RT info:eu-repo/semantics/article
T1 Trend Assessment for a CO2 and CH4 Data Series in Northern Spain
A1 Fernández Duque, Beatriz
A1 Pérez Bartolomé, Isidro Alberto
A1 García Pérez, María Ángeles
A1 Pardo Gómez, Nuria
A1 Sánchez Gómez, María Luisa
AB The main objective of this paper is to implement different methods to assess the salientfeatures of the data trend for a CO2 and CH4 data series. Said series was obtained at the LowAtmosphere Research Centre (41°48′49″ N, 4°55′59″ W) using a Picarro analyser (G1301). Different functions were employed to determine and quantify the data trend. The first was a harmonic function based on a third-degree polynomial. An increasing trend, below 2.30 ppm year−1 for CO2 and below 11.90 ppb year−1 for CH4, was reported. Epanechnikov, Gaussian, biweight, tricubic, rectangular and triangle kernels, were applied with a 500-day bandwidth for the trend. The best fit was obtained by the biweight kernel (r > 0.20), with an increasing trend around 1.80 ppm year−1 for CO2 and around 7.15 ppb year−1 for CH4. The final analysis, which included local linear regression functions also applying a 500-day bandwidth, revealed increasing trends for both CO2, around 1.98 ppm year−1, and CH4, around 10.85 ppb year−1. Trend values were far more accelerated in the latter years of the series, regardless of the chosen function. This paper demonstrated the usefulness of the mathematical functions, allowing for an accurate determination of the data trend.
YR 2017
FD 2017
LK http://uvadoc.uva.es/handle/10324/32893
UL http://uvadoc.uva.es/handle/10324/32893
LA eng
NO Proceedings 2017, 1, 146
DS UVaDOC
RD 11-jul-2024