understanding the ocean carbon cycle from atmospheric measurements of o 2 and co 2 andrew manning,...
Post on 12-Jan-2016
216 Views
Preview:
TRANSCRIPT
Understanding the Ocean Carbon Cycle
from Atmospheric Measurements of O2 and CO2
Andrew Manning, UEA, UK
Year
1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 2006
CO
2 co
ncen
trat
ion
(ppm
)
310314318322326330334338342346350354358362366370374378382
Mauna Loa CO2
South Pole CO2
Dave Keeling
The Keeling Curve
Year
1958 1962 1966 1970 1974 1978 1982 1986 1990 1994 1998 2002 2006
O2/
N2
ratio
(pp
m E
q)
-80-76-72-68-64-60-56-52-48-44-40-36-32-28-24-20-16-12-8
CO
2 co
ncen
trat
ion
(ppm
)
310314318322326330334338342346350354358362366370374378382
Mauna Loa CO2
South Pole CO2
Mauna Loa O2
South Pole O2
Dave Keeling
Ralph Keeling
The Keeling Curves
Simplified Global Budgets:CO2 = F – O – L
Atmosphere-Oceangas exchange
Photosynthesis Respiration
Fossil fuel burning
Simplified global CO2 cycle
F = fossil fuel carbon emissionsO = net oceanic carbon sinkL = net land biotic carbon sink
+ Z
Z = net oceanic O2 source
O2 = –FF + LL
F = average fossil fuel O2:CO2 ratioL = average land biotic O2:CO2 ratio
and O2 cycles
(CO2)global (ppm)354 358 362 366 370 374 378 382 386
(O2/
N2)
glo
bal (
per
meg
)
-360
-340
-320
-300
-280
-260
-240
-220
-200
-180
-160
-140
-120
-100
Jan. 1993
change due to fossil fuelcombustion only
Jan. 2003
Atmosphericchange
Quantifying global oceanic and land biotic carbon sinks
Manning, 2001& IPCC TAR, 2001
Manning & Keeling, Tellus, 2006& IPCC AR4 draft, 2006
Units: Pg C yr-1
1990-2000 1993-2003Fossil-fuel emissions: 6.3 ± 0.4 6.5 ± 0.4Atmospheric CO2 increase: 3.2 ± 0.1 3.7 ± 0.1Net oceanic carbon sink: 1.7 ± 0.5 2.2 ± 0.6Net land biotic carbon sink: 1.4 ± 0.7 0.5 ± 0.7
O2 = –FF + LL + Z
CO2 = F – O – L(CO2)global (ppm)354 358 362 366 370 374 378 382 386
(O2/
N2)
glo
bal (
per
meg
)
-360
-340
-320
-300
-280
-260
-240
-220
-200
-180
-160
-140
-120
-100
Jan. 1993
change due to fossil fuelcombustion only
Jan. 2003
Ocean uptake
Atmosphericchange
Terrestrial uptake
Ocean O2 outgassing
Quantifying global oceanic and land biotic carbon sinks
ALT (82°N, 63°W)
89 90 91 92 93 94 95 96 97 98 99 00 01 02 03
AP
O (
pe
r m
eg
)
-210
-180
-150
-120
-90
-60
-30
0
APO - Atmospheric Potential Oxygen
APO = O2 + LCO2
APO is conservative with respect to land biotic processes
So APO variations result only from:
- oceanic CO2 sink (long term)
- oceanic O2 fluxes (short term)
ALT (82°N, 63°W)
89 90 91 92 93 94 95 96 97 98 99 00 01 02 03
CO
2 c
on
cen
tra
tion
(p
pm
)
346350354358362366370374378382
ALT (82°N, 63°W)
89 90 91 92 93 94 95 96 97 98 99 00 01 02 03O
2/N
2 r
atio
(p
er
me
g)
-360-320-280-240-200-160-120
-80-40
0
From atmospheric O2 (APO) observations and transport model inversion get FO2
(oceanic O2 flux).
Then calculate kg2 from: FO2 = kg2 [ pO2(oc) – pO2(atm)]
Use this kg2 with CO2 observations to derive air-sea CO2 fluxes with less uncertainty.
Wanninkhof and McGillis, GRL, 1999
Gas exchange velocities from APO measurements Regional quantification of ocean carbon sinks
FCO2 = kg1[pCO2(oc) –
pCO2(atm)]
Large uncertainties in kg1
Large uncertainties in calculated air-sea CO2 fluxes.
