How much (how little) do we know about inter-annual variability of CO2 in coastal environments?

Does it matter ?Can we improve this ?"

Alberto V. Borges

Chemical Oceanography UnitUniversité de Liège

Belgium

www.co2.ulg.ac.be

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Two achievements of CARBOOCEAN were:

- to encourage sustained C observations in coastal environments- compilation of large data-set including the coastal realm (SOCAT)

In this presentation :- Tasmania continental shelf- Celtic Sea and English Channel- North Sea- Scheldt estuary

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Tasmania

Borges et al. (2008) BG 5:141–155

SAM + SAM + SAM +

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Tasmania

Borges et al. (2008) BG 5:141–155

SAM +Wind –

SAM +Wind –

SAM +Wind –

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Tasmania

Borges et al. (2008) BG 5:141–155

SAM +Wind –SST +

SAM +Wind –SST +

SAM +Wind –SST +

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Tasmania

Borges et al. (2008) BG 5:141–155

SAM +Wind –SST +pCO2 –

SAM +Wind –SST +pCO2 –

SAM +Wind –SST +pCO2 –

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Tasmania

SAM +Wind –SST +pCO2 –FCO2 –

SAM +Wind –SST +pCO2 –FCO2 –

SAM +Wind –SST +pCO2 –FCO2 –

Borges et al. (2008) BG 5:141–155

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Tasmania

Warmer yearsLesser mixingLesser ↑ DIC

Cooler yearsMore mixingMore ↑ DIC

Borges et al. (2008) BG 5:141–155

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Celtic Sea & English Channel

Deliverable 12.26

Year-to-year change 50 µatm max.

Year-to-year change 200 µatm max.

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

North Sea

Omar et al. (2009) Ocean Sci. Discuss. 6:1655-1686

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

North Sea

Omar et al. (2009) Ocean Sci. Discuss. 6:1655-1686

Northern Box Southern Box

Year-to-year change 160 µatm

Year-to-year change 220 µatm

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Scheldt estuary

Borges (unpublished)

months

2009

months

2008

dis

tan

ce f

rom

mo

uh

t (k

m)

500 1500 2500 3500 4500 5500 6500 7500

120

110

100

90

80

70

60

50

40

30

20

10

0J F M A M J J A S O N D J F M A M J J A S O N D

River

North Sea

pCO2 (ppm)

7220 ppm 4880 ppm

100 ppm 210 ppm

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Conclusions

Inter-annual Δ drivers

Tasmania + mixingCeltic Sea + mixing (?)English Channel ++ mixing (?)North Sea ++ biologyScheldt estuary +++ nutrient & C river inputs

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Conclusions

How much (how little) do we know about inter-annual variability of CO2 in coastal environments?

Does it matter ?

Can we improve this ?"

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Conclusions

How much (how little) do we know about inter-annual variability of CO2 in coastal environments?

A little, not much

Does it matter ?

Can we improve this ?"

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Open ocean Coastal ocean

Large scale oscillations

Land

Conclusions

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Open ocean Coastal ocean

Large scale oscillations

Land

Conclusions

physics biology

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Open ocean Coastal ocean

Large scale oscillations

CO2Land

Conclusions

physics biology

ΔDIC

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Open ocean Coastal ocean

Large scale oscillations

CO2Land

Conclusions

physics biology

ΔDIC

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Open ocean Coastal ocean

Large scale oscillations

CO2Land

Conclusions

physics biology

ΔDIC

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Open ocean Coastal ocean

Large scale oscillations

CO2Land

Conclusions

physics biology

ΔDIC

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Open ocean Coastal ocean

Large scale oscillations

CO2Land

Conclusions

physics biologyphysics biology

ΔDIC

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Open ocean Coastal ocean

Large scale oscillations

ΔDIC

CO2

ΔDIC

CO2Land

Conclusions

physics biologyphysics biology

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Conclusions

How much (how little) do we know about inter-annual variability of CO2 in coastal environments?

A little, not much

Does it matter ?

Yes

Can we improve this ?"

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Conclusions

sink for atmospheric CO2

22%

Surface area

7%

Coastal ocean

Tasmania : ± 10% inter-annual variability of air-sea CO2 fluxes=> Coastal ocean 20% to 24% of the open ocean CO2 sink

North Sea : ± 50% inter-annual variability of air-sea CO2 fluxes=> Coastal ocean 11% to 33% of the open ocean CO2 sink

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Conclusions

How much (how little) do we know about inter-annual variability of CO2 in coastal environments?

A little, not much

Does it matter ?

Yes

Can we improve this ?"

Yes we can

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Conclusions

- Need for sustained observatories of CO2 in coastal environments

- Need to develop and maintain QCed and uniform format data-bases that include coastal data (SOCAT)

- Describe inter-annual variability and understand underlying mechanisms :

- Data synthesis- regional modelling

CARBOOCEANBergen, 5-9 October 2009http://www.co2.ulg.ac.be/

Open ocean Coastal ocean

Large scale oscillations

ΔDIC

CO2

ΔDIC

CO2Land

Conclusions

physics biologyphysics biology