Long-term trend in CO2 concentration in the surface atmosphere over Central Siberia

Тимохина, А. В.; Прокушкин, А. С.; Онучин, А. А.; Панов, А. В.; Kofman, G. B.; Verkhovets, S. V.; Heimann, Martin

doi:10.3103/s106837391503005x

Cited by 13 publications

(6 citation statements)

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“…The growth rates calculated in this paper, 2.24 and 9.6 10 À3 ppm year À1 for the CO 2 and CH 4 monthly medians, respectively, are close to 2.02 ppm year À1 obtained for CO 2 in Central Siberia in the period 2006e2013 (Timokhina et al, 2015) and 0.0074 ppm year À1 for CH 4 at Cabaw, The Netherlands, in the period 2005e2010 (Vermeulen et al, 2011). However, they are far from the 3.8 ppm year À1 for CO 2 recorded at Shangdianzi, China, under the Beijing-Tianjin-Hebei influence (Fang et al, 2016) and around 0.017 ppm year À1 for CH 4 observed at Hegyh ats al, Hungary (Haszpra et al, 2011).…”

Section: Co 2 and Ch 4 Trendssupporting

confidence: 86%

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The influence of meteorological variables on CO2 and CH4 trends recorded at a semi-natural station

Pérez

Sánchez

García

et al. 2018

Journal of Environmental Management

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CO and CH evolution is usually linked with sources, sinks and their changes. However, this study highlights the role of meteorological variables. It aims to quantify their contribution to the trend of these greenhouse gases and to determine which contribute most. Six years of measurements at a semi-natural site in northern Spain were considered. Three sections are established: the first focuses on monthly deciles, the second explores the relationship between pairs of meteorological variables, and the third investigates the relationship between meteorological variables and changes in CO and CH. In the first section, monthly outliers were more marked for CO than for CH. The evolution of monthly deciles was fitted to three simple expressions, linear, quadratic and exponential. The linear and exponential are similar, whereas the quadratic evolution is the most flexible since it provided a variable rate of concentration change and a better fit. With this last evolution, a decrease in the change rate was observed for low CO deciles, whereas an increasing change rate prevailed for the rest and was more accentuated for CH. In the second section, meteorological variables were provided by a trajectory model. Backward trajectories from 1-day prior to reaching the measurement site were used to calculate distance and direction averages as well as the recirculation factor. Terciles of these variables were determined in order to establish three intervals with low, medium and high values. These intervals were used to classify the variables following their interval widths and skewnesses. The best correlation between pairs of meteorological variables was observed for the average distance, in particular with horizontal wind speed. Sinusoidal relationships with the average direction were obtained for average distance and for vertical wind speed. Finally, in the third section, the quadratic evolution was considered in each interval of all the meteorological variables. As regards the main result, the greatest increases were obtained for high potential temperature for both gases followed by low and medium boundary layer height for CO and CH, respectively. Combining both meteorological variables provided increases of 22 ± 9 and 0.070 ± 0.019 ppm for CO and CH, respectively, although the number of observations affected is small, around 7%.

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Section: Co 2 and Ch 4 Trendssupporting

confidence: 86%

“…Most authors describe GHG evolution by a linear expression (Eneroth et al, 2005;Timokhina et al, 2015;Wu et al, 2012), since it is simple and provides an accurate value of the trend. Other studies consider second order polynomials (Fang et al, 2016) whilst only a few include higher order polynomials (Inoue et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

The influence of meteorological variables on CO2 and CH4 trends recorded at a semi-natural station

Pérez

Sánchez

García

et al. 2018

Journal of Environmental Management

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“…Vermeulen et al [35] studied daily trimmed means of CO 2 and CH 4 among other gases at Cabaw, in the Netherlands, using an equation with a linear trend and four harmonics, and obtained an increase of 2.00 ppm year −1 for CO 2 in the period 2005-2009 and 0.0074 ppm year −1 for CH 4 in 2005-2010, which is slightly below those recorded in this research. Timokhina et al [36] used the same equation for CO 2 over central Siberia in the period 2006-2013 and obtained an increase of 2.02 ppm year −1 for CO 2 , which is similar to that of Vermeulen et al [35]. Bergamaschi et al [37] recorded a growth rate of around 0.004 ppm year −1 for CH 4 in early 2010 in the Northern Hemisphere.…”

Section: Annual Trendsupporting

confidence: 61%

“…Several harmonics have often been used to fit observations with enough detail. The most complex analyses consider four harmonics [35,36,39]. However, expressions with three harmonics have also been used [40][41][42].…”

