DYNAMIC ANALYSIS OF THE TETHERING CABLE PORTION OF A HIGH ALTITUDE TETHERED BALLOON SYSTEM UNDER FULLY DEPLOYED CONDITIONS

Abstract. This study provides the first experimental validation of Swiss agricultural methane emission estimates at the farm scale. We measured CH4 concentrations at a Swiss farmstead during two intensive field campaigns in August 2011 and July 2012 to (1) quantify the source strength of livestock methane emissions using a tethered balloon system, and (2) to validate inventory emission estimates via nocturnal boundary layer (NBL) budgets. Field measurements were performed at a distance of 150 m from the nearest farm buildings with a tethered balloon system in combination with gradient measurements at eight heights on a 10 m tower to better resolve the near-surface concentrations. Vertical profiles of air temperature, relative humidity, CH4 concentration, wind speed and wind direction showed that the NBL was strongly influenced by local transport processes and by the valley wind system. Methane concentrations showed a pronounced time course, with highest concentrations in the second half of the night. NBL budget flux estimates were obtained via a time–space kriging approach. Main uncertainties of NBL budget flux estimates were associated with instationary atmospheric conditions and the estimate of the inversion height zi (top of volume integration). The mean NBL budget fluxes of 1.60 ± 0.31 μg CH4 m-2 s-1 (1.40 ± 0.50 and 1.66 ± 0.20 μg CH4 m-2 s-1 in 2011 and 2012, respectively) were in good agreement with local inventory estimates based on current livestock number and default emission factors, with 1.29 ± 0.47 and 1.74 ± 0.63 μg CH4 m-2 s-1 for 2011 and 2012, respectively. This indicates that emission factors used for the national inventory reports are adequate, and we conclude that the NBL budget approach is a useful tool to validate emission inventory estimates.

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An aerial netting study of insects migrating at high altitude over England

Bulletin of Entomological Research ◽

10.1079/ber2004287 ◽

2004 ◽

Vol 94 (2) ◽

pp. 123-136 ◽

Cited By ~ 74

Author(s):

J.W. Chapman ◽

D.R. Reynolds ◽

A.D. Smith ◽

E.T. Smith ◽

I.P. Woiwod

Keyword(s):

Global Warming ◽

High Altitude ◽

North Sea ◽

Ground Level ◽

Diel Periodicity ◽

Tethered Balloon ◽

Extensive Survey ◽

Economic Significance ◽

Large Populations ◽

The Uk

AbstractDay and night sampling of windborne arthropods at a height of 200 m above ground was undertaken at Cardington, Bedfordshire, UK, during July 1999, 2000 and 2002, using a net supported by a tethered balloon. The results from this study are compared with those from the classic aerial sampling programmes carried out by Hardy, Freeman and colleagues over the UK and North Sea in the 1930s. In the present study, aerial netting was undertaken at night as well as daytime, and so the diel periodicity of migration could be investigated, and comparisons made with the results from Lewis and Taylor’s extensive survey of flight periodicity near ground level. In some taxa with day-time emigration, quite large populations could continue in high-altitude flight after dark, perhaps to a previously underrated extent, and this would greatly increase their potential migratory range. Any trend towards increases in night temperatures, associated with global warming, would facilitate movements of this type in the UK. Observations on the windborne migration of a variety of species, particularly those of economic significance or of radar-detectable size, are briefly discussed.

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