Marta Álvarez Rodríguez

1. Asignatura 1.02 Sumideros de Carbono en la biosfera Accumulation-release of carbon in the marine reservoires Temporal evolution of CO2 in the ocean Marta Álvarez Rodríguez IEO A Coruña Palma de Mallorca, March 2012

2. Temporal evolution of CO2 in the ocean Perspectivas actuales en el estudio de la evolución del CO2 en la superficie del océano => case studies Perspectivas actuales en el estudio de la evolución del CO2 en el interior del océano => case studies Cómo se conectan ambos?

3. Surface CO2 climatology

4. Surface CO2 climatology Atlántico Pacífico Indico Global

5. Fig. 14. Zonal mean sea–air CO2 flux in the four major ocean basins. The flux values are expressed in Tg-C y−1 (Tg=1012 g) for each 4°-wide zonal band across each ocean basin. This plot gives a total global air-to-sea flux of 1.42 Pg-C y−1. The wind speed data are from the 1979–2005 NCEP-DOE AMIP-II Reanalysis, and the gas transfer coefficient is computed using Eq. (8). Fig. 11. Difference maps for the surface water pCO2 values for this study and Takahashi et al. (2002): (A) February and (B) August. In order to make the results of these two studies comparable, the 2002 values, which were normalized to a reference year 1995, are corrected by adding 7.5 μatm (=1.5 μatm y−1×5 y) to adjust to the reference year 2000 used for this study. Surface CO2 climatology

6. Relevance of CO2 seasonality

7. Long term trends in surface CO2

8. Long term trends in surface CO2 Le Quéré et al. (Nature, 2009). Trends in the sources and sinks of CO2.

9. Long term trends in surface CO2 Le Quéré et al. (Global Biogeochemical Cycles, 2010). Impact of climate change and variability on the global CO2 oceanic sink.

10. Global reduction of uptake due to climate related issues Not in the northern latitudes Tropics and Equatorial area (mainly Pacifc) climate changes contributes with a great reduction (0.13 PgC/yr) SO climate changes dimishes uptake (0.06 PgC/yr)

11. Variability in surface pCO2 North Atlantic Schuster et al. (DSRII, 2009). Trends in the North Atlantic Sea surface fCO2 from 1990 to 2006.

12. Decreasing trend in areas where warming is higher Lower decreasing trend asssociated with NAO, effect of winter mixed layer & Warming, change from low to high NAO index Variability in surface pCO2 North Atlantic Schuster et al. (DSRII, 2009). Trends in the North Atlantic Sea surface fCO2 from 1990 to 2006.

13. POSITIVE • The Positive NAO index phase shows a stronger than usual subtropical high pressure center and a deeper than normal Icelandic low. • The increased pressure difference results in more and stronger winter storms crossing the Atlantic Ocean on a more northerly track. • This results in warm and wet winters in Europe and in cold and dry winters in northern Canada and Greenland • The eastern US experiences mild and wet winter conditions NEGATIVE • The negative NAO index phase shows a weak subtropical high and a weak Icelandic low. • The reduced pressure gradient results in fewer and weaker winter storms crossing on a more west-east pathway. • They bring moist air into the Mediterranean and cold air to northern Europe • The US east coast experiences more cold air outbreaks and hence snowy weather conditions. • Greenland, however, will have milder winter temperatures Variability in surface pCO2 North Atlantic http://www.ldeo.columbia.edu/res/pi/NAO/ The NAO is the dominant mode of winter climate variability in the North Atlantic region ranging from central North America to Europe and much into Northern Asia. The NAO is a large scale seesaw in atmospheric mass between the subtropical high and the polar low. The corresponding index varies from year to year, but also exhibits a tendency to remain in one phase for intervals lasting several years.

14. The North Atlantic Oscillation, Dec to Mar from 1980 to 2008 + 3 + 2 + 1 NAO index 0 + 1 High index + 2 Lower index Lower index 1980 1985 1990 1995 2000 2005 Climate Research Unit, University of East Anglia Year

15. Variability in surface pCO2 North Atlantic

16. Variability in surface pCO2 North Atlantic Increase uptake, - pCO2, due to cooling Reduced uptake, + pCO2, + saline & warmer waters delivered with NAC

17. Variability in surface pCO2 North Atlantic

18. Variability in surface pCO2 North Atlantic

19. Variability in surface pCO2 North Atlantic

20. Variability in surface pCO2 North Atlantic

21. Variability in surface pCO2 North Atlantic

22. Variability in surface pCO2 North Atlantic

23. Variability in surface pCO2 North Atlantic

24. Variability in surface pCO2 North Atlantic

25. Variability in surface pCO2 North Atlantic

26. Variability in surface pCO2 North Atlantic

27. Variability in surface pCO2 North Atlantic

28. Variability in surface pCO2 North Atlantic

29. Variability in surface pCO2 North Atlantic

30. Variability in surface pCO2 North Atlantic

31. Variability in surface pCO2 North Atlantic

33. Interior CO2 variability Inventory of CANT for year 1994 = 110 ± 13 Pg C

34. ENACW MW LSW NEADW Ríos et al, 2003 Interior CO2 variability

35. Interior CO2 variability

36. Interior CO2 variability CANT inventory in the Atlantic for 1997 and 2003 and its relationship to the formation of North Atlantic Deep Water (NADW) was analysed. For the whole region between 20°S and 65°N the inventory amounts to 32.5 ± 9.5 Pg C in 1997 and increases up to 36.0 ± 10.5 Pg C in 2003.

37. Change in the whole water column between 2005 and 1997 is only 3% much less than the 14% expected from atmospheric CO2 increase Temporal variation in the water mass formation in the North Atlantic has a very strong impact in the CANT storage rates.

39. Temporal evolution of the CANT storage rate was estimated along more than two decades (1981–2006) in the Subpolar North Atlantic Ocean, covering the Iberian, Iceland and Irminger basins A tendency of decreasing CANT storage rates towards the deep layers

40. The storage rates (±std. err. of the estimate) Strong reduction, of about three times, in the CANT inventory between high and low NAO scenarios in the Irminger Sea related with the water mass formation.

44. Interior CO2 variability