OBSERVED TRENDS OF CARBON STORAGE ACIDIFICATION AND … · (C ANT). OBSERVED TRENDS OF CARBON...
1
AIMS To quantify the acidification rates in the northern North Atlantic. To verify the impacts of the acidification on the calcium carbonate saturation and total alkalinity (A T ). To estimate the concentrations of anthropogenic CO 2 (C ANT ). OBSERVED TRENDS OF CARBON STORAGE, ACIDIFICATION AND CALCIUM CARBONATE SATURATION ALONG THE OVIDE SECTION García-Ibáñez, Maribel I.* 1 , Noelia M. Fajar 1 , Aida F. Ríos 1 , Herlé Mercier 2 and Fiz F. Pérez 1 1 Department of Oceanography, Instituto de Investigaciones Marinas, IIM-CSIC, Eduardo Cabello, 6, E-36208 Vigo, Spain 2 Laboratoire de Physique des Océans (LPO), CNRS Ifremer IRD UBO, IFREMER Centre de Brest, B.P. 70 29280 Plouzané, France *Corresponding author: [email protected] 9th International Carbon Dioxide Conference 3-7 June, 2013 Beijing, China REFERENCES Clayton, T.D.; Byrne, R.H. (1993) Calibration of m-cresol purple on the total hydrogen ion concentration scale and its application to CO 2 -system characteristics in seawater. Deep Sea Res., Part I, 40, 2115-2129. Mintrop, L.; Pérez ,F.; González-Dávila, M.; Santana-Casiano, J.; Körtzinger, A. (2000) Alkalinity determination by potentiometry: Intercalibration using three different methods. Cienc. Mar., 26, 23-37. Pérez, F.F.; Vázquez-Rodríguez, M.; Louarn, E.; Padin, X.A.; Mercier, H.; Ríos, A.F. (2008) Temporal variability of the anthropogenic CO 2 storage in the Irminger Sea. Biogeosciences, 5, 1669-1679. Pérez, F.F.; Vázquez-Rodríguez, M.; Mercier, H.; Velo, A.; Lherminier, P.; Ríos, A.F. (2010) Trends of anthropogenic CO 2 storage in North Atlantic water masses. Biogeosciences, 7, 1789-1807. Sabine, C.L.; Feely, R.A.; Gruber, N.; Key, R.M.; Lee, K.; Bullister, J.L.; Wanninkhof, R.; Wong, C.S.; Wallace, D.W.R.; Tilbrook, B.; Millero, F.J.; Peng T.-H.; Kozyr, A.; Ono, T.; Ríos, A.F. (2004) The oceanic sink for anthropogenic CO 2 . Science, 305, 367-371. Vázquez-Rodríıguez, M.; Padin, X.A.; Ríos, A.F.; Bellerby, R.G.J.; Pérez, F.F. (2009) An upgraded carbon-based method to estimate the anthropogenic fraction of dissolved CO 2 in the Atlantic Ocean. Biogeosciences Discuss., 6, 4527-4571. HIGHLIGHTS The C ANT storage rates in the North Atlantic subpolar gyre during the first half of the 1990s, when a high North Atlantic Oscillation (NAO) phase was dominant, were ~48% higher than during the 1997- 2006 low NAO phase that followed. The observed C ANT storages are increasing during the OVIDE period (2002-2012), reaching similar rates to those observed during the early 90’s. High acidification rates in mode and intermediate waters of the subpolar gyre, and a general decrease of acification rates through the subtropical zone. A significant negative trend of the saturation state of CaCO 3 in terms of aragonite (Ω arag ) in all water masses except in deep water