- 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?

Atlántico Pacífico

Indico Global

-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.

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

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.

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

20052000199519901985

+ 3

+ 2

+ 1

0

+ 1

+ 2

1980

NA

O in

dex

Lower index

Increase uptake, - pCO2, due to cooling

Reduced uptake, + pCO2, + saline & warmer waters delivered with NAC

Inventory of CInventory of CANTANT for year 1994 = 110 ± 13 Pg C for year 1994 = 110 ± 13 Pg C

- 2 0 - 1 8 - 1 6 - 1 4 - 1 2 - 1 0 - 8

3 6

3 8

4 0

4 2

4 4

4 6

4 8

1975 1980 1985 1990 1995

CA

NT (

µm

ol.kg

-1)

0

10

20

30

40

50

60

Surface

0-700

700-1400

1400-2000

2000-bottom

Ríos et al, 2003

ENACW

MW

LSW

NEADW

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.

Temporal variation in the water mass formation in the North Atlantic has a very strong impact in the CANT storage rates.

Change in the whole water column between 2005 and 1997 is only 3% much less than the 14% expected from atmospheric CO2 increase

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

Basin NAO Phase (time period)

Cant Specific Inventory Rates (mol C m-2 yr-1)

Storage Rate (kmol s-1)

Storage Rate (Gt yr-1)

High (1991-1997) 1.74±0.24 34±5 0.013±0.002 Irminger Low (1997-2006) 0.4±0.3 8±6 0.006±0.002 High (1991-1998) 1.88±0.45 57±14 0.022±0.005

Iceland Low (1997-2006) 0.3±0.2 9±6 0.0035±0.003

ENA (1981-2006) 0.72±0.03 51±2 0.019±0.001

High NAO 4.3±0.6 142±15 0.054±0.006 TOTAL (OVIDE

BOX)

Low NAO 1.4±0.2 68±9 0.026±0.003

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.