Working Group 3:
Sponsored Links
This presentation is the property of its rightful owner.
1 / 19

Working Group 3: What aspects of coastal ecosystems are significant globally? PowerPoint PPT Presentation


  • 89 Views
  • Uploaded on
  • Presentation posted in: General

Working Group 3: What aspects of coastal ecosystems are significant globally?. Contributed by G.-K. Plattner, J. Kleypas, C. Nevison, A. Subramaniam. Coastal Zone Impacts on Global Biogeochemistry NCAR, June 2004. Outline: Key questions / areas.

Download Presentation

Working Group 3: What aspects of coastal ecosystems are significant globally?

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Working Group 3:

What aspects of coastal ecosystems are significant globally?

Contributed by

G.-K. Plattner, J. Kleypas, C. Nevison, A. Subramaniam

Coastal Zone Impacts on Global Biogeochemistry

NCAR, June 2004


Outline: Key questions / areas

  • How much do coastal zones matter for global atmospheric CO2?

  • How large is the impact on atmospheric chemistry and aerosols at different spatial scales?

  • e.g. N2O,CH4,DMS

  • Role of coastal salt marsh and mangrove swamps?

  • Role of river discharge?


The global carbon budget 1980-1999

(Sabine et al., SCOPE 2004)


Coastal Ocean and Global Carbon Cycle

  • Conventional wisdom suggests that due to large river inputs of organic and inorganic carbon and due to fast local remineralization, the coastal oceans act as a net source of CO2 to the atmosphere.

  • Recent studies suggest a global net sink for atmospheric CO2(0.36Gt C yr-1; valuesrange from of 0.2 to 1 Gt C yr-1).


The global ocean carbon budget 1980-1999

  • Units: Reservoirs in Gt C, Fluxes in Gt C yr-1

(Sabine et al., SCOPE 2004)


The global ocean carbon budget 1980-1999

  • Estim. coastal fluxes:

  • - River input

  • inorg. ~0.6

  • org. ~0.5

  • - Sedimentation

  • ~0.4

  • - Net sea-air CO2 flux

  • ~0.36? (Chen, 2004)

  • - Export open ocean?

  • Units: Reservoirs in Gt C, Fluxes in Gt C yr-1

?

?

(Sabine et al., SCOPE 2004)


Coastal Ocean and Global Carbon Cycle

  •  The coastal zone fluxes represent the largest unknown in the CO2 balance of the oceans

  • Why?

  • Net fluxes of CO2 are small compared to gross fluxes

  •  difficult to measure

  • Global analysis of net air-sea gas exchange does not resolve coastal zones (Takahashi et al., 2002)


Sea-air CO2 flux: Annual mean

~106 measurements, 4ox5o grid

Global net CO2 flux : 1.5 GtC yr-1


Satellite Chlorophyll: Annual mean


Coastal Ocean and Global Carbon Cycle

  •  The coastal zone fluxes represent the largest unknown in the CO2 balance of the oceans

  • Net fluxes of CO2 are small compared to gross fluxes

  •  difficult to measure

  • Global analysis of net air-sea gas exchange does not

    • resolve coastal zones (Takahashi et al., 2002).

  • Large temporal and spatial (incl. meso- and submesoscale eddies) variability in the coastal ocean


Large variability of pCO2 in coastal systems: e.g. in an upwelling system (California)

(Friederich et al., AGU 2002)


Coastal Ocean and Global Carbon Cycle

  •  The coastal zone fluxes represent the largest unknown in the CO2 balance of the oceans

  • Net fluxes of CO2 are small compared to gross fluxes

  •  difficult to measure

  • Global analysis of net air-sea gas exchange does not

    • resolve coastal zones (Takahashi et al., 2002).

  • Large temporal and spatial (incl. meso- and submesoscale eddies) variability in the coastal ocean

  • Net sink or source of atmospheric CO2?

  • Models can’t help: coastal oceans not represented in current global ocean carbon cycle models

    •  see working group 4 outline


Past, Present and Future Role?

(Chen, SCOPE 2004; adapted from Ver et al. 1999)


Summary

  • Significant river input of carbon (~0.6 Gt C yr-1 inorganic, ~0.5 Gt C yr-1organic) into coastal ocean

  • Sedimentation in the coastal zone is only ~0.4 Gt C yr-1

  • Recent studies nevertheless suggest a sink for atm. CO2of 0.36Gt C yr-1(range of 0.2 to 1 Gt C yr-1)

  • Export to open ocean?

  •  The coastal zone fluxes represent the largest unknown in the CO2 balance of the oceans


Proposed outline: Key questions / areas

  • How much do coastal zones matter for global atmospheric CO2?

  • How much do coastal zones matter for other atmospheric compounds?

  • e.g. N2O, CH4, DMS

  • Topics:

  • Which coastal ecosystems are of relevance?

  • What’s their relative importance?

  • Role of biology vs. physical processes (incl. river discharge)?

  • Natural flux vs. anthropogenic perturbation?


The end


The global carbon budget 1980-1999

(Sabine et al., SCOPE 2003)


Modern annual carbon budgetfor continental margins

(Chen, SCOPE 2004)


Preindustrial organic carbon cyclefor coastal oceans

(Chen, SCOPE 2004; after Rabouille et al., 2001)


  • Login