‐FTS measurements

Climatology and variability of trace gases in extratropical double‐tropopause regions from MLS, HIRDLS, and ACE‐FTS measurements

The double tropopause and its dynamical relationship to the tropopause inversion layer in storm track regions

Characteristics of the subtropical tropopause region based on long‐term highly resolved sonde records over Tenerife

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