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1. The Australian terrestrial carbon budget

Author

Haverd, V., Raupach, M. R, Briggs, P. R, Canadell., J. G, Davis, S. J, Law, R. M, Meyer, C. P, Peters, G. P, Pickett-Heaps, C., and Sherman, B.

Subjects
dioxide emissions, vegetation cover, climate, trends, forest, model, dust, consumption, sinks, river
Abstract

This paper reports a study of the full carbon (C-CO2) budget of the Australian continent, focussing on 1990–2011 in the context of estimates over two centuries. The work is a contribution to the RECCAP (REgional Carbon Cycle Assessment and Processes) project, as one of numerous regional studies. In constructing the budget, we estimate the following component carbon fluxes: net primary production (NPP); net ecosystem production (NEP); fire; land use change (LUC); riverine export; dust export; harvest (wood, crop and livestock) and fossil fuel emissions (both territorial and non-territorial). Major biospheric fluxes were derived using BIOS2 (Haverd et al., 2012), a fine-spatial-resolution (0.05°) offline modelling environment in which predictions of CABLE (Wang et al., 2011), a sophisticated land surface model with carbon cycle, are constrained by multiple observation types. The mean NEP reveals that climate variability and rising CO2 contributed 12 ± 24 (1σ error on mean) and 68 ± 15 TgC yr−1, respectively. However these gains were partially offset by fire and LUC (along with other minor fluxes), which caused net losses of 26 ± 4 TgC yr−1 and 18 ± 7 TgC yr−1, respectively. The resultant net biome production (NBP) is 36 ± 29 TgC yr−1, in which the largest contributions to uncertainty are NEP, fire and LUC. This NBP offset fossil fuel emissions (95 ± 6 TgC yr−1) by 38 ± 30%. The interannual variability (IAV) in the Australian carbon budget exceeds Australia's total carbon emissions by fossil fuel combustion and is dominated by IAV in NEP. Territorial fossil fuel emissions are significantly smaller than the rapidly growing fossil fuel exports: in 2009–2010, Australia exported 2.5 times more carbon in fossil fuels than it emitted by burning fossil fuels.

Published
2013

2. Precision requirements for space-based X CO 2 data

Author

Miller, C. E, Crisp, D., DeCola, P. L, Olsen, S. C, Randerson, J. T, Michalak, A. M, Alkhaled, A., Rayner, P., Jacob, D. J, Suntharalingam, P., Jones, D. B. A, Denning, A. S, Nicholls, M. E, Doney, S. C, Pawson, S., Boesch, H., Connor, B. J, Fung, I. Y, O'Brien, D., Salawitch, R. J, Sander, S. P, Sen, B., Tans, P., Toon, G. C, Wennberg, P. O, Wofsy, S. C, Yung, Y. L, and Law, R. M

Subjects
atmospheric composition, carbon dioxide, mathematical models, uncertainty analysis, assessment method, carbon dioxide, carbon flux, precision, sampling, simulation, spatiotemporal analysis
Abstract

Precision requirements are determined for space-based column-averaged CO2 dry air mole fraction data. These requirements result from an assessment of spatial and temporal gradients in the relationship between precision and surface CO2 flux uncertainties inferred from inversions of the data, and the effects of biases on the fidelity of CO2 flux inversions. Observational system simulation experiments and synthesis inversion modeling demonstrate that the Orbiting Carbon Observatory mission design and sampling strategy provide the means to achieve these data precision requirements.

Published
2007

3. TransCom 3 inversion intercomparison: Impact of transport model errors on the interannual variability of regional CO 2 fluxes, 1988-2003

Author

Baker, D. F, Law, R. M, Gurney, K. R, Rayner, P., Peylin, P., Denning, A. S, Bousquet, P., Bruhwiler, L., Chen, Y.-H., Ciais, P., Fung, I. Y, Heimann, M., John, J., Maki, T., Maksyutov, S., Masarie, K., Prather, M., Pak, B., Taguchi, S., and Zhu, Z.

Subjects
annual variation, atmospheric transport, carbon cycle, carbon dioxide, carbon emission
Abstract

Monthly CO2 fluxes are estimated across 1988–2003 for 22 emission regions using data from 78 CO2 measurement sites. The same inversion (method, priors, data) is performed with 13 different atmospheric transport models, and the spread in the results is taken as a measure of transport model error. Interannual variability (IAV) in the winds is not modeled, so any IAV in the measurements is attributed to IAV in the fluxes. When both this transport error and the random estimation errors are considered, the flux IAV obtained is statistically significant at P ≤ 0.05 when the fluxes are grouped into land and ocean components for three broad latitude bands, but is much less so when grouped into continents and basins. The transport errors have the largest impact in the extratropical northern latitudes. A third of the 22 emission regions have significant IAV, including the Tropical East Pacific (with physically plausible uptake/release across the 1997–2000 El Niño/La Niña) and Tropical Asia (with strong release in 1997/1998 coinciding with large-scale fires there). Most of the global IAV is attributed robustly to the tropical/southern land biosphere, including both the large release during the 1997/1998 El Niño and the post-Pinatubo uptake.

Published
2006

4. Impact of Fraserdale CO 2 observations on annual flux inversion of the North American boreal region

Author

Yuen, C.-W., Higuchi, K., Baker, D., Bousquet, P, Bruhwiler, L., Chen, Y.-H., Ciais, P., Denning, A. S., Fan, S., Fung, L., Gloor, M., Gurney, K. R., Heimann, M., John, J., Law, R. M., Maki, T,, Maksyutov, S., Pak, B., Peylin, P., Prather, M., Rayner, P., Sarmiento, J,, Taguchi, S., and Takahashi, T.

Subjects
boreal forest, carbon dioxide, carbon flux, monitoring system
Abstract

In TransCom-3 (Level 1), atmospheric CO2 measurements from 76 monitoring stations for the period 1992–1996 and 16 atmospheric transport models were used to constrain annual mean CO2 fluxes over 11 land and 11 ocean regions. The tower measurements of atmospheric CO2 from Fraserdale, a continental site in northern Ontario, Canada are now available and processed for use in the TransCom-3 inverse modelling framework. In this short study, we show that by including this set of continental CO2 data, the estimated flux for the North American boreal region becomes nearly zero, a reduction of about 0.26 Pg C yr−1 from the previous estimate. The uncertainty of the estimated flux for this region is also reduced by ∼30%. All transport models show negative changes for boreal North America, with the strongest responses (∼−0.5 Pg C yr−1) shown by NIRE, NIES, CSU and SKYHI. Furthermore, models showing a strong response in boreal North America tend to show strong sensitivity in middle- and high-latitude Asian regions.

