An empirical characterisation of signal versus noise in CO<sub>2</sub> data

I. G. Enting

doi:10.3402/tellusb.v54i4.16667

An empirical characterisation of signal versus noise in CO₂ data

Author:

I. G. Enting

CSIRO Atmospheric Research, AU

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Abstract

Uncertainties in the interpretations of CO₂ data arise from errors in the observations and model relations. The space–time variations of CO₂ on the global scale are analysed in terms of the singular-value decomposition, in order to obtain a characterisation of observational error that matches the requirements of global-scale estimation of fluxes. It is found that for monthly-mean data, a first-order moving average model of error is a far better representation than earlier assumptions of independent white noise.

How to Cite: Enting, I.G., 2002. An empirical characterisation of signal versus noise in CO₂ data. Tellus B: Chemical and Physical Meteorology, 54(4), pp.301–306. DOI: http://doi.org/10.3402/tellusb.v54i4.16667

Accepted on 8 Apr 2002 Submitted on 7 May 2001

References

Bloomfield , P. , Heimann , M. , Prather , M. and Prinn , R . 1994 . Inferred lifetimes. Chapter 3 of Report on concen- trations, lifetimes, and trends of CFCs, halons, and related species (eds. J. A. Kaye, S. A. Penkett and F. M. Ormond) (NASAReference Publication 1339), NASA, Washington.

Bousquet , P. , Ciais , P. , Peylin , P. and Monfray , P . 1999a . Inverse modelling of annual atmospheric CO2 sources and sinks. 1 Method and control inversion. J. Geophys. Res . 104D , 26,161 - 26,178 .

Bousquet , P. , Ciais , P. , Peylin , P. and Monfray , P . 1999b . Inverse modelling of annual atmospheric CO2 sources and sinks. 2 Sensitivity study. J. Geophys. Res . 104D , 26,179 - 26,193 .

Ciais , P. , Tans , P. P. , Trolier , M. , White , J. W. C. and Francey , R. J . 1995a . A large northern hemisphere terrestrial CO2 sink indicated by the “C/12C ratio of atmospheric CO2. Science 269 , 1098 – 1102 .

Ciais , P. , Tans , P. P. , White , J. W. C. , Trolier , M. , Francey , R. J. , Berry , J. A. , Randall , D. R. , Sellers , P. J. , Collatz , J. G. and Schimel , D. S. 1995b. Partition-ing of ocean and land uptake of CO2 as inferred by S“C measurements from the NOAA Climate Mon-itoring and Diagnostics Laboratory air sampling net-work. J. Geophys. Res . 102D , 5857 - 5872 .

Cleveland , W. S. , Freeny , A. E. and Graedel , T. E . 1983 . The seasonal component of atmospheric CO2. Information from new approaches to the decomposi-tion of seasonal time series. J. Geophys. Res . 88C , 10,934 - 10,946 .

Conway , T. J. and Tans , P. P . 1999 . Monthly-mean concentration summary (CO2). In: WMO WDCGG Data Report . Japan Meteorological Agency , Tokyo , 41 – 135 .

Conway , T. J. , Tans , P. P. , Waterman , L. S. , Thoning , K. A. , Kitzis , D. R. , Masarie , K. A. and Zhang , N. 1994 . Evidence for interannual variability of the carbon cycle from the National Oceanic and Atmo-spheric Administration/Climate Monitoring and Dia-gnostics Laboratory global air sampling network. J. Geophys. Res . 99D , 22,831 - 22,855 .

Dargaville , R. J . 1999 . The variability of atmospheric CO2 and its surface sources. Ph.D. Thesis , Melbourne University .

Enting , I. G . 1993 . Inverse problems in atmospheric con-stituent studies: III. Estimating errors in surface sources. Inverse Problems 9 , 649 – 665 .

Enting , I. G . 1999 . Characterising the temporal variability of the global carbon cycle . CSIRO Atmospheric Research Technical Paper No. 40. CSIRO, Australia. Also electronic edition available at: http://www.dar.csiro.au/publications/Enting.2000a.pdf Enting, I. G. 2000. Green's function methods of tracer inversion. In: Inverse methods in global biogeochem-ical cycles. Geophysical Monograph No. 114 (eds. P. Kasibhatla, M. Heimann, P. Rayner, N. Mahowald, R. G. Prinn and D. E. Hartle). AGU, Washington, 19 - 31 .

Enting , I. G . 2002 . Inverse problems in atmospheric con-stituent transport. CUP, Cambridge , UK .

Enting , I. G. and Mansbridge , J. V . 1989 . Seasonal sources and sinks of atmospheric CO2: direct inversion of filtered data. Tellus 41B , 111 – 126 .

Enting , I. G. and Mansbridge , J. V . 1991 . Latitudinal distribution of sources and sinks of CO2: results of an inversion study. Tellus 43B , 156 – 170 .

Enting , I. G. and Pearman , G. I . 1993 . Average global distributions of CO2. In: The global carbon cycle (ed. M. Heimann). Springer-Verlag , Berlin , 31 – 64 .

