Tracer correlations in the northern high latitude lowermost stratosphere: Influence of cross‐tropopause mass exchange

Fischer, H.; Wienhold, F. G.; Hoor, Peter; Bujok, O.; Schiller, C.; Siegmund, P.; Ambaum, Maarten H. P.; Scheeren, H. A.; Lelieveld, Jos

doi:10.1029/1999gl010879

Cited by 160 publications

(189 citation statements)

References 24 publications

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“…The lowermost stratosphere is a region with mostly stratospheric character, episodically spiced with tropospheric air. This has lead to the concept of a mixing zone just above the tropopause at higher latitudes, where upwelling tropospheric air is mixed with downwelling stratospheric air [Fischer et al, 2000;Zahn, 2001;Dethof et al, 2000]. The relative importance of these two sources varies, with transport from the overworld being strongest in spring, and transport from the troposphere being possibly strongest in fall [Ray et al, 1999].…”

Section: Ste In the Extratropicsmentioning

confidence: 99%

“…Tropopause folds are considered a region of especially strong mixing between stratospheric and tropospheric air, due to clear air turbulence [Gidel and Shapiro, 1979;Shapiro, 1980;Hartjenstein, 2000]. It has become quite popular to infer information on mixing by analyzing tracer-tracer scatter plots [Fischer et al, 2000;Parrish et al, 2000;Zahn, 2001]. All these efforts, however, are in the stage of case studies, and correct quantification of mixing is still an unsolved problem.…”

Section: Mixing Of Stratospheric and Tropospheric Air 171 Mixing Pmentioning

confidence: 99%

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Stratosphere‐troposphere exchange: A review, and what we have learned from STACCATO

et al. 2003

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[1] This paper provides a review of stratosphere-troposphere exchange (STE), with a focus on processes in the extratropics. It also addresses the relevance of STE for tropospheric chemistry, particularly its influence on the oxidative capacity of the troposphere. After summarizing the current state of knowledge, the objectives of the project Influence of Stratosphere-Troposphere Exchange in a Changing Climate on Atmospheric Transport and Oxidation Capacity (STACCATO), recently funded by the European Union, are outlined. Several papers in this Journal of Geophysical ResearchAtmospheres special section present the results of this project, of which this paper gives an overview. STACCATO developed a new concept of STE in the extratropics, explored the capacities of different types of methods and models to diagnose STE, and identified their various strengths and shortcomings. Extensive measurements were made in central Europe, including the first monitoring over an extended period of time of beryllium-10 ( 10 Be), to provide a suitable database for case studies of stratospheric intrusions and for model validation. Photochemical models were used to examine the impact of STE on tropospheric ozone and the oxidizing capacity of the troposphere. Studies of the present interannual variability of STE and projections into the future were made using reanalysis data and climate models.

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Section: Ste In the Extratropicsmentioning

confidence: 99%

Section: Mixing Of Stratospheric and Tropospheric Air 171 Mixing Pmentioning

confidence: 99%

Stratosphere‐troposphere exchange: A review, and what we have learned from STACCATO

et al. 2003

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“…These data sets have been used in many studies of the tropopause region e.g. Lelieveld et al (1997), Bregmann et al (1997), Fischer et al (2000), Beuermann et al (2002) and Hoor et al (2002). The whole STREAM data set has been recompiled.…”

Section: Datamentioning

confidence: 99%

On the structural changes in the Brewer-Dobson circulation after 2000

et al. 2011

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Abstract. In this paper we present evidence that the observed increase in tropical upwelling after the year 2000 may be attributed to a change in the Brewer-Dobson circulation pattern. For this purpose, we use the concept of transit times derived from residual circulation trajectories and different in-situ measurements of ozone and nitrous dioxide. Observations from the Canadian midlatitude ozone profile record, probability density functions of in-situ N 2 O observations and a shift of the N 2 O-O 3 correlation slopes, taken together, indicate that the increased upwelling in the tropics after the year 2000 appears to have triggered an intensification of tracer transport from the tropics into the extratropics in the lower stratosphere below about 500 K. This finding is corroborated by the fact that transit times along the shallow branch of the residual circulation into the LMS have decreased for the same time period (1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003). On a longer time scale , the transit time of the shallow residual circulation branch show a steady decrease of about −1 month/decade over the last 30 yr, while the transit times of the deep branch remain unchanged. This highlights that changes in the upwelling across the tropical tropopause are not sufficient as an indicator for changes in the entire BrewerDobson circulation.