Published
2005

5. On error estimation in atmospheric CO 2 inversions

Author

Engelen, Richard J, Denning, A S, Gurney, K R, Law, R M, Rayner, P J, Baker, D, Bousquet, P, Bruhwiler, L, Chen, Y H, Ciais, P, Fan, S, Fung, I Y, Gloor, M, Heimann, M, Higuchi, K, John, J, Maki, T, Maksyutov, S, Masarie, K, Peylin, P, Prather, M, Pak, B C, Sarmiento, J, Taguchi, S, Takahashi, T, and Yuen, C W

Subjects
atmospheric movements, carbon dioxide, earth atmosphere, error analysis, inverse problems, problem solving, transport properties, error, fluxes, model inversion
Abstract

This paper explores various sources of error in atmospheric CO2 synthesis inversions using global circulation models. The estimation of prior, observation, model transport, and representation errors is described, and the latter two error sources are explored in more detail. Not accounting for these errors will act as a hard constraint on the inversion and will produce incorrect solutions to the problem as is shown in some example inversions. The magnitude of these errors falls generally between about 10% and 100% in the retrieved fluxes but can be even larger. This makes it highly desirable to avoid hard constraints and apply any prior information we have about the surface fluxes as a weak constraint to the inversion problem.

Published
2002

6. ACCESS datasets for CMIP6: methodology and idealised experiments

Author

Mackallah, C., primary, Chamberlain, M. A., additional, Law, R. M., additional, Dix, M., additional, Ziehn, T., additional, Bi, D., additional, Bodman, R., additional, Brown, J. R., additional, Dobrohotoff, P., additional, Druken, K., additional, Evans, B., additional, Harman, I. N., additional, Hayashida, H., additional, Holmes, R., additional, Kiss, A. E., additional, Lenton, A., additional, Liu, Y., additional, Marsland, S., additional, Meissner, K., additional, Menviel, L., additional, O’Farrell, S., additional, Rashid, H. A., additional, Ridzwan, S., additional, Savita, A., additional, Srbinovsky, J., additional, Sullivan, A., additional, Trenham, C., additional, Vohralik, P. F., additional, Wang, Y.-P., additional, Williams, G., additional, Woodhouse, M. T., additional, and Yeung, N., additional

Published
2022
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7. ACCESS datasets for CMIP6: methodology and idealised experiments

Author

Mackallah, C., Chamberlain, M. A., Law, R. M., Dix, M., Ziehn, T., Bi, D., Bodman, R., Brown, J. R., Dobrohotoff, P., Druken, K., Evans, B., Harman, I. N., Hayashida, H., Holmes, R., Kiss, A. E., Lenton, A., Liu, Y., Marsland, S., Meissner, K., Menviel, L., O’Farrell, S., Rashid, H. A., Ridzwan, S., Savita, Abhishek, Srbinovsky, J., Sullivan, A., Trenham, C., Vohralik, P. F., Wang, Y.-P., Williams, G., Woodhouse, M. T., Yeung, N., Mackallah, C., Chamberlain, M. A., Law, R. M., Dix, M., Ziehn, T., Bi, D., Bodman, R., Brown, J. R., Dobrohotoff, P., Druken, K., Evans, B., Harman, I. N., Hayashida, H., Holmes, R., Kiss, A. E., Lenton, A., Liu, Y., Marsland, S., Meissner, K., Menviel, L., O’Farrell, S., Rashid, H. A., Ridzwan, S., Savita, Abhishek, Srbinovsky, J., Sullivan, A., Trenham, C., Vohralik, P. F., Wang, Y.-P., Williams, G., Woodhouse, M. T., and Yeung, N.

Abstract

The Australian Community Climate and Earth System Simulator (ACCESS) has contributed to the World Climate Research Programme’s Coupled Model Intercomparison Project Phase 6 (CMIP6) using two fully coupled model versions (ACCESS-CM2 and ACCESS-ESM1.5) and two ocean–sea-ice model versions (1° and 0.25° resolution versions of ACCESS-OM2). The fully coupled models differ primarily in the configuration and version of their atmosphere components (including the aerosol scheme), with smaller differences in their sea-ice and land model versions. Additionally, ACCESS-ESM1.5 includes biogeochemistry in the land and ocean components and can be run with an interactive carbon cycle. CMIP6 comprises core experiments and associated thematic Model Intercomparison Projects (MIPs). This paper provides an overview of the CMIP6 submission, including the methods used for the preparation of input forcing datasets and the post-processing of model output, along with a comprehensive list of experiments performed, detailing their initialisation, duration, ensemble number and computational cost. A small selection of model output is presented, focusing on idealised experiments and their variants at global scale. Differences in the climate simulation of the two coupled models are highlighted. ACCESS-CM2 produces a larger equilibrium climate sensitivity (4.7°C) than ACCESS-ESM1.5 (3.9°C), likely a result of updated atmospheric parameterisation in recent versions of the atmospheric component of ACCESS-CM2. The idealised experiments run with ACCESS-ESM1.5 show that land and ocean carbon fluxes respond to both changing atmospheric CO2 and to changing temperature. ACCESS data submitted to CMIP6 are available from the Earth System Grid Federation (https://doi.org/10.22033/ESGF/CMIP6.2281 and https://doi.org/10.22033/ESGF/CMIP6.2288). The information provided in this paper should facilitate easier use of these significant datasets by the broader climate community.

Published
2022
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9. Global atmospheric carbon budget: results from an ensemble of atmospheric CO2 inversions

Author

Peylin, P., Law, R. M., Gurney, K. R., Chevallier, F., Jacobson, A. R., Maki, T., Niwa, Y., Patra, P. K., Peters, W., Rayner, P. J., Rödenbeck, C., van der Laan-Luijkx, I. T., Zhang, X., Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), CSIRO Marine and Atmospheric Research (CSIRO-MAR), Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Arizona State University [Tempe] (ASU), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Meteorological Research Institute [Tsukuba] (MRI), Japan Meteorological Agency (JMA), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Wageningen University and Research [Wageningen] (WUR), University of Melbourne, Max Planck Institute for Biogeochemistry (MPI-BGC), Max-Planck-Gesellschaft, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), and Energy and Sustainability Research Institute Groni

Subjects
Meteorologie en Luchtkwaliteit, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, WIMEK, Meteorology and Air Quality, sinks, cycle, interannual variability, transport model, lcsh:QE1-996.5, emissions, lcsh:Life, dioxide exchange, sensitivity, ocean, fluxes, land, lcsh:Geology, lcsh:QH501-531, lcsh:QH540-549.5, lcsh:Ecology, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment
Abstract

