Articles | Volume 12, issue 4
Biogeosciences, 12, 1131–1150, 2015
https://doi.org/10.5194/bg-12-1131-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Biogeosciences, 12, 1131–1150, 2015
https://doi.org/10.5194/bg-12-1131-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article 24 Feb 2015
Research article | 24 Feb 2015
A global carbon assimilation system based on a dual optimization method
H. Zheng et al.
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Fei Jiang, Hengmao Wang, Jing M. Chen, Weimin Ju, Xiangjun Tian, Shuzhuang Feng, Guicai Li, Zhuoqi Chen, Shupeng Zhang, Xuehe Lu, Jane Liu, Haikun Wang, Jun Wang, Wei He, and Mousong Wu
Atmos. Chem. Phys., 21, 1963–1985, https://doi.org/10.5194/acp-21-1963-2021, https://doi.org/10.5194/acp-21-1963-2021, 2021
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We present a 6-year inversion from 2010 to 2015 for the global and regional carbon fluxes using only the GOSAT XCO2 retrievals. We find that the XCO2 retrievals could significantly improve the modeling of atmospheric CO2 concentrations and that the inferred interannual variations in the terrestrial carbon fluxes in most land regions have a better relationship with the changes in severe drought area or leaf area index, or are more consistent with the previous estimates about drought impact.
Yi Zheng, Ruoque Shen, Yawen Wang, Xiangqian Li, Shuguang Liu, Shunlin Liang, Jing M. Chen, Weimin Ju, Li Zhang, and Wenping Yuan
Earth Syst. Sci. Data, 12, 2725–2746, https://doi.org/10.5194/essd-12-2725-2020, https://doi.org/10.5194/essd-12-2725-2020, 2020
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Accurately reproducing the interannual variations in vegetation gross primary production (GPP) is a major challenge. A global GPP dataset was generated by integrating the regulations of several major environmental variables with long-term changes. The dataset can effectively reproduce the spatial, seasonal, and particularly interannual variations in global GPP. Our study will contribute to accurate carbon flux estimates at long timescales.
Bo Dan, Xiaogu Zheng, Guocan Wu, and Tao Li
Hydrol. Earth Syst. Sci., 24, 5187–5201, https://doi.org/10.5194/hess-24-5187-2020, https://doi.org/10.5194/hess-24-5187-2020, 2020
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Data assimilation is a procedure to generate an optimal combination of the state variable in geoscience, based on the model outputs and observations. The ensemble Kalman filter (EnKF) scheme is a widely used assimilation method in soil moisture estimation. This study proposed several modifications of EnKF for improving this assimilation. The study shows that the quality of the assimilation result is improved, while the degree of water budget imbalance is reduced.
Zhi-Zhen Ni, Kun Luo, Yang Gao, Xiang Gao, Fei Jiang, Cheng Huang, Jian-Ren Fan, Joshua S. Fu, and Chang-Hong Chen
Atmos. Chem. Phys., 20, 5963–5976, https://doi.org/10.5194/acp-20-5963-2020, https://doi.org/10.5194/acp-20-5963-2020, 2020
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The Weather Research Forecast with Chemistry (WRF-Chem) model was used to simulate spatial and temporal O3 evolution in the Yangtze River Delta (YRD) region. Various atmospheric processes were analyzed to determine the influential factors of ozone formation through the integrated process rate method. This paper provides insight into urban O3 formation and dispersion during tropical cyclone events and supports the Model Intercomparison Study Asia Phase III (MICS-Asia Phase III).
Hengmao Wang, Fei Jiang, Jun Wang, Weimin Ju, and Jing M. Chen
Atmos. Chem. Phys., 19, 12067–12082, https://doi.org/10.5194/acp-19-12067-2019, https://doi.org/10.5194/acp-19-12067-2019, 2019
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The differences in inverted global and regional carbon fluxes from GOSAT and OCO-2 XCO2 from 1 January to 31 December 2015 are studied. We find significant differences for inverted terrestrial carbon fluxes on both global and regional scales. Overall, GOSAT XCO2 has a better performance than OCO-2, and GOSAT data can effectively improve carbon flux estimates in the Northern Hemisphere, while OCO-2 data, with the specific version used in this study, show only slight improvement.
Xiaojin Qian, Liangyun Liu, Holly Croft, and Jingming Chen
Biogeosciences Discuss., https://doi.org/10.5194/bg-2019-228, https://doi.org/10.5194/bg-2019-228, 2019
Preprint withdrawn
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The leaf maximum carboxylation rate (Vcmax) is a key photosynthesis parameter. We attempt to investigate whether a universal and stable relationship exists between leaf Vcmax25 and chlorophyll content across different C3 plant types from a plant physiological perspective and verify it using field experiments. The results confirm that leaf chlorophyll can be a reliable proxy for estimating Vcmax25, providing an operational approach for the global mapping of Vcmax25 across different plant types.
Xufei Liu, Xiaopu Lyu, Yu Wang, Fei Jiang, and Hai Guo
Atmos. Chem. Phys., 19, 5127–5145, https://doi.org/10.5194/acp-19-5127-2019, https://doi.org/10.5194/acp-19-5127-2019, 2019
Anna Katinka Petersen, Guy P. Brasseur, Idir Bouarar, Johannes Flemming, Michael Gauss, Fei Jiang, Rostislav Kouznetsov, Richard Kranenburg, Bas Mijling, Vincent-Henri Peuch, Matthieu Pommier, Arjo Segers, Mikhail Sofiev, Renske Timmermans, Ronald van der A, Stacy Walters, Ying Xie, Jianming Xu, and Guangqiang Zhou
Geosci. Model Dev., 12, 1241–1266, https://doi.org/10.5194/gmd-12-1241-2019, https://doi.org/10.5194/gmd-12-1241-2019, 2019
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An operational multi-model forecasting system for air quality is providing daily forecasts of ozone, nitrogen oxides, and particulate matter for 37 urban areas of China. The paper presents the evaluation of the different forecasts performed during the first year of operation.
Xiaopu Lyu, Nan Wang, Hai Guo, Likun Xue, Fei Jiang, Yangzong Zeren, Hairong Cheng, Zhe Cai, Lihui Han, and Ying Zhou
Atmos. Chem. Phys., 19, 3025–3042, https://doi.org/10.5194/acp-19-3025-2019, https://doi.org/10.5194/acp-19-3025-2019, 2019
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Through analyses on the synoptic systems, pollution characteristics of O3 precursors, and modeling of local O3 formation and processes influencing O3 level, we found that this O3 pollution event was induced by a uniform pressure field over the Shandong Peninsula and also aggravated by a low-pressure trough in the last few days. This finding indicated that the NCP might be an O3 source region, which exported photochemical pollution to the adjoining regions or even to the neighboring countries.