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“…Trace gas correlations have been shown to be an effective method to diagnose stratosphere-troposphere exchange (STE) and mixing processes in the LMS. Tracer-tracer correlation methods in the LMS are introduced by Fischer et al (2000). A following study, Hoor et al (2002), attempted to diagnose the seasonal variation of the tracer-tracer relationship in the LMS.…”

Section: Introductionmentioning

confidence: 99%

“…Fischer et al (2000), Hoor et al (2002) and Pan et al (2004) used aircraft in situ measurements to provide an analysis of trace gas (H 2 O, CO, CO 2 , N 2 O, NO y and O 3 ) correlations in the LMS. Trace gas correlations have been shown to be an effective method to diagnose stratosphere-troposphere exchange (STE) and mixing processes in the LMS.…”

Section: Introductionmentioning

confidence: 99%

Diagnosing the transition layer at extratropical latitudes using MLS O<sub>3</sub> and MOPITT CO analyses

Barré¹,

Amraoui²,

Ricaud³

et al. 2013

Atmos. Chem. Phys.

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Abstract. The behavior of the extratropical transition layer (ExTL) is investigated using a chemistry transport model (CTM) and analyses derived from assimilation of MLS (Microwave Limb Sounder) O3 and MOPITT (Measurements Of Pollution In The Troposphere) CO data. We firstly focus on a stratosphere–troposphere exchange (STE) case study that occurred on 15 August 2007 over the British Isles (50° N, 10° W). We evaluate the effect of data assimilation on the O3–CO correlations. It is shown that data assimilation disrupts the relationship in the transition region. When MLS O3 is assimilated, CO and O3 values are not consistent between each other, leading to unphysical correlations at the STE location. When MLS O3 and MOPITT CO assimilated fields are taken into account in the diagnostics the relationship happens to be more physical. We then use O3–CO correlations to quantify the effect of data assimilation on the height and depth of the ExTL. When the free-model run O3 and CO fields are used in the diagnostics, the ExTL distribution is found 1.1 km above the thermal tropopause and is 2.6 km wide (2σ). MOPITT CO analyses only slightly sharpen (by −0.02 km) and lower (by −0.2 km) the ExTL distribution. MLS O3 analyses provide an expansion (by +0.9 km) of the ExTL distribution, suggesting a more intense O3 mixing. However, the MLS O3 analyses ExTL distribution shows a maximum close to the thermal tropopause and a mean location closer to the thermal tropopause (+0.45 km). When MLS O3 and MOPITT CO analyses are used together, the ExTL shows a mean location that is the closest to the thermal tropopause (+0.16 km). We also extend the study at the global scale on 15 August 2007 and for the month of August 2007. MOPITT CO analyses still show a narrower chemical transition between stratosphere and troposphere than the free-model run. MLS O3 analyses move the ExTL toward the troposphere and broaden it. When MLS O3 analyses and MOPITT CO analyses are used together, the ExTL matches the thermal tropopause poleward of 50°.

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Tracer correlations in the northern high latitude lowermost stratosphere: Influence of cross‐tropopause mass exchange

Cited by 160 publications

References 24 publications

Stratosphere‐troposphere exchange: A review, and what we have learned from STACCATO

Stratosphere‐troposphere exchange: A review, and what we have learned from STACCATO

On the structural changes in the Brewer-Dobson circulation after 2000

Diagnosing the transition layer at extratropical latitudes using MLS O<sub>3</sub> and MOPITT CO analyses

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Tracer correlations in the northern high latitude lowermost stratosphere: Influence of cross‐tropopause mass exchange

Cited by 160 publications

References 24 publications

Stratosphere‐troposphere exchange: A review, and what we have learned from STACCATO

Stratosphere‐troposphere exchange: A review, and what we have learned from STACCATO

On the structural changes in the Brewer-Dobson circulation after 2000

Diagnosing the transition layer at extratropical latitudes using MLS O&lt;sub&gt;3&lt;/sub&gt; and MOPITT CO analyses

Contact Info

Product

Resources

About

Diagnosing the transition layer at extratropical latitudes using MLS O<sub>3</sub> and MOPITT CO analyses