Section: Harmonic Analysismentioning

confidence: 99%

Statistical Analysis of the CO2 and CH4 Annual Cycle on the Northern Plateau of the Iberian Peninsula

et al. 2020

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Outliers are frequent in CO2 and CH4 observations at rural sites. The aim of this paper is to establish a procedure based on the lag-1 autocorrelation to form measurement groups, some of which include outliers, and the rest include regular measurements. Once observations are classified, a second objective is to determine the number of harmonics in order to suitably describe the annual evolution of both gases. Monthly CO2 and CH4 percentiles were calculated over a six-year period. Linear trends for most of the percentiles were around 2.24 and 0.0097 ppm year−1, and the interquartile ranges of residuals calculated from detrended concentrations were 6 and 0.02 ppm for CO2 and CH4, respectively. Five concentration groups were proposed for CO2 and six were proposed for CH4 from the lag-1 autocorrelation applied to detrended observations. Monthly medians were calculated in each group, and combinations of harmonics were applied in an effort to fit the annual cycle. Finally, adding annual and semi-annual harmonics successfully described the cycle where one step was observed in the concentration decrease in spring, not only for high CO2 percentiles but also for low CH4 percentiles.

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“…Fang et al () presented CO 2 trends of 2.7 and 3.8 ppm year −1 for two directions of air masses reaching Shangdianzi, China, for the period 2009–2013. Hernández‐Paniagua et al () obtained 2.45 ppm year −1 at Egham, UK, in the period 2000–2012, although this rate reached 3.26 ppm year −1 for the W sector, and Timokhina et al () observed 2.02 ppm year −1 in central Siberia, Russia, in 2006–2013. For CH 4 , the annual rate was 0.0085 ppm year −1 , in agreement with values of 0.006 and 0.010 ppm year −1 presented by Fang et al () or by Vermeulen et al (), who recorded a value of 0.0074 ppm year −1 at Cabaw, The Netherlands, for the period 2005–2010.…”

Section: Resultsmentioning

confidence: 99%

Analysis of the airflow at the centre of the upper plateau on the Iberian Peninsula and its link to CO₂ and CH₄ concentrations

Pérez

Sánchez

García

et al. 2017

Intl Journal of Climatology

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Air trajectories are useful tools to investigate the airflow and transport of substances released into the atmosphere. Web‐based models are widely used to calculate trajectories reaching places that are being studied. This article considers 6 years of air trajectories as of October 2010 together with CO2 and CH4 concentrations. A bivariate smoothing function that employs the radial distance and direction of the trajectory to the measuring site was used to form trajectory groups from the minima of this function. Varied radial and angular windows were assayed to investigate the behaviour of the smoothing function. Curves associated with the number of minima were L‐shaped and the windows selected corresponded to the ‘knee’ of the curves. Seven trajectory groups were considered to observe the response of the procedure against the radial distance and the direction. Seasonal evolution revealed the greatest radial extent for winter and the lowest for summer. Moreover, trajectories from the Atlantic Ocean were the most frequent. CO2 and CH4 concentrations were detrended using a linear function, and average trends were 2.34 and 0.0085 ppm year−1, respectively. Annual cycles of detrended concentrations were very soft and were linked to the site's ecosystem. CO2 presented one maximum in spring linked to substantial vegetation growth, and one minimum in summer, when vegetation dies and dispersion is maximum. CH4 maximum was observed in winter although the minimum was found in summer and attributed to oxidation with the hydroxyl radical in the troposphere and to dispersion in this season. Analysis of concentration trends for the groups proposed revealed the opposite behaviour of both gases in summer. Finally, maximum CO2 concentrations were marked by trajectories from North Africa affected by nearby cities, whereas minimum concentrations for both gases were noticeable for trajectories from the ocean in summer.

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Long-term trend in CO2 concentration in the surface atmosphere over Central Siberia

Cited by 13 publications

References 1 publication

The influence of meteorological variables on CO2 and CH4 trends recorded at a semi-natural station

The influence of meteorological variables on CO2 and CH4 trends recorded at a semi-natural station

Statistical Analysis of the CO2 and CH4 Annual Cycle on the Northern Plateau of the Iberian Peninsula

Analysis of the airflow at the centre of the upper plateau on the Iberian Peninsula and its link to CO₂ and CH₄ concentrations

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Long-term trend in CO2 concentration in the surface atmosphere over Central Siberia

Cited by 13 publications

References 1 publication

The influence of meteorological variables on CO2 and CH4 trends recorded at a semi-natural station

The influence of meteorological variables on CO2 and CH4 trends recorded at a semi-natural station

Statistical Analysis of the CO2 and CH4 Annual Cycle on the Northern Plateau of the Iberian Peninsula

Analysis of the airflow at the centre of the upper plateau on the Iberian Peninsula and its link to CO2 and CH4 concentrations

Contact Info

Product

Resources

About

Analysis of the airflow at the centre of the upper plateau on the Iberian Peninsula and its link to CO₂ and CH₄ concentrations