Presentation on theme: "- Perspectivas actuales en el estudio de la evolución del CO2 en la superficie del océano => case studies - Perspectivas actuales en el estudio de la."— Presentation transcript:
- 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?
-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. 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).
Le Quéré et al. (Nature, 2009). Trends in the sources and sinks of CO2.
Le Quéré et al. (Global Biogeochemical Cycles, 2010). Impact of climate change and variability on the global CO2 oceanic sink.
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)
Schuster et al. (DSRII, 2009). Trends in the North Atlantic Sea surface fCO2 from 1990 to 2006.
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
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. 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 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
The North Atlantic Oscillation, Dec to Mar from 1980 to 2008 Climate Research Unit, University of East Anglia High index Lower index Year NAO index Lower index
Increase uptake, - pCO2, due to cooling Reduced uptake, + pCO2, + saline & warmer waters delivered with NAC
Inventory of C ANT for year 1994 = 110 ± 13 Pg C
Ríos et al, 2003 ENACW MW LSW NEADW
C ANT 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.
Temporal variation in the water mass formation in the North Atlantic has a very strong impact in the C ANT storage rates. Change in the whole water column between 2005 and 1997 is only 3% much less than the 14% expected from atmospheric CO 2 increase
Temporal evolution of the C ANT 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 C ANT storage rates towards the deep layers
The storage rates (±std. err. of the estimate) Strong reduction, of about three times, in the C ANT inventory between high and low NAO scenarios in the Irminger Sea related with the water mass formation.