Long-term variations of the mole fraction and carbon isotope ratio of atmospheric methane observed at Ny-Ålesund, Svalbard from 1996 to 2013

Shinji Morimoto; Ryo Fujita; Shuji Aoki; Daisuke Goto; Takakiyo Nakazawa

doi:10.1080/16000889.2017.1380497

$Long-term variations of the mole fraction and carbon isotope ratio of atmospheric methane observed at Ny-Ålesund, Svalbard from 1996 to 2013 Cover$

Long-term variations of the mole fraction and carbon isotope ratio of atmospheric methane observed at Ny-Ålesund, Svalbard from 1996 to 2013

Tellus B: Chemical and Physical Meteorology

Volume 69 (2017): Issue 1

By: Shinji Morimoto, Ryo Fujita, Shuji Aoki, Daisuke Goto and Takakiyo Nakazawa

Open Access

|Jan 2017

Figures & Tables

Temporal variations of the CH₄ mole fraction (a) and δ¹³C of CH₄ (b) observed at Ny-Ålesund, Svalbard. Also shown are their best-fit curves (solid lines) and long-term trends (broken lines).

Long-term components of the CH₄ mole fraction (a) and δ¹³C (b) at Ny-Ålesund, Svalbard obtained by using the digital filtering technique in which the cut-off period was set to 5 years. Also shown are the regression lines for each segment obtained by the stepwise fitting, given the points of slope change at 2000.8 and 2005.8 (decimal year).

Table 1.

The average rate of increase in CH₄ (ppb yr⁻¹) (a) and δ¹³C (‰ yr⁻¹) (b) for given periods, together with their respective standard errors (s.e.) and 95% confidence intervals (C.I.) obtained using the bootstrap analysis.

PeriodIncrease rates.e.95% C.I.(a)1991.0–2000.84.50.2[4.2, 4.8]2000.8–2005.80.30.2[–0.1, 0.8]2005.8–2014.05.50.2[5.1, 5.8](b)1996.0–2000.80.0060.003[0.000, 0.012]2000.8–2005.80.0120.002[0.008, 0.017]2005.8–2014.0−0.0140.005[–0.024, −0.004]

Yearly anomalies of precipitation (open circles and triangles) and soil moisture content (solid circles and triangles) calculated for wetland and rice paddy regions (Matthews and Fung, 2003) in 44–90°N and 24°S-24°N. Soil moisture is expressed as water equivalent depth.

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DOI: https://doi.org/10.1080/16000889.2017.1380497 | Journal eISSN: 1600-0889

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Language: English

Page range: 1380497 - 1380497

Submitted on: Apr 13, 2017

Accepted on: Sep 12, 2017

Published on: Jan 1, 2017

Published by: Stockholm University Press

In partnership with: Paradigm Publishing Services

Keywords:

atmospheric methane,

stable carbon isotope,

greenhouse gas,

Arctic

© 2017 Shinji Morimoto, Ryo Fujita, Shuji Aoki, Daisuke Goto, Takakiyo Nakazawa, published by Stockholm University Press
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 69 (2017): Issue 1

Long-term variations of the mole fraction and carbon isotope ratio of atmospheric methane observed at Ny-Ålesund, Svalbard from 1996 to 2013

Figures & Tables

Fig. 1.

Fig. 2.

Table 1.

The average rate of increase in CH₄ (ppb yr⁻¹) (a) and δ¹³C (‰ yr⁻¹) (b) for given periods, together with their respective standard errors (s.e.) and 95% confidence intervals (C.I.) obtained using the bootstrap analysis.

Fig. 3.

Paradigm

My account

Long-term variations of the mole fraction and carbon isotope ratio of atmospheric methane observed at Ny-Ålesund, Svalbard from 1996 to 2013

Figures & Tables

Fig. 1.

Fig. 2.

Table 1.

The average rate of increase in CH4 (ppb yr−1) (a) and δ13C (‰ yr−1) (b) for given periods, together with their respective standard errors (s.e.) and 95% confidence intervals (C.I.) obtained using the bootstrap analysis.

Fig. 3.

The average rate of increase in CH₄ (ppb yr⁻¹) (a) and δ¹³C (‰ yr⁻¹) (b) for given periods, together with their respective standard errors (s.e.) and 95% confidence intervals (C.I.) obtained using the bootstrap analysis.