Guy P. Brasseur, Ying Xie, Anna Katinka Petersen, Idir Bouarar, Johannes Flemming, Michael Gauss, Fei Jiang, Rostislav Kouznetsov, Richard Kranenburg, Bas Mijling, Vincent-Henri Peuch, Matthieu Pommier, Arjo Segers, Mikhail Sofiev, Renske Timmermans, Ronald van der A, Stacy Walters, Jianming Xu, and Guangqiang Zhou
Geosci. Model Dev., 12, 33–67, https://doi.org/10.5194/gmd-12-33-2019, https://doi.org/10.5194/gmd-12-33-2019, 2019
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An operational multi-model forecasting system for air quality provides daily forecasts of ozone, nitrogen oxides, and particulate matter for 37 urban areas in China. The paper presents an intercomparison of the different forecasts performed during a specific period of time and highlights recurrent differences between the model output. Pathways to improve the forecasts by the multi-model system are suggested.
Derong Zhou, Ke Ding, Xin Huang, Lixia Liu, Qiang Liu, Zhengning Xu, Fei Jiang, Congbin Fu, and Aijun Ding
Atmos. Chem. Phys., 18, 16345–16361, https://doi.org/10.5194/acp-18-16345-2018, https://doi.org/10.5194/acp-18-16345-2018, 2018
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We investigate the vertical distribution, transport characteristics, source contribution and meteorological feedback of dust, biomass burning and fossil fuel combustion aerosols for a unique pollution episode that occurred in late March 2015 in eastern Asia, based on various measurement data and modeling methods. We found that cold front played an important role in the long-range transport of different pollutants and caused a three-layer vertical structure of pollutants over eastern China.
Jun Wang, Ning Zeng, Meirong Wang, Fei Jiang, Jingming Chen, Pierre Friedlingstein, Atul K. Jain, Ziqiang Jiang, Weimin Ju, Sebastian Lienert, Julia Nabel, Stephen Sitch, Nicolas Viovy, Hengmao Wang, and Andrew J. Wiltshire
Atmos. Chem. Phys., 18, 10333–10345, https://doi.org/10.5194/acp-18-10333-2018, https://doi.org/10.5194/acp-18-10333-2018, 2018
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Based on the Mauna Loa CO2 records and TRENDY multi-model historical simulations, we investigate the different impacts of EP and CP El Niños on interannual carbon cycle variability. Composite analysis indicates that the evolutions of CO2 growth rate anomalies have three clear differences in terms of precursors (negative and neutral), amplitudes (strong and weak), and durations of peak (Dec–Apr and Oct–Jan) during EP and CP El Niños, respectively. We further discuss their terrestrial mechanisms.
Zhi-zhen Ni, Kun Luo, Yang Gao, Fei Jiang, Xiang Gao, Jian-ren Fan, and Chang-hong Chen
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2018-76, https://doi.org/10.5194/acp-2018-76, 2018
Revised manuscript not accepted
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A unique mechanism was found to modulate the high ozone episodes in Hangzhou during G20 summit: Driven by tropical cyclone convergence, prevailing north winds brought in emission sources; with invasion of tropical cycle, subsidence air and stagnant weather was induced, as well as the urban heat island effect, intensifying the ozone enhancement. Different atmospheric processes were further analyzed to elucidate the control factors of ozone formation through integrated process rate method.
Hao Wang, Xiaopu Lyu, Hai Guo, Yu Wang, Shichun Zou, Zhenhao Ling, Xinming Wang, Fei Jiang, Yangzong Zeren, Wenzhuo Pan, Xiaobo Huang, and Jin Shen
Atmos. Chem. Phys., 18, 4277–4295, https://doi.org/10.5194/acp-18-4277-2018, https://doi.org/10.5194/acp-18-4277-2018, 2018
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While oceanic air is generally thought to be clean, the air pollution over waters in proximity to the coasts is not well recognized. This research indicated that ozone was higher over South China Sea (SCS) than that in the adjacent continental area, while continental anticyclone, tropical cyclone and land breeze favored O3 formation over SCS. In addition, weaker NO titration and stronger atmospheric oxidative capacity led to higher O3 production efficiency over SCS.
Jun Wang, Ning Zeng, Meirong Wang, Fei Jiang, Hengmao Wang, and Ziqiang Jiang
Earth Syst. Dynam., 9, 1–14, https://doi.org/10.5194/esd-9-1-2018, https://doi.org/10.5194/esd-9-1-2018, 2018
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Behaviors of terrestrial ecosystems differ in different El Niños. We analyze terrestrial carbon cycle responses to two extreme El Niños (2015/16 and 1997/98), and find large differences. We find that global land–atmosphere carbon flux anomaly was about 2 times smaller in 2015/16 than in 1997/98 event, without the obvious lagged response. Then we illustrate the climatic and biological mechanisms of the different terrestrial carbon cycle responses in 2015/16 and 1997/98 El Niños regionally.
Guocan Wu and Xiaogu Zheng
Nonlin. Processes Geophys., 24, 329–341, https://doi.org/10.5194/npg-24-329-2017, https://doi.org/10.5194/npg-24-329-2017, 2017
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The accuracy of the assimilation results crucially relies on the estimate accuracy of forecast error covariance matrix in data assimilation. Ensemble Kalman filter estimates the forecast error covariance matrix as the sampling covariance matrix of the ensemble forecast states, which need to be further inflated. The experiment results on the Lorenz-96 model show that the analysis error is reduced and the analysis sensitivity to observations is improved using the proposed inflation technique.
Yang Liu, Ronggao Liu, Jan Pisek, and Jing M. Chen
Biogeosciences, 14, 1093–1110, https://doi.org/10.5194/bg-14-1093-2017, https://doi.org/10.5194/bg-14-1093-2017, 2017
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Forest overstory and understory layers differ in carbon and water cycle regimes and phenology, as well as ecosystem functions. In this paper, overstory and understory LAI values were estimated separately for global needleleaf and deciduous broadleaf forests. This work would help us better understand the seasonal patterns of forest structure, evaluate the ecosystem functions and improve the modeling of the forest carbon and water cycles.
Chengcheng Huang, Andrew J. Newman, Martyn P. Clark, Andrew W. Wood, and Xiaogu Zheng
Hydrol. Earth Syst. Sci., 21, 635–650, https://doi.org/10.5194/hess-21-635-2017, https://doi.org/10.5194/hess-21-635-2017, 2017
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This study examined the potential of snow water equivalent data assimilation to improve seasonal streamflow predictions. We examined aspects of the data assimilation system over basins with varying climates across the western US. We found that varying how the data assimilation system is implemented impacts forecast performance, and basins with good initial calibrations see less benefit. This implies that basin-specific configurations and benefits should be expected given this modeling system.
