Supplementary material to "Studying the impact of biomass burning aerosol radiative and climate effects on the Amazon rainforest productivity with an Earth System Model"

Abstract. Diffuse light conditions can increase the efficiency of photosynthesis and carbon uptake by vegetation canopies. The diffuse fraction of photosynthetically active radiation (PAR) can be affected by either a change in the atmospheric aerosol burden and/or a change in cloudiness. During the dry season, a hotspot of biomass burning on the edges of the Amazon rainforest emits a complex mixture of aerosols and their precursors and climate-active trace gases (e.g. CO2, CH4, NOx). This creates potential for significant interactions between chemistry, aerosol, cloud, radiation and the biosphere across the Amazon region. The combined effects of biomass burning on the terrestrial carbon cycle for the present day are potentially large, yet poorly quantified. Here, we quantify such effects using the Met Office Hadley Centre Earth system model HadGEM2-ES, which provides a fully coupled framework with interactive aerosol, radiative transfer, dynamic vegetation, atmospheric chemistry and biogenic volatile organic compound emission components. Results show that for present day, defined as year 2000 climate, the overall net impact of biomass burning aerosols is to increase net primary productivity (NPP) by +80 to +105 TgC yr−1, or 1.9 % to 2.7 %, over the central Amazon Basin on annual mean. For the first time we show that this enhancement is the net result of multiple competing effects: an increase in diffuse light which stimulates photosynthetic activity in the shaded part of the canopy (+65 to +110 TgC yr−1), a reduction in the total amount of radiation (−52 to −105 TgC yr−1) which reduces photosynthesis and feedback from climate adjustments in response to the aerosol forcing which increases the efficiency of biochemical processes (+67 to +100 TgC yr−1). These results illustrate that despite a modest direct aerosol effect (the sum of the first two counteracting mechanisms), the overall net impact of biomass burning aerosols on vegetation is sizeable when indirect climate feedbacks are considered. We demonstrate that capturing the net impact of aerosols on vegetation should be assessed considering the system-wide behaviour.

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Studying the impact of biomass burning aerosol radiative and climate effects on the Amazon rainforest productivity with an Earth System Model

10.5194/acp-2018-924 ◽

2018 ◽

Author(s):

Florent F. Malavelle ◽

Jim M. Haywood ◽

Lina M. Mercado ◽

Gerd A. Folberth ◽

Nicolas Bellouin ◽

...

Keyword(s):

Biomass Burning ◽

Atmospheric Chemistry ◽

Complex Mixture ◽

Earth System Model ◽

System Model ◽

Amazon Rainforest ◽

Diffuse Light ◽

Earth System ◽

The Impact ◽

Aerosol Radiative

Abstract. Diffuse light conditions can increase the efficiency of photosynthesis and carbon uptake by vegetation canopies. The diffuse fraction of photosynthetically active radiation (PAR) can be affected by either a change in the atmospheric aerosol burden and/or a change in cloudiness. During the dry season, a hotspot of Biomass Burning on the edges of the Amazon rainforest emits a complex mixture of aerosols and their precursors and climate-active trace gases (e.g. CO2, CH4, NOx etc). This creates potential for significant interactions between chemistry, aerosol, cloud, radiation and the biosphere across the Amazon region. The combined effects of biomass burning on the terrestrial carbon cycle for the present-day are potentially large, yet poorly quantified. Here, we quantify such effects using the Met Office Hadley Centre Earth System Model HadGEM2-ES which provides a fully coupled framework with interactive aerosol, radiative transfer, dynamic vegetation, atmospheric chemistry and biogenic volatile organic compound emission components. Results show that the overall net impact of present-day biomass burning aerosols is to increase net primary productivity (NPP) by +80 to +105 TgC/yr, or 1.9 to 2.7 %, over the central Amazon basin on annual mean. For the first time we show that this enhancement is the net result of multiple competing effects: an increase in diffuse light which stimulates photosynthetic activity in the shaded part of the canopy (+65 to +110 TgC/yr), a reduction in the total amount of radiation (−52 to −105 TgC/yr) which reduces photosynthesis and feedback from climate adjustments in response to the aerosol forcing which increases the efficiency of biochemical processes (+67 to +100 TgC/yr). These results illustrate that despite a modest direct aerosol effect (the sum of the first two counteracting mechanisms) the overall, net impact of biomass burning aerosols on vegetation, is sizeable, when indirect climate feedbacks are considered. We demonstrate that capturing the net impact of aerosols on vegetation should be assessed considering the system-wide behaviour.

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Supplementary material to "Holocene biome changes in Asia – an analysis of different transient Earth system model simulations"

10.5194/cp-2016-67-supplement ◽

2016 ◽

Author(s):

Anne Dallmeyer ◽

Martin Claussen ◽

Jian Ni ◽

Xianyong Cao ◽

Yongbo Wang ◽

...

Keyword(s):

Earth System Model ◽

System Model ◽

Earth System ◽

Model Simulations ◽

Supplementary Material

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Supplementary material to "Multiphase processes in the EC-Earth Earth System model and their relevance to the atmospheric oxalate, sulfate, and iron cycles"

10.5194/gmd-2021-357-supplement ◽

2021 ◽

Author(s):

Stelios Myriokefalitakis ◽

Elisa Bergas-Massó ◽

María Gonçalves-Ageitos ◽

Carlos Pérez García-Pando ◽

Twan van Noije ◽

...

Keyword(s):

Earth System Model ◽

System Model ◽

Earth System ◽

Supplementary Material

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Progress towards a probabilistic Earth system model: examining the impact of stochasticity in the atmosphere and land component of EC-Earth v3.2

Geoscientific Model Development ◽

10.5194/gmd-12-3099-2019 ◽

2019 ◽

Vol 12 (7) ◽

pp. 3099-3118 ◽

Cited By ~ 2

Author(s):

Kristian Strommen ◽

Hannah M. Christensen ◽

Dave MacLeod ◽

Stephan Juricke ◽

Tim N. Palmer

Keyword(s):

Climate Model ◽

Weather Forecasting ◽

Southern Oscillation ◽

Earth System Model ◽

System Model ◽

Earth System ◽

Beneficial Impact ◽

The Impact ◽

Mean State

Abstract. We introduce and study the impact of three stochastic schemes in the EC-Earth climate model: two atmospheric schemes and one stochastic land scheme. These form the basis for a probabilistic Earth system model in atmosphere-only mode. Stochastic parametrization have become standard in several operational weather-forecasting models, in particular due to their beneficial impact on model spread. In recent years, stochastic schemes in the atmospheric component of a model have been shown to improve aspects important for the models long-term climate, such as El Niño–Southern Oscillation (ENSO), North Atlantic weather regimes, and the Indian monsoon. Stochasticity in the land component has been shown to improve the variability of soil processes and improve the representation of heatwaves over Europe. However, the raw impact of such schemes on the model mean is less well studied. It is shown that the inclusion of all three schemes notably changes the model mean state. While many of the impacts are beneficial, some are too large in amplitude, leading to significant changes in the model's energy budget and atmospheric circulation. This implies that in order to maintain the benefits of stochastic physics without shifting the mean state too far from observations, a full re-tuning of the model will typically be required.

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