Enting , I. G. , Trudinger , C. M. and Francey , R. J . 1995 . A synthesis inversion of the concentration and S“C of atmospheric CO2. Tellus 47B , 35 – 52 .

Halter , B. C. , Harris , J. M. and Conway , T. J . 1988 . Component signals in the record of atmospheric carbon dioxide concentration at American Samoa. J. Geophys. Res . 93D , 15,914 - 15,918 .

Manning , M. R . 1993 . Seasonal cycles in atmospheric CO2 concentrations. In: The global carbon cycle (ed. M. Heimann). Springer-Verlag , Berlin , 65 – 94 .

Martin , F. and Diaz , A . 1991 . Different methods of modeling the variability in the monthly mean concentrations of atmospheric CO2 at Mauna Loa. J. Geophys. Res . 96D , 18,689 - 18,704 .

Priestley , M. B . 1981 . Spectral analysis and time series. Academic Press , London .

Rayner , P. J. , Enting , I. G. , Francey , R. J. and Langen-felds , R. L . 1999a . Reconstructing the recent carbon cycle from atmospheric CO2, PC and 02/N2 obser-vations. Tellus 51B , 213 – 232 .

Rayner , P. J. , Law , R. M. and Dargaville , R . 1999b . The relationship between tropical CO2 fluxes and the El Nifio-Southern Oscillation. Geophys. Res. Lett . 26 , 493 – 496 .

von Storch , H . 1999 . Empirical orthogonal functions. In: Analysis of climate variability - applications of statistical techniques (eds. H. von Storch and A. Navarra). Springer-Verlag , Berlin , 231 – 263 .

Surendran , S. and Mulholland , R. J . 1987 . Modeling the variability in measured atmospheric CO2 data. J. Geo-phys. Res . 92D , 9733 – 9739 .

Tans , P. P. , Conway , T. J. and Nakazawa , T . 1989 . Latitudinal distribution of the sources and sinks of atmospheric carbon dioxide derived from surface observations and an atmospheric transport model. J. Geophys. Res 94D , 5151 – 5172 .

Tans , P. P. , Fung , I. Y. and Takahashi , T . 1990a . Obser-vational constraints on the global atmospheric CO2 budget. Science 247 , 1431 – 1438 .

Tans , P. P. , Thoning , K. W. , Elliott , W. P. and Conway , T. J . 1990b . Error estimates of background atmo-spheric CO2 patterns from weekly flask samples. J. Geophys. Res . 95D , 14,063 - 14,070 .

WDCGG 1999 . WMO World Data Centre for Greenhouse Gases CD-ROM No . 5. Published on behalf of the WMO by Japan Meteorological Agency, Tokyo.

[CIT0001] Bloomfield , P. , Heimann , M. , Prather , M. and Prinn , R . 1994 . Inferred lifetimes. Chapter 3 of Report on concen- trations, lifetimes, and trends of CFCs, halons, and related species (eds. J. A. Kaye, S. A. Penkett and F. M. Ormond) (NASAReference Publication 1339), NASA, Washington.

[CIT0002] Bousquet , P. , Ciais , P. , Peylin , P. and Monfray , P . 1999a . Inverse modelling of annual atmospheric CO2 sources and sinks. 1 Method and control inversion. J. Geophys. Res . 104D , 26,161 - 26,178 .

[CIT0003] Bousquet , P. , Ciais , P. , Peylin , P. and Monfray , P . 1999b . Inverse modelling of annual atmospheric CO2 sources and sinks. 2 Sensitivity study. J. Geophys. Res . 104D , 26,179 - 26,193 .

[CIT0004] Ciais , P. , Tans , P. P. , Trolier , M. , White , J. W. C. and Francey , R. J . 1995a . A large northern hemisphere terrestrial CO2 sink indicated by the “C/12C ratio of atmospheric CO2. Science 269 , 1098 – 1102 .

[CIT0005] Ciais , P. , Tans , P. P. , White , J. W. C. , Trolier , M. , Francey , R. J. , Berry , J. A. , Randall , D. R. , Sellers , P. J. , Collatz , J. G. and Schimel , D. S. 1995b. Partition-ing of ocean and land uptake of CO2 as inferred by S“C measurements from the NOAA Climate Mon-itoring and Diagnostics Laboratory air sampling net-work. J. Geophys. Res . 102D , 5857 - 5872 .

[CIT0006] Cleveland , W. S. , Freeny , A. E. and Graedel , T. E . 1983 . The seasonal component of atmospheric CO2. Information from new approaches to the decomposi-tion of seasonal time series. J. Geophys. Res . 88C , 10,934 - 10,946 .

[CIT0007] Conway , T. J. and Tans , P. P . 1999 . Monthly-mean concentration summary (CO2). In: WMO WDCGG Data Report . Japan Meteorological Agency , Tokyo , 41 – 135 .

