Secondary maxima in ozone profiles

Lemoine, René

doi:10.5194/acp-4-1085-2004

Cited by 16 publications

(14 citation statements)

References 24 publications

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“…However, looking at individual profiles we see that the occurrence of layers of enhanced ozone at altitudes below 15 km is rather common, with their frequency of occurrence and persistence changing from year to year. Similar features have been observed in ozone profile data at mid-latitude sites in Europe and Asia (Lemoine, 2004;Hwang et al, 2007). Climatologically, these layers of enhanced ozone appear to coincide with the temperature "tropopause inversion layer" discussed by Birner et al (2006) and shown to be stronger in summer.…”

Section: Discussion and Summarysupporting

confidence: 63%

Summertime stratospheric processes at northern mid-latitudes: comparisons between MANTRA balloon measurements and the Canadian Middle Atmosphere Model

et al. 2008

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Abstract. In this paper we report on a study conducted using the Middle Atmospheric Nitrogen TRend Assessment (MANTRA) balloon measurements of stratospheric constituents and temperature and the Canadian Middle Atmosphere Model (CMAM). Three different kinds of data are used to assess the inter-consistency of the combined dataset: single profiles of long-lived species from MANTRA 1998, sparse climatologies from the ozonesonde measurements during the four MANTRA campaigns and from HALOE satellite measurements, and the CMAM climatology. In doing so, we evaluate the ability of the model to reproduce the measured fields and to thereby test our ability to describe mid-latitude summertime stratospheric processes. The MANTRA campaigns were conducted at Vanscoy, Saskatchewan, Canada (52 • N, 107 • W) in late August and early September of 1998September of , 2000September of , 2002September of and 2004 During late summer at mid-latitudes, the stratosphere is close to photochemical control, providing an ideal scenario for the study reported here. From this analysis we find that: (1) reducing the value for the vertical diffusion coefficient in CMAM to a more physically reasonable value results in the model better reproducing the measured profiles of long-lived species; (2) the existence of compact correlations among the constituents, as expected from independent measurements in the literature and from models, confirms the self-consistency of Correspondence to: S. M. L. Melo (stella.melo@space.gc.ca) the MANTRA measurements; and (3) the 1998 measurements show structures in the chemical species profiles that can be associated with transport, adding to the growing evidence that the summertime stratosphere can be much more disturbed than anticipated. The mechanisms responsible for such disturbances need to be understood in order to assess the representativeness of the measurements and to isolate longterm trends.

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Section: Discussion and Summarysupporting

confidence: 63%

Summertime stratospheric processes at northern mid-latitudes: comparisons between MANTRA balloon measurements and the Canadian Middle Atmosphere Model

et al. 2008

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“…In spring, the CO concentration is also constant above the mixing layer with a mixing ratio of 40 ppbv indicating a tropical origin [Hoor et al, 2004]. Several studies [Bradshaw et al, 2002a[Bradshaw et al, , 2002bLemoine, 2004] have shown that Rossby waves can break in winter and spring near the subtropical jet, resulting in a poleward transport of tropical air into the extratropical lower stratosphere, resulting in air masses with low ozone and tropical CO mixing ratios above the mixing layer in midlatitudes. This process reduces the lower stratospheric ozone concentrations in winter and spring.…”

Section: Regional Differencesmentioning

confidence: 99%

Characterization of the composition, structure, and seasonal variation of the mixing layer above the extratropical tropopause as revealed by MOZAIC measurements

