Influence of dataset density on CO2 and CH4 trend calculation

摘要: Trend analysis requires long-time series of observations, the continuity which is not usually obtained since gaps emerge linked to problems with device or external reasons. This paper explores influence dataset density on parameters involved in linear trends CO2 and CH4 half-hourly observations daily ranges measured at a semi-rural site over 6-year period. Half-hourly observation were 2.40 0.0085 ppm year−1 for respectively, noticeable value 1.98 ppm year−1 was range, whereas range remained steady. Random samples variable numbers extracted from these time series. Robust statistics location, spread, symmetry concentration calculated fitted third-degree polynomial expression equation range. In general, medians interquartile provided best fits. Confidence intervals also obtained. Around 350 760 95% statistically significant correlations 0.1% level. Finally, evolution revealed contrast between two trace gases where increased ramp during night that ended cliff sinusoidal associated CH4. Moreover, presented cycle but