E 3 SM V 1 BGC experiments CarbonClimate
E 3 SM V 1 BGC experiments: Carbon-Climate feedbacks during the historical period Peter Thornton, Xiaoying Shi, Xiaojuan Yang, Dan Ricciuto, Mat Maltrud, Nicole Jeffery, Lee Brent, Susannah Burrows, Qing Zhu, Bill Riley, Jinyun Tang, and the E 3 SM v 1 BGC team
Major climate-carbon and climate-ecosystem feedbacks Ocean system βO γO Fossil Fuel Emissions Atm CO 2 α γL βL Land system Climate (T, P, q, rad)
Experimental Design Radiative Warming BCRC BCRD BDRC BDRD CNTL CO 2 Fertilization Constant 1850 forcings Historical forcings for LULCC, Ndep
Experimental Design Radiative Warming CO 2 Fertilization BCRC BCRD BDRC BDRD Historical forcings for LULCC, Ndep Influence of radiative warming on carbon cycle = BCRD - BCRC
Experimental Design Radiative Warming CO 2 Fertilization BCRC BCRD BDRC BDRD Historical forcings for LULCC, Ndep Influence of CO 2 fertilization on carbon cycle = BDRC - BCRC
Climate-carbon cycle feedback analysis • Following Friedlingstein et al. 2006: Gain - ( L + O) / (1 + L + O) (K ppm-1) (Pg. C K-1) = transient climate sensitivity to CO 2 = (land or ocean) carbon storage sensitivity to climate
Prescribed CO 2 concentration Global temperature response to increased CO 2 CTC ECA
Land carbon response to CO 2 fertilization Land carbon response to radiativelyforced warming CTC ECA
Land carbon vs. change in CO 2 Land carbon vs. radiatively forced warming CTC ECA
Near-surface air temperature response to CO 2 CTC 100 CTC 75 ECA 100 ECA 75
Land carbon response to CO 2 CTC 100 CTC 75 ECA 100 ECA 75
Land carbon response to Tair CTC 100 CTC 75 ECA 100 ECA 75
Ocean carbon response to CO 2 CTC 100 CTC 75
Ocean carbon response to Tair CTC 100 CTC 75
E 3 SM v 1 BGC estimate Alpha: transient climate sensitivity to CO 2 Differences: • Different physical climate • Different land model • Physics and BGC • Active P cycle • E 3 SM is using dynamic LULCC Plotted on data from Thornton et al. 2009
E 3 SM v 1 BGC estimate Beta_land: land carbon sensitivity to CO 2 Notes • Like CESM 1, E 3 SM v 1 CTC has a lower CO 2 fertilization effect than many other land models • Consistent with nutrient constraint hypothesis, and with other models that include nutrient limitations Plotted on data from Thornton et al. 2009
E 3 SM v 1 BGC estimate Gamma_land: land carbon sensitivity to Tair Notes • Like CESM 1, E 3 SM v 1 has a near-neutral land carbon sensitivity to rising temperature • Mainly a function of nutrient dynamics: • Warming makes more nutrients available, mitigating losses due to increased respiration Plotted on data from Thornton et al. 2009
E 3 SM v 1 BGC estimate Beta_ocean: ocean carbon sensitivity to CO 2 Notes • E 3 SM v 1 has a lower sensitivity of ocean carbon uptake to rising CO 2 than CESM 1, which itself was at the low end of the CMIP 5 models Plotted on data from Thornton et al. 2009
E 3 SM v 1 BGC estimate Gamma_ocean: ocean carbon sensitivity to Tair Notes • Like CESM 1, E 3 SM v 1 has a near-neutral ocean carbon sensitivity to rising temperature Plotted on data from Thornton et al. 2009
Next steps • Extend simulations to future scenarios – Hoping this can include overshoot and negative emissions scenario • New simulations with revised ocean physics and BGC • Improved handling of LULCC • Quantify interaction effects (non-linear terms coupling beta and gamma)
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