Drought sensitivity of Amazonian carbon balance revealed by atmospheric measurements

Gatti, Luciana V.; Gloor, M.; Miller, J. B.; Doughty, Christopher E.; Malhi, Yadvinder; Domingues, Lucas G.; Basso, Luana S.; Martinewski, Alexandre; Correia, Caio; Borges, V.F.; Freitas, Sérgio de; Braz, Rodrigo; Anderson, Liana O.; Rocha, Humberto Ribeiro da; Grace, John; Phillips, Oliver L.; Lloyd, J.

doi:10.1038/nature12957

Cited by 456 publications

(546 citation statements)

References 43 publications

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“…Such observations can also be used to test remote-sensing measurement from space or from the surface and bring them on the same scale as the in situ surface measurements. Aircraft measurements have been undertaken in various regions either during campaigns (Wofsy, 2011;Beck et al, 2012;Chang et al, 2014;Paris et al, 2010) or in a recurrent mode using small aircrafts in the planetary boundary layer Umezawa et al, 2014;Gatti et al, 2014) and commercial aircrafts (Schuck et al, 2012;Brenninkmeijer et al, 2007;Umezawa et al, 2012Umezawa et al, , 2014Machida et al, 2008). Balloons can carry in situ instruments (e.g.…”

Section: Other Atmospheric Observationsmentioning

confidence: 99%

The global methane budget 2000–2012

Saunois

Bousquet

Poulter

et al. 2016

Earth Syst. Sci. Data

945

733

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Abstract. The global methane (CH 4 ) budget is becoming an increasingly important component for managing realistic pathways to mitigate climate change. This relevance, due to a shorter atmospheric lifetime and a stronger warming potential than carbon dioxide, is challenged by the still unexplained changes of atmospheric CH 4 over the past decade. Emissions and concentrations of CH 4 are continuing to increase, making CH 4 the second most important human-induced greenhouse gas after carbon dioxide. Two major difficulties in reducing uncertainties come from the large variety of diffusive CH 4 sources that overlap geographically, and from the destruction of CH 4 by the very short-lived hydroxyl radical (OH). To address these difficulties, we have established a consortium of multi-disciplinary scientists under the umbrella of the Global Carbon Project to synthesize and stimulate research on the methane cycle, and producing regular (∼ biennial) updates of the global methane budget. This consortium includes atmospheric physicists and chemists, biogeochemists of surface and marine emissions, and socio-economists who study anthropogenic emissions. Following Kirschke et al. (2013), we propose here the first version of a living review paper that integrates results of top-down studies (exploiting atmospheric observations within an atmospheric inverse-modelling framework) and bottom-up models, inventories and data-driven approaches (including process-based models for estimating land surface emissions and atmospheric chemistry, and inventories for anthropogenic emissions, data-driven extrapolations). . Top-down inversions consistently infer lower emissions in China (∼ 58 Tg CH 4 yr −1 , range 51-72, −14 %) and higher emissions in Africa (86 Tg CH 4 yr −1 , range 73-108, +19 %) than bottom-up values used as prior estimates. Overall, uncertainties for anthropogenic emissions appear smaller than those from natural sources, and the uncertainties on source categories appear larger for top-down inversions than for bottom-up inventories and models.The most important source of uncertainty on the methane budget is attributable to emissions from wetland and other inland waters. We show that the wetland extent could contribute 30-40 % on the estimated range for wetland emissions. Other priorities for improving the methane budget include the following: (i) the development of process-based models for inland-water emissions, (ii) the intensification of methane observations at local scale (flux measurements) to constrain bottom-up land surface models, and at regional scale (surface networks and satellites) to constrain top-down inversions, (iii) improvements in the estimation of atmospheric loss by OH, and (iv) improvements of the transport models integrated in top-down inversions.