Atmospheric CO2 inversions estimate surface carbon fluxes from an optimal fit to atmospheric CO2 measurements, usually including prior constraints on the flux estimates. Eleven sets of carbon flux estimates are compared, generated by different inversions systems that vary in their inversions methods, choice of atmospheric data, transport model and prior information. The inversions were run for at least 5 yr in the period between 1990 and 2010. Mean fluxes for 2001–2004, seasonal cycles, interannual variability and trends are compared for the tropics and northern and southern extra-tropics, and separately for land and ocean. Some continental/basin-scale subdivisions are also considered where the atmospheric network is denser. Four-year mean fluxes are reasonably consistent across inversions at global/latitudinal scale, with a large total (land plus ocean) carbon uptake in the north (−3.4 Pg C yr−1 (±0.5 Pg C yr−1 standard deviation), with slightly more uptake over land than over ocean), a significant although more variable source over the tropics (1.6 ± 0.9 Pg C yr−1) and a compensatory sink of similar magnitude in the south (−1.4 ± 0.5 Pg C yr−1) corresponding mainly to an ocean sink. Largest differences across inversions occur in the balance between tropical land sources and southern land sinks. Interannual variability (IAV) in carbon fluxes is larger for land than ocean regions (standard deviation around 1.06 versus 0.33 Pg C yr−1 for the 1996–2007 period), with much higher consistency among the inversions for the land. While the tropical land explains most of the IAV (standard deviation ~ 0.65 Pg C yr−1), the northern and southern land also contribute (standard deviation ~ 0.39 Pg C yr−1). Most inversions tend to indicate an increase of the northern land carbon uptake from late 1990s to 2008 (around 0.1 Pg C yr−1, predominantly in North Asia. The mean seasonal cycle appears to be well constrained by the atmospheric data over the northern land (at the continental scale), but still highly dependent on the prior flux seasonality over the ocean. Finally we provide recommendations to interpret the regional fluxes, along with the uncertainty estimates.

Published
2013

10. TransCom model simulations of CH4 and related species: linking transport, surface flux and chemical loss with CH4 variability in the troposphere and lower stratosphere

Author

Patra, P. K., Houweling, S., Krol, M., Bousquet, P., Belikov, D., Bergmann, D., Bian, H., Cameron-Smith, P., Chipperfield, M. P., Corbin, K., Fortems-Cheiney, A., Fraser, A., Gloor, E., Hess, P., Ito, A., Kawa, S. R., Law, R. M., Loh, Z., Maksyutov, S., Meng, L., Palmer, P. I., Prinn, R. G., Rigby, M., Saito, R., Wilson, C., and Earth and Climate

Subjects
lcsh:Chemistry, Atmospheric Science, lcsh:QD1-999, lcsh:Physics, lcsh:QC1-999
Abstract

A chemistry-transport model (CTM) intercomparison experiment (TransCom-CH4) has been designed to investigate the roles of surface emissions, transport and chemical loss in simulating the global methane distribution. Model simulations were conducted using twelve models and four model variants and results were archived for the period of 1990–2007. All but one model transports were driven by reanalysis products from 3 different meteorological agencies. The transport and removal of CH4 in six different emission scenarios were simulated, with net global emissions of 513 ± 9 and 514 ± 14 Tg CH4 yr−1 for the 1990s and 2000s, respectively. Additionally, sulfur hexafluoride (SF6) was simulated to check the interhemispheric transport, radon (222Rn) to check the subgrid scale transport, and methyl chloroform (CH3CCl3) to check the chemical removal by the tropospheric hydroxyl radical (OH). The results are compared to monthly or annual mean time series of CH4, SF6 and CH3CCl3 measurements from 8 selected background sites, and to satellite observations of CH4 in the upper troposphere and stratosphere. Most models adequately capture the vertical gradients in the stratosphere, the average long-term trends, seasonal cycles, interannual variations (IAVs) and interhemispheric (IH) gradients at the surface sites for SF6, CH3CCl3 and CH4. The vertical gradients of all tracers between the surface and the upper troposphere are consistent within the models, revealing vertical transport differences between models. An average IH exchange time of 1.39 ± 0.18 yr is derived from SF6 time series. Sensitivity simulations suggest that the estimated trends in exchange time, over the period of 1996–2007, are caused by a change of SF6 emissions towards the tropics. Using six sets of emission scenarios, we show that the decadal average CH4 growth rate likely reached equilibrium in the early 2000s due to the flattening of anthropogenic emission growth since the late 1990s. Up to 60% of the IAVs in the observed CH4 concentrations can be explained by accounting for the IAVs in emissions, from biomass burning and wetlands, as well as meteorology in the forward models. The modeled CH4 budget is shown to depend strongly on the troposphere-stratosphere exchange rate and thus on the model's vertical grid structure and circulation in the lower stratosphere. The 15-model median CH4 and CH3CCl3 atmospheric lifetimes are estimated to be 9.99 ± 0.08 and 4.61 ± 0.13 yr, respectively, with little IAV due to transport and temperature.

Published
2011

11. Data and modelling requirements for CO2 inversions using high-frequency data

Author

Law, R. M., Rayner, P. J., Steele, L. P., and Enting, I. G.

Subjects
Atmospheric Science
Abstract

We explore the future possibilities for CO2 source estimation from atmospheric concentration data by performing synthetic data experiments. Synthetic data are used to test seasonal CO2 inversions using high-frequency data. Monthly CO2 sources over the Australian region are calculated for inversions with data at 4-hourly frequency and averaged over 1 d, 2.5 d, 5 d, 12.17 d and 1 month. The inversion quality, as determined by bias and uncertainty, is degraded when averaging over longer periods. This shows the value of the strong but relatively short-lived signals present in high-frequency records that are removed in averaged and particularly filtered records. Sensitivity tests are performed in which the synthetic data are ‘corrupted’ to simulate systematic measurement errors such as intercalibration differences or to simulate transport modelling errors. The inversion is also used to estimate the effect of calibration offsets between sites. We find that at short data-averaging periods the inversion is reasonably robust to measurement-type errors. For transport-type errors, the best results are achieved for synoptic (2–5 d) timescales. Overall the tests indicate that improved source estimates should be possible by incorporating continuous measurements into CO2 inversions.DOI: 10.1034/j.1600-0889.2003.00029.x

Published
2003

12. Top–down assessment of the Asian carbon budget since the mid 1990s

Author

Thompson, R. L., primary, Patra, P. K., additional, Chevallier, F., additional, Maksyutov, S., additional, Law, R. M., additional, Ziehn, T., additional, van der Laan-Luijkx, I. T., additional, Peters, W., additional, Ganshin, A., additional, Zhuravlev, R., additional, Maki, T., additional, Nakamura, T., additional, Shirai, T., additional, Ishizawa, M., additional, Saeki, T., additional, Machida, T., additional, Poulter, B., additional, Canadell, J. G., additional, and Ciais, P., additional

Published
2016
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14. Sea-air CO2 fluxes in the Indian Ocean between 1990 and 2009

Author

Sarma, V. V. S. S., Lenton, Andrew, Law, R. M., Metzl, Nicolas, Patra, P. K., Doney, Scott C., Lima, Ivan D., Dlugokencky, E., Ramonet, Michel, Valsala, Vinu, National Institute of Oceanography (CSIR), National Institute of Oceanography [India] (NIO), CSIRO Marine and Atmospheric Research (CSIRO-MAR), Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN), Research Institute for Global Change (RIGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Woods Hole Oceanographic Institution (WHOI), NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Indian Institute of Tropical Meteorology (IITM)

