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Tjiputra j 20150707_1700_upmc_jussieu_-_room_101

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Tjiputra j 20150707_1700_upmc_jussieu_-_room_101

  1. 1. Positive future climate feedback due to changes in oceanic DMS emissions OCFUCC INT SCIENT. CONF., PARIS, FRANCE, 7-10 JULY 2015 Jerry Tjiputra1,5, Katharina Six2, Øyvind Seland3, and Christoph Heinze1,4,5 1Uni Research Climate, Bergen, Norway 2Max-Planck-Institute of Meteorology, Hamburg, Germany 3Norwegian meteorological Institute, Oslo, Norway 4University of Bergen, Bergen, Norway 5Bjerknes Centre for Climate Research, Bergen, Norway DMS
  2. 2. 2 Motivations Modified from Friedlingstein et al. (2006) COUPLED UNCOUPLED Atmospheric CO2 concentration IPCC-AR4 WG1-Ch.7, Fig 10.20 (2007) [2.6–4.1°C][2.4–5.6°C] Additional warming of 0.1 to 1.5 °C With biogeochemistry Without biogeochemistry • Biogeochemical process introduce feedback to future climate change.
  3. 3. 3 Motivations • DMS-climate feedback is currently not included in CMIP5 (IPCC-AR5) models • Cloud component in the climate system contributes with the largest source of uncertainties in future projection (IPCC, 2013). • Marine dimethylsulphide (DMS) emissions encompass the largest natural source of atmospheric gaseous sulphur. • Once released, DMS particles act as CCN, altering cloud composition in the atmosphere and radiative balance. • Ocean acidification has been identified to alter DMS production, a potential additional source of biologically induced feedback on climate.
  4. 4. 4 Methods: Norwegian Earth System Model (NorESM1-ME) CLM-CN CAM (Atmosphere, ~2°) CICE HAMOCC MICOM (Ocean) ~1°, 53L Atmospheric chemistry River routing Sulfur chemistry and aerosol microphysics NorESM1-ME model diagram (Bentsen et al., 2013; Tjiputra et al., 2013) - Fully interactive with prescribed CO2 emissions - Historical + RCP8.5 scenario (1850-2100)
  5. 5. Marine DMS emissions 5 PO4, NO3, Fe RC:P N Phyt oplankt on Diat oms Calcifiers NPP Det rit us Zooplankton DOC POC Chlorophyll grazing phot oadapt ion fecal pellet s excret ion bact erial removal export & mort alit y Ocean surface (euphotic layer) Atmosphere DMS Emissions to atmosphere Six and Maier-Reimer, 2006 Prescribed from observation
  6. 6. Marine DMS emissions 6 PO4, NO3, Fe RC:P N Phyt oplankt on Diat oms Calcifiers NPP Det rit us Zooplankton DOC POC Chlorophyll grazing phot oadapt ion fecal pellet s excret ion bact erial removal export & mort alit y Ocean surface (euphotic layer) Atmosphere DMS Bacterial activity Photolysis loss Emissions to atmosphere Six and Maier-Reimer, 2006 Climate feedback Ocean acidification feedback
  7. 7. Processes influence the DMS emissions and feedback 7 • Ocean circulation/upwelling: nutrient availability • Sea-ice variations: irradiation • Warming: phytoplankton growth period • Ocean acidification: DMS production rate Bopp et al. (2013) Six et al. (2013)
  8. 8. Validation of annual DMS concentrations and emissions 8 ConcentrationEmissions Observation (Lana et al., 2010) Model Global annual emissions: - Prescribed: 18. Tg S - Interactive: 25. Tg S - Obs: 17-34 Tg S
  9. 9. Experiment configurations 9 Historical + future scenario RCP8.5 simulations: • Reference -> no interactive DMS (prescribes DMS concentration) • Clim -> consider only climate change impact on DMS production • Clim+pH -> climate change impact and acidification Clim_pH NPP pHREF Clim Temperature, wind-speed, sea-ice, circulations, etc.
  10. 10. Projected global DMS emissions (1850-2100) 10 REF Clim Clim+pH -8% -37%
  11. 11. Projected regional change in DMS emissions 11 Regional changes relative to the preindustrial fluxes (1850s) Reduce Increase 30-40% decrease
  12. 12. Projected regional change in DMS emissions 12 +200% +90% -40% -30% -12% +4% Climate change induces heterogeneous regional effect on net primary production Ocean acidification leads to reduction in DMS emissions (largest at high latitudes)
  13. 13. Projected global mean surface air temperature (1850-2200) 13 ±1σ ~+0.4 ~+0.5
  14. 14. Projected regional change in mean surface air temperature 14 Projected ∆T (by end of 21st century) is similar between all experiments (REF, Clim, and Clim+pH) When acidification effect is considered, additional warming as much as 4K are simulated in the Arctic and Antarctic
  15. 15. Additional temperature change due to DMS-climate feedback 15 pH-effect on DMS production induces additional warming in majority of Earth’s surface, particularly in the high latitude, potentially due to polar amplification
  16. 16. Impact beyond surface temperature 16
  17. 17. Summary 17 • Oceanic DMS emission is projected to decrease in low- and mid-latitudes, attributed to climate change (reduction in net primary production). • In high latitude, warming (higher phytoplankton growth rate) and retreat of sea-ice lead to increase in DMS outgassing. • Future ocean acidification broadly decreases the DMS emissions. • Globally, DMS is projected to introduce additional positive climate feedback. • The mean global surface temperature at the end of 21st century is projected to be warmer by approximately 0.4K compare to the simulation without DMS. • Regionally, as much as 4K additional warming is projected, e.g., in the Arctic. Funding acknowledged: NFR-EVA (no229771)

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