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Benchmarking the seasonal cycle of CO2 fluxes simulated by terrestrial ecosystem models

Peng, Shushi; Ciais, Philippe; Chevallier, Frederic; Peylin, Philippe; Cadule, Patricia; Sitch, Stephen; Piao, Shilong; Ahlström, Anders LU ; Huntingford, Chris and Levy, Peter, et al. (2015) In Global Biogeochemical Cycles 29(1). p.46-64
Abstract
We evaluated the seasonality of CO2 fluxes simulated by nine terrestrial ecosystem models of the TRENDY project against (1) the seasonal cycle of gross primary production (GPP) and net ecosystem exchange (NEE) measured at flux tower sites over different biomes, (2) gridded monthly Model Tree Ensembles-estimated GPP (MTE-GPP) and MTE-NEE obtained by interpolating many flux tower measurements with a machine-learning algorithm, (3) atmospheric CO2 mole fraction measurements at surface sites, and (4) CO2 total columns (X-CO2) measurements from the Total Carbon Column Observing Network (TCCON). For comparison with atmospheric CO2 measurements, the LMDZ4 transport model was run with time-varying CO2 fluxes of each model as surface boundary... (More)
We evaluated the seasonality of CO2 fluxes simulated by nine terrestrial ecosystem models of the TRENDY project against (1) the seasonal cycle of gross primary production (GPP) and net ecosystem exchange (NEE) measured at flux tower sites over different biomes, (2) gridded monthly Model Tree Ensembles-estimated GPP (MTE-GPP) and MTE-NEE obtained by interpolating many flux tower measurements with a machine-learning algorithm, (3) atmospheric CO2 mole fraction measurements at surface sites, and (4) CO2 total columns (X-CO2) measurements from the Total Carbon Column Observing Network (TCCON). For comparison with atmospheric CO2 measurements, the LMDZ4 transport model was run with time-varying CO2 fluxes of each model as surface boundary conditions. Seven out of the nine models overestimate the seasonal amplitude of GPP and produce a too early start in spring at most flux sites. Despite their positive bias for GPP, the nine models underestimate NEE at most flux sites and in the Northern Hemisphere compared with MTE-NEE. Comparison with surface atmospheric CO2 measurements confirms that most models underestimate the seasonal amplitude of NEE in the Northern Hemisphere (except CLM4C and SDGVM). Comparison with TCCON data also shows that the seasonal amplitude of X-CO2 is underestimated by more than 10% for seven out of the nine models (except for CLM4C and SDGVM) and that the MTE-NEE product is closer to the TCCON data using LMDZ4. From CO2 columns measured routinely at 10 TCCON sites, the constrained amplitude of NEE over the Northern Hemisphere is of 1.60.4 gC m(-2)d(-1), which translates into a net CO2 uptake during the carbon uptake period in the Northern Hemisphere of 7.92.0 PgC yr(-1). (Less)
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Contribution to journal
publication status
published
subject
keywords
carbon cycle, GPP, NEE, seasonal cycle, CO2, TCCON
in
Global Biogeochemical Cycles
volume
29
issue
1
pages
46 - 64
publisher
American Geophysical Union
external identifiers
  • wos:000349894600004
  • scopus:85027919673
ISSN
0886-6236
DOI
10.1002/2014GB004931
language
English
LU publication?
yes
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72d45b52-47c4-4d1c-ba5f-4b30a910b8fb (old id 5305668)
date added to LUP
2015-04-23 16:29:48
date last changed
2017-10-22 04:07:33
@article{72d45b52-47c4-4d1c-ba5f-4b30a910b8fb,
  abstract     = {We evaluated the seasonality of CO2 fluxes simulated by nine terrestrial ecosystem models of the TRENDY project against (1) the seasonal cycle of gross primary production (GPP) and net ecosystem exchange (NEE) measured at flux tower sites over different biomes, (2) gridded monthly Model Tree Ensembles-estimated GPP (MTE-GPP) and MTE-NEE obtained by interpolating many flux tower measurements with a machine-learning algorithm, (3) atmospheric CO2 mole fraction measurements at surface sites, and (4) CO2 total columns (X-CO2) measurements from the Total Carbon Column Observing Network (TCCON). For comparison with atmospheric CO2 measurements, the LMDZ4 transport model was run with time-varying CO2 fluxes of each model as surface boundary conditions. Seven out of the nine models overestimate the seasonal amplitude of GPP and produce a too early start in spring at most flux sites. Despite their positive bias for GPP, the nine models underestimate NEE at most flux sites and in the Northern Hemisphere compared with MTE-NEE. Comparison with surface atmospheric CO2 measurements confirms that most models underestimate the seasonal amplitude of NEE in the Northern Hemisphere (except CLM4C and SDGVM). Comparison with TCCON data also shows that the seasonal amplitude of X-CO2 is underestimated by more than 10% for seven out of the nine models (except for CLM4C and SDGVM) and that the MTE-NEE product is closer to the TCCON data using LMDZ4. From CO2 columns measured routinely at 10 TCCON sites, the constrained amplitude of NEE over the Northern Hemisphere is of 1.60.4 gC m(-2)d(-1), which translates into a net CO2 uptake during the carbon uptake period in the Northern Hemisphere of 7.92.0 PgC yr(-1).},
  author       = {Peng, Shushi and Ciais, Philippe and Chevallier, Frederic and Peylin, Philippe and Cadule, Patricia and Sitch, Stephen and Piao, Shilong and Ahlström, Anders and Huntingford, Chris and Levy, Peter and Li, Xiran and Liu, Yongwen and Lomas, Mark and Poulter, Benjamin and Viovy, Nicolas and Wang, Tao and Wang, Xuhui and Zaehle, Soenke and Zeng, Ning and Zhao, Fang and Zhao, Hongfang},
  issn         = {0886-6236},
  keyword      = {carbon cycle,GPP,NEE,seasonal cycle,CO2,TCCON},
  language     = {eng},
  number       = {1},
  pages        = {46--64},
  publisher    = {American Geophysical Union},
  series       = {Global Biogeochemical Cycles},
  title        = {Benchmarking the seasonal cycle of CO2 fluxes simulated by terrestrial ecosystem models},
  url          = {http://dx.doi.org/10.1002/2014GB004931},
  volume       = {29},
  year         = {2015},
}