long-term observation of co 2 concentration and its isotope ratios over the western pacific h....
TRANSCRIPT
Long-term Observation of CO2 concentration and its isotope ratios over the Western Pacific
H. Mukai, Y. Nojiri, Y. Tohjima, T. Machida, Y. Shibata and H. Kitagawa
Center for Global Environmental Research,National Institute for Environmental Studies
AndNagoya University
Monitoring by using commercial cargo ships Atmospheric CO2 samples from wide range of latitude can be
colleted.
Frequent commercial cargo ship service enable us to observed seasonal variation of CO2 in addition to long-term variation.
Japan-Oceania cruise can provide us a good chance to observe latitudinal difference in behavior of CO2 from Northern Hemisphere to Southern Hemisphere.
Relatively economic monitoring if it goes as planed.
92 93 94 95 96 97 98 99 00 01 02 03 04 05 06 07
Japan -N America(30N-55N)
Japan –Oceania(30N-35S)
NOV
Hakuba
SKAUBRYN ( Seaboard)
Southern Cross
SKAUGRAN ( Seaboard) PYXIS(TOYOFUJI)
FUJITRANS WORLD
MOL Glory
Golden Wattle(MOL)
Alligator Hope(MOL)
Trans Future
Special thanks to MOL, Toyofuji, Fuji Trans, Nihhon Usen,Seaboard International Shipping Co.
FUJITRANS WORLD
PYXIS
FUJITRANS WORD and PYXIS routes2003 Sep – 2004 Nov
1) Bottle Sampling : Stainless-steel bottle 3L (+ Glass bottle 2.5L ) ~10 times/y since 1995 ~ 3 samples / 10 degree in latitude 2) Gas analysis in the bottle: CO2, N2O, CH4 (NDIR, GC-ECD, GC-FID)
delta 13C, delta 18O (MAT252, dual inlet) 14C is measured by Accelerator MASS in NIES
Air Inlet
Temperature sensorGPS sensor
(1) Metal bellows pump
GPS receiver
(2) Cooler (-45 oC)
(3) Sampling Flask Box
Sampling Controller
CO2 analyzer
12CO213CO2
C3 plant
C4 plant
14CO2
Soil
Isotope signature of CO2 (13C, 14C, 18O)will provide important clues about CO2 budget and climatic effects on CO2 uptake mechanism
H218O 12C18O2
(N40-N50)
-2.4-2
-1.6-1.2-0.8-0.4
00.40.81.2
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Del
ta O
18 (p
er m
il)
(N20-N30)
-2.4-2
-1.6-1.2-0.8-0.4
00.40.81.2
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Del
ta
O18
(per
mil)
(0-N10)
-2.4-2
-1.6-1.2-0.8-0.4
00.40.81.2
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Del
ta
O18
(per
mil)
(S20-S10)
-2.4-2
-1.6-1.2-0.8-0.4
00.40.81.2
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Del
ta O
18 (p
er m
il)
(N40-N50)
350
355
360
365
370
375
380
385
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
CO
2 (p
pm)
(N20-N30)
350
355
360
365
370
375
380
385
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
CO
2 (p
pm)
(0-N10)
350
355
360
365
370
375
380
385
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
CO
2 (p
pm)
(S20-S10)
350
355
360
365
370
375
380
385
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
CO
2 (p
pm)
(N40-N50)
-8.8
-8.6
-8.4
-8.2
-8
-7.8
-7.6
-7.4
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Del
ta C
13 (p
er m
il)
(S20-S10)
-8.8
-8.6
-8.4
-8.2
-8
-7.8
-7.6
-7.4
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Del
ta C
13 (p
er m
il)
(N20-N30)
-8.8
-8.6
-8.4
-8.2
-8
-7.8
-7.6
-7.4
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Delta
C13
(per
mil)
(0-N10)
-8.8
-8.6
-8.4
-8.2
-8
-7.8
-7.6
-7.4
1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Del
ta C
13 (p
er m
il)CO2 Delta 13C Delta 18O
40N-50N
20N-30N
0-10N
20S-10S
Carbon isotope ratio
-1
0
1
2
3
4
5
6
-40 -20 0 20 40 60
Latitude
CO
2 d
evia
tion fro
m 3
5S
(ppm
)CO2 concentration
-0.35
-0.25
-0.15
-0.05
0.05
-40 -20 0 20 40 60
Latitude
Delta 1
3C
devia
tion f
rom
35S
(per
mil)
Delta 13C
Latitudinal distribution
0
0.5
1
1.5
2
2.5
3
3.5
19
95
19
96
19
97
19
98
19
99
20
00
20
01
20
02
20
03
20
04
20
05
CO
2 G
row
th r
ate
(p
pm
/y)
30S-10S
10S-10N
10N-30N
30N-50N
-0.1
-0.08
-0.06
-0.04
-0.02
0
0.02
0.04
199
5
199
6
199
7
199
8
199
9
200
0
200
1
200
2
200
3
200
4
200
5
delta
13
C c
ha
ng
e r
ate
(p
er
mil/
y)
30S-10S
10S-10N10N-30N
30N-50N
CO
2 gr
owth
rat
e (p
pm
/y)
Del
ta 1
3C c
han
ge r
ate
(per
mil/
y)
Simple Global Flux Estimation 12C flux dCa/dt = CF + CNs + CNb ------------------(1)
13C flux dδ13Ca/dt = CFδF+ CNs(δa +εas) + CNb(δa +εab)
+ CGs(δs –δa) + CGb(δb –δa) ------(2)
CF = anthropegenic input ( Fossil combustion and Cement production)CNs = Net Sea flux CNb = Net land biological flux CGS = Gross exchange flux between Sea and atmosphereCGb = Gross exchange flux between land biosphere and atmosphere
Isotope disequilibrium term CGs(δs –δa) + CGb(δb –δa)
= 93 Gt-C per mli / year (Francey et al )
BiologicalDiscrimination
-4
-2
0
2
4
6
8
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Flux
(Gt-C
/ y)
, SO
IAnthropogenic CO2 input Land
Ocean CO2 in the atmosphere
Land
Ocean
Atmosphere
Preliminary estimation of flux
Atmosphere
Land Biosphere
Ocean
Anthropogenic input
-4
-2
0
2
4
6
8
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Flux
(Gt-C
/ y)
, -S
OI
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Glo
bal T
emp.
