9th International Carbon Dioxide Conference (ICDC9) Editor(s): L. Bopp, V. Brovkin, J. Canadell, C. Gerbig, D. Griffith, M. Heimann, R. Keeling, Y. Luo, A. C. Manning, A. Michalak, Z. Xie, and N. Zeng Special issue jointly organized between Earth System Dynamics, Atmospheric Chemistry and Physics, Atmospheric Measurement Techniques, and Biogeosciences
The International Carbon Dioxide Conference (ICDC) is the single largest conference organized by the global research community every four years to present the latest scientific findings on the science of the carbon cycle and its perturbation by human activities. The ICDC in 2013 is the 9th conference. The conference topics encompass the global carbon cycle, global and regional budgets, and processes with specialized sessions on the individual components of atmosphere, ocean and land, in the timeframes of past, present and future. It covers both fundamental science advancement and discovery, the generation of policy relevant information, and new technological observational platforms, datasets, and modeling approaches.
The three main themes of the conference are:
Theme 1: Past and present changes and variability
Theme 2: Carbon sources and sinks, their changes and trends
Theme 3: Future of the carbon cycle: drivers, vulnerabilities, feedbacks and management options
Estimating Asian terrestrial carbon fluxes from CONTRAIL aircraft and surface CO2 observations for the period 2006–2010
H. F. Zhang, B. Z. Chen, I. T. van der Laan-Luijk, T. Machida, H. Matsueda, Y. Sawa, Y. Fukuyama, R. Langenfelds, M. van der Schoot, G. Xu, J. W. Yan, M. L. Cheng, L. X. Zhou, P. P. Tans, and W. Peters Atmos. Chem. Phys., 14, 5807-5824, 2014 AbstractFinal Revised Paper (PDF, 3080 KB)Supplement (361 KB)Discussion Paper (ACPD)
11 Jun 2014
Quantifying the biophysical climate change mitigation potential of Canada's forest sector
Simulating the integrated summertime Δ14CO2 signature from anthropogenic emissions over Western Europe
D. Bozhinova, M. K. van der Molen, I. R. van der Velde, M. C. Krol, S. van der Laan, H. A. J. Meijer, and W. Peters Atmos. Chem. Phys., 14, 7273-7290, 2014 AbstractFinal Revised Paper (PDF, 3707 KB)Discussion Paper (ACPD)
17 Jul 2014
High-precision quasi-continuous atmospheric greenhouse gas measurements at Trainou tower (Orléans forest, France)
M. Schmidt, M. Lopez, C. Yver Kwok, C. Messager, M. Ramonet, B. Wastine, C. Vuillemin, F. Truong, B. Gal, E. Parmentier, O. Cloué, and P. Ciais Atmos. Meas. Tech., 7, 2283-2296, 2014 AbstractFinal Revised Paper (PDF, 2008 KB)Discussion Paper (AMTD)
30 Jul 2014
Interannual sea–air CO2 flux variability from an observation-driven ocean mixed-layer scheme
Impacts of freezing and thawing dynamics on foliar litter carbon release in alpine/subalpine forests along an altitudinal gradient in the eastern Tibetan Plateau
Summary: A 2-year field litter decomposition experiment was conducted along an altitudinal gradient in the eastern Tibetan Plateau. More rapid 2-year C is released from fresh foliar litter at upper elevations compared to lower elevations. However, high C release was observed at low altitudes during winter, but high altitudes exhibited high C release during growing season. The results suggested that the onset of C release in fresh litter could delay in this cold region in the scenario of climate warming.
W. Fuzhong, P. Changhui, Z. Jianxiao, Z. Jian, T. Bo, and Y. Wanqin Biogeosciences, 11, 6471-6481, 2014 Abstract
Notice on Corrigendum The requested paper has a corresponding Corrigendum published. Please read the
Corrigendum first before downloading the article.
Continued increase in atmospheric CO2 seasonal amplitude in the 21st century projected by the CMIP5 Earth system models
Summary: This paper presents the CMIP5 model predictions on the seasonal characteristics of global carbon cycle. We show a model consensus that the amplitude of this seasonal cycle will increase in the future under the RCP8.5 emission scenario. This is mostly due to enhanced ecosystem productivity in high latitude regions. While the models' ensemble CO2 amplitude increase is close to observation, our results suggest the underlying mechanisms may not be realistic.
