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  • Climatology  (1)
  • Ips acuminatus  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Climatological Ertel’s potential-vorticity flux and mean meridional circulation in the extratropical troposphere – lower stratosphere (1998)
    Springer
    Annales geophysicae 16 (1998), S. 250-265 
    Details
    ISSN: 0992-7689
    Keywords: Meteorology and atmospheric dynamics ; Climatology ; General circulation ; Middle atmosphere
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract We investigated to what extent the isentropic, non-geostrophic formulation of zonally averaged circulation derived for stratospheric conditions is applicable to climatological transport in the extratropical troposphere and lower stratosphere. The study is based on 10 years of daily data of ECMWF analysis and on the ECHAM3 climate model of the German Climate Computing Centre. The main result is a scalar isentropic mixing coefficient, Kyy, and a mean meridional transport circulation consistently derived from the same data base. For both data sources, isentropic mean meridional circulation is derived from horizontal mass flow rate for 4 representative months. Alternatively, a mean meridional circulation is calculated from total diabatic heating rates of the ECHAM3 model. It is shown that only the latter is in good agreement with the ECMWF mean meridional circulation. Isentropic analysis also comprises the seasonal cycle of the climatological meridional gradient and flux of Ertel’s potential vorticity (PV). Application of Tung’s flux-gradient relation yields that for all seasons Kyy is positive in height-latitude regions where statistical significance is reached. Large Kyy values, marking regions of more efficient mixing, have been found in the subtropical vertical band of weak westerly wind and in mid-latitudes in regions of upward-propagating baroclinic wave activity in the middle and upper troposphere. Based on the ECMWF data and results of baroclinic-wave behaviour, strong indications are presented that positive zonally averaged PV flux polewards of the jet core in the NH is strengthened by stationary waves and nonlinear effects. Reduced eddy transport is apparent in winter and spring slightly below the subtropical tropopause jet. The seasonal cycle of Kyy from ECHAM3 data is to a great extent in agreement with the result based on ECMWF analysis. In the model, reduced interannual variability enlarges the height-latitude range where sign of Kyy is significant.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s00585-998-0250-3
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  • 2
    Electronic Resource
    Electronic Resource
    Aggregation response of European engraver beetles of the genus Ips mediated by terpenoid pheromones (1988)
    Springer
    Entomologia experimentalis et applicata 49 (1988), S. 43-53 
    Details
    ISSN: 1570-7458
    Keywords: chemical communication systems ; bark beetles ; Ips acuminatus ; Ips cembrae ; Ips erosus ; Ips sex-dentatus ; terpenoids ; verbenol ; myrtenol ; ipsdienol ; ipsenol ; amitinol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Upon exposure to vapours of the host tree's monoterpene (−)-α-pinene, Ips acuminatus produces the terpene alcohol cis-verbenol which, besides ipsdienol and ipsenol, is a component of its aggregation pheromone. I. cembrae transforms the same monoterpene predominantly into myrtenol and trans-verbenol but little into cis-verbenol, which interrupts pheromone response under field conditions. On the other hand, I. cembrae releases, upon feeding in the bark, the terpene alcohol amitinol in major amounts. Amitinol significantly enhances field response to the aggregation pheromone that also includes ipsdienol, ipsenol, and 3-methyl-3-buten-1-ol. However, amitinol reduces pheromone response in I. acuminatus and I. erosus. Also, males of I. sexdentatus release amitinol which appears to increase response to its attractive principle pheromone component, racemic ipsdienol. There is some evidence that present knowledge of the chemical communication systems among European Ips spp. still lacks satisfactory explanation of the naturally occuring aggregation en masse, perhaps with the exception of I. erosus and I. typographus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00188237
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    Paper (German National Licenses)
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