Subjects
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]
Abstract

publication Equipe CO2 qui intègre des analyses issues de OISO/CARAUS; International audience; The Indian Ocean (44° S-30° N) plays an important role in the global carbon cycle, yet remains one of the most poorly sampled ocean regions. Several approaches have been used to estimate net sea-air CO2 fluxes in this region: interpolated observations, ocean biogeochemical models, atmospheric and ocean inversions. As part of the RECCAP (REgional Carbon Cycle Assessment and Processes) project, we combine these different approaches to quantify and assess the magnitude and variability in Indian Ocean sea-air CO2 fluxes between 1990 and 2009. Using all of the models and inversions, the median annual mean sea-air CO2 uptake of -0.37 ± 0.06 Pg C yr-1, is consistent with the -0.24 ± 0.12 Pg C yr-1 calculated from observations. The fluxes from the Southern Indian Ocean (18° S-44° S; -0.43 ± 0.07 Pg C yr-1) are similar in magnitude to the annual uptake for the entire Indian Ocean. All models capture the observed pattern of fluxes in the Indian Ocean with the following exceptions: underestimation of upwelling fluxes in the northwestern region (off Oman and Somalia), over estimation in the northeastern region (Bay of Bengal) and underestimation of the CO2 sink in the subtropical convergence zone. These differences were mainly driven by a lack of atmospheric CO2 data in atmospheric inversions, and poor simulation of monsoonal currents and freshwater discharge in ocean biogeochemical models. Overall, the models and inversions do capture the phase of the observed seasonality for the entire Indian Ocean but over estimate the magnitude. The predicted sea-air CO2 fluxes by Ocean BioGeochemical Models (OBGM) respond to seasonal variability with strong phase lags with reference to climatological CO2 flux, whereas the atmospheric inversions predict an order of magnitude higher seasonal flux than OBGMs. The simulated interannual variability by the OBGMs is weaker than atmospheric inversions. Prediction of such weak interannual variability in CO2 fluxes by atmospheric inversions was mainly caused by lack of atmospheric data in the Indian Ocean. The OBGM models suggest a small strengthening of the sink over the period 1990-2009 of -0.01 Pg C decade-1. This is inconsistent with the observations in the southwest Indian Ocean that shows the growth rate of oceanic pCO2 was faster than the observed atmospheric CO2 growth, a finding attributed to the trend of the Southern Annual Mode (SAM) during the 1990s.

Published
2013

15. The HadGEM2-ES implementation of CMIP5 centennial simulations

Author

Jones, C. D., Hughes, J. K., Bellouin, N., Hardimann, S. C., Jones, G. S., Knight, J., Liddicoat, S., O'Connor, F. M., Andres, R. J., Bell, C., Boo, K.-O., Bozzo, A., Butchart, N., Cadule, P., Corbin, K. D., Doutriaux-Boucher, M., Friedlingstein, P., Gornall, J., Gray, L., Halloran, P. R., Hurtt, G., Ingram, W. J., Lamarque, J.-F., Law, R. M., Meinshausen, M., Osprey, S., Palin, E. J., Parsons Chini, L., Raddatz, T., Sanderson, M. G., Sellar, A. A., Schurer, A., Valdes, P., Wood, N., Woodward, S., Yoshioka, M., and Zerroukat, M.

Subjects
ddc:550
Published
2011

17. Supplementary material to "The carbon cycle in the Australian Community Climate and Earth System Simulator (ACCESS-ESM1) – Part 1: Model description and pre-industrial simulation"

Author

Law, R. M., primary, Ziehn, T., additional, Matear, R. J., additional, Lenton, A., additional, Chamberlain, M. A., additional, Stevens, L. E., additional, Wang, Y. P., additional, Srbinovsky, J., additional, Bi, D., additional, Yan, H., additional, and Vohralik, P. F., additional

Published
2015
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22. Sea–air CO2 fluxes in the Indian Ocean between 1990 and 2009

Author

Sarma, V. V. S. S., Lenton, Andrew, Law, R. M., Metzl, Nicolas, Patra, Prabir K., Doney, Scott C., Lima, Ivan D., Dlugokencky, Edward J., Ramonet, M., Valsala, V., Sarma, V. V. S. S., Lenton, Andrew, Law, R. M., Metzl, Nicolas, Patra, Prabir K., Doney, Scott C., Lima, Ivan D., Dlugokencky, Edward J., Ramonet, M., and Valsala, V.

Abstract

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeosciences 10 (2013): 7035-7052, doi:10.5194/bg-10-7035-2013., The Indian Ocean (44° S–30° N) plays an important role in the global carbon cycle, yet it remains one of the most poorly sampled ocean regions. Several approaches have been used to estimate net sea–air CO2 fluxes in this region: interpolated observations, ocean biogeochemical models, atmospheric and ocean inversions. As part of the RECCAP (REgional Carbon Cycle Assessment and Processes) project, we combine these different approaches to quantify and assess the magnitude and variability in Indian Ocean sea–air CO2 fluxes between 1990 and 2009. Using all of the models and inversions, the median annual mean sea–air CO2 uptake of −0.37 ± 0.06 PgC yr−1 is consistent with the −0.24 ± 0.12 PgC yr−1 calculated from observations. The fluxes from the southern Indian Ocean (18–44° S; −0.43 ± 0.07 PgC yr−1 are similar in magnitude to the annual uptake for the entire Indian Ocean. All models capture the observed pattern of fluxes in the Indian Ocean with the following exceptions: underestimation of upwelling fluxes in the northwestern region (off Oman and Somalia), overestimation in the northeastern region (Bay of Bengal) and underestimation of the CO2 sink in the subtropical convergence zone. These differences were mainly driven by lack of atmospheric CO2 data in atmospheric inversions, and poor simulation of monsoonal currents and freshwater discharge in ocean biogeochemical models. Overall, the models and inversions do capture the phase of the observed seasonality for the entire Indian Ocean but overestimate the magnitude. The predicted sea–air CO2 fluxes by ocean biogeochemical models (OBGMs) respond to seasonal variability with strong phase lags with reference to climatological CO2 flux, whereas the atmospheric inversions predicted an order of magnitude higher seasonal flux than OBGMs. The simulated interannual variability by the OBGMs is weaker than that found by atmospheric inversions. Prediction of such weak interannual variability in CO2 fluxes by atmospheric inversions, V. V. S. S. Sarma acknowledges support and encouragement from S. W. A. Naqvi, Director, CSIR-National Institute of Oceanography. A. Lenton and R. M. Law acknowledge support from the Australian Climate Change Science Program, funded by the Australian Government Department of Industry, Innovation, Climate Change, Science, Research and Tertiary Education, and by the Bureau of Meteorology and by CSIRO. S. C. Doney and I. D. Lima acknowledge support from the National Science Foundation (NSF AGS-1048827). N. Metzl acknowledges support of the EU grant 264879 CARBOCHANGE.

Published
2014

23. TransCom model simulations of hourly atmospheric CO2: Analysis of synoptic-scale variations for the period 2002-2003

Author

Patra, P. K., Law, R. M., Peters, W., Rödenbeck, C., Takigawa, M., Baker, I., Bruhwiler, L., Fan, S., Bousquet, P., Brandt, Jørgen, Cameron-Smith, P.J., Christensen, Jesper Heile, Delage, F., Denning, A.S., Geels, Camilla, Houweling, S., Imasu, R., Karstens, U., Kawa, S. R., Kleist, J., Krol, M.C., Lin, S.-J., Lokupitiya, R., Maki, T., Maksyutov, S., Niwa, Y., Onishi, R., Parazoo, N., Pieterse, G., Rivier, L., Satoh, M., Serrar, S., Taguchi, S., Vautard, R., Vermeulen, A.T., and Zhu, Z.