masses. Typical negative trends of -1.8 to -5.2·10 -3 y -1 are observed in intermediate waters which correspond with an upward migration of 8.6-16 m·y -1 in the saturation horizons. A positive trend in A T for subsurface Eastern North Atlantic waters of 0.26±0.12 μmol·kg -1 ·y -1 between 1981 and 2012. Iberia Fig.1 Tracks of the sixteen cruises of marine carbon system measurements used in this study (1981-2012). The black straight lines are the boundaries of Irminger, Iceland and East North Atlantic basins. Some of the TYRO stations are masked under the CHAOS, OACES and A16N cruise symbol sets. RR=Reykjanes Ridge; BFZ=Bight Fracture Zone; CGFZ=Charlie-Gibbs Fracture Zone; ES=Eriador Seamount. 40ºW 30ºW 20ºW 10ºW 40ºN 50ºN 60ºN 6000m 5000m 4000m 3000m 2000m 1000m 500m Irminger Basin Iceland Basin BFZ East North Atlantic Basin CGFZ HOW WAS IT DONE? A total of sixteen cruises were selected, spanning over 31 years (1981-2012) (Fig. 1). They were accessed from the Carbon In the Atlantic (CARINA) data website (http://store.pangaea.de/Projects/CARBOOCEAN/carina/index.htm), except for the OVIDE ‘06 to OVIDE ‘12 data, which are not publicly available yet. All cruise data here used are compliant with the latest carbon system analytical recommendations for seawater. The pH measurements are spectrophotometric (Clayton and Byrne, 1993) adding m-cresol purple as the indicator. When pH is not measured, it is computed from total inorganic carbon (C T ) and A T in the CARINA data base. Most of the A T is determined potentiometrically (Mintrop et al., 2000). The C ANT concentrations were estimated applying the 0 method (Pérez et al., 2008; Vázquez-Rodríguez et al., 2009). The study area was divided in 3 basins: Irminger, between the main axis of the Reykjanes Ridge and the east coast of Greenland; Iceland, between the Reykjanes Ridge axis and the line joining the Eriador Seamount and the Faroe Islands; and Eastern North Atlantic (ENA), which extends south from the Eriador-Faroe line (Fig. 1). Moreover, the water column is classified in 5 layers delimited by density (Fig. 2), where the water mass properties are closely linked with a specific water mass with very homogenous T/S properties (Pérez et al., 2010). For each water mass in each region the average pH, A T and saturation of aragonite (Ω Arag ) was computed. Fig.2 pH SWS at 25ºC for the OVIDE 12 section. White lines are the boundary isopicnals (σ in kg·m -3 ). SAIW: Sub Arctic Intermediate Water; LSW: Labrador Sea Water; NADW: North Atlantic Deep Water; SPMW: Sub Polar Mode Water; NACW: North Atlantic Central Water; MW: Mediterranean Water. “c” classical, “u” upper and “l” lower varities of some water masses are shown. 7.80 7.85 7.90 7.95 7.75 7.70 Distance from Portugal (km) 3000 2000 1000 0 Depth (m) 3000 2000 1000 0 4000 5000 σ 0 =27.68 σ 0 =27.76 σ 0 =27.81 σ 0 =27.88 σ 0 =27.60 σ 1 =32.35 σ 2 =37.00 σ 4 =45.84 σ 0 =27.20 σ 1 =32.35 σ 2 =37.00 σ 4 =45.84 Irminger Basin Iceland Basin East North Atlantic Basin SAIW SPMW NACW uLSW uLSW MW cLSW cLSW cLSW uNADW uNADW uNADW DSOW lNADW 1980 1985 1990 1995 2000 2005 2010 Year 2340 NA T (μmol kg -1 ) 2320 2300 2360 2380 NA T (μmol kg -1 ) 2325 2330 2320 2315 2310 2305 1980 1985 1990 1995 2000 2005 2010 Year 0.06±0.06; R 2 =0.12; P=0.29 0.03±0.05; R 2 =0.06; P=0.47 0.08±0.05; R 2 =0.25; P=0.12 0.09±0.07; R 2 =0.19; P=0.18 0.18±0.06; R 2 =0.59; P=0.01 rates (μmol kg -1 yr -1 ) 0.10±0.10; R 2 =0.11; P=0.29 0.02±0.08; R 2 =0.01; P=0.47 -0.02±0.09; R 2 =0.005; P=0.12 0.01±0.17; R 2 =0.0003; P=0.18 rates (μmol kg -1 yr -1 ) 0.26±0.12; R 2 =0.34; P=0.03 0.23±0.07; R 2 =0.53; P<0.01 0.10±0.07; R 2 =0.15; P=0.17 0.11±0.08; R 2 =0.15; P=0.17 0.16±0.07; R 2 =0.35; P=0.03 rates (μmol kg -1 yr -1 ) NA T (μmol kg -1 ) 2325 2330 2320 2315 2310 2305 Ω arag 1.8 2.0 1.6 1.4 1.2 1.0 2.2 1980 1985 1990 1995 2000 2005 2010 Year Ω arag 1.8 2.0 1.6 1.4 1.2 1.0 2.2 c) East North Atlantic Basin -2.8±1.2; R 2 =0.41; P=0.03 -5.2±1.7; R 2 =0.57; P=0.01 -3.0±0.9; R 2 =0.63; P<0.01 -1.8±0.5; R 2 =0.65; P<0.01 -1.4±0.9; R 2 =0.23; P=0.13 rates (10 -3 yr -1 ) rates (10 -3 yr -1 ) -3.9±1.6; R 2 =0.39; P=0.02 -1.8±0.9; R 2 =0.29; P=0.06 -2.2±0.7; R 2 =0.52; P=0.01 -3.6±0.8; R 2 =0.67; P<0.01 -4.5±0.9; R 2 =0.69; P<0.01 -4.0±1.2; R 2 =0.51; P<0.01 -2.3±0.4; R 2 =0.76; P<0.01 -0.9±0.5; R 2 =0.20; P=0.11 -0.2±0.9; R 2 =0.003; P=0.85 1980 1985 1990 1995 2000 2005 2010 Year Ω arag 1.8 2.0 1.6 1.2 1.0 0.8 2.2 2.4 1.4 rates (10 -3 yr -1 ) C ant (μmol kg -1 ) 60 70 50 40 30 20 10 1980 1985 1990 1995 2000 2005 2010 Year C ant inventory (mol·C m -2 ) 80 90 70 60 50 40 30 C ant (μmol kg -1 ) 60 50 40 30 20 10 C ant inventory (mol·C m -2 ) 80 70 60 50 40 30 SAIW u LSW c LSW u NADW DSOW Inventory a) Irminger Basin SAIW u LSW c LSW u NADW Inventory b) Iceland Basin NACW MW LSW u NADW l NADW Inventory c) East North Atlantic Basin C ant (μmol kg -1 ) 60 50 40 30 20 10 1980 1985 1990 1995 2000 2005 2010 Year C ant inventory (mol·C m -2 ) 80 70 60 50 40 30 1980 1985 1990 1995 2000 2005 2010 Year pH sws25 7.84 7.86 7.82 7.78 7.76 7.74 7.88 7.80 pH sws25 7.82 7.78 7.76 7.74 7.80 7.72 1980 1985 1990 1995 2000 2005 2010 Year -0.9±0.3; R 2 =0.51; P=0.01 -1.2±0.2; R 2 =0.82; P<0.01 -1.12±0.15; R 2 =0.88; P<0.01 -1.11±0.12; R 2 =0.92; P<0.01 -0.96±0.17; R 2 =0.82; P<0.01 Acidification rates (10 -3 pH units yr -1 ) Acidification rates (10 -3 pH units yr -1 ) -1.9±0.3; R 2 =0.81; P<0.01 -1.2±0.12; R 2 =0.92; P<0.01 -1.0±0.2; R 2 =0.68; P<0.01 -0.9±0.18; R 2 =0.73; P<0.01 -0.9±0.2; R 2 =0.67; P<0.01 -1.0±0.2; R 2 =0.67; P<0.01 -0.71±0.12; R 2 =0.77; P<0.01 -0.2±0.2; R 2 =0.08; P=0.33 0.19±0.13; R 2 =0.17; P=0.15 Acidification rates (10 -3 pH units yr -1 ) pH sws25 7.78 7.76 7.74 7.72 7.72
Transcript of OBSERVED TRENDS OF CARBON STORAGE ACIDIFICATION AND … · (C ANT). OBSERVED TRENDS OF CARBON...
AIMS
To quantify the acidification rates in the northern North Atlantic.
To verify the impacts of the acidification on the calcium carbonate saturation and total alkalinity (AT).
To estimate the concentrations of anthropogenic CO2 (CANT).
OBSERVED TRENDS OF CARBON STORAGE, ACIDIFICATION AND CALCIUM CARBONATE SATURATION ALONG THE OVIDE SECTION
García-Ibáñez, Maribel I.*1, Noelia M. Fajar1, Aida F. Ríos1, Herlé Mercier2 and Fiz F. Pérez1
1 Department of Oceanography, Instituto de Investigaciones Marinas, IIM-CSIC, Eduardo Cabello, 6, E-36208 Vigo, Spain 2 Laboratoire de Physique des Océans (LPO), CNRS Ifremer IRD UBO, IFREMER Centre de Brest, B.P. 70 29280 Plouzané, France
*Corresponding author: [email protected]
9th International Carbon Dioxide Conference
3-7 June, 2013 Beijing, China
REFERENCES
Clayton, T.D.; Byrne, R.H. (1993) Calibration of m-cresol purple on the total hydrogen ion concentration scale and its application to CO2-system characteristics in seawater. Deep Sea Res., Part I, 40, 2115-2129.
Mintrop, L.; Pérez ,F.; González-Dávila, M.; Santana-Casiano, J.; Körtzinger, A. (2000) Alkalinity determination by potentiometry: Intercalibration using three different methods. Cienc. Mar., 26, 23-37.
Pérez, F.F.; Vázquez-Rodríguez, M.; Louarn, E.; Padin, X.A.; Mercier, H.; Ríos, A.F. (2008) Temporal variability of the anthropogenic CO2 storage in the Irminger Sea. Biogeosciences, 5, 1669-1679.
Pérez, F.F.; Vázquez-Rodríguez, M.; Mercier, H.; Velo, A.; Lherminier, P.; Ríos, A.F. (2010) Trends of anthropogenic CO2 storage in North Atlantic water masses. Biogeosciences, 7, 1789-1807.
Sabine, C.L.; Feely, R.A.; Gruber, N.; Key, R.M.; Lee, K.; Bullister, J.L.; Wanninkhof, R.; Wong, C.S.; Wallace, D.W.R.; Tilbrook, B.; Millero, F.J.; Peng T.-H.; Kozyr, A.; Ono, T.; Ríos, A.F. (2004) The oceanic sink for anthropogenic CO2. Science, 305, 367-371.
Vázquez-Rodríıguez, M.; Padin, X.A.; Ríos, A.F.; Bellerby, R.G.J.; Pérez, F.F. (2009) An upgraded carbon-based method to estimate the anthropogenic fraction of dissolved CO2 in the Atlantic Ocean. Biogeosciences Discuss., 6, 4527-4571.
HIGHLIGHTS
The CANT storage rates in the North Atlantic subpolar gyre during the first half of the 1990s, when a high North Atlantic Oscillation (NAO) phase was dominant, were ~48% higher than during the 1997-
2006 low NAO phase that followed. The observed CANT storages are increasing during the OVIDE period (2002-2012), reaching similar rates to those observed during the early 90’s.
High acidification rates in mode and intermediate waters of the subpolar gyre, and a general decrease of acification rates through the subtropical zone.
A significant negative trend of the saturation state of CaCO3 in terms of aragonite (Ωarag) in all water masses except in deep water masses. Typical negative trends of -1.8 to -5.2·10-3 y-1 are observed in
intermediate waters which correspond with an upward migration of 8.6-16 m·y-1 in the saturation horizons.
A positive trend in AT for subsurface Eastern North Atlantic waters of 0.26±0.12 μmol·kg-1·y-1 between 1981 and 2012.
Ibe
ria
Fig.1 Tracks of the sixteen cruises of marine carbon system measurements used in this study (1981-2012). The black straight lines are the boundaries of Irminger, Iceland and East North Atlantic basins. Some of the TYRO stations are masked under the CHAOS, OACES and A16N cruise symbol sets. RR=Reykjanes Ridge; BFZ=Bight Fracture Zone; CGFZ=Charlie-Gibbs Fracture Zone; ES=Eriador Seamount.
40ºW 30ºW 20ºW 10ºW
40ºN
50ºN
60ºN
6000m
5000m
4000m
3000m
2000m
1000m
500m
Irminger Basin
Iceland Basin
BFZ
East North Atlantic Basin
CGFZ
HOW WAS IT DONE?
A total of sixteen cruises were selected, spanning over 31 years (1981-2012) (Fig. 1). They were accessed from the Carbon In the Atlantic
(CARINA) data website (http://store.pangaea.de/Projects/CARBOOCEAN/carina/index.htm), except for the OVIDE ‘06 to OVIDE ‘12 data, which
are not publicly available yet. All cruise data here used are compliant with the latest carbon system analytical recommendations for seawater. The
pH measurements are spectrophotometric (Clayton and Byrne, 1993) adding m-cresol purple as the indicator. When pH is not measured, it is
computed from total inorganic carbon (CT) and AT in the CARINA data base. Most of the AT is determined potentiometrically (Mintrop et al., 2000).
The CANT concentrations were estimated applying the 𝜑𝐶𝑇0 method (Pérez et al., 2008; Vázquez-Rodríguez et al., 2009).
The study area was divided in 3 basins: Irminger, between the main axis of the Reykjanes Ridge and the east coast of Greenland; Iceland,
between the Reykjanes Ridge axis and the line joining the Eriador Seamount and the Faroe Islands; and Eastern North Atlantic (ENA), which
extends south from the Eriador-Faroe line (Fig. 1). Moreover, the water column is classified in 5 layers delimited by density (Fig. 2), where the
water mass properties are closely linked with a specific water mass with very homogenous T/S properties (Pérez et al., 2010). For each water
mass in each region the average pH, AT and saturation of aragonite (ΩArag) was computed.
Fig.2 pHSWS at 25ºC for the OVIDE 12 section. White lines are the boundary isopicnals (σ in kg·m-3). SAIW: Sub Arctic Intermediate Water; LSW: Labrador Sea Water; NADW: North Atlantic Deep Water; SPMW: Sub Polar Mode Water; NACW: North Atlantic Central Water; MW: Mediterranean Water. “c” classical, “u” upper and “l” lower varities of some water masses are shown.
7.80
7.85
7.90
7.95
7.75
7.70
Distance from Portugal (km)
3000 2000 1000 0
Depth
(m
)
3000
2000
1000
0
4000
5000
σ0=27.68
σ0=27.76
σ0=27.81
σ0=27.88
σ0=27.60
σ1=32.35
σ2=37.00
σ4=45.84
σ0=27.20
σ1=32.35
σ2=37.00
σ4=45.84
Irminger Basin Iceland Basin East North Atlantic Basin
SAIW SPMW NACW uLSW uLSW MW
cLSW cLSW
cLSW uNADW
uNADW
uNADW DSOW
lNADW
1980 1985 1990 1995 2000 2005 2010 Year
2340
NA
T (μ
mo
l k
g-1
) 2320
2300
2360
2380
NA
T (μ
mo
l k
g-1
)
2325
2330
2320
2315
2310
2305
1980 1985 1990 1995 2000 2005 2010
Year
0.06±0.06; R2=0.12; P=0.29 0.03±0.05; R2=0.06; P=0.47 0.08±0.05; R2=0.25; P=0.12 0.09±0.07; R2=0.19; P=0.18 0.18±0.06; R2=0.59; P=0.01
rates (μmol kg-1 yr-1)
0.10±0.10; R2=0.11; P=0.29 0.02±0.08; R2=0.01; P=0.47
-0.02±0.09; R2=0.005; P=0.12 0.01±0.17; R2=0.0003; P=0.18
rates (μmol kg-1 yr-1)
0.26±0.12; R2=0.34; P=0.03 0.23±0.07; R2=0.53; P<0.01 0.10±0.07; R2=0.15; P=0.17 0.11±0.08; R2=0.15; P=0.17 0.16±0.07; R2=0.35; P=0.03
rates (μmol kg-1 yr-1)
NA
T (μ
mo
l k
g-1
)
2325
2330
2320
2315
2310
2305
Ωa
rag
1.8
2.0
1.6
1.4
1.2
1.0
2.2
1980 1985 1990 1995 2000 2005 2010
Year
Ωa
rag
1.8
2.0
1.6
1.4
1.2
1.0
2.2
c) East North Atlantic Basin
-2.8±1.2; R2=0.41; P=0.03 -5.2±1.7; R2=0.57; P=0.01 -3.0±0.9; R2=0.63; P<0.01 -1.8±0.5; R2=0.65; P<0.01 -1.4±0.9; R2=0.23; P=0.13
rates (10-3 yr-1)
rates (10-3 yr-1)
-3.9±1.6; R2=0.39; P=0.02 -1.8±0.9; R2=0.29; P=0.06
-2.2±0.7; R2=0.52; P=0.01 -3.6±0.8; R2=0.67; P<0.01
-4.5±0.9; R2=0.69; P<0.01 -4.0±1.2; R2=0.51; P<0.01 -2.3±0.4; R2=0.76; P<0.01 -0.9±0.5; R2=0.20; P=0.11 -0.2±0.9; R2=0.003; P=0.85
1980 1985 1990 1995 2000 2005 2010 Year
Ωa
rag
1.8
2.0
1.6
1.2
1.0
0.8
2.2
2.4
1.4
rates (10-3 yr-1)
Ca
nt (μ
mo
l k
g-1
)
60
70
50
40
30
20
10
1980 1985 1990 1995 2000 2005 2010 Year
Ca
nt in
ve
nto
ry (m
ol·C
m-2)
80
90
70
60
50
40
30
Ca
nt (μ
mo
l k
g-1
)
60
50
40
30
20
10
Ca
nt in
ve
nto
ry (m
ol·C
m-2)
80
70
60
50
40
30
SAIW u LSW c LSW u NADW DSOW Inventory
a) Irminger Basin
SAIW u LSW c LSW u NADW Inventory
b) Iceland Basin
NACW MW LSW u NADW l NADW Inventory
c) East North Atlantic Basin
Ca
nt (μ
mo
l k
g-1
)
60
50
40
30
20
10
1980 1985 1990 1995 2000 2005 2010
Year
Ca
nt in
ve
nto
ry (m
ol·C
m-2)
80
70
60
50
40
30
1980 1985 1990 1995 2000 2005 2010 Year
pH
sw
s2
5
7.84
7.86
7.82
7.78
7.76
7.74
7.88
7.80
pH
sw
s2
5
7.82
7.78
7.76
7.74
7.80
7.72
1980 1985 1990 1995 2000 2005 2010
Year
-0.9±0.3; R2=0.51; P=0.01 -1.2±0.2; R2=0.82; P<0.01 -1.12±0.15; R2=0.88; P<0.01 -1.11±0.12; R2=0.92; P<0.01 -0.96±0.17; R2=0.82; P<0.01
Acidification rates (10-3 pH units yr-1)
Acidification rates (10-3 pH units yr-1)
-1.9±0.3; R2=0.81; P<0.01 -1.2±0.12; R2=0.92; P<0.01
-1.0±0.2; R2=0.68; P<0.01 -0.9±0.18; R2=0.73; P<0.01
-0.9±0.2; R2=0.67; P<0.01 -1.0±0.2; R2=0.67; P<0.01 -0.71±0.12; R2=0.77; P<0.01 -0.2±0.2; R2=0.08; P=0.33 0.19±0.13; R2=0.17; P=0.15
Acidification rates (10-3 pH units yr-1)
pH
sw
s2
5
7.78
7.76
7.74
7.72
7.72
