Library

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
    Springer
    Annales geophysicae 14 (1996), S. 574-583 
    ISSN: 0992-7689
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The observational systems utilised during the TRACT experimental campaign (September 1992) can roughly be divided into: existing climate stations and towers: background chemical monitoring stations; aerological measurements; instrumented aircraft; and special micrometeorological stations operated only during the experimental period. Database 4, which contains the latter surface measurements, includes station descriptions and data from 21 sites operated by nine different groups during the campaign period. These data will be described briefly. There are a number of advantages in using a relational database for analysis of this data. Without creating an unnecessarily large database which is awkward to view and slow to process, specific measurements can be selected easily since data from each site have been standardized using a common time index. This allows comparison of the same or different variables from one or more sites for investigating data quality or the effects of site location. Data can readily be combined into hourly or daily averages or time series for comparison with other data sets (e.g. model or aircraft data). Spatial analysis is also straightforward, although the clustering of the sites in the centre of the investigation area means that care must be taken. Some preliminary comparisons are made here in order to demonstrate the availability and reliability of the data.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The European Air Chemistry Network (EACN) database used here contains, amongst other data, monthly values for precipitation and nitrate and sulphate concentration2-3. As in ref. 1, extreme outliers in the monthly chemistry data were removed before analysis. Excluding values greater than four ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    [s.l.] : Nature Publishing Group
    Nature 322 (1986), S. 359-361 
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] The potential importance of climatic change in influencing precipitation acidity has been acknowledged3"6 but not assessed, although significant changes in climate and the atmospheric circulation have occurred in the European area over the past 100 yr (refs 7-9). As the frequency and character of ...
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Annales geophysicae 16 (1998), S. 882-888 
    ISSN: 0992-7689
    Keywords: Meteorology and atmospheric dynamics ; Mesoscale meteorology ; Ocean-atmosphere interaction ; Marine meteorology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Conditional sampling is used herein to examine the effect of fetch, stability, and surface roughness changes on wind speeds in the coastal zone. Using data from an offshore wind farm it is shown that at a distance of 1.2–1.7 km from the coast, up to a height of 20 m above the surface, differences in wind speed distributions from onshore and offshore masts are statistically significant for flow moving offshore under all stability conditions. In contrast, differences between the distribution of wind speeds at 38 and 48 m at masts located at the coast and in the coastal zone are not significant for flow moving offshore, indicating that flow at these heights is not fully adjusted to the change in surface roughness (land to sea). These findings are in accordance with calculations of the internal boundary layer (IBL) height which indicate that the IBL would frequently be below the two upper measurement heights at 1.2–1.6 km from the coast. The analyses presented here indicate that the wind speed distribution at a potential offshore wind farm site is not solely dependent on fetch (distance from the coast) but also depends on the stability climate.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Boundary layer meteorology 66 (1993), S. 19-47 
    ISSN: 1573-1472
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract An estimate of roughness length is required by some atmospheric models and is also used in the logarithmic profile to determine the increase of wind speed with height under neutral conditions. The choice of technique for determining roughness lengths is generally constrained by the available input data. Here, we compare sets of roughness lengths derived by different methods for the same site and evaluate their impact on the prediction of the vertical wind speed profile. Wind speed and direction data have been collected at four heights over a three-year period at the North Norfolk Wind Monitoring Site. Wind speed profiles were used to generate sector roughness lengths based on the logarithmic profile formula. This is the only direct way of determining roughness lengths. The simplest and cheapest method is to use maps with published tables giving roughness length estimates for different terrain types. Alternatively Wieringa (1976, 1986) and Beljaars (1987) give formulae for determining roughness lengths from wind speed gusts or standard deviations. The four sets of estimated roughness lengths vary considerably. They were used to estimate 34 m wind speeds from 12.7 m observations. The profile-derived roughnesses are used simply as a check on the prediction of the wind speed profiles. The terrain-derived roughness lengths give reasonable results. Gust-derived and standard deviation roughnesses both predict wind speeds which are lower than the observed ones. The error is greater in the case of standard deviation roughnesses. If stability corrections are applied in the prediction of the vertical wind speed profile, the results are considerably improved.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...