Published
2008

24. TransCom model simulations of hourly atmospheric CO2: Experimental overview and diurnal cycle results for 2002

Author

Law, R. M., Peters, W., RöDenbeck, C., Aulagnier, C., Baker, I., Bergmann, D. J., Bousquet, P., Brandt, J., Bruhwiler, L., Cameron-Smith, P. J., Christensen, J. H., Delage, F., Denning, A. S., Fan, S., Geels, C., Houweling, S., Imasu, R., Karstens, U., Kawa, S. R., Kleist, J., Krol, M. C., Lin, S.-J., Lokupitiya, R., Maki, T., Maksyutov, S., Niwa, Y., Onishi, R., Parazoo, N., Patra, P. K., Pieterse, G., Rivier, L., Satoh, M., Serrar, S., Taguchi, S., Takigawa, M., Vautard, R., Vermeulen, A. T., Zhu, Z., Hydrology and Geo-environmental sciences, Earth and Climate, Physics of Living Systems, Team Higher Education, and Energy and Sustainability Research Institute Groni

Subjects
FLUXES, Atmospheric Composition and Structure: Constituent sources and sinks, EUROPE, IMPACT, carbon dioxide, RECORD, transport model comparison, FOREST, TRENDS, TRANSPORT, 4928), diurnal cycle, CARBON-DIOXIDE, VARIABILITY, Atmospheric Composition and Structure: Troposphere: constituent transport and chemistry, INVERSIONS, Biogeosciences: Carbon cycling (4806), SDG 14 - Life Below Water, Global Change: Global climate models (3337
Abstract

1

Published
2008

25. Transcom 3 inversion intercomparison: Model mean results for the estimation of seasonal carbon sources and sinks

Author

Gurney, K. R., Law, R. M., Denning, A. S., Rayner, P. J., Pak, B. C., Baker, D., Philippe Bousquet, Bruhwiler, L., Chen, Y. -H, Ciais, P., Fung, I. Y., Heimann, M., John, J., Maki, T., Maksyutov, S., Peylin, P., Prather, M., Taguchi, S., Department of Atmospheric Science [Fort Collins], Colorado State University [Fort Collins] (CSU), CSIRO Marine and Atmospheric Research [Aspendale], Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO), Department of Earth System Science [Irvine] (ESS), University of California [Irvine] (UC Irvine), University of California (UC)-University of California (UC), National Center for Atmospheric Research [Boulder] (NCAR), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), NOAA Climate Monitoring and Diagnostics Laboratory (CMDL), National Oceanic and Atmospheric Administration (NOAA), Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), ICOS-ATC (ICOS-ATC), University of California [Berkeley] (UC Berkeley), University of California (UC), Max-Planck-Institut für Biogeochemie (MPI-BGC), Japan Meteorological Agency (JMA), Frontier Research System for Global Change (FRSGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Biogéochimie et écologie des milieux continentaux (Bioemco), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-AgroParisTech-Centre National de la Recherche Scientifique (CNRS), Modélisation des Surfaces et Interfaces Continentales (MOSAIC), National Institute of Advanced Industrial Science and Technology (AIST), University of California [Irvine] (UCI), University of California-University of California, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), University of California [Berkeley], University of California, Centre National de la Recherche Scientifique (CNRS)-AgroParisTech-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut National de la Recherche Agronomique (INRA)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), CSIRO Marine and Atmospheric Research (CSIRO-MAR), School of Earth Sciences [Melbourne], Faculty of Science [Melbourne], University of Melbourne-University of Melbourne, NOAA Earth System Research Laboratory (ESRL), Department of Earth and Planetary Science [UC Berkeley] (EPS), and National Institute for Environmental Studies (NIES)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, inversion, annual variation, carbon transport, atmospheric transport, [SDE.MCG]Environmental Sciences/Global Changes, carbon cycle, Physical Sciences and Mathematics, carbon dioxide, carbon emission, [SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; The TransCom 3 experiment was begun to explore the estimation of carbon sources and sinks via the inversion of simulated tracer transport. We build upon previous TransCom work by presenting the seasonal inverse results which provide estimates of carbon flux for 11 land and 11 ocean regions using 12 atmospheric transport models. The monthly fluxes represent the mean seasonal cycle for the 1992 to 1996 time period. The spread among the model results is larger than the average of their estimated flux uncertainty in the northern extratropics and vice versa in the tropical regions. In the northern land regions, the model spread is largest during the growing season. Compared to a seasonally balanced biosphere prior flux generated by the CASA model, we find significant changes to the carbon exchange in the European region with greater growing season net uptake which persists into the fall months. Both Boreal North America and Boreal Asia show lessened net uptake at the onset of the growing season with Boreal Asia also exhibiting greater peak growing season net uptake. Temperate Asia shows a dramatic springward shift in the peak timing of growing season net uptake relative to the neutral CASA flux while Temperate North America exhibits a broad flattening of the seasonal cycle. In most of the ocean regions, the inverse fluxes exhibit much greater seasonality than that implied by the DeltapCO(2) derived fluxes though this may be due, in part, to misallocation of adjacent land flux. In the Southern Ocean, the austral spring and fall exhibits much less carbon uptake than implied by DeltapCO2 derived fluxes. Sensitivity testing indicates that the inverse estimates are not overly influenced by the prior flux choices. Considerable agreement exists between the model mean, annual mean results of this study and that of the previously published TransCom annual mean inversion. The differences that do exist are in poorly constrained regions and tend to exhibit compensatory fluxes in order to match the global mass constraint. The differences between the estimated fluxes and the prior model over the northern land regions could be due to the prior model respiration response to temperature. Significant phase differences, such as that in the Temperate Asia region, may be due to the limited observations for that region. Finally, differences in the boreal land regions between the prior model and the estimated fluxes may be a reflection of the timing of spring thaw and an imbalance in respiration versus photosynthesis.

Published
2004

26. Technical note: an interannual inversion method forcontinuous CO2 data

Author

Law, R. M., EGU, Publication, CSIRO Atmospheric Research, and Commonwealth Scientific and Industrial Research Organisation [Canberra] (CSIRO)

Subjects
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:Chemistry, lcsh:QD1-999, [SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere, lcsh:Physics, lcsh:QC1-999
Abstract

International audience; A sequential synthesis inversion method is described to estimate CO2 sources from continuous atmospheric data. The sequential method makes the problem computationally feasible. The method is assessed using four-hourly synthetic concentration data generated from known sources. Multi-year mean sources and seasonal cycles are estimated with comparable quality as those from a traditional inversion of monthly mean data. Interannual variations in the estimated sources are closer to those of the known sources using the four-hourly data rather than monthly data. The computational cost of the basis function simulations can be reduced by generating responses that are only six months long. This does not significantly degrade the inversion results compared to using responses that are 12 months in length.