S. Zhang, X. Zheng, J. M. Chen, Z. Chen, B. Dan, X. Yi, L. Wang, and G. Wu
Geosci. Model Dev., 8, 805–816, https://doi.org/10.5194/gmd-8-805-2015, https://doi.org/10.5194/gmd-8-805-2015, 2015
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A Global Carbon Assimilation System based on the Ensemble Kalman filter (GCAS-EK) is developed for assimilating atmospheric CO2 data into an ecosystem model to simultaneously estimate the surface carbon fluxes and atmospheric CO2 distribution. This assimilation approach is similar to CarbonTracker, but with several new developments. The results showed that this assimilation approach can effectively reduce the biases and uncertainties of the carbon fluxes simulated by the ecosystem model.
K. Ding, J. Liu, A. Ding, Q. Liu, T. L. Zhao, J. Shi, Y. Han, H. Wang, and F. Jiang
Atmos. Chem. Phys., 15, 2843–2866, https://doi.org/10.5194/acp-15-2843-2015, https://doi.org/10.5194/acp-15-2843-2015, 2015
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1. High CO abundances of 300-550 ppbv is shown in aircraft MOZAIC data between 700 and 300 hPa over East Asia in three episodes. Correspondingly, elevated CO is observed in satellite MOPITT data at similar altitudes.
2. GEOS-Chem and FLEXPART simulations reveal distinct uplifting processes for CO from fires and anthropogenic sources in the cases.
3. Topography in East Asia affects uplifting of CO in different ways.
4. The new version 5 MOPITT data can help diagnose vertical transport of CO.
G. Wu, X. Yi, L. Wang, X. Liang, S. Zhang, X. Zhang, and X. Zheng
Nonlin. Processes Geophys., 21, 955–970, https://doi.org/10.5194/npg-21-955-2014, https://doi.org/10.5194/npg-21-955-2014, 2014
F. Jiang, H. M. Wang, J. M. Chen, T. Machida, L. X. Zhou, W. M. Ju, H. Matsueda, and Y. Sawa
Atmos. Chem. Phys., 14, 10133–10144, https://doi.org/10.5194/acp-14-10133-2014, https://doi.org/10.5194/acp-14-10133-2014, 2014
M. Liu, H. Wang, H. Wang, T. Oda, Y. Zhao, X. Yang, R. Zang, B. Zang, J. Bi, and J. Chen
Atmos. Chem. Phys., 13, 10873–10882, https://doi.org/10.5194/acp-13-10873-2013, https://doi.org/10.5194/acp-13-10873-2013, 2013
F. Jiang, H. W. Wang, J. M. Chen, L. X. Zhou, W. M. Ju, A. J. Ding, L. X. Liu, and W. Peters
Biogeosciences, 10, 5311–5324, https://doi.org/10.5194/bg-10-5311-2013, https://doi.org/10.5194/bg-10-5311-2013, 2013
W. P. Yuan, D. Liu, W. J. Dong, S. G. Liu, G. S. Zhou, G. R. Yu, T. B. Zhao, J. M. Feng, Z. G. Ma, J. Q. Chen, Y. Chen, S. P. Chen, S. J. Han, J. P. Huang, L. H. Li, H. Z. Liu, S. M. Liu, M. G. Ma, Y. F. Wang, J. Z. Xia, W. F. Xu, Q. Zhang, X. Q. Zhao, and L. Zhao
Biogeosciences Discuss., https://doi.org/10.5194/bgd-10-1605-2013, https://doi.org/10.5194/bgd-10-1605-2013, 2013
Revised manuscript not accepted
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Paul C. Stoy, Adam A. Cook, John E. Dore, Natascha Kljun, William Kleindl, E. N. Jack Brookshire, and Tobias Gerken
Biogeosciences, 18, 961–975, https://doi.org/10.5194/bg-18-961-2021, https://doi.org/10.5194/bg-18-961-2021, 2021
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The reintroduction of American bison creates multiple environmental benefits. Ruminants like bison also emit methane – a potent greenhouse gas – to the atmosphere, which has not been measured to date in a field setting. We measured methane efflux from an American bison herd during winter using eddy covariance. Automated cameras were used to approximate their location to calculate per-animal flux. From the measurements, bison do not emit more methane than the cattle they often replace.
Philipp A. Nauer, Eleonora Chiri, Thanavit Jirapanjawat, Chris Greening, and Perran L. M. Cook
Biogeosciences, 18, 729–737, https://doi.org/10.5194/bg-18-729-2021, https://doi.org/10.5194/bg-18-729-2021, 2021
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Jize Jiang, David S. Stevenson, Aimable Uwizeye, Giuseppe Tempio, and Mark A. Sutton
Biogeosciences, 18, 135–158, https://doi.org/10.5194/bg-18-135-2021, https://doi.org/10.5194/bg-18-135-2021, 2021
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Ammonia is a key water and air pollutant and impacts human health and climate change. Ammonia emissions mainly originate from agriculture. We find that chicken agriculture contributes to large ammonia emissions, especially in hot and wet regions. These emissions can be greatly affected by the local environment, i.e. temperature and humidity, and also by human management. We develop a model that suggests ammonia emissions from chicken farming are likely to increase under a warming climate.
Richard Wehr and Scott R. Saleska
Biogeosciences, 18, 13–24, https://doi.org/10.5194/bg-18-13-2021, https://doi.org/10.5194/bg-18-13-2021, 2021
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Water and carbon exchange between plants and the atmosphere is governed by stomata: adjustable pores in the surfaces of leaves. The combined gas conductance of all the stomata in a canopy has long been estimated using an equation that is shown here to be systematically incorrect because it relies on measurements that are generally inadequate. An alternative approach is shown to be more accurate in all probable scenarios and to imply different responses of stomatal conductance to the environment.
Bart Schilperoort, Miriam Coenders-Gerrits, César Jiménez Rodríguez, Christiaan van der Tol, Bas van de Wiel, and Hubert Savenije
Biogeosciences, 17, 6423–6439, https://doi.org/10.5194/bg-17-6423-2020, https://doi.org/10.5194/bg-17-6423-2020, 2020
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With distributed temperature sensing (DTS) we measured a vertical temperature profile in a forest, from the forest floor to above the treetops. Using this temperature profile we can see which parts of the forest canopy are colder (thus more dense) or warmer (and less dense) and study the effect this has on the suppression of turbulent mixing. This can be used to improve our knowledge of the interaction between the atmosphere and forests and improve carbon dioxide flux measurements over forests.