et al. 2008

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[1] The chemical composition of the mixing layer above the tropopause, which is mainly influenced by stratosphere troposphere exchange, impacts the chemistry and radiative balance of the troposphere. A better understanding of its seasonal and spatial variation is needed to reduce uncertainties of global chemistry-transport models. In this paper, we use the Measurements of Ozone, Water Vapour, Nitrogen Oxides and Carbon Monoxide by Airbus In-Service Aircraft (MOZAIC) ozone and carbon monoxide data from 2003. The five MOZAIC aircraft fly daily between Europe and North America and between Europe and Asia, at 9-12 km crossing the tropopause when transecting upper level troughs. We present a new coordinate system consisting of potential vorticity on the y axis and the angle between the local PV surface and the horizontal on the x axis to study the mixing that occurs in the tropopause region. This coordinate system allows us to view the typical distribution of ozone and CO within upper level troughs. Using in situ measurements and a Lagrangian analysis, we have identified a mixing layer associated with stirring and mixing in the tropopause region between 2 and 6 pvu. Regional variations of the ozone and CO distributions and chemical anomalies between the center and the borders of the upper level troughs are found within the mixing layer.Citation: Brioude, J., J.-P. Cammas, O. R. Cooper, and P. Nedelec (2008), Characterization of the composition, structure, and seasonal variation of the mixing layer above the extratropical tropopause as revealed by MOZAIC measurements, J. Geophys. Res., 113, D00B01,

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“…The occurrences of SOPs, underlying processes and their global distribution have been discussed in a limited number of studies (Dobson, 1973;Reid and Vaughan, 1991;Varotsos et al, 1994), reviewed by Lemoine (2004). SOPs have been commonly observed at high latitudes, for example, as laminated structures of ozone with the highest frequency of occurrence during the spring season (Dobson, 1973).…”

Section: Introductionmentioning

confidence: 99%

“…Varotsos et al (1994) suggested that the northern and north-western atmospheric circulations in the lower stratosphere play a key role in the formation of SOPs observed over Athens, Greece. Overall, the occurrence of SOPs is typically considered to be a Northern Hemispheric phenomenon, with no SOPs reported in the tropics and the Southern Hemisphere (Lemoine, 2004). Trickl et al (2011) showed the influences of ozone import from the stratosphere and transport along the subtropical jet stream over Europe.…”

Section: Introductionmentioning

confidence: 99%

Secondary ozone peaks in the troposphere over the Himalayas

et al. 2017

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Abstract. Layers with strongly enhanced ozone concentrations in the middle-upper troposphere, referred to as secondary ozone peaks (SOPs), have been observed in different regions of the world. Here we use the global ECHAM5/MESSy atmospheric chemistry model (EMAC) to (i) investigate the processes causing SOPs, (ii) explore both their frequency of occurrence and seasonality, and (iii) assess their effects on the tropospheric ozone budget over the Himalayas. The vertical profiles of potential vorticity (PV) and a stratospheric ozone tracer (O 3 s) in EMAC simulations, in conjunction with the structure of SOPs, suggest that SOPs over the Himalayas are formed by stratosphereto-troposphere transport (STT) of ozone. The spatial distribution of O 3 s further shows that such effects are in general most pronounced in the northern part of India. Model simulated ozone distributions and backward air trajectories show that ozone rich air masses, associated with STT, originate as far as northern Africa and the North Atlantic Ocean, the Middle East, as well as in nearby regions in Afghanistan and Pakistan, and are rapidly (within 2-3 days) transported to the Himalayas. Analysis of a 15-year (2000-2014) EMAC simulation shows that the frequency of SOPs is highest during the pre-monsoon season (e.g. 11 % of the time in May), while no intense SOP events are found during the July-October period. The SOPs are estimated to enhance the tropospheric column ozone (TCO) over the central Himalayas by up to 21 %.

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Secondary maxima in ozone profiles

Cited by 16 publications

References 24 publications

Summertime stratospheric processes at northern mid-latitudes: comparisons between MANTRA balloon measurements and the Canadian Middle Atmosphere Model

Summertime stratospheric processes at northern mid-latitudes: comparisons between MANTRA balloon measurements and the Canadian Middle Atmosphere Model

Characterization of the composition, structure, and seasonal variation of the mixing layer above the extratropical tropopause as revealed by MOZAIC measurements

Secondary ozone peaks in the troposphere over the Himalayas

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