Published
2004

31. Technical note: an interannual inversion method for continuous CO2 data

Author

Law, R. M. and EGU, Publication

Subjects
[SDU.OCEAN] Sciences of the Universe [physics]/Ocean, Atmosphere
Abstract

A sequential synthesis inversion method is described to estimate CO2 sources from continuous atmospheric data. The sequential method makes the problem computationally feasible. The method is assessed using four-hourly synthetic concentration data generated from known sources. Multi-year mean sources and seasonal cycles are estimated with comparable quality as those from a traditional inversion of monthly mean data. Interannual variations in the estimated sources are closer to those of the known sources using the four-hourly data rather than monthly data. The computational cost of the basis function simulations can be reduced by generating responses that are only six months long. This does not significantly degrade the inversion results compared to using responses that are 12 months in length.

Published
2003

32. Sea-air CO2 fluxes in the Southern Ocean for the period 1990-2009

Author

Lenton, A., Tilbrook, B., Law, R. M., Bakker, D., Doney, S. C., Gruber, N., Ishii, M., Hoppema, M., Lovenduski, N. S., Matear, R. J., Mcneil, B. I., Metzl, N., Mikaloff Fletcher, S. E., Monteiro, P. M. S., Roedenbeck, C., Sweeney, C., Takahashi, T., Lenton, A., Tilbrook, B., Law, R. M., Bakker, D., Doney, S. C., Gruber, N., Ishii, M., Hoppema, M., Lovenduski, N. S., Matear, R. J., Mcneil, B. I., Metzl, N., Mikaloff Fletcher, S. E., Monteiro, P. M. S., Roedenbeck, C., Sweeney, C., and Takahashi, T.

Abstract

The Southern Ocean (44-75 degrees S) plays a critical role in the global carbon cycle, yet remains one of the most poorly sampled ocean regions. Different approaches have been used to estimate sea-air CO2 fluxes in this region: synthesis of surface ocean observations, ocean biogeochemical models, and atmospheric and ocean inversions. As part of the RECCAP (REgional Carbon Cycle Assessment and Processes) project, we combine these different approaches to quantify and assess the magnitude and variability in Southern Ocean sea-air CO2 fluxes between 1990-2009. Using all models and inversions (26), the integrated median annual sea-air CO2 flux of -0.42+/-0.07 Pg C yr(-1) for the 44-75 degrees S region, is consistent with the -0.27+/-0.13 Pg C yr(-1) calculated using surface observations. The circumpolar region south of 58 degrees S has a small net annual flux (model and inversion median: -0.04+/-0.07 Pg C yr(-1) and observations: +0.04+/-0.02 Pg C yr(-1)), with most of the net annual flux located in the 44 to 58 degrees S circumpolar band (model and inversion median: -0.36+/-0.09 Pg C yr(-1) and observations: -0.35+/-0.09 Pg C yr(-1)). Seasonally, in the 44-58 degrees S region, the median of 5 ocean biogeochemical models captures the observed sea-air CO2 flux seasonal cycle, while the median of 11 atmospheric inversions shows little seasonal change in the net flux. South of 58 degrees S, neither atmospheric inversions nor ocean biogeochemical models reproduce the phase and amplitude of the observed seasonal sea-air CO2 flux, particularly in the Austral Winter. Importantly, no individual atmospheric inversion or ocean biogeochemical model is capable of reproducing both the observed annual mean uptake and the observed seasonal cycle. This raises concerns about projecting future changes in Southern Ocean CO2 fluxes. The median interannual variability from atmospheric inversions and ocean biogeochemical models is substantial in the Southern Ocean; up to 25% of the annual mea

Published
2013
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33. Sea–air CO2 fluxes in the Southern Ocean for the period 1990–2009

Author

Lenton, Andrew, Tilbrook, Bronte, Law, R. M., Bakker, Dorothee C. E., Doney, Scott C., Gruber, Nicolas, Ishii, Masao, Hoppema, Mario, Lovenduski, Nicole S., Matear, Richard J., McNeil, B. I., Metzl, Nicolas, Mikaloff Fletcher, Sara E., Monteiro, Pedro M. S., Rodenbeck, C., Sweeney, Colm, Takahashi, Taro, Lenton, Andrew, Tilbrook, Bronte, Law, R. M., Bakker, Dorothee C. E., Doney, Scott C., Gruber, Nicolas, Ishii, Masao, Hoppema, Mario, Lovenduski, Nicole S., Matear, Richard J., McNeil, B. I., Metzl, Nicolas, Mikaloff Fletcher, Sara E., Monteiro, Pedro M. S., Rodenbeck, C., Sweeney, Colm, and Takahashi, Taro

Abstract

© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeosciences 19 (2013): 4037-4054, doi:10.5194/bg-10-4037-2013., The Southern Ocean (44–75° S) plays a critical role in the global carbon cycle, yet remains one of the most poorly sampled ocean regions. Different approaches have been used to estimate sea–air CO2 fluxes in this region: synthesis of surface ocean observations, ocean biogeochemical models, and atmospheric and ocean inversions. As part of the RECCAP (REgional Carbon Cycle Assessment and Processes) project, we combine these different approaches to quantify and assess the magnitude and variability in Southern Ocean sea–air CO2 fluxes between 1990–2009. Using all models and inversions (26), the integrated median annual sea–air CO2 flux of −0.42 ± 0.07 Pg C yr−1 for the 44–75° S region, is consistent with the −0.27 ± 0.13 Pg C yr−1 calculated using surface observations. The circumpolar region south of 58° S has a small net annual flux (model and inversion median: −0.04 ± 0.07 Pg C yr−1 and observations: +0.04 ± 0.02 Pg C yr−1), with most of the net annual flux located in the 44 to 58° S circumpolar band (model and inversion median: −0.36 ± 0.09 Pg C yr−1 and observations: −0.35 ± 0.09 Pg C yr−1). Seasonally, in the 44–58° S region, the median of 5 ocean biogeochemical models captures the observed sea–air CO2 flux seasonal cycle, while the median of 11 atmospheric inversions shows little seasonal change in the net flux. South of 58° S, neither atmospheric inversions nor ocean biogeochemical models reproduce the phase and amplitude of the observed seasonal sea–air CO2 flux, particularly in the Austral Winter. Importantly, no individual atmospheric inversion or ocean biogeochemical model is capable of reproducing both the observed annual mean uptake and the observed seasonal cycle. This raises concerns about projecting future changes in Southern Ocean CO2 fluxes. The median interannual variability from atmospheric inversions and ocean biogeochemical models is substantial in the Southern Ocean; up to 25% of the annual mean flux, with 25% of this interannual variability attri, A. Lenton, B. Tilbrook, R. J. Matear and R. M. Law were funded by the Australian Climate Change Science Program and theWealth from Oceans National Research Flagship. S. C. Doney acknowledges support from the National Science Foundation (OPP-0823101), T. Takahashi is supported by grants from United States NOAA (NA08OAR4320754) and National Science Foundation (ANT 06-36879). D. Baker, N. Gruber, M. Hoppema, N. Metzl acknowledge the support of EU FP7 project CARBOCHANGE (264879). S. C. Doney acknowledges support from the National Science Foundation (OPP-0823101). N. S. Lovenduski is grateful for support from NSF (OCE-1155240) and NOAA (NA12OAR4310058). This study is also a contribution to the international IMBER/SOLAS Projects. C. Sweeney acknowledges support from the United States NOAA (NA12OAR4310058) and National Science Foundation (0944761).