Using atmospheric observations to evaluate the spatiotemporal variability of CO2 fluxes simulated by terrestrial biospheric models
Summary: Terrestrial biospheric models (TBMs) are used to assess carbon--climate interactions. We present a new and complementary approach for evaluating the spatiotemporal patterns, rather than magnitudes, of biosphere--atmosphere carbon exchange predicted by TBMs, based on atmospheric observations. Experiments demonstrate that the performance of TBMs varies substantially across seasons and biomes, with best performance during the growing season and more limited skill during transition seasons.
A joint data assimilation system (Tan-Tracker) to simultaneously estimate surface CO2 fluxes and 3-D atmospheric CO2 concentrations from observations
Summary: A new carbon cycle data assimilation system (Tan-Tracker) is developed based on an advanced hybrid assimilation approach, as a part of the preparation for the launch of the Chinese carbon dioxide observation satellite (TanSat). Tan-Tracker adopts a joint data assimilation framework to simultaneously estimate CO2 concentrations and CFs and thus gradually reduce the uncertainty in the CO2 concentration evolution through continuously fitting model CO2 concentration simulations to the observations.
Comparison of continuous in situ CO2 observations at Jungfraujoch using two different measurement techniques
M. F. Schibig, M. Steinbacher, B. Buchmann, I. T. van der Laan-Luijkx, S. van der Laan, S. Ranjan, and M. C. Leuenberger Atmos. Meas. Tech., 8, 57-68, 2015 AbstractFinal Revised Paper (PDF, 2363 KB)Discussion Paper (AMTD)
06 Jan 2015
Two perspectives on the coupled carbon, water and energy exchange in the planetary boundary layer
Summary: This study investigates the interactions among the carbon, water and heat cycles above a maize field at the diurnal scale. We couple two land-surface schemes, corresponding to two different modelling approaches, to the same atmospheric boundary-layer (ABL) model. We find the simpler meteorological approach best reproduces the surface and upper-air observations. Finally, we show that the interaction of subsidence with ABL dynamics is key to explain the daytime atmospheric CO2 budget.
Evaluating the ocean biogeochemical components of Earth system models using atmospheric potential oxygen and ocean color data
Summary: The observed seasonal cycles in atmospheric potential oxygen (APO) at five surface monitoring sites are compared to those inferred from the air-sea O2 fluxes of six ocean biogeochemistry models. The simulated air-sea fluxes are translated into APO seasonal cycles using a matrix method that takes into account atmospheric transport model (ATM) uncertainty among 13 different ATMs. Net primary production (NPP), estimated from satellite ocean color data, is also compared to model output.
Atmospheric inversion of surface carbon flux with consideration of the spatial distribution of US crop production and consumption
Summary: The major findings of this article are the following. 1. Atmospheric CO2 observations alone are not sufficient to estimate the spatial distribution of carbon sources and sinks over North America, even though it is one of the most densely observed regions in the world. 2. To improve atmospheric inversion, lateral carbon transfer in agricultural products should be considered in the prior flux used to constrain the inversion.
Recent changes in the global and regional carbon cycle: analysis of first-order diagnostics
Summary: Recent papers suggest a slow-down in the natural uptake of
anthropogenic CO2. We analyse recent trends in atmospheric concentration and
known inputs to test for such a slow-down. We see, rather, an increase
in uptake compared to a simple response to changing CO2 concentration. Using atmospheric models and statistical techniques we isolate this increased uptake to the northern temperate and boreal continents during summer, suggesting a stronger growing season.
Uncertainty analysis of eddy covariance CO2 flux measurements for different EC tower distances using an extended two-tower approach
Summary: This study introduces an extension of the classical two-tower approach for uncertainty estimation of measured net CO2 fluxes (NEE). Because land surface properties cannot be assumed identical at two eddy covariance towers, a correction for systematic flux differences is proposed to be added to the classical weather filter. With this extension, the overestimation of NEE uncertainty due to systematic flux differences (which are assumed to increase with tower distance) can considerably be reduced.
Greenhouse gas network design using backward Lagrangian particle dispersion modelling – Part 2: Sensitivity analyses and South African test case
Summary: This study aims to provide an optimal network design for the placement of new atmospheric monitoring stations around South Africa, to best estimate the emission and uptake of carbon dioxide fluxes due to both anthropogenic and natural sources. In addition, a sensitivity analysis was performed on the impact that certain parameters would have on the final network solution, considering the inverse modelling framework, the transport model and the use of a different optimisation routine.