2022
Murray-Tortarolo, Guillermo; Poulter, Benjamin; Vargas, Rodrigo; Hayes, Daniel; Michalak, Anna M.; Williams, Christopher; Windham-Myers, Lisamarie; Wang, Jonathan A.; Wickland, Kimberly P.; Butman, David; Tian, Hanqin; Sitch, Stephen; Friedlingstein, Pierre; O’Sullivan, Mike; Briggs, Peter; Arora, Vivek; Lombardozzi, Danica; Jain, Atul K.; Yuan, Wenping; Séférian, Roland; Nabel, Julia; Wiltshire, Andy; Arneth, Almut; Lienert, Sebastian; Zaehle, Sönke; Bastrikov, Vladislav; Goll, Daniel; Vuichard, Nicolas; Walker, Anthony; Kato, Etsushi; Yue, Xu; Zhang, Zhen; Chaterjee, Abhishek; Kurz, Werner
A Process-Model Perspective on Recent Changes in the Carbon Cycle of North America Journal Article
In: Journal of Geophysical Research: Biogeosciences, vol. 127, no. 9, 2022.
Links | BibTeX | Tags: carbon cycle, DGVMs
@article{MurrayTortarolo2022,
title = {A Process-Model Perspective on Recent Changes in the Carbon Cycle of North America},
author = {Guillermo Murray-Tortarolo and Benjamin Poulter and Rodrigo Vargas and Daniel Hayes and Anna M. Michalak and Christopher Williams and Lisamarie Windham-Myers and Jonathan A. Wang and Kimberly P. Wickland and David Butman and Hanqin Tian and Stephen Sitch and Pierre Friedlingstein and Mike O'Sullivan and Peter Briggs and Vivek Arora and Danica Lombardozzi and Atul K. Jain and Wenping Yuan and Roland Séférian and Julia Nabel and Andy Wiltshire and Almut Arneth and Sebastian Lienert and Sönke Zaehle and Vladislav Bastrikov and Daniel Goll and Nicolas Vuichard and Anthony Walker and Etsushi Kato and Xu Yue and Zhen Zhang and Abhishek Chaterjee and Werner Kurz},
url = {https://doi.org/10.1029/2022jg006904},
doi = {10.1029/2022jg006904},
year = {2022},
date = {2022-09-01},
urldate = {2022-09-01},
journal = {Journal of Geophysical Research: Biogeosciences},
volume = {127},
number = {9},
publisher = {American Geophysical Union (AGU)},
keywords = {carbon cycle, DGVMs},
pubstate = {published},
tppubtype = {article}
}
2016
Murray-Tortarolo, G; Friedlingstein, P; Sitch, S; Jaramillo, V J; Murguia-Flores, F; Anav, A; Liu, Y; Arneth, A; Arvanitis, A; Harper, A; Jain, A; Kato, E; Koven, C; Poulter, B; Stocker, B D; Wiltshire, A; Zaehle, S; Zeng, N
The carbon cycle in Mexico: Past, present and future of C stocks and fluxes Journal Article
In: Biogeosciences, vol. 13, no. 1, pp. 223–238, 2016, ISSN: 17264189.
Abstract | Links | BibTeX | Tags: carbon cycle, Mexico
@article{Murray-Tortarolo2016,
title = {The carbon cycle in Mexico: Past, present and future of C stocks and fluxes},
author = {G Murray-Tortarolo and P Friedlingstein and S Sitch and V J Jaramillo and F Murguia-Flores and A Anav and Y Liu and A Arneth and A Arvanitis and A Harper and A Jain and E Kato and C Koven and B Poulter and B D Stocker and A Wiltshire and S Zaehle and N Zeng},
doi = {10.5194/bg-13-223-2016},
issn = {17264189},
year = {2016},
date = {2016-01-01},
journal = {Biogeosciences},
volume = {13},
number = {1},
pages = {223--238},
abstract = {textlessptextgreaterWe modelled the carbon (C) cycle in Mexico with a process-based approach. We used different available products (satellite data, field measurements, models and flux towers) to estimate C stocks and fluxes in the country at three different time frames: present (defined as the period 2000–2005), the past century (1901–2000) and the remainder of this century (2010–2100). Our estimate of the gross primary productivity (GPP) for the country was 2137 ± 1023 Tg C yrtextlesssuptextgreater−1textless/suptextgreater and a total C stock of 34 506 ± 7483 Tg C, with 20 347 ± 4622 Pg C in vegetation and 14 159 ± 3861 in the soil. textlessbrtextgreatertextless/brtextgreater Contrary to other current estimates for recent decades, our results showed that Mexico was a C sink over the period 1990–2009 (+31 Tg C yrtextlesssuptextgreater−1textless/suptextgreater) and that C accumulation over the last century amounted to 1210 ± 1040 Tg C. We attributed this sink to the COtextlesssubtextgreater2textless/subtextgreater fertilization effect on GPP, which led to an increase of 3408 ± 1060 Tg C, while both climate and land use reduced the country C stocks by −458 ± 1001 and −1740 ± 878 Tg C, respectively. Under different future scenarios the C sink will likely continue over 21st century, with decreasing C uptake as the climate forcing becomes more extreme. Our work provides valuable insights on relevant driving processes of the C-cycle such as the role of drought in marginal lands (e.g. grasslands and shrublands) and the impact of climate change on the mean residence time of C in tropical ecosystems.textless/ptextgreater},
keywords = {carbon cycle, Mexico},
pubstate = {published},
tppubtype = {article}
}
2015
Sitch, S; Friedlingstein, P; Gruber, N; Jones, S D; Murray-Tortarolo, G; Ahlström, A; Doney, S C; Graven, H; Heinze, C; Huntingford, C; Levis, S; Levy, P E; Lomas, M; Poulter, B; Viovy, N; Zaehle, S; Zeng, N; Arneth, A; Bonan, G; Bopp, L; Canadell, J G; Chevallier, F; Ciais, P; Ellis, R; Gloor, M; Peylin, P; Piao, S L; Quéré, C Le; Smith, B; Zhu, Z; Myneni, R
Recent trends and drivers of regional sources and sinks of carbon dioxide Journal Article
In: Biogeosciences, vol. 12, no. 3, pp. 653–679, 2015, ISSN: 17264189.