Published
2013

34. Off-line algorithm for calculation of vertical tracer transport in the troposphere due to deep convection

Author

Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Belikov, Dmitry, Maksyutov, Shamil, Krol, Maarten, Fraser, A., Rigby, M., Bian, H., Agusti-Panareda, Anna, Bergmann, D., Bousquet, P., Cameron-Smith, P., Chipperfield, M. P., Fortems-Cheiney, A., Gloor, E., Haynes, K., Hess, P., Houweling, S., Kawa, Stephan R., Law, R. M., Loh, Zoe, Meng, Lei, Palmer, Paul I., Patra, P. K., Saito, R., Wilson, C., Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Belikov, Dmitry, Maksyutov, Shamil, Krol, Maarten, Fraser, A., Rigby, M., Bian, H., Agusti-Panareda, Anna, Bergmann, D., Bousquet, P., Cameron-Smith, P., Chipperfield, M. P., Fortems-Cheiney, A., Gloor, E., Haynes, K., Hess, P., Houweling, S., Kawa, Stephan R., Law, R. M., Loh, Zoe, Meng, Lei, Palmer, Paul I., Patra, P. K., Saito, R., and Wilson, C.

Abstract

A modified cumulus convection parametrisation scheme is presented. This scheme computes the mass of air transported upward in a cumulus cell using conservation of moisture and a detailed distribution of convective precipitation provided by a reanalysis dataset. The representation of vertical transport within the scheme includes entrainment and detrainment processes in convective updrafts and downdrafts. Output from the proposed parametrisation scheme is employed in the National Institute for Environmental Studies (NIES) global chemical transport model driven by JRA-25/JCDAS reanalysis. The simulated convective precipitation rate and mass fluxes are compared with observations and reanalysis data. A simulation of the short-lived tracer [superscript 222]Rn is used to further evaluate the performance of the cumulus convection scheme. Simulated distributions of [superscript 222]Rn are evaluated against observations at the surface and in the free troposphere, and compared with output from models that participated in the TransCom-CH4 Transport Model Intercomparison. From this comparison, we demonstrate that the proposed convective scheme in general is consistent with observed and modeled results.

Published
2013

36. TransCom model simulations of CH₄ and related species: linking transport, surface flux and chemical loss with CH₄ variability in the troposphere and lower stratosphere

Author

Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Rigby, Matthew, Patra, P. K., Houweling, S., Krol, Maarten, Bousquet, P., Belikov, Dmitry, Bergmann, D., Bian, H., Cameron-Smith, P., Chipperfield, M. P., Corbin, K., Fortems-Cheiney, A., Fraser, A., Gloor, E., Hess, P., Ito, A., Kawa, Stephan R., Law, R. M., Loh, Zoe, Maksyutov, Shamil, Meng, Lei, Palmer, Paul I., Rigby, M., Saito, R., Wilson, C., Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Rigby, Matthew, Patra, P. K., Houweling, S., Krol, Maarten, Bousquet, P., Belikov, Dmitry, Bergmann, D., Bian, H., Cameron-Smith, P., Chipperfield, M. P., Corbin, K., Fortems-Cheiney, A., Fraser, A., Gloor, E., Hess, P., Ito, A., Kawa, Stephan R., Law, R. M., Loh, Zoe, Maksyutov, Shamil, Meng, Lei, Palmer, Paul I., Rigby, M., Saito, R., and Wilson, C.

Abstract

A chemistry-transport model (CTM) intercomparison experiment (TransCom-CH₄) has been designed to investigate the roles of surface emissions, transport and chemical loss in simulating the global methane distribution. Model simulations were conducted using twelve models and four model variants and results were archived for the period of 1990–2007. All but one model transports were driven by reanalysis products from 3 different meteorological agencies. The transport and removal of CH₄ in six different emission scenarios were simulated, with net global emissions of 513 ± 9 and 514 ± 14 Tg CH₄ yr[superscript −1] for the 1990s and 2000s, respectively. Additionally, sulfur hexafluoride (SF₆) was simulated to check the interhemispheric transport, radon ([supercript 222]Rn) to check the subgrid scale transport, and methyl chloroform (CH₃CCl₃) to check the chemical removal by the tropospheric hydroxyl radical (OH). The results are compared to monthly or annual mean time series of CH₄, SF₆ and CH₃CCl₃ measurements from 8 selected background sites, and to satellite observations of CH₄ in the upper troposphere and stratosphere. Most models adequately capture the vertical gradients in the stratosphere, the average long-term trends, seasonal cycles, interannual variations (IAVs) and interhemispheric (IH) gradients at the surface sites for SF₆, CH₃CCl₃ and CH₄. The vertical gradients of all tracers between the surface and the upper troposphere are consistent within the models, revealing vertical transport differences between models. An average IH exchange time of 1.39 ± 0.18 yr is derived from SF₆ time series. Sensitivity simulations suggest that the estimated trends in exchange time, over the period of 1996–2007, are caused by a change of SF₆ emissions towards the tropics. Using six sets of emission scenarios, we show that the decadal average CH₄ growth rate likely reached equilibrium in the early 2000s due to the flattening of anthropogenic emission growth since the late 1990s. U, United States. National Aeronautics and Space Administration (NASA-AGAGE Grant NNX11AF17G)

Published
2012

37. Precision requirements for space-based XCO2 data

Author

Miller, C. E., Crisp, D., DeCola, P. L., Olsen, S. C., Randerson, James T., Michalak, Anna M., Alkhaled, A., Rayner, Peter, Jacob, Daniel J., Suntharalingam, Parvadha, Jones, D. B. A., Denning, A. S., Nicholls, M. E., Doney, Scott C., Pawson, S., Boesch, H., Connor, B. J., Fung, Inez Y., O'Brien, D., Salawitch, R. J., Sander, S. P., Sen, B., Tans, Pieter P., Toon, G. C., Wennberg, Paul O., Wofsy, Steven C., Yung, Y. L., Law, R. M., Miller, C. E., Crisp, D., DeCola, P. L., Olsen, S. C., Randerson, James T., Michalak, Anna M., Alkhaled, A., Rayner, Peter, Jacob, Daniel J., Suntharalingam, Parvadha, Jones, D. B. A., Denning, A. S., Nicholls, M. E., Doney, Scott C., Pawson, S., Boesch, H., Connor, B. J., Fung, Inez Y., O'Brien, D., Salawitch, R. J., Sander, S. P., Sen, B., Tans, Pieter P., Toon, G. C., Wennberg, Paul O., Wofsy, Steven C., Yung, Y. L., and Law, R. M.