Stephens et al., GBC, 1998
Gruber et al., GBC, 2001
Latidudinal distribtion of APO fluxes Validation and improvement of ocean BGC models
Battle et al., GBC, 2006
Tohjima et al., GRL, 2005
DurbanDurban
FelixstoweFelixstowe
Felixstowe to DurbanPeriodicity = 45 days
8 cruises/yr
CarboOcean atmospheric O2/CO2 measurements
-500
-450
-400
-350
-300
-250
-200
-150
-100
19Aug 20Aug 21Aug 22Aug 23Aug 24Aug 25Aug 26Aug 27Aug 28Aug 29Aug 30Aug 31Aug 01Sep 02Sep 03Sep 04Sep
Day in 2006
O2
(per
meg
)
360
365
370
375
380
385
CO
2 (pp
m)
O2CO22 hr moving averages
See poster by Michael Patecki for more info
Atmospheric O2/CO2 measurements in CarboOcean:
Michael Patecki, UEA, U.K.Poster: System development and preliminary results of atmospheric O2 and CO2 from shipboard measurements in the North Atlantic Ocean.
Jost Lavric, LSCE, FrancePoster: Continuous high accuracy atmospheric O2/N2 and CO2 measurement – a new automatic station on Cape Farewell, Southern Greenland.
Ingrid Luijkx, RuG, The NetherlandsPoster: Continuous atmospheric CO2 and O2 measurements on the F3 North Sea gas and oil platform.
Harro Meijer, RuG, The Netherlands
1) Atlantic O2 + CO2 measurementsa) CarboOcean, with Michael Patecki
Continuous, automated measurements, achieved with:- “Oxzilla” fuel cell O2 analyser - Siemens NDIR CO2 analyser- “Blue Box” for calib. gases- 2-stage drying system
Stephens et al. (1998)
Gruber et al. (2001)
Lack of O2 observation!
CO2
Month
50N-40N
40N-30N
30N-20N
20N-10N
10N-EQ
EQ-10S
10S-20S
20S-30S
10 ppm
1 3 5 7 9 11
30S-40S
O2/N
2
Month
50 per meg
1 3 5 7 9 11
APO
Month
50 per meg
1 3 5 7 9 11
Data and figure courtesy of Y. Tohjima, NIES, Japan
Pacific Ocean shipboard flask measurements, 2002-2004
40S
20S
0
20N
40N
60N
120E 180 120W 60W
PYXISGolden WattleMOL GloryFujitrans World
-250
-200
-150
-100
-50
0
30N-20N
2002 2003 2004
O2/
N2
(per
meg
)
APO interannual variabilitym
ol O
2/y
r x1
01
4
- ocean models under-estimate observed variability
Buitenhuis, Le Quéré, Keeling
Simplified Global Budgets:CO2 = F – O – L
Atmosphere-Oceangas exchange
Photosynthesis Respiration
Fossil fuel burning
Simplified global CO2 and O2 cycles
F = fossil fuel carbon emissionsO = net oceanic carbon sinkL = net land biotic carbon sink
O2 = –FF + LL
F = average fossil fuel O2:CO2 ratioL = average land biotic O2:CO2 ratio
+ Z
Z = net oceanic O2 source
APO - Atmospheric Potential Oxygen
(CO2 = F – O – L ) x L
+O2 = –FF + LL + Z
APO Fossil fuel APO loss
Oceanic APO loss
O2 + LCO2 = (L – F)F – (LO – Z)
1) Solve ‘O’ with APO
2) Solve ‘L’ with CO2
- land sink more variable, and have larger CO2 network
- less “noise” in long-term APO trend
CO2
O2
Atmosphere
Ocean
O2
CO2
Relative reservoir sizes Long-term trends
O2
CO2
Seasonal effects
CO2
O2
Keeling and Garcia, PNAS, 2002.
CarboOcean – observations theme led by UEA- 5 year, 15 million Euro programme-main objective: to quantify net annual air-quantify net annual air-sea COsea CO2 2 fluxes in North Atlantic Ocean fluxes in North Atlantic Ocean (and (and world ocean)world ocean)
My contribution:continuous, automated system for measurements of atmospheric O2 and CO2 from ships(to complement measurements of dissolved O2 and CO2)
FelixstoweAntwerp
Gran Canaria
Cape Town
Port Elizabeth
Durban
Felixstowe to Durban
Periodicity: Felixstowe is visited every 45 days
top related