Abstract | Links | BibTeX | Tags: carbon cycle, DGVMs
@article{Sitch2015,
title = {Recent trends and drivers of regional sources and sinks of carbon dioxide},
author = {S Sitch and P Friedlingstein and N Gruber and S D Jones and G Murray-Tortarolo and A Ahlström and S C Doney and H Graven and C Heinze and C Huntingford and S Levis and P E Levy and M Lomas and B Poulter and N Viovy and S Zaehle and N Zeng and A Arneth and G Bonan and L Bopp and J G Canadell and F Chevallier and P Ciais and R Ellis and M Gloor and P Peylin and S L Piao and C {Le Quéré} and B Smith and Z Zhu and R Myneni},
doi = {10.5194/bg-12-653-2015},
issn = {17264189},
year = {2015},
date = {2015-01-01},
journal = {Biogeosciences},
volume = {12},
number = {3},
pages = {653--679},
abstract = {textlessptextgreatertextlessstrongtextgreaterAbstract.textless/strongtextgreater The land and ocean absorb on average just over half of the anthropogenic emissions of carbon dioxide (COtextlesssubtextgreater2textless/subtextgreater) every year. These COtextlesssubtextgreater2textless/subtextgreater "sinks" are modulated by climate change and variability. Here we use a suite of nine dynamic global vegetation models (DGVMs) and four ocean biogeochemical general circulation models (OBGCMs) to estimate trends driven by global and regional climate and atmospheric COtextlesssubtextgreater2textless/subtextgreater in land and oceanic COtextlesssubtextgreater2textless/subtextgreater exchanges with the atmosphere over the period 1990–2009, to attribute these trends to underlying processes in the models, and to quantify the uncertainty and level of inter-model agreement. The models were forced with reconstructed climate fields and observed global atmospheric COtextlesssubtextgreater2textless/subtextgreater; land use and land cover changes are not included for the DGVMs. Over the period 1990–2009, the DGVMs simulate a mean global land carbon sink of −2.4 ± 0.7 Pg C yrtextlesssuptextgreater−1textless/suptextgreater with a small significant trend of −0.06 ± 0.03 Pg C yrtextlesssuptextgreater−2textless/suptextgreater (increasing sink). Over the more limited period 1990–2004, the ocean models simulate a mean ocean sink of −2.2 ± 0.2 Pg C yrtextlesssuptextgreater−1textless/suptextgreater with a trend in the net C uptake that is indistinguishable from zero (−0.01 ± 0.02 Pg C yrtextlesssuptextgreater−2textless/suptextgreater). The two ocean models that extended the simulations until 2009 suggest a slightly stronger, but still small, trend of −0.02 ± 0.01 Pg C yrtextlesssuptextgreater−2textless/suptextgreater. Trends from land and ocean models compare favourably to the land greenness trends from remote sensing, atmospheric inversion results, and the residual land sink required to close the global carbon budget. Trends in the land sink are driven by increasing net primary production (NPP), whose statistically significant trend of 0.22 ± 0.08 Pg C yrtextlesssuptextgreater−2textless/suptextgreater exceeds a significant trend in heterotrophic respiration of 0.16 ± 0.05 Pg C yrtextlesssuptextgreater−2textless/suptextgreater – primarily as a consequence of widespread COtextlesssubtextgreater2textless/subtextgreater fertilisation of plant production. Most of the land-based trend in simulated net carbon uptake originates from natural ecosystems in the tropics (−0.04 ± 0.01 Pg C yrtextlesssuptextgreater−2textless/suptextgreater), with almost no trend over the northern land region, where recent warming and reduced rainfall offsets the positive impact of elevated atmospheric COtextlesssubtextgreater2textless/subtextgreater and changes in growing season length on carbon storage. The small uptake trend in the ocean models emerges because climate variability and change, and in particular increasing sea surface temperatures, tend to counter$backslash$$backslash$-act the trend in ocean uptake driven by the increase in atmospheric COtextlesssubtextgreater2textless/subtextgreater. Large uncertainty remains in the magnitude and sign of modelled carbon trends in several regions, as well as regarding the influence of land use and land cover changes on regional trends.textless/ptextgreater},
keywords = {carbon cycle, DGVMs},
pubstate = {published},
tppubtype = {article}
}
2014
Valentini, R; Arneth, A; Bombelli, A; Castaldi, S; Gatti, R Cazzolla; Chevallier, F; Ciais, P; Grieco, E; Hartmann, J; Henry, M; Houghton, R A; Jung, M; Kutsch, W L; Malhi, Y; Mayorga, E; Merbold, L; Murray-Tortarolo, G; Papale, D; Peylin, P; Poulter, B; Raymond, P A; Santini, M; Sitch, S; Laurin, G Vaglio; Werf, G R Van Der; Williams, C A; Scholes, R J
A full greenhouse gases budget of africa: Synthesis, uncertainties, and vulnerabilities Journal Article
In: Biogeosciences, vol. 11, no. 2, pp. 381–407, 2014, ISSN: 17264170.