Yayi Niu, Yuqiang Li, Hanbo Yun, Xuyang Wang, Xiangwen Gong, Yulong Duan, and Jing Liu
Biogeosciences, 17, 6309–6326, https://doi.org/10.5194/bg-17-6309-2020, https://doi.org/10.5194/bg-17-6309-2020, 2020
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We report the results from continuous year-round CO2 observations from a sandy grassland in the Horqin Sandy Land using the eddy covariance technique. To quantify the diurnal, seasonal, and annual variation in net ecosystem CO2 exchange, gross primary productivity, and ecosystem respiration and to identify the different scales of environmental factors and the underlying mechanisms, we also explored how the annual precipitation affects the net ecosystem CO2 exchange and its components.
Gemma Purser, Julia Drewer, Mathew R. Heal, Robert A. S. Sircus, Lara K. Dunn, and James I. L. Morison
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-437, https://doi.org/10.5194/bg-2020-437, 2020
Revised manuscript accepted for BG
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Short-rotation forest plantations could help reduce greenhouse gases, but can emit biogenic volatile organic compounds. Emissions were measured at a plantation trial in Scotland. Standardised emissions of isoprene from foliage were higher from hybrid aspen than from Sitka spruce, and low from Italian alder. Emissions of total monoterpene were lower. The forest floor was only a small source. Model estimates suggest an SRF expansion of 0.7 Mha could increase total UK emissions between < 1 %–35 %.
Hélène Angot, Katelyn McErlean, Lu Hu, Dylan B. Millet, Jacques Hueber, Kaixin Cui, Jacob Moss, Catherine Wielgasz, Tyler Milligan, Damien Ketcherside, M. Syndonia Bret-Harte, and Detlev Helmig
Biogeosciences, 17, 6219–6236, https://doi.org/10.5194/bg-17-6219-2020, https://doi.org/10.5194/bg-17-6219-2020, 2020
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We report biogenic volatile organic compounds (BVOCs) ambient levels and emission rates from key vegetation species in the Alaskan arctic tundra, providing a new data set to further constrain isoprene chemistry under low NOx conditions in models. We add to the growing body of evidence that climate-induced changes in the vegetation composition will significantly affect the BVOC emission potential of the tundra, with implications for atmospheric oxidation processes and climate feedbacks.
Teresa M. Seifried, Paul Bieber, Laura Felgitsch, Julian Vlasich, Florian Reyzek, David G. Schmale III, and Hinrich Grothe
Biogeosciences, 17, 5655–5667, https://doi.org/10.5194/bg-17-5655-2020, https://doi.org/10.5194/bg-17-5655-2020, 2020
Dario Papale
Biogeosciences, 17, 5587–5598, https://doi.org/10.5194/bg-17-5587-2020, https://doi.org/10.5194/bg-17-5587-2020, 2020
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FLUXNET is a large, bottom-up, self-coordinated network of sites. It provided ecosystem–atmosphere greenhouse gas fluxes from stations around the world that were used as bases for a large number of publications and studies. Today many applications require recent updates on the data to track more closely the ecosystem responses to climate change and link ground data with satellite programs. For this reason, a new organization of FLUXNET is needed, keeping as its target the FAIR principles.
Christian Markwitz, Alexander Knohl, and Lukas Siebicke
Biogeosciences, 17, 5183–5208, https://doi.org/10.5194/bg-17-5183-2020, https://doi.org/10.5194/bg-17-5183-2020, 2020
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Agroforestry has been shown to alter the microclimate and to lead to higher carbon sequestration above ground and in the soil. In this study, we investigated the impact of agroforestry systems on system-scale evapotranspiration (ET) due to concerns about increased water losses to the atmosphere. Results showed small differences in annual sums of ET over agroforestry relative to monoculture systems, indicating that agroforestry in Germany can be a land use alternative to monoculture agriculture.
Arnaud P. Praplan, Toni Tykkä, Simon Schallhart, Virpi Tarvainen, Jaana Bäck, and Heidi Hellén
Biogeosciences, 17, 4681–4705, https://doi.org/10.5194/bg-17-4681-2020, https://doi.org/10.5194/bg-17-4681-2020, 2020
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In this paper, we study emissions of volatile organic compounds (VOCs) from three boreal tree species. Individual compounds are quantified with on-line separation analytical techniques, while the total reactivity of the emissions is measured using a custom-built instrument. On some occasions, in particular when the trees suffer from stress, the total reactivity measured is higher than the sum of the reactivity of individual compounds. This indicates that the threes emit VOCs that remain unknown.
Daniel Diaz-de-Quijano, Aleksander Vladimirovich Ageev, Elena Anatolevna Ivanova, and Olesia Valerevna Anishchenko
Biogeosciences Discuss., https://doi.org/10.5194/bg-2020-125, https://doi.org/10.5194/bg-2020-125, 2020
Revised manuscript accepted for BG
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Winter atmospheric nitrogen and phosphorus depositions were measured for the first time in the West Sayan mountains (Siberia). The low and very low atmospheric N and P depositions could be responsible for the observed lake phytoplankton N-P colimitation. We hypothesize that slight imbalances in the nutrient deposition, as expected in the context of global change (climate, forest fire regime, and anthropogenic nitrogen emissions), could have important effects on the ecology of these lakes.
June Skeeter, Andreas Christen, Andrée-Anne Laforce, Elyn Humphreys, and Greg Henry
Biogeosciences, 17, 4421–4441, https://doi.org/10.5194/bg-17-4421-2020, https://doi.org/10.5194/bg-17-4421-2020, 2020
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This study investigates carbon fluxes at Illisarvik, an artificial drained thermokarst lake basin (DTLB) in Canada's Northwest Territories. This is the first carbon balance study in a DTLB outside of Alaska. We used neural networks to identify the factors controlling fluxes and to model the effects of the controlling factors. We discuss the role of vegetation heterogeneity in fluxes, especially of methane, and we show how the carbon fluxes differ from Alaskan DTLBs.
Anne J. Hoek van Dijke, Kaniska Mallick, Martin Schlerf, Miriam Machwitz, Martin Herold, and Adriaan J. Teuling
Biogeosciences, 17, 4443–4457, https://doi.org/10.5194/bg-17-4443-2020, https://doi.org/10.5194/bg-17-4443-2020, 2020
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We investigated the link between the vegetation leaf area index (LAI) and the land–atmosphere exchange of water, energy, and carbon fluxes. We show that the correlation between the LAI and water and energy fluxes depends on the vegetation type and aridity. For carbon fluxes, however, the correlation with the LAI was strong and independent of vegetation and aridity. This study provides insight into when the vegetation LAI can be used to model or extrapolate land–atmosphere fluxes.
