Research ArticleCLIMATOLOGY

Accelerating rates of Arctic carbon cycling revealed by long-term atmospheric CO2 measurements

See allHide authors and affiliations

Science Advances  11 Jul 2018:
Vol. 4, no. 7, eaao1167
DOI: 10.1126/sciadv.aao1167
  • Fig. 1 Changes in seasonal variations of ΔCO2 (CO2local − CO2background) for the last four decades (1974–2015).

    (A) Monthly mean ΔCO2 for the period 1974–1983 and that for the period 2006–2015. (B) Changes in annual amplitude of ΔCO2 (maximum ΔCO2 − minimum ΔCO2). (C) Changes in annual ΔCO2 (sum of monthly ΔCO2). Gray dots in (A) show daily values of ΔCO2. The asterisk indicates statistical significance at the 95% confidence level.

  • Fig. 2 Retrieved changes in carbon residence time based on the difference between 1979–1988 and 2004–2013 10-year periods.

    The vertical red line indicates the average of retrieved changes in carbon residence time. The blue line indicates mean (solid line) and range (shading) in the equivalent residence time change estimates from the MsTMIP model ensemble.

Supplementary Materials

  • Supplementary material for this article is available at http://advances.sciencemag.org/cgi/content/full/4/7/eaao1167/DC1

    Table S1. Prior parameter value ranges.

    Table S2. MsTMIP models in this study (BG1 simulations).

    Fig. S1. Comparison between simulated NEE and observed ΔCO2.

    Fig. S2. Comparison of net primary productivity and heterotrophic respiration between optimized model and MsTMIP terrestrial biosphere models.

    Fig. S3. Posterior probability distribution of the ratio of effective Q10 temperature sensitivity parameters p2 (NPP) and p4 (Rhet) [see Materials and Methods (Retrieved residence time change and temperature sensitivities) and table S1 for details].

    Fig. S4. Relationships between ΔCO2 and soil temperature (0 to 40 cm).

    Fig. S5. Lagged (0 to 3 months) relationships between summertime vegetation greenness and autumn ΔCO2.

    References (42, 43)

  • Supplementary Materials

    This PDF file includes:

    • Table S1. Prior parameter value ranges.
    • Table S2. MsTMIP models in this study (BG1 simulations).
    • Fig. S1. Comparison between simulated NEE and observed ΔCO2.
    • Fig. S2. Comparison of net primary productivity and heterotrophic respiration between optimized model and MsTMIP terrestrial biosphere models.
    • Fig. S3. Posterior probability distribution of the ratio of effective Q10 temperature sensitivity parameters p2 (NPP) and p4 (Rhet) see Materials and Methods (Retrieved residence time change and temperature sensitivities) and table S1 for details.
    • Fig. S4. Relationships between ΔCO2 and soil temperature (0 to 40 cm).
    • Fig. S5. Lagged (0 to 3 months) relationships between summertime vegetation greenness and autumn ΔCO2.
    • References (42, 43)

    Download PDF

    Files in this Data Supplement: