How much (how little) do we know about inter-annual variability of CO 2 in coastal environments? Does it matter ? Can we improve this ?" Alberto V. Borges Chemical Oceanography Unit Université de Liège Belgium CARBOOCEAN Bergen, 5-9 October

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 CARBOOCEAN Bergen, 5-9 October

CARBOOCEAN Bergen, 5-9 October Tasmania Borges et al. (2008) BG 5:141–155 SAM +

CARBOOCEAN Bergen, 5-9 October Tasmania Borges et al. (2008) BG 5:141–155 SAM + Wind – SAM + Wind – SAM + Wind –

CARBOOCEAN Bergen, 5-9 October Tasmania Borges et al. (2008) BG 5:141–155 SAM + Wind – SST + SAM + Wind – SST + SAM + Wind – SST +

CARBOOCEAN Bergen, 5-9 October Tasmania Borges et al. (2008) BG 5:141–155 SAM + Wind – SST + pCO 2 – SAM + Wind – SST + pCO 2 – SAM + Wind – SST + pCO 2 –

CARBOOCEAN Bergen, 5-9 October Tasmania SAM + Wind – SST + pCO 2 – FCO 2 – SAM + Wind – SST + pCO 2 – FCO 2 – SAM + Wind – SST + pCO 2 – FCO 2 – Borges et al. (2008) BG 5:141–155

CARBOOCEAN Bergen, 5-9 October Tasmania Warmer years Lesser mixing Lesser ↑ DIC Cooler years More mixing More ↑ DIC Borges et al. (2008) BG 5:141–155

CARBOOCEAN Bergen, 5-9 October Celtic Sea & English Channel Deliverable Year-to-year change 50 µatm max. Year-to-year change 200 µatm max.

CARBOOCEAN Bergen, 5-9 October North Sea Omar et al. (2009) Ocean Sci. Discuss. 6:

CARBOOCEAN Bergen, 5-9 October North Sea Omar et al. (2009) Ocean Sci. Discuss. 6: Northern BoxSouthern Box Year-to-year change 160 µatm Year-to-year change 220 µatm

CARBOOCEAN Bergen, 5-9 October Scheldt estuary Borges (unpublished) pCO 2 (ppm) 7220 ppm4880 ppm 100 ppm210 ppm

CARBOOCEAN Bergen, 5-9 October Conclusions Inter-annual Δ drivers Tasmania+mixing Celtic Sea+mixing (?) English Channel++mixing (?) North Sea++biology Scheldt estuary+++nutrient & C river inputs

CARBOOCEAN Bergen, 5-9 October Conclusions How much (how little) do we know about inter-annual variability of CO 2 in coastal environments? Does it matter ? Can we improve this ?"

CARBOOCEAN Bergen, 5-9 October Conclusions How much (how little) do we know about inter-annual variability of CO 2 in coastal environments? A little, not much Does it matter ? Can we improve this ?"

CARBOOCEAN Bergen, 5-9 October Open oceanCoastal ocean Large scale oscillations Land Conclusions

CARBOOCEAN Bergen, 5-9 October Open oceanCoastal ocean Large scale oscillations Land Conclusions physicsbiology

CARBOOCEAN Bergen, 5-9 October Open oceanCoastal ocean Large scale oscillations CO 2 Land Conclusions physicsbiology ΔDI C

CARBOOCEAN Bergen, 5-9 October Open oceanCoastal ocean Large scale oscillations CO 2 Land Conclusions physicsbiology ΔDI C

CARBOOCEAN Bergen, 5-9 October Open oceanCoastal ocean Large scale oscillations CO 2 Land Conclusions physicsbiology ΔDI C

CARBOOCEAN Bergen, 5-9 October Open oceanCoastal ocean Large scale oscillations CO 2 Land Conclusions physicsbiology ΔDI C

CARBOOCEAN Bergen, 5-9 October Open oceanCoastal ocean Large scale oscillations CO 2 Land Conclusions physicsbiology physicsbiology ΔDI C

CARBOOCEAN Bergen, 5-9 October Open oceanCoastal ocean Large scale oscillations ΔDI C CO 2 ΔDI C CO 2 Land Conclusions physicsbiology physicsbiology

CARBOOCEAN Bergen, 5-9 October Conclusions How much (how little) do we know about inter-annual variability of CO 2 in coastal environments? A little, not much Does it matter ? Yes Can we improve this ?"

CARBOOCEAN Bergen, 5-9 October Conclusions Coastal ocean Tasmania : ± 10% inter-annual variability of air-sea CO 2 fluxes => Coastal ocean 20% to 24% of the open ocean CO 2 sink North Sea : ± 50% inter-annual variability of air-sea CO 2 fluxes => Coastal ocean 11% to 33% of the open ocean CO 2 sink

CARBOOCEAN Bergen, 5-9 October Conclusions How much (how little) do we know about inter-annual variability of CO 2 in coastal environments? A little, not much Does it matter ? Yes Can we improve this ?" Yes we can

CARBOOCEAN Bergen, 5-9 October Conclusions - Need for sustained observatories of CO 2 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

CARBOOCEAN Bergen, 5-9 October Open oceanCoastal ocean Large scale oscillations ΔDI C CO 2 ΔDI C CO 2 Land Conclusions physicsbiology physicsbiology