Ano
mal
y
Anthropogenic CO2 input LandOcean CO2 in the atmosphereSOI Temp Anomaly
LandOcean
Atmosphere
-SOI
Temp
25N
15S
Biomass burning signal can be detected ?
A preliminary guess of net Carbon flux budget (PgC/y) to assess isotope signature and its usability
These values for terrestrial and oceanic sinks may have a large uncertainty (over +1Pg/y)
Terrestrial Oceanic Atmospheric Anthropogenic1996 -1.5 -2.1 2.9 6.51997 -0.1 -3.0 3.6 6.71998 0.1 -2.1 4.7 6.71999 -1.6 -1.5 3.4 6.52000 -2.5 -1.3 2.9 6.72001 -1.4 -1.6 3.9 6.82002 -0.1 -1.6 5.3 7.02003 -0.9 -1.3 4.8 7.02004 -2.7 -1.1 3.2 7.0
Avearge -1.2 -1.7 3.9 6.8
Assessment of isotopic balance equationAssessment of isotopic balance equation Oceanic sink looked too variable. Oceanic sink variation = +1 PgC and decrease trend ???
c.f. Reported oceanic variation on flux is about +0.4 PgC What is possible causes ?
If we set Oceanic sink variation to be Zero How much percent we have to change the parameters such as Discrimination factor? It is most important for both disequilibrium and biological uptake term.1) Discrimination for CO2 uptake by plants fractionation factor decreases? C4 plant fraction to C3 plant increase? 2) Gross primary production decreases or increase?
-19.1
-19
-18.9
-18.8
-18.7
-18.619
95
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
Dis
crim
inat
ion
expe
cted
(per
mil)
-12
-10
-8
-6
-4
-2
0
2
SO
I
0.2 per mil decrease can be possibleby high T and low humidity , but Gross primary production can not decrease by corresponding amount (over 50%)
SOI
Apparent variation of oceanic sink can be compensated by biological discrimination adjustment by up to 0.2 per mil
-1.5
-1
-0.5
0
0.5
1
1.5
219
95
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
delta
18O
tren
d (p
er m
il)
-19
-16
-13
-10
-7
-4
-1
2
-25
-15
-5
5
15
25
35
45
55
SOI
Delta 18O trend showed some increase over 10 years
SOI
El N
ino
Increase delta 18O of water? GPP decrease?
Conclusion
(1) Ten-year observation of CO2 and isotopes over Western Pacific from 30S to 50N was conducted by using 8 commercial cargo ships.
(2) By simple carbon budget equations using isotopic data, oceanic and terrestrial uptake amounts were estimated. Oceanic sink was relatively stable but still had 1Pg-C variation. Terrestrial sink seemed to decrease rapidly by higher and more dry condition at El Nino event. Apparent oceanic fluctuation may be partly caused by the change of C isotopic discrimination due to climatic condition.
(3) Oxygen isotope ratio showed increasing trends in all latitude during 10 years. It was different tendency from that of 1990’s. It may be related to high
temperature and low humidity tendency including lower GPP in recent years.
(4) Carbon-14 measurements will give an another angle to look at carbon budget. Further analysis is needed.
(5) Seasonal variations of CO2 and carbon isotope ratio were large in Northern Hemisphere but small in Southern Hemisphere. Isotope fractionation factor was about –19 per mil on average, but –14 per mil in 20S, which showed some C4 plants effect at that latitude. (not shown)
-30-28-26-24-22-20-18-16-14-12-10
-30 -20 -10 0 10 20 30 40 50
Latitude
delta
13C
(per
mil)
Keeling Geometric mean Tanskeeling classic Delta (Tans )Delta (Keeling Classic) Delta (Geometric mean)
Seasonal component and biological discrimination
Source and sink delta 13C
Apparent Biological discrimination -19 per mil
CF: Merland
δF: -28 per mil (estimated)
εas: 1.8 per mil
εab: 19 per mil
Gb: 125PgC/y
Go: 90PgC/y
Disequilibrium Sea-Atmosphere: 0.6 per mil
Disequilibrium Terrestrial biosphere-Atmosphere: 0.394 as standard case
355
360
365
370
375
380
385
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
CO
2 tre
nd (p
pm)
-25
-15
-5
5
15
25
35
45
55
CO2 trend in each latitude
-8.5
-8.4
-8.3
-8.2
-8.1
-8
-7.9
-7.8
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
delta
13C
trend
(per
mil)
-25
-15
-5
5
15
25
35
45
55
13C isotope ratio trend in each latitude
Oxygen isotope ratiode
lta 18
O
-4
-2
0
2
4
6
8
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Flux
(Gt-C
/ y)
, SO
IAnthropogenic CO2 input Land
Ocean CO2 in the atmosphere
Land
Ocean
Atmosphere
Sampling inlet