deletions | additions       diff --git a/The_timeseries_of_derived_X__.tex b/The_timeseries_of_derived_X__.tex  index 6cf739e..be4fe30 100644  --- a/The_timeseries_of_derived_X__.tex  +++ b/The_timeseries_of_derived_X__.tex 
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Assuming that VC$_{O_2}$ is relatively constant, X$_{air}$ is most affected by changes in the instrument and differences between the observed and expected lightpath.  The timeseries of derived X$_{air}$ values at Wollongong  is shown in Figure \ref{fig:xair_ts}. The mean value of approximately 0.98 rather than 1 is due to a bias of approximately 2\% in the O$_2$ spectroscopy. Apart from a few occasions, the X$_{air}$ is within 0.5\% of its mean value of approximately 0.98 in the filtered dataset, indicating good instrument stability throughout the time series.