1. 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

2. Outline CO 2 Exchange Atmospheric Inputs of Nitrogen and Dust to the Oceans Emissions of Salt and Biogenic Gases from the Ocean Atmosphere Ocean Feedback Cycles

3. Global Ocean Colour Composite Image from CZCS scanner

4. Global Carbon Cycle from IPCC Reservoirs in GtC and fluxes in GtC/yr

5. Nitrate Concentrations In Surface Ocean Waters

6. Deposition to the Ocean

7. Current Fixed Nitrogen Inputs to the World Oceans 10 12 mol yr -1 Source Biological N 2 Fixation Lightning Rivers Atmospheric Flux 5.7 0.6 5.4 3.1-7.9

8. 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. Human Activity has had little effect on Biological N 2 Fixation and Lightning approximately doubled Riverine Inputs approximately doubled Inorganic Atmospheric Inputs (NO x and NH 3 )

9. Global Ocean Colour Composite Image from CZCS scanner

10. Fixed Nitrogen Inputs Source Biological N 2 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.

11. Map of the North Sea

12. Nitrate and ammonium concentrations measured in air at the North Sea coast illustrating the magnitude of pollution events 0 50 100 150 200 250 300 350 16-Aug-9923-Aug-9930-Aug-99 aerosol nitrate nmol m -3 coarse nitrate fine nitrate highly polluted southeasterly winds 0 50 100 150 200 250 300 350 400 450 500 16-Aug-9923-Aug-9930-Aug-9906-Sep-99 aerosol ammonium nmol m -3 coarse ammonium fine ammonium unpolluted northerly air 06-Sep-99

13. Chlorophyll concentrations in the North Sea based on CZCS Images

14. Composite satellite image of aerosols over the oceans

15. Nitrate Concentrations In Surface Ocean Waters

16. 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). Days since beginning of the experiment

17. Nitrate Concentrations In Surface Ocean Waters

18. Fixed Nitrogen Inputs Source Biological N 2 Fixation Lightning Rivers Atmospheric Flux 5.7 0.6 5.4 3.1-7.9 Nitrogen Fixation Requires Iron

19. Emissions From The Oceans

20. Schematic illustrating the biogeochemical cycle of iodine including the role of iodine-accumulating macroalgae. CH 2 I 2 O3O3 O2O2 CH 3 I Precipitation (rain & aerosol) Reactive Iodine Pool hh VOI I.I. I-I- IO 3 - Iodine-Accumulating Macroalgae Bacteria / Phytoplankton

21. IPCC estimates of the magnitude and uncertainties of radiative forcing on the climate system.

22. 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). Days since beginning of the experiment

23. 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).

24. Algae DMS Degradation/Loss DMS SO 2 Sulphate Aerosol H 2 SO 4 Radiation Budget

25. Algae DMS Degradation/Loss DMS SO 2 Sulphate Aerosol Ammoniun Sulphate Radiation Budget Nitrate NH 3 /NH 4 + NH 3 NH 4 +

26. Fe Algae DMS Degradation/Loss DMS SO 2 Sulphate Aerosol Ammonium Sulphate Radiation Budget Nitrate NH 3 /NH 4 + NH 3 NH 4 + DUST FeIII s FeII d +OH SO 2 +OH H 2 SO 4 Sea Salt Cl Ozone

28. 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.