Methane budget estimates in Finland from the CarbonTracker Europe-CH4 data assimilation system

[mm/yyyy]SMRHyytiäläFinlandUHEL61.8524.28306 (125)2511/2011–12/2014KJNKjølnesNorwayMPI&UE70.8529.2430 (5)1510/2013–12/2014KMPKumpulaFinlandFMI60.2024.9653 (30)305/2010–12/2014PAL

^{†}

PallasFinlandFMI67.9724.12572 (7)152/2004–12/2014PAL

^{†}

PallasFinlandNOAA67.9724.12570 (7)151/2004–12/2014PUIPuijoFinlandFMI&UEF62.9127.66316 (80)306/20110–12/2014SODSodankyläFinlandFMI67.3626.64227 (48)256/20128–12/2014UTOUtöFinlandFMI59.7821.3765 (57)253/2012–12/2014

Observation Uncertainty (Obs. Unc.) is used to define diagonal values in the observation covariance matrix. This contains both measurement and model representativity error.

* Sampling heights from which atmospheric CH₄ is sampled in TM5. The numbers in the parenthesis are the measurement heights above ground.

** Date range for this study period, 2004–2014. Note that most of the observations are continuously updated, and measurements at Pallas (NOAA) started as early as in 2001.

† Observations from Pallas are coordinated by FMI and NOAA, of which NOAA observations are from discrete, and FMI observations are from continuous air samples.

Table 2.

List of inversion setups.

InversionPrior [anthropogenic]Prior [biospheric]ObservationsPeriodJ1EDGAR v4.2 FT2010LPX-Bern-DYPTOPAll available2004–2014J2EDGAR v4.2 FT2010LPX-Bern-DYPTOPAll but KMP and PUI2010–2014J3EDGAR v4.2 FT2010LPJG-WHyMeAll available2010–2014J4EDGAR v4.2 FT2010LPX-Bern v1.0All available2010–2014J5FIN-EDGARLPX-Bern-DYPTOPAll available2010–2014

Statistics (bias, correlation and root mean squared error (RMSE)) of posterior atmospheric CH₄ compared with assimilated observations from sites in Finland and surrounding regions. Negative bias shows model underestimation. The statistics were calculated from 2010–2014 observations, except for KJN, where 2013–2014 data were used. The statistics for Puijo (PUI) and Kumpula (KMP) for J2 were plotted separately, as those were not assimilated in J2, and the statistics are calculated from posterior estimates and all prepossessed daily observations.

Observed and simulated atmospheric CH₄ at sites in Finland and surrounding regions for 2012, except for Kjølnes which shows data from 2014. For continuous observations, the daily averaged values are shown. For complete time series for all inversions, see Supplementary Material.

[Top and middle] Monthly prior and posterior anthropogenic and biospheric emission estimates for Finland. The shaded areas show uncertainty ranges of the prior (grey) and the J1 posterior (blue). [Bottom] Number of Fennoscandian stations assimilated in J1 and J5. Note the number in J2 was same as in J1.

Measured CH₄ fluxes at Lompolojänkkä and Siikaneva, and estimated regional monthly mean biospheric CH₄ fluxes around the sites.

Mean annual emission estimates for 2010–2014 [10^–8mol m⁻² s⁻¹], their uncertainty reduction ( $1 - σ_{posterior}^{2} / σ_{prior}^{2}$ ), and locations of observations in Fennoscandia. The triangles show sites with continuous observations and the star shows the site with both continuous and discrete observations. For other inversions, see Supplementary Material.

Table 3.

Average annual CH₄ emission estimates between 2010 and 2014 in Finland [Tg CH₄ yr⁻¹].

AnthropogenicBiosphere(Prior) EDGAR v4.2 FT20100.39 FIN-EDGAR0.38 LPX-Bern-DYPTOP0.19LPJG-WHyMe2.15LPX-Bern v1.01.29(Posterior) J10.27 ± 0.340.27 ± 0.23J20.41 ± 0.340.27 ± 0.23J30.19 ± 0.340.73 ± 1.43J40.20 ± 0.340.87 ± 1.02J50.44 ± 0.330.26 ± 0.22

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DOI: https://doi.org/10.1080/16000889.2018.1565030 | Journal eISSN: 1600-0889

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Language: English

Page range: 1565030 - 1565030

Published on: Jan 1, 2019

Published by: Stockholm University Press

In partnership with: Paradigm Publishing Services

Keywords:

CH₄ flux,

atmospheric CH₄,

Finland,

data assimilation,

flux estimation

© 2019 Aki Tsuruta, Tuula Aalto, Leif Backman, Maarten C. Krol, Wouter Peters, Sebastian Lienert, Fortunat Joos, Paul A. Miller, Wenxin Zhang, Tuomas Laurila, Juha Hatakka, Ari Leskinen, Kari E. J. Lehtinen, Olli Peltola, Timo Vesala, Janne Levula, Ed Dlugokencky, Martin Heimann, Elena Kozlova, Mika Aurela, Annalea Lohila, Mari Kauhaniemi, Angel J. Gomez-Pelaez, published by Stockholm University Press
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 71 (2019): Issue 1

Methane budget estimates in Finland from the CarbonTracker Europe-CH4 data assimilation system

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