Jordi Vilà-Guerau de Arellano, Patrizia Ney, Oscar Hartogensis, Hugo de Boer, Kevin van Diepen, Dzhaner Emin, Geiske de Groot, Anne Klosterhalfen, Matthias Langensiepen, Maria Matveeva, Gabriela Miranda-García, Arnold F. Moene, Uwe Rascher, Thomas Röckmann, Getachew Adnew, Nicolas Brüggemann, Youri Rothfuss, and Alexander Graf
Biogeosciences, 17, 4375–4404, https://doi.org/10.5194/bg-17-4375-2020, https://doi.org/10.5194/bg-17-4375-2020, 2020
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The CloudRoots field experiment has obtained an open comprehensive observational data set that includes soil, plant, and atmospheric variables to investigate the interactions between a heterogeneous land surface and its overlying atmospheric boundary layer, including the rapid perturbations of clouds in evapotranspiration. Our findings demonstrate that in order to understand and represent diurnal variability, we need to measure and model processes from the leaf to the landscape scales.
Dean Howard, Yannick Agnan, Detlev Helmig, Yu Yang, and Daniel Obrist
Biogeosciences, 17, 4025–4042, https://doi.org/10.5194/bg-17-4025-2020, https://doi.org/10.5194/bg-17-4025-2020, 2020
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The Arctic tundra represents a vast store of carbon that may be broken down by microbial activity into greenhouse gases such as CO2 and CH4. Though microbes are less active in winter, the long duration of the cold season makes this period very important for carbon cycling. We show that, under conditions of warmer winter air temperatures and greater snowfall, deeper soils can remain warm enough to sustain significantly enhanced CH4 emission. This could have large implications for future climates.
Kristina Bohm, Joachim Ingwersen, Josipa Milovac, and Thilo Streck
Biogeosciences, 17, 2791–2805, https://doi.org/10.5194/bg-17-2791-2020, https://doi.org/10.5194/bg-17-2791-2020, 2020
Domenico Vitale, Gerardo Fratini, Massimo Bilancia, Giacomo Nicolini, Simone Sabbatini, and Dario Papale
Biogeosciences, 17, 1367–1391, https://doi.org/10.5194/bg-17-1367-2020, https://doi.org/10.5194/bg-17-1367-2020, 2020
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This work describes a data cleaning procedure for the detection of eddy covariance fluxes affected by systematic errors. We believe that the proposed procedure can serve as a basis toward a unified quality control strategy suitable for the centralized data processing pipelines, where the use of completely data-driven and scalable procedures that guarantee high-quality standards and reproducibility of the released products constitutes an essential prerequisite.
Martin Jung, Christopher Schwalm, Mirco Migliavacca, Sophia Walther, Gustau Camps-Valls, Sujan Koirala, Peter Anthoni, Simon Besnard, Paul Bodesheim, Nuno Carvalhais, Frédéric Chevallier, Fabian Gans, Daniel S. Goll, Vanessa Haverd, Philipp Köhler, Kazuhito Ichii, Atul K. Jain, Junzhi Liu, Danica Lombardozzi, Julia E. M. S. Nabel, Jacob A. Nelson, Michael O'Sullivan, Martijn Pallandt, Dario Papale, Wouter Peters, Julia Pongratz, Christian Rödenbeck, Stephen Sitch, Gianluca Tramontana, Anthony Walker, Ulrich Weber, and Markus Reichstein
Biogeosciences, 17, 1343–1365, https://doi.org/10.5194/bg-17-1343-2020, https://doi.org/10.5194/bg-17-1343-2020, 2020
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We test the approach of producing global gridded carbon fluxes based on combining machine learning with local measurements, remote sensing and climate data. We show that we can reproduce seasonal variations in carbon assimilated by plants via photosynthesis and in ecosystem net carbon balance. The ecosystem’s mean carbon balance and carbon flux trends require cautious interpretation. The analysis paves the way for future improvements of the data-driven assessment of carbon fluxes.
Samantha J. Basile, Xin Lin, William R. Wieder, Melannie D. Hartman, and Gretchen Keppel-Aleks
Biogeosciences, 17, 1293–1308, https://doi.org/10.5194/bg-17-1293-2020, https://doi.org/10.5194/bg-17-1293-2020, 2020
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Soil heterotrophic respiration (HR) is an important component of land–atmosphere carbon exchange but is difficult to observe globally. We analyzed the imprint that this flux leaves on atmospheric CO2 using a set of simulations from HR models with common inputs. Models that represent microbial processes are more variable and have stronger temperature sensitivity than those that do not. Our results show that we can use atmospheric CO2 observations to evaluate and improve models of HR.
Christopher Krich, Jakob Runge, Diego G. Miralles, Mirco Migliavacca, Oscar Perez-Priego, Tarek El-Madany, Arnaud Carrara, and Miguel D. Mahecha
Biogeosciences, 17, 1033–1061, https://doi.org/10.5194/bg-17-1033-2020, https://doi.org/10.5194/bg-17-1033-2020, 2020
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Causal inference promises new insight into biosphere–atmosphere interactions using time series only. To understand the behaviour of a specific method on such data, we used artificial and observation-based data. The observed structures are very interpretable and reveal certain ecosystem-specific behaviour, as only a few relevant links remain, in contrast to pure correlation techniques. Thus, causal inference allows to us gain well-constrained insights into processes and interactions.
Alexander J. Turner, Philipp Köhler, Troy S. Magney, Christian Frankenberg, Inez Fung, and Ronald C. Cohen
Biogeosciences, 17, 405–422, https://doi.org/10.5194/bg-17-405-2020, https://doi.org/10.5194/bg-17-405-2020, 2020
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We present the highest resolution solar-induced chlorophyll fluorescence (SIF) dataset from satellite measurements, providing previously unobservable phenomena related to plant photosynthesis. We find a strong correspondence between TROPOMI SIF and AmeriFlux GPP. We then observe a double peak in the seasonality of California's photosynthesis, not seen by traditional vegetation indices (e.g., MODIS). This is further corroborated by EOF/PC analysis.
Nicholas Cowan, Peter Levy, Andrea Moring, Ivan Simmons, Colin Bache, Amy Stephens, Joana Marinheiro, Jocelyn Brichet, Ling Song, Amy Pickard, Connie McNeill, Roseanne McDonald, Juliette Maire, Benjamin Loubet, Polina Voylokov, Mark Sutton, and Ute Skiba
Biogeosciences, 16, 4731–4745, https://doi.org/10.5194/bg-16-4731-2019, https://doi.org/10.5194/bg-16-4731-2019, 2019
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Commonly used nitrogen fertilisers, ammonium nitrate, urea and urea coated with a urease inhibitor, were applied to experimental plots. Fertilisation with ammonium nitrate supported the largest yields but also resulted in the largest nitrous oxide emissions. Urea was the largest emitter of ammonia. The coated urea did not significantly increase yields; however, ammonia emissions were substantially smaller than urea. The coated urea was the best environmentally but is economically unattractive.
