PhD Thesis, 2010 - University College Cork

Recommendations for further research
analysing methane (CH 4 ) production and emission might be beneficial to both
better accounting of the greenhouse gas balance and the understanding of the
N 2 O flux.
To further explore close occurrences of intensive uptake and emission periods, as
well as noted gaps in peak events (Chapter 4), a number of approaches can be used to
investigate possible causes:
• Co-spectra analysis of the identified peak periods, with the emphasis on the
uptake peaks. This would allow for analysis of advective effects that are
present in flux time series originating from heterogeneous footprint area as the
one studied in this project.
• Studying clustering properties of the flux and associated time series with
telegraph approximation allows for magnitude-independent analysis of
turbulent time series. The different types of signal will have generically
different types of probability density function of the interpulse distance of the
telegraph approximation signals.
• Using wavelet thresholding method to identify groups of periods with high and
low contributions towards the annual N 2 O balance. It was shown by Katul and
Vidakovic (1996) that the Lorentz thresholding function is particularly suitable
for such application.
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