Abstract

Author Posting. © American Geophysical Union, 2007. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 112 (2007): D10314, doi:10.1029/2006JD007659., Precision requirements are determined for space-based column-averaged CO2 dry air mole fraction (XCO2) data. These requirements result from an assessment of spatial and temporal gradients in XCO2, the relationship between XCO2 precision and surface CO2 flux uncertainties inferred from inversions of the XCO2 data, and the effects of XCO2 biases on the fidelity of CO2 flux inversions. Observational system simulation experiments and synthesis inversion modeling demonstrate that the Orbiting Carbon Observatory mission design and sampling strategy provide the means to achieve these XCO2 data precision requirements., This work was supported by the Orbiting Carbon Observatory (OCO) project through NASA’s Earth System Science Pathfinder (ESSP) program. SCO and JTR were supported by a NASA IDS grant (NAG5-9462) to JTR.

Published
2010

39. Sea–air CO<sub>2</sub> fluxes in the Southern Ocean for the period 1990–2009

Author

Lenton, A., primary, Tilbrook, B., additional, Law, R. M., additional, Bakker, D., additional, Doney, S. C., additional, Gruber, N., additional, Ishii, M., additional, Hoppema, M., additional, Lovenduski, N. S., additional, Matear, R. J., additional, McNeil, B. I., additional, Metzl, N., additional, Mikaloff Fletcher, S. E., additional, Monteiro, P. M. S., additional, Rödenbeck, C., additional, Sweeney, C., additional, and Takahashi, T., additional

Published
2013
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42. Off-line algorithm for calculation of vertical tracer transport in the troposphere due to deep convection

Author

Belikov, D. A., primary, Maksyutov, S., additional, Krol, M., additional, Fraser, A., additional, Rigby, M., additional, Bian, H., additional, Agusti-Panareda, A., additional, Bergmann, D., additional, Bousquet, P., additional, Cameron-Smith, P., additional, Chipperfield, M. P., additional, Fortems-Cheiney, A., additional, Gloor, E., additional, Haynes, K., additional, Hess, P., additional, Houweling, S., additional, Kawa, S. R., additional, Law, R. M., additional, Loh, Z., additional, Meng, L., additional, Palmer, P. I., additional, Patra, P. K., additional, Prinn, R. G., additional, Saito, R., additional, and Wilson, C., additional

Published
2013
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44. The Australian terrestrial carbon budget

Author

Haverd, V., primary, Raupach, M. R., additional, Briggs, P. R., additional, Canadell, J. G., additional, Davis, S. J., additional, Law, R. M., additional, Meyer, C. P., additional, Peters, G. P., additional, Pickett-Heaps, C., additional, and Sherman, B., additional

Published
2012
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45. Off-line algorithm for calculation of vertical tracer transport in the troposphere due to deep convection

Author

Belikov, D. A., primary, Maksyutov, S., additional, Krol, M., additional, Fraser, A., additional, Rigby, M., additional, Bian, H., additional, Agusti-Panareda, A., additional, Bergmann, D., additional, Bousquet, P., additional, Cameron-Smith, P., additional, Chipperfield, M. P., additional, Fortems-Cheiney, A., additional, Gloor, E., additional, Haynes, K., additional, Hess, P., additional, Houweling, S., additional, Kawa, S. R., additional, Law, R. M., additional, Loh, Z., additional, Meng, L., additional, Palmer, P. I., additional, Patra, P. K., additional, Prinn, R. G., additional, Saito, R., additional, and Wilson, C., additional

Published
2012
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47. Supplementary material to "TransCom model simulations of CH<sub>4</sub> and related species: linking transport, surface flux and chemical loss with CH<sub>4</sub> variability in the troposphere and lower stratosphere"

Author

Patra, P. K., primary, Houweling, S., additional, Krol, M., additional, Bousquet, P., additional, Belikov, D., additional, Bergmann, D., additional, Bian, H., additional, Cameron-Smith, P., additional, Chipperfield, M. P., additional, Corbin, K., additional, Fortems-Cheiney, A., additional, Fraser, A., additional, Gloor, E., additional, Hess, P., additional, Ito, A., additional, Kawa, S. R., additional, Law, R. M., additional, Loh, Z., additional, Maksyutov, S., additional, Meng, L., additional, Palmer, P. I., additional, Prinn, R. G., additional, Rigby, M., additional, Saito, R., additional, and Wilson, C., additional

Published
2011
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48. TransCom model simulations of CH4 and related species: linking transport, surface flux and chemical loss with CH4 variability in the troposphere and lower stratosphere

Author

Patra, P. K., primary, Houweling, S., additional, Krol, M., additional, Bousquet, P., additional, Belikov, D., additional, Bergmann, D., additional, Bian, H., additional, Cameron-Smith, P., additional, Chipperfield, M. P., additional, Corbin, K., additional, Fortems-Cheiney, A., additional, Fraser, A., additional, Gloor, E., additional, Hess, P., additional, Ito, A., additional, Kawa, S. R., additional, Law, R. M., additional, Loh, Z., additional, Maksyutov, S., additional, Meng, L., additional, Palmer, P. I., additional, Prinn, R. G., additional, Rigby, M., additional, Saito, R., additional, and Wilson, C., additional

Published
2011
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49. The HadGEM2-ES implementation of CMIP5 centennial simulations

Author

Jones, C. D., primary, Hughes, J. K., additional, Bellouin, N., additional, Hardiman, S. C., additional, Jones, G. S., additional, Knight, J., additional, Liddicoat, S., additional, O'Connor, F. M., additional, Andres, R. J., additional, Bell, C., additional, Boo, K.-O., additional, Bozzo, A., additional, Butchart, N., additional, Cadule, P., additional, Corbin, K. D., additional, Doutriaux-Boucher, M., additional, Friedlingstein, P., additional, Gornall, J., additional, Gray, L., additional, Halloran, P. R., additional, Hurtt, G., additional, Ingram, W. J., additional, Lamarque, J.-F., additional, Law, R. M., additional, Meinshausen, M., additional, Osprey, S., additional, Palin, E. J., additional, Parsons Chini, L., additional, Raddatz, T., additional, Sanderson, M. G., additional, Sellar, A. A., additional, Schurer, A., additional, Valdes, P., additional, Wood, N., additional, Woodward, S., additional, Yoshioka, M., additional, and Zerroukat, M., additional

Published
2011
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50. Atmospheric CO2inversion validation using vertical profile measurements: Analysis of four independent inversion models

Author

Pickett-Heaps, C. A., primary, Rayner, P. J., additional, Law, R. M., additional, Ciais, P., additional, Patra, P. K., additional, Bousquet, P., additional, Peylin, P., additional, Maksyutov, S., additional, Marshall, J., additional, Rödenbeck, C., additional, Langenfelds, R. L., additional, Steele, L. P., additional, Francey, R. J., additional, Tans, P., additional, and Sweeney, C., additional

Published
2011
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