Boris Bonn, Ruth-Kristina Magh, Joseph Rombach, and Jürgen Kreuzwieser
Biogeosciences, 16, 4627–4645, https://doi.org/10.5194/bg-16-4627-2019, https://doi.org/10.5194/bg-16-4627-2019, 2019
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The effect of soil water availability (SWA) on emissions of isoprenoids by trees was studied by setting up a parameterization from published data. SWA impact on isoprene emissions can be described by a growth type curve, while monoterpene emissions display a pattern reflecting plants’ stomata opening. Sesquiterpene fluxes tend to increase at the start of severe drought until resources decline. Feedbacks on atmospheric processes such as ozone and aerosol particles are further studied.
Martin Jiskra, Jeroen E. Sonke, Yannick Agnan, Detlev Helmig, and Daniel Obrist
Biogeosciences, 16, 4051–4064, https://doi.org/10.5194/bg-16-4051-2019, https://doi.org/10.5194/bg-16-4051-2019, 2019
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The tundra plays a pivotal role in Arctic mercury cycling by storing atmospheric mercury deposition and shuttling it to the Arctic Ocean. We used the isotopic fingerprint of mercury to investigate the processes controlling atmospheric mercury deposition. We found that the uptake of atmospheric mercury by vegetation was the major deposition source. Direct deposition to snow or soils only played a minor role. These results improve our understanding of Arctic mercury cycling.
Paul C. Stoy, Tarek S. El-Madany, Joshua B. Fisher, Pierre Gentine, Tobias Gerken, Stephen P. Good, Anne Klosterhalfen, Shuguang Liu, Diego G. Miralles, Oscar Perez-Priego, Angela J. Rigden, Todd H. Skaggs, Georg Wohlfahrt, Ray G. Anderson, A. Miriam J. Coenders-Gerrits, Martin Jung, Wouter H. Maes, Ivan Mammarella, Matthias Mauder, Mirco Migliavacca, Jacob A. Nelson, Rafael Poyatos, Markus Reichstein, Russell L. Scott, and Sebastian Wolf
Biogeosciences, 16, 3747–3775, https://doi.org/10.5194/bg-16-3747-2019, https://doi.org/10.5194/bg-16-3747-2019, 2019
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Key findings are the nearly optimal response of T to atmospheric water vapor pressure deficits across methods and scales. Additionally, the notion that T / ET intermittently approaches 1, which is a basis for many partitioning methods, does not hold for certain methods and ecosystems. To better constrain estimates of E and T from combined ET measurements, we propose a combination of independent measurement techniques to better constrain E and T at the ecosystem scale.
Christian Stiegler, Ana Meijide, Yuanchao Fan, Ashehad Ashween Ali, Tania June, and Alexander Knohl
Biogeosciences, 16, 2873–2890, https://doi.org/10.5194/bg-16-2873-2019, https://doi.org/10.5194/bg-16-2873-2019, 2019
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We show the response of a commercial oil palm plantation in Indonesia to the extreme El Niño–Southern Oscillation (ENSO) event in 2015. Our measurements and model suggest that without human-induced forest fires and related smoke emissions, the observed negative impact on oil palm carbon dioxide greenhouse gas fluxes, carbon accumulation and yield due to ENSO-related drought would have been less pronounced. With respect to climate change we highlight the importance of fire prevention in the area.
Sven Boese, Martin Jung, Nuno Carvalhais, Adriaan J. Teuling, and Markus Reichstein
Biogeosciences, 16, 2557–2572, https://doi.org/10.5194/bg-16-2557-2019, https://doi.org/10.5194/bg-16-2557-2019, 2019
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This study examines how limited water availability during droughts affects water-use efficiency. This metric describes how much carbon an ecosystem can assimilate for each unit of water lost by transpiration. We test how well different water-use efficiency models can capture the dynamics of transpiration decrease due to increased soil-water limitation. Accounting for the interacting effects of radiation and water limitation is necessary to accurately predict transpiration during these periods.
Raia Silvia Massad, Juliette Lathière, Susanna Strada, Mathieu Perrin, Erwan Personne, Marc Stéfanon, Patrick Stella, Sophie Szopa, and Nathalie de Noblet-Ducoudré
Biogeosciences, 16, 2369–2408, https://doi.org/10.5194/bg-16-2369-2019, https://doi.org/10.5194/bg-16-2369-2019, 2019
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Human activities strongly interfere in the land–atmosphere interactions through changes in land use and land cover changes and land management. The objectives of this review are to synthesize the existing experimental and modelling works that investigate physical, chemical, and biogeochemical interactions between land surface and the atmosphere. Greater consideration of atmospheric chemistry, through land–atmosphere interactions, as a decision parameter for land management is essential.
Yuzo Miyazaki, Divyavani Gowda, Eri Tachibana, Yoshiyuki Takahashi, and Tsutom Hiura
Biogeosciences, 16, 2181–2188, https://doi.org/10.5194/bg-16-2181-2019, https://doi.org/10.5194/bg-16-2181-2019, 2019
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Fatty alcohols (FAs) are major components of surface lipids and can act as surface-active atmospheric organic aerosols, influencing the cloud formation. We identified five secondary FAs in atmospheric aerosols at two temperate forest sites and revealed their distinct seasonal variation for the first time. Our results suggest that they originated mostly from plant wax and could be used as useful tracers for primary biological aerosol particles.
Claire Delon, Corinne Galy-Lacaux, Dominique Serça, Erwan Personne, Eric Mougin, Marcellin Adon, Valérie Le Dantec, Benjamin Loubet, Rasmus Fensholt, and Torbern Tagesson
Biogeosciences, 16, 2049–2077, https://doi.org/10.5194/bg-16-2049-2019, https://doi.org/10.5194/bg-16-2049-2019, 2019
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In the Sahel region during the wet season, CO2 and NO are released to the atmosphere, and NH3 is deposited on the soil. During the dry season, processes are strongly reduced. This paper shows the temporal variation in these soil–atmosphere exchanges of trace gases for 2 years, their sharp increase when the first rains fall onto dry soils, and how microbial processes are involved. We use a modelling approach, which is necessary when continuous measurements are not possible in remote regions.
Anne Sofie Lansø, Thomas Luke Smallman, Jesper Heile Christensen, Mathew Williams, Kim Pilegaard, Lise-Lotte Sørensen, and Camilla Geels
Biogeosciences, 16, 1505–1524, https://doi.org/10.5194/bg-16-1505-2019, https://doi.org/10.5194/bg-16-1505-2019, 2019
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Although coastal regions only amount to 7 % of the global oceans, their contribution to the global oceanic surface exchange of CO2 is much greater. In this study, we gain detailed insight into how these coastal marine fluxes compare to CO2 exchange from coastal land regions. Annually, the coastal marine exchanges are smaller than the total uptake of CO2 from the land surfaces within the study area but comparable in size to terrestrial fluxes from individual land cover classes of the region.
