1. Biosphere/Atmosphere Interactions in the Tropics

4. NO emission from soil VOC emitted from leaf surface O 3 deposition to leaf surface O 3 and NO 2 deposition to stomata NO + O 3  NO 2 + O 3 NO + O 3  NO 2 + O 2 NO 2 + O 2  NO + O 3 RO’ 2 + NO  RO’ + NO 2 NO, NO 2, O 3, VOC hv VOCNO NO 2 NO O3O3 O3O3 Modified after Coe et al. 1993 HNO 3 NH 3 HONO?

5. OH and the Amazon, an untested hypothesis

6. Some Questions What are the timescales of transport and chemical processes in nitrogen cycling between ecosystems and atmosphere? How do they interact to determine N species flux in and out the ecosystems? How does ecosystem exchange on VOC and N species affect the atmospheric oxidant cycle?

7. CCN sources in the “clean” tropics: Dust, Sea Spray: Over the humid continental tropics, too few to be important Marine biogenic sulfate (from DMS): Probably important some of the time Terrestrial biogenic sulfate (from DMS and H 2 S): May play a key role in providing soluble aerosol component Secondary Organic Aerosol: May provide a significant part of aerosol mass, but mode of particle formation still under question Primary biogenic aerosol: Bacteria, spores, plant debris may account for a large fraction of aerosol mass and number!

8. CCN Efficiency Spectra

9. Pyrogenic CCN have pronounced impact on cloud droplet size spectra!

10. Aerosol pollution increases the height where cloud drops grow big enough to grow by coagulation and form “warm” rain (Andreae et al., SCIENCE, 2004)

11. Some Questions What is the source of “background” Amazonian aerosols, and what are their properties? What determines the cloud droplet and ice nucleating ability of Amazonian aerosols? How do aerosols affect the formation and properties of ice phase in clouds over Amazonia? How do aerosols affect rainfall amount and rain rate over Amazonia?

12. Compare flash rates in January...

13. … and in September

14. How does smoke get into the stratosphere?? Simulation of a Pyrocumulus Blowup Potential Temperature on the 100 µg/m³ aerosol-isosurface

15. Some Questions Do aerosols affect the amount and distribution of lightning over Amazonia? Does this affect the chemical properties of the atmosphere? Do fires and aerosols affect the intensity of deep convection in the tropics? Is this important for the chemistry and physical properties of the UTLS?