[CIT0008] Conway , T. J. , Tans , P. P. , Waterman , L. S. , Thoning , K. A. , Kitzis , D. R. , Masarie , K. A. and Zhang , N. 1994 . Evidence for interannual variability of the carbon cycle from the National Oceanic and Atmo-spheric Administration/Climate Monitoring and Dia-gnostics Laboratory global air sampling network. J. Geophys. Res . 99D , 22,831 - 22,855 .

[CIT0009] Dargaville , R. J . 1999 . The variability of atmospheric CO2 and its surface sources. Ph.D. Thesis , Melbourne University .

[CIT0010] Enting , I. G . 1993 . Inverse problems in atmospheric con-stituent studies: III. Estimating errors in surface sources. Inverse Problems 9 , 649 – 665 .

[CIT0011] Enting , I. G . 1999 . Characterising the temporal variability of the global carbon cycle . CSIRO Atmospheric Research Technical Paper No. 40. CSIRO, Australia. Also electronic edition available at: http://www.dar.csiro.au/publications/Enting.2000a.pdf Enting, I. G. 2000. Green's function methods of tracer inversion. In: Inverse methods in global biogeochem-ical cycles. Geophysical Monograph No. 114 (eds. P. Kasibhatla, M. Heimann, P. Rayner, N. Mahowald, R. G. Prinn and D. E. Hartle). AGU, Washington, 19 - 31 .

[CIT0012] Enting , I. G . 2002 . Inverse problems in atmospheric con-stituent transport. CUP, Cambridge , UK .

[CIT0013] Enting , I. G. and Mansbridge , J. V . 1989 . Seasonal sources and sinks of atmospheric CO2: direct inversion of filtered data. Tellus 41B , 111 – 126 .

[CIT0014] Enting , I. G. and Mansbridge , J. V . 1991 . Latitudinal distribution of sources and sinks of CO2: results of an inversion study. Tellus 43B , 156 – 170 .

[CIT0015] Enting , I. G. and Pearman , G. I . 1993 . Average global distributions of CO2. In: The global carbon cycle (ed. M. Heimann). Springer-Verlag , Berlin , 31 – 64 .

[CIT0016] Enting , I. G. , Trudinger , C. M. and Francey , R. J . 1995 . A synthesis inversion of the concentration and S“C of atmospheric CO2. Tellus 47B , 35 – 52 .

[CIT0017] Halter , B. C. , Harris , J. M. and Conway , T. J . 1988 . Component signals in the record of atmospheric carbon dioxide concentration at American Samoa. J. Geophys. Res . 93D , 15,914 - 15,918 .

[CIT0018] Manning , M. R . 1993 . Seasonal cycles in atmospheric CO2 concentrations. In: The global carbon cycle (ed. M. Heimann). Springer-Verlag , Berlin , 65 – 94 .

[CIT0019] Martin , F. and Diaz , A . 1991 . Different methods of modeling the variability in the monthly mean concentrations of atmospheric CO2 at Mauna Loa. J. Geophys. Res . 96D , 18,689 - 18,704 .

[CIT0020] Priestley , M. B . 1981 . Spectral analysis and time series. Academic Press , London .

[CIT0021] Rayner , P. J. , Enting , I. G. , Francey , R. J. and Langen-felds , R. L . 1999a . Reconstructing the recent carbon cycle from atmospheric CO2, PC and 02/N2 obser-vations. Tellus 51B , 213 – 232 .

[CIT0022] Rayner , P. J. , Law , R. M. and Dargaville , R . 1999b . The relationship between tropical CO2 fluxes and the El Nifio-Southern Oscillation. Geophys. Res. Lett . 26 , 493 – 496 .

[CIT0023] von Storch , H . 1999 . Empirical orthogonal functions. In: Analysis of climate variability - applications of statistical techniques (eds. H. von Storch and A. Navarra). Springer-Verlag , Berlin , 231 – 263 .

[CIT0024] Surendran , S. and Mulholland , R. J . 1987 . Modeling the variability in measured atmospheric CO2 data. J. Geo-phys. Res . 92D , 9733 – 9739 .

[CIT0025] Tans , P. P. , Conway , T. J. and Nakazawa , T . 1989 . Latitudinal distribution of the sources and sinks of atmospheric carbon dioxide derived from surface observations and an atmospheric transport model. J. Geophys. Res 94D , 5151 – 5172 .

[CIT0026] Tans , P. P. , Fung , I. Y. and Takahashi , T . 1990a . Obser-vational constraints on the global atmospheric CO2 budget. Science 247 , 1431 – 1438 .

[CIT0027] Tans , P. P. , Thoning , K. W. , Elliott , W. P. and Conway , T. J . 1990b . Error estimates of background atmo-spheric CO2 patterns from weekly flask samples. J. Geophys. Res . 95D , 14,063 - 14,070 .

[CIT0028] WDCGG 1999 . WMO World Data Centre for Greenhouse Gases CD-ROM No . 5. Published on behalf of the WMO by Japan Meteorological Agency, Tokyo.

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