Ravshan Eshonkulov, Arne Poyda, Joachim Ingwersen, Hans-Dieter Wizemann, Tobias K. D. Weber, Pascal Kremer, Petra Högy, Alim Pulatov, and Thilo Streck
Biogeosciences, 16, 521–540, https://doi.org/10.5194/bg-16-521-2019, https://doi.org/10.5194/bg-16-521-2019, 2019
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We compared the energy balance closure (EBC) under varying environmental conditions and investigated a wide range of possible reasons for the energy imbalance. As measures for the imbalance, we used ordinary linear regression, the energy balance ratio (EBR), and the energy residual. The EBR was also investigated as a function of buoyancy, friction velocity, and atmospheric stability. Moreover, the relationship between the EBC and flux source area or footprint was also investigated.
Juha-Pekka Tuovinen, Mika Aurela, Juha Hatakka, Aleksi Räsänen, Tarmo Virtanen, Juha Mikola, Viktor Ivakhov, Vladimir Kondratyev, and Tuomas Laurila
Biogeosciences, 16, 255–274, https://doi.org/10.5194/bg-16-255-2019, https://doi.org/10.5194/bg-16-255-2019, 2019
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We analysed ecosystem-scale measurements of methane exchange between Arctic tundra and the atmosphere, taking into account the large variations in vegetation and soil properties. The measurements are spatial averages, but using meteorological and statistical modelling techniques we could estimate methane emissions for different land cover types and quantify how well the measurements correspond to the spatial variability. This provides a more accurate estimate of the regional methane emission.
Benjamin Gaubert, Britton B. Stephens, Sourish Basu, Frédéric Chevallier, Feng Deng, Eric A. Kort, Prabir K. Patra, Wouter Peters, Christian Rödenbeck, Tazu Saeki, David Schimel, Ingrid Van der Laan-Luijkx, Steven Wofsy, and Yi Yin
Biogeosciences, 16, 117–134, https://doi.org/10.5194/bg-16-117-2019, https://doi.org/10.5194/bg-16-117-2019, 2019
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We have compared global carbon budgets calculated from numerical inverse models and CO2 observations, and evaluated how these systems reproduce vertical gradients in atmospheric CO2 from aircraft measurements. We found that available models have converged on near-neutral tropical total fluxes for several decades, implying consistent sinks in intact tropical forests, and that assumed fossil fuel emissions and predicted atmospheric growth rates are now the dominant axes of disagreement.
Archana Dayalu, J. William Munger, Steven C. Wofsy, Yuxuan Wang, Thomas Nehrkorn, Yu Zhao, Michael B. McElroy, Chris P. Nielsen, and Kristina Luus
Biogeosciences, 15, 6713–6729, https://doi.org/10.5194/bg-15-6713-2018, https://doi.org/10.5194/bg-15-6713-2018, 2018
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Accounting for the vegetation signal is critical for comprehensive CO2 budget assessment in China. We model and evaluate hourly vegetation carbon dioxide (CO2) exchange (mass per unit area per unit time) in northern China from 2005 to 2009. The model is driven by satellite and meteorological data, is linked to ground-level ecosystem observations, and is applicable to other time periods. We find vegetation uptake of CO2 in summer is comparable to emissions from fossil fuels in northern China.
Sophia Walther, Luis Guanter, Birgit Heim, Martin Jung, Gregory Duveiller, Aleksandra Wolanin, and Torsten Sachs
Biogeosciences, 15, 6221–6256, https://doi.org/10.5194/bg-15-6221-2018, https://doi.org/10.5194/bg-15-6221-2018, 2018
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We explored the timing of the peak of the short annual growing season in tundra ecosystems as indicated by an extensive suite of satellite indicators of vegetation productivity. Delayed peak greenness compared to peak photosynthesis is consistently found across years and land-cover classes. Plants also experience growth after optimal conditions for assimilation regarding light and temperature have passed. Our results have implications for the modelling of the circumpolar carbon balance.
Stefano Manzoni, Petr Čapek, Philipp Porada, Martin Thurner, Mattias Winterdahl, Christian Beer, Volker Brüchert, Jan Frouz, Anke M. Herrmann, Björn D. Lindahl, Steve W. Lyon, Hana Šantrůčková, Giulia Vico, and Danielle Way
Biogeosciences, 15, 5929–5949, https://doi.org/10.5194/bg-15-5929-2018, https://doi.org/10.5194/bg-15-5929-2018, 2018
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Carbon fixed by plants and phytoplankton through photosynthesis is ultimately stored in soils and sediments or released to the atmosphere during decomposition of dead biomass. Carbon-use efficiency is a useful metric to quantify the fate of carbon – higher efficiency means higher storage and lower release to the atmosphere. Here we summarize many definitions of carbon-use efficiency and study how this metric changes from organisms to ecosystems and from terrestrial to aquatic environments.
Gerardo Fratini, Simone Sabbatini, Kevin Ediger, Brad Riensche, George Burba, Giacomo Nicolini, Domenico Vitale, and Dario Papale
Biogeosciences, 15, 5473–5487, https://doi.org/10.5194/bg-15-5473-2018, https://doi.org/10.5194/bg-15-5473-2018, 2018
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Using a simulation study and field data, we quantify the biases that can be introduced in fluxes measured by eddy covariance (EC) if the raw high-frequency data are affected by random and systematic timing misalignments. Our study was motivated by the increasingly widespread adoption of fully digital EC systems potentially subject to such timing errors. We found biases as large as 10 %. We further propose a test to evaluate EC data logging systems for their time synchronization capabilities.
Jason A. Ducker, Christopher D. Holmes, Trevor F. Keenan, Silvano Fares, Allen H. Goldstein, Ivan Mammarella, J. William Munger, and Jordan Schnell
Biogeosciences, 15, 5395–5413, https://doi.org/10.5194/bg-15-5395-2018, https://doi.org/10.5194/bg-15-5395-2018, 2018
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We have developed an accurate method (SynFlux) to estimate ozone deposition and stomatal uptake across 103 flux tower sites (43 US, 60 Europe), where ozone concentrations and fluxes have not been measured. In all, the SynFlux public dataset provides monthly values of ozone dry deposition for 926 site years across a wide array of ecosystems. The SynFlux dataset will promote further applications to ecosystem, air quality, or climate modeling across the geoscience community.
