atoc 220 the contemporary global carbon cycle the contemporary record of atmospheric co 2 –the...
TRANSCRIPT
![Page 1: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/1.jpg)
ATOC 220The Contemporary
Global Carbon Cycle
• The contemporary record of atmospheric CO2– The best ‘known’, ‘beautiful’ and ‘most
disturbing’ graphs in all of geoscience• Overall C cycle
– Terrestrial component of the C cycle– Ocean component of the C cycle
• Putting it all together to explain the contemporary record of change in atmospheric CO2
Professor NT Roulet, November 20, 2006
![Page 2: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/2.jpg)
Seasonal fluctuation in atmospheric CO2
(at Mauna Loa, Hawaii)
![Page 3: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/3.jpg)
Black: pre-industrial Red: + industrial era up to ~1990
Sedimentary rock40,000,000 (CaCO3)
(IPCC, 2006)
Global Carbon Cycle
![Page 4: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/4.jpg)
• C is stored in different reservoirs and is exchanged between these reservoirs.
• Material enters & leaves at certain rates.
• Material remains in a reservoir temporarily.
Residence time of material
Reservoir volume (at steady state) flow rate
inflow outflow
=
reservoir volume
![Page 5: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/5.jpg)
Carbon storage & transfer in a terrestrial ecosystem
Atmosphere
Primaryproducers
Consumers
Deadorganic matter
Soil
![Page 6: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/6.jpg)
Atmospheric CO2
590 (751) Gt COutflow:60 Gt C/yr
Inflow:60 Gt C/yr
Respiration &decomposition
Photosynthesis
C exchange between atmosphere & terrestrial plants
600 Gt C1700 Gt C
![Page 7: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/7.jpg)
AtmosphericCO2
590 (751) Gt C
60 Gt C/yr 60 Gt C/yr
C exchange between atmosphere & the terrestrial biosphere
Residence time of C in terrestrial biosphere
reservoir size flow rate
600 (2300) Gt 60 Gt/yr
=
=10 (38) yrs
Live terrestrial C has a residence time of ~10 yrs (total terrestrial C ~ 40 yrs)
600 Gt C
1700 Gt C
![Page 8: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/8.jpg)
Rondonia (Amazon)
1975
1986
1992
![Page 9: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/9.jpg)
Forest Regrowth
Pool changes were evaluated as the difference between the late 1990s and early 1980s pool estimates, pixel-by-pixel, and quoted on a per year basis.The carbon pool in the woody biomass of northern forests (1.5 billion ha) is estimated to be 61 20 Gt C during the late 1990s.
Our sink estimate for the woody biomass during the 1980s and 1990s is 0.680.34 Gt C/yr.http://cybele.bu.edu/greeningearth/ge.html
![Page 10: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/10.jpg)
Step 1convert absorbed radiation to optimal gross production
Step 2downgrade by climate limiting
factors to obtain gpp
Step 3subtract respiration to obtain npp
Average of interannual trends (1982-99) in growing season NPP estimated with GIMMS and PAL (v3) FPAR
Trends in NPP are positive over 55% of the global vegetated area and are statistically more significant than the declining trends
observed over 19% of the vegetated area.
The NPP Algorithm
http://cybele.bu.edu/greeningearth/ge.html
![Page 11: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/11.jpg)
1. The marine biological pump
Deep Ocean
Ocean surface
atmospheric CO2
Phytoplankton
sedimentationof organic C
BacterialdecompositionCO2
Nutrients
upwelling
![Page 12: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/12.jpg)
2. The solubility pump
Ocean surfaceAtmosphere
H2CO3 H+ + HCO3-
HCO3- H+ + CO3
2-
CO2
CO2 + H2O H2CO3
bicarbonate
carbonate
carbonic acid
![Page 13: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/13.jpg)
CO2(aq) dissociates rapidly into DIC while increasing acidity: pH
K1 K2
CO2 + H2O HCO3- + H+ CO3
2- + 2H+
Bjerrum Plot:pH = 8.1
T = 250C, S = 35 [CO2] : [HCO3
-] : [CO3=]
0.5% : 86.5% : 13%
(Zeebe & Wolf-Gladrow, 2002)
bicarbonate carbonate
![Page 14: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/14.jpg)
Ocean surfaceAtmosphere
H2CO3 H+ + HCO3-
CO2
CO2 + H2O H2CO3
Ca2+ + 2HCO3- CaCO3 + H2CO3
shelled organisms
The solubility pump &calcium carbonate formation
![Page 15: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/15.jpg)
Ca2+ + 2HCO3- CaCO3 + H2CO3
rockweathering
solubilitypump
shelled organisms
Sediments
![Page 16: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/16.jpg)
Foraminiferans (Protozoa)
• <0.5 mm in size.
• live in the plankton & in the sediments.
• feed on bacteria.
• produce ~1 billion tons of CaCO3 per yr.
![Page 17: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/17.jpg)
Coccolithophores (algae)• planktonic• produce 1.5 million tons of CaCO3 per yr• sometimes form “blooms” at the ocean surface which reflect visible light
SeaWiFS image 16 July 2000
![Page 18: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/18.jpg)
Atmospheric CO2
590 (751) Gt C
Outflow:70 (20) Gt C/yr
Inflow:70 (22) Gt C/yr
Gas exchange Gas exchange
C exchange between atmosphere & the ocean
3 Gt C
900 Gt C
![Page 19: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/19.jpg)
AtmosphericCO2
590 (751) Gt C
70 (90) Gt C/yr 70 (90) Gt C/yr
C exchange between atmosphere & the ocean
Residence time of C in surface ocean
reservoir size flow rate
900 Gt 170 (190) Gt/yr
=
=5 (4.7) yrs
3 Gt C900 Gt C
90 Gt C/yr
11 Gt C/yr101 Gt C/yr
![Page 20: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/20.jpg)
AtmosphericCO2
590 (751) Gt C
70 (90) Gt C/yr 70 (90) Gt C/yr
C exchange between atmosphere & the ocean
3 Gt C900 Gt C
90 Gt C/yr
11 Gt C/yr101 Gt C/yr
One more issue
How can you have more organic C export than exists in living biomass?
![Page 21: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/21.jpg)
Ocean net primary production
Global Ocean NPP ~ 50 to 60 Gt C/yr
Therefore if the living biomass is 3 Gt C it means the residence time of the plankton < a few weeks
NP
P g
C/m
2 /yr
![Page 22: ATOC 220 The Contemporary Global Carbon Cycle The contemporary record of atmospheric CO 2 –The best ‘known’, ‘beautiful’ and ‘most disturbing’ graphs in](https://reader033.vdocuments.net/reader033/viewer/2022052702/56649f305503460f94c4b9b4/html5/thumbnails/22.jpg)
Pulling this all together
• Terrestrial system exchanging ~ 60 Gt C/yr with the atmosphere but with a definite seasonality
• Ocean system exchanging ~ 90 Gt C/yr with the atmosphere of ocean NPP forms part of the uptake and solubility the rest