Abstract | Links | BibTeX | Tags: carbon cycle, DGVMs
@article{Valentini2014,
title = {A full greenhouse gases budget of africa: Synthesis, uncertainties, and vulnerabilities},
author = {R Valentini and A Arneth and A Bombelli and S Castaldi and R {Cazzolla Gatti} and F Chevallier and P Ciais and E Grieco and J Hartmann and M Henry and R A Houghton and M Jung and W L Kutsch and Y Malhi and E Mayorga and L Merbold and G Murray-Tortarolo and D Papale and P Peylin and B Poulter and P A Raymond and M Santini and S Sitch and G {Vaglio Laurin} and G R {Van Der Werf} and C A Williams and R J Scholes},
doi = {10.5194/bg-11-381-2014},
issn = {17264170},
year = {2014},
date = {2014-01-01},
journal = {Biogeosciences},
volume = {11},
number = {2},
pages = {381--407},
abstract = {textlessptextgreatertextlessstrongtextgreaterAbstract.textless/strongtextgreater This paper, developed under the framework of the RECCAP initiative, aims at providing improved estimates of the carbon and GHG (COtextlesssubtextgreater2textless/subtextgreater, CHtextlesssubtextgreater4textless/subtextgreater and Ntextlesssubtextgreater2textless/subtextgreaterO) balance of continental Africa. The various components and processes of the African carbon and GHG budget are considered, existing data reviewed, and new data from different methodologies (inventories, ecosystem flux measurements, models, and atmospheric inversions) presented. Uncertainties are quantified and current gaps and weaknesses in knowledge and monitoring systems described in order to guide future requirements. The majority of results agree that Africa is a small sink of carbon on an annual scale, with an average value of −0.61 ± 0.58 Pg C yrtextlesssuptextgreater−1textless/suptextgreater. Nevertheless, the emissions of CHtextlesssubtextgreater4textless/subtextgreater and Ntextlesssubtextgreater2textless/subtextgreaterO may turn Africa into a net source of radiative forcing in COtextlesssubtextgreater2textless/subtextgreater equivalent terms. At sub-regional level, there is significant spatial variability in both sources and sinks, due to the diversity of biomes represented and differences in the degree of anthropic impacts. Southern Africa is the main source region; while central Africa, with its evergreen tropical forests, is the main sink. Emissions from land-use change in Africa are significant (around 0.32 ± 0.05 Pg C yrtextlesssuptextgreater−1textless/suptextgreater), even higher than the fossil fuel emissions: this is a unique feature among all the continents. There could be significant carbon losses from forest land even without deforestation, resulting from the impact of selective logging. Fires play a significant role in the African carbon cycle, with 1.03 ± 0.22 Pg C yrtextlesssuptextgreater−1textless/suptextgreater of carbon emissions, and 90% originating in savannas and dry woodlands. A large portion of the wild fire emissions are compensated by COtextlesssubtextgreater2textless/subtextgreater uptake during the growing season, but an uncertain fraction of the emission from wood harvested for domestic use is not. Most of these fluxes have large interannual variability, on the order of ±0.5 Pg C yrtextlesssuptextgreater−1textless/suptextgreater in standard deviation, accounting for around 25% of the year-to-year variation in the global carbon budget. textlessbrtextgreatertextlessbrtextgreater Despite the high uncertainty, the estimates provided in this paper show the important role that Africa plays in the global carbon cycle, both in terms of absolute contribution, and as a key source of interannual variability.textless/ptextgreater},
keywords = {carbon cycle, DGVMs},
pubstate = {published},
tppubtype = {article}
}