Carmen Emmel, Annina Winkler, Lukas Hörtnagl, Andrew Revill, Christof Ammann, Petra D'Odorico, Nina Buchmann, and Werner Eugster
Biogeosciences, 15, 5377–5393, https://doi.org/10.5194/bg-15-5377-2018, https://doi.org/10.5194/bg-15-5377-2018, 2018
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It is of great interest to know whether croplands act as a net source or sink of atmospheric CO2 and if soil carbon (C) stocks are preserved over long timescales due to the role of C in soil fertility. For a cropland in Switzerland it was found that managing the field under the Swiss framework of the Proof of Ecological Performance (PEP) resulted in soil C losses of 18.0 %. Additional efforts are needed to bring Swiss management practices closer to the goal of preserving soil C in the long term.
Thomas Wutzler, Antje Lucas-Moffat, Mirco Migliavacca, Jürgen Knauer, Kerstin Sickel, Ladislav Šigut, Olaf Menzer, and Markus Reichstein
Biogeosciences, 15, 5015–5030, https://doi.org/10.5194/bg-15-5015-2018, https://doi.org/10.5194/bg-15-5015-2018, 2018
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Net fluxes of carbon dioxide at the ecosystem level measured by eddy covariance are a main source for understanding biosphere–atmosphere interactions. However, there is a need for more usable and extensible tools for post-processing steps of the half-hourly flux data. Therefore, we developed the REddyProc package, providing data filtering, gap filling, and flux partitioning. The extensible functions are compatible with state-of-the-art tools but allow easier integration in extended analysis.
Matthew N. Hayek, Marcos Longo, Jin Wu, Marielle N. Smith, Natalia Restrepo-Coupe, Raphael Tapajós, Rodrigo da Silva, David R. Fitzjarrald, Plinio B. Camargo, Lucy R. Hutyra, Luciana F. Alves, Bruce Daube, J. William Munger, Kenia T. Wiedemann, Scott R. Saleska, and Steven C. Wofsy
Biogeosciences, 15, 4833–4848, https://doi.org/10.5194/bg-15-4833-2018, https://doi.org/10.5194/bg-15-4833-2018, 2018
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We investigated the roles that weather and forest disturbances like drought play in shaping changes in ecosystem photosynthesis and carbon exchange in an Amazon forest. We discovered that weather largely influenced differences between years, but a prior drought, which occurred 3 years before measurements started, likely hampered photosynthesis in the first year. This is the first atmospheric evidence that drought can have legacy impacts on Amazon forest photosynthesis.
Anne-Cyrielle Genard-Zielinski, Christophe Boissard, Elena Ormeño, Juliette Lathière, Ilja M. Reiter, Henri Wortham, Jean-Philippe Orts, Brice Temime-Roussel, Bertrand Guenet, Svenja Bartsch, Thierry Gauquelin, and Catherine Fernandez
Biogeosciences, 15, 4711–4730, https://doi.org/10.5194/bg-15-4711-2018, https://doi.org/10.5194/bg-15-4711-2018, 2018
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From seasonal in situ observations on how a Mediterranean ecosystem responds to drought, a specific isoprene emission (ER, emission rates) algorithm was developed, upon which 2100 projections (IPCC RCP2.6 and RCP8.5 scenarios) were made. Emission rates were found to be mainly sensitive to future temperature changes and poorly represented by current empirical emission models. Drought was found to aggravate thermal stress on emission rates.
Vivek K. Arora, Joe R. Melton, and David Plummer
Biogeosciences, 15, 4683–4709, https://doi.org/10.5194/bg-15-4683-2018, https://doi.org/10.5194/bg-15-4683-2018, 2018
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Earth system models (ESMs) project future changes in climate in response to changes in anthropogenic emissions of greenhouse gases (GHGs). However, before this can be achieved the natural fluxes of a given GHG must also be modelled. This paper evaluates the natural methane fluxes simulated by the CLASS-CTEM model (which is the land component of the Canadian ESM) against observations to show that the simulated methane emissions from wetlands and fires, and soil uptake of methane are realistic.
Karl Voglmeier, Markus Jocher, Christoph Häni, and Christof Ammann
Biogeosciences, 15, 4593–4608, https://doi.org/10.5194/bg-15-4593-2018, https://doi.org/10.5194/bg-15-4593-2018, 2018
Luke D. Schiferl, Colette L. Heald, and David Kelly
Biogeosciences, 15, 4301–4315, https://doi.org/10.5194/bg-15-4301-2018, https://doi.org/10.5194/bg-15-4301-2018, 2018
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To understand future food security, it is critical to develop realistic crop models with reliable sensitivity to environmental factors. We find that particulate matter (PM) causes a significant, but smaller, enhancement for global wheat and rice production than estimated without nutrient and physiological limitations imposed by a crop model. In contrast, maize grows near its physiological maximum, with little enhancement from PM. Nitrogen deposition leads to a small increase in crop production.
Guillaume Soulet, Robert G. Hilton, Mark H. Garnett, Mathieu Dellinger, Thomas Croissant, Mateja Ogrič, and Sébastien Klotz
Biogeosciences, 15, 4087–4102, https://doi.org/10.5194/bg-15-4087-2018, https://doi.org/10.5194/bg-15-4087-2018, 2018
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Oxidative weathering of sedimentary rocks can release carbon dioxide to the atmosphere. Here, we designed a chamber-based method to measure these CO2 emissions directly for the first time. The chamber is drilled in the rock and allows us to collect the CO2 to fingerprint its source using carbon isotopes. We tested our method in Draix (France). The measured CO2 fluxes were substantial, with ~20% originating from oxidation of the rock organic matter and ~80% from dissolution of carbonate minerals.
Eliane G. Alves, Julio Tóta, Andrew Turnipseed, Alex B. Guenther, José Oscar W. Vega Bustillos, Raoni A. Santana, Glauber G. Cirino, Julia V. Tavares, Aline P. Lopes, Bruce W. Nelson, Rodrigo A. de Souza, Dasa Gu, Trissevgeni Stavrakou, David K. Adams, Jin Wu, Scott Saleska, and Antonio O. Manzi
Biogeosciences, 15, 4019–4032, https://doi.org/10.5194/bg-15-4019-2018, https://doi.org/10.5194/bg-15-4019-2018, 2018
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This study shows that leaf quantity and leaf age have an important effect on seasonal changes in isoprene emissions and that these could play an even more important role in regulating ecosystem isoprene fluxes than light and temperature at seasonal timescales in tropical forests. These results bring novelty and new insight for future research because in the past leaf phenology was not considered as an important factor that controls biological processes in the tropics.
Cited articles
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Short summary
Ecological models often suffer from substantial biases due to inaccurate simulations of complex ecological processes. We introduce a set of scaling factors (parameters) for an ecological model on the basis of plant functional type (PFT) and latitudes. A global carbon assimilation system (GCAS-DOM) is developed by employing a dual optimization method (DOM) to invert the time-dependent ecological model parameter state and the net carbon flux state on 1 degree grid cells simultaneously.
Ecological models often suffer from substantial biases due to inaccurate simulations of complex...
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