Transcript Emissions From The Oceans To The Atmosphere Deposition

Emissions From The Oceans To The Atmosphere
Deposition From The Atmosphere To The Oceans
And
The Interactions Between Them
Tim Jickells
Laboratory for Global Marine and Atmospheric Chemistry
School of Environmental Sciences University of East Anglia
Norwich UK
Outline
CO2 Exchange
Atmospheric Inputs of Nitrogen and Dust to the Oceans
Emissions of Salt and Biogenic Gases from the Ocean
Atmosphere Ocean Feedback Cycles
Global Ocean Colour Composite Image from CZCS scanner
Global Carbon Cycle from IPCC
Reservoirs in GtC and fluxes in GtC/yr
Nitrate Concentrations In Surface Ocean Waters
Deposition to the Ocean
Current Fixed Nitrogen Inputs to the
World Oceans 1012mol yr -1
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•
•
•
•
Source
Biological N2 Fixation
Lightning
Rivers
Atmospheric
•
•
•
•
•
Flux
5.7
0.6
5.4
3.1-7.9
Human Activity has
• had little effect on Biological N2 Fixation and Lightning
• approximately doubled Riverine Inputs
• approximately doubled Inorganic Atmospheric Inputs (NOx and
NH3)
Organic Nitrogen
• About a third, and perhaps more, of the atmospheric N input is
organic.
• The sources and role of aerosol organic material is very uncertain.
Global Ocean Colour Composite Image from CZCS scanner
Fixed Nitrogen Inputs
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Source
Biological N2 Fixation
Lightning
Rivers
Atmospheric
•
•
•
•
•
Flux
5.7
0.6
5.4
3.1-7.9
Atmospheric Inputs of Fixed Nitrogen may be increasing algal
growth rates by only a few percent globally because of the large
reservoirs of nitrate in deep water but if we consider only
“export” production the impact rises to more than 10% in some
areas.
Map of the North Sea
coarse nitrate
fine nitrate
350
450
highly polluted
southeasterly
winds
aerosol ammonium nmol-3m
m
aerosol nitrate nmol -3
300
250
200
150
100
50
400
350
300
250
200
unpolluted
northerly air
150
100
50
0
16-Aug-99
coarse ammonium
fine ammonium
500
0
23-Aug-99
30-Aug-99
06-Sep-99
16-Aug-99
23-Aug-99
30-Aug-99
Nitrate and ammonium concentrations measured in air at the North Sea coast
illustrating the magnitude of pollution events
06-Sep-99
Chlorophyll concentrations in the North Sea based on CZCS Images
Composite satellite image of aerosols over the oceans
Nitrate Concentrations In Surface Ocean Waters
Days since beginning of the experiment
Chlorophyll measurements during the SOIREE experiment in the Southern Ocean
showing dramatic increases in chlorophyll in the iron fertilised area (open circles)
compared to the unfertilised area (dark circles).
Nitrate Concentrations In Surface Ocean Waters
Fixed Nitrogen Inputs
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•
•
•
•
Source
Biological N2 Fixation
Lightning
Rivers
Atmospheric
•
•
•
•
•
Flux
5.7
0.6
5.4
3.1-7.9
Nitrogen Fixation Requires Iron
Emissions From The Oceans
O3
O2
Precipitation
(rain & aerosol)
Reactive Iodine
Pool
I
hu
.
VOI
Bacteria /
Phytoplankton
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IO3
CH2I2
CH3I
I
-
Iodine-Accumulating
Macroalgae
Schematic illustrating the biogeochemical cycle of iodine
including the role of iodine-accumulating macroalgae.
IPCC estimates of the magnitude and uncertainties of radiative forcing on the climate
system.
Days since beginning of the experiment
Chlorophyll measurements during the SOIREE experiment in the Southern Ocean
showing dramatic increases in chlorophyll in the iron fertilised area (open circles)
compared to the unfertilised area (dark circles).
Dimethyl Sulphide (DMS) measurements during the SOIREE experiment in the
Southern Ocean showing dramatic increases in DMS in the iron fertilised area (open
circles) compared to the unfertilised area (dark circles).
Sulphate Aerosol
H2SO4
Radiation
Budget
SO2
DMS
Algae
DMS
Degradation/Loss
Sulphate Aerosol
Ammoniun Sulphate
SO2
Radiation
Budget
NH4+
NH3
DMS
NH3/NH4+
Algae
DMS
Degradation/Loss
Nitrate
Ozone
DUST
FeIIIs FeIId+OH
SO2 +OH H2SO4
Cl
Sulphate Aerosol
Ammonium Sulphate
Sea
Salt
Fe
SO2
Radiation
Budget
NH4+
NH3
DMS
NH3/NH4+
Algae
DMS
Degradation/Loss
Nitrate
Conclusions
• Inputs of material from the continents to the Oceans can
significantly modify ocean biogeochemical processes.
• Emissions of trace gases and salt from the oceans have a
major impact on atmospheric chemistry.
• These emission and deposition processes interact and
may play an important role in climate regulation.