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Section: Other Atmospheric Observationsmentioning

confidence: 99%

The global methane budget 2000–2012

Saunois

Bousquet

Poulter

et al. 2016

Earth Syst. Sci. Data

945

733

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“…In the more humid Western part of the basin, surface incoming radiation, evapotranspiration, and photosynthesis all tend to peak in the dry season (15-17), whereas GCMs simulate peaks of those fluxes in the wet season (10, 11). Those issues might be related to the representation of convection (1,2,4,5,13,14) and vegetation water stress (6)(7)(8)(15)(16)(17) in GCMs.We here show that we can represent the Amazonian climate using a strategy opposite to GCMs in which we resolve convection and parameterize the large-scale circulation (Methods). The simulations lack many of the biases observed in GCMs and more accurately capture the differences between the dry and wet season of the Amazon in surface heat fluxes and precipitation.…”

mentioning

confidence: 99%

“…Besides the difficulty of estimating carbon pools (1-3), our incapacity to correctly predict CO 2 fluxes in the continental tropics largely results from inaccurate simulation of the tropical climate (1,2,4,5). More frequent and more intense droughts in particular are expected to affect the future health of the Amazon and its capacity to act as a major carbon sink (6)(7)(8). The land surface is not isolated, however, but interacts with the weather and climate through a series of land−atmosphere feedback loops, which couple the energy, carbon, and water cycles through stomata regulation and boundary layer mediation (9).…”

mentioning

confidence: 99%

“…In the more humid Western part of the basin, surface incoming radiation, evapotranspiration, and photosynthesis all tend to peak in the dry season (15)(16)(17), whereas GCMs simulate peaks of those fluxes in the wet season (10,11). Those issues might be related to the representation of convection (1,2,4,5,13,14) and vegetation water stress (6)(7)(8)(15)(16)(17) in GCMs.…”

mentioning

confidence: 99%

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Fog and rain in the Amazon

Anber

Gentine

Wang

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

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The diurnal and seasonal water cycles in the Amazon remain poorly simulated in general circulation models, exhibiting peak evapotranspiration in the wrong season and rain too early in the day. We show that those biases are not present in cloud-resolving simulations with parameterized large-scale circulation. The difference is attributed to the representation of the morning fog layer, and to more accurate characterization of convection and its coupling with large-scale circulation. The morning fog layer, present in the wet season but absent in the dry season, dramatically increases cloud albedo, which reduces evapotranspiration through its modulation of the surface energy budget. These results highlight the importance of the coupling between the energy and hydrological cycles and the key role of cloud albedo feedback for climates over tropical continents.cloud-resolving models T ropical forests, and the Amazon in particular, are the biggest terrestrial CO 2 sinks on the planet, accounting for about 30% of the total net primary productivity in terrestrial ecosystems. Hence, the climate of the Amazon is of particular importance for the fate of global CO 2 concentration in the atmosphere (1). Besides the difficulty of estimating carbon pools (1-3), our incapacity to correctly predict CO 2 fluxes in the continental tropics largely results from inaccurate simulation of the tropical climate (1, 2, 4, 5). More frequent and more intense droughts in particular are expected to affect the future health of the Amazon and its capacity to act as a major carbon sink (6-8). The land surface is not isolated, however, but interacts with the weather and climate through a series of land−atmosphere feedback loops, which couple the energy, carbon, and water cycles through stomata regulation and boundary layer mediation (9).Current General Circulation Models (GCMs) fail to correctly represent some of the key features of the Amazon climate. In particular, they (i) underestimate the precipitation in the region (10, 11), (ii) do not reproduce the seasonality of either precipitation (10, 11) or surface fluxes such as evapotranspiration (12), and (iii) produce errors in the diurnal cycle and intensity of precipitation, with a tendency to rain too little and too early in the day (13,14). In the more humid Western part of the basin, surface incoming radiation, evapotranspiration, and photosynthesis all tend to peak in the dry season (15-17), whereas GCMs simulate peaks of those fluxes in the wet season (10, 11). Those issues might be related to the representation of convection (1,2,4,5,13,14) and vegetation water stress (6)(7)(8)(15)(16)(17) in GCMs.We here show that we can represent the Amazonian climate using a strategy opposite to GCMs in which we resolve convection and parameterize the large-scale circulation (Methods). The simulations lack many of the biases observed in GCMs and more accurately capture the differences between the dry and wet season of the Amazon in surface heat fluxes and precipitation. Besides top-of-the-atmosphere inso...

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“…Led by concerns about forest growth and productivity and carbon storage being affected by changing climates in tropical regions (e.g., Gatti et al, 2014;Doughty et al, 2015), the issues of water yield for forest-dominated landscapes are only beginning to play out. These issues are significant worldwide, including areas such as Europe (e.g., Ellison et al, 2012Ellison et al, , 2017 where water yield from forests has long been a given.…”

Section: Watermentioning

confidence: 99%