GLORIA

GEOMAR Library Ocean Research Information Access

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [s.l.] : Macmillan Magazines Ltd.
    Nature 388 (1997), S. 661-663 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] High concentrations of ozone are found in the Earth's stratosphere, but strong stratification suppresses efficient exchange of this ozone-rich air with the underlying troposphere. Upward transport of tropospheric trace constituents occurs mainly through equatorial deep convective systems. In ...
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Humidity and temperature fluctuations at pressure levels between 166 and 290 hPa on the grid scale of general circulation models for a region coveredn by the routes of airliners, mainly over the Atlantic, have been determined by evaluation of the data obtained with almost 2000 flights within the MOZAIC programme. It is found that the distributions of the fluctuations cannot be modelled by Gaussian distributions, because large fluctuations appear with a relatively high frequency. Lorentz distributions were used for the analytical representation of the fluctuation distributions. From these a joint probability distribution has been derived for simultaneous temperature and humidity fluctuations. This function together with the criteria for the formation and persistence of contrails are used to derive the maximum possible fractional coverage of persistent contrails in a grid cell of a GCM. This can be employed in a statistical formulation of contrail appearance in a climate model.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-0662
    Keywords: stratosphere-troposphere exchange ; tropopause folding ; cross tropopause ozone transfer ; vertical ozone profiles ; potential vorticity ; Q-vector divergence ; 7beryllium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract This paper gives a synthesis of three algorithms to detect the presenceof tropopause folds from vertical ozone/radio-sounding profiles and frommeteorological analysis. Also an algorithm to identify injection ofstratospheric air into the lower troposphere fromozone/7beryllium time series is presented. Differences in theresults obtained from the algorithms are observed and discussed with respectto the criteria for fold detection and input data used. Spatial gradients inthe obtained folding frequencies are made evident on a global scale from thealgorithm based on meteorological analysis (Q-vector/potential vorticity)and probably also on a regional European scale from algorithms both basedmeteorological analyses and on ozone/PTU soundings. The observed seasonalvariation of folding occurrence is rather flat except during summer whenalso some differences appear between the algorithms. By combining thefolding frequencies with literature estimates of the cross-tropopause ozonetransfer in single folding events, an average stratospheric ozone influxinto the troposphere of 5.7 ± 1.3× 1010 mol.cm-2 s-1 is obtained for the Northern hemisphereand 12± 2.7× 1010 mol. cm-2s-1 for Western Europe. Potential additional contributions dueto other stratosphere-troposphere exchange processes than folds are not yetincluded in these estimates. Finally, the link between statistics fromozone/7beryllium data and folding statistics is brieflydiscussed.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-0662
    Keywords: Vertical ozone profiles ; Tropospheric Ozone Research Project ; Brewer-Mast sondes ; ground-based UV-DIAL
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract An intercomparison campaign was conducted at the Observatoire de Haute Provence (OHP) in Southern France in September 1989 in order to compare the three instruments used for vertical tropospheric ozone profiling in the European TOR (Tropospheric Ozone Research Project) network: balloon borne ECC and Brewer-Mast sondes and a ground based UV-DIAL (DifferentialAbsorptionLidar). Additionally, a stratospheric lidar system and the Dobson spectrophotometer of the OHP were operated. Seven simultaneously measured vertical ozone profiles gave evidence for systematic differences of 15% between both types of electrochemical sondes in the troposphere, the Brewer-Mast sondes reading the smaller ozone values. These differences might be explained on the one hand by a possible contamination of the ozone sensor with reducing substances, causing a negative bias mainly for Brewer-Mast sondes and, on the other hand, by the evolution of the sonde background current during the flight, causing a positive bias for ECC sondes and a negative bias for Brewer-Mast sondes. The tropospheric lidar system, measuring the vertical ozone distribution between 6 and 12–15 km, showed ozone concentrations intermediate between the sonde results. This is in good agreement with its estimated systematic error of better than 7% in the upper troposphere. In the stratosphere, the differences between electrochemical sondes and the lidar are between 5 and 10% before the normalisation with the total ozone values measured by the Dobson spectrophotometer, and always below 5% after. While the Dobson normalisation thus corrects rather well the stratospheric part of the sonde profile, it only partially reduces errors occurring in the troposphere.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of atmospheric chemistry 25 (1996), S. 215-226 
    ISSN: 1573-0662
    Keywords: ECC ; ozone ; troposphere ; Bendix ; intercomparison
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Geosciences
    Notes: Abstract Measurements of atmospheric ozone at concentrations typical of the free troposphere have been compared for ECC sondes and a UV-absorption photometer, using a Bendix chemiluminescent analyser as a transfer standard. Comparisons were conducted in the laboratory and in the tropospheric part of the atmosphere. It was found that the measurements agreed to within 4% provided that the background current for the ECC sonde was measured before exposure to ozone in the preparation procedure, and was assumed to be constant throughout the sonde flight. These results confirm those of earlier experiments and mean that the methods currently used to correct for the background current in the troposphere need to be revised.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2019-07-17
    Repository Name: EPIC Alfred Wegener Institut
    Type: Article , isiRev
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...