Atmospheric Chemistry, Global Change and IGBP

1. Atmospheric Chemistry, Global Change and IGBP Guy P. Brasseur Max Planck Institute for Meteorology, Hamburg and International Geosphere-Biosphere Programme

2. Outline • The Past 50 Years • Towards a Systemic Approach: IGBP • Atmospheric Chemistry: Themes for the Future: • Oxidizing Power of the Atmosphere • Chemistry-Climate Interactions • Long-range Transport of Pollutants • Stratospheric Ozone Recovery • Conclusions

3. The Past 50 Years

4. 1950’s • The atmosphere was viewed as a chemical inert fluid • that moves heat, momentum and moisture • that transports pollutants away from cities • Importance of photochemistry limited to the upper atmosphere (ionosphere) • Urban Photochemistry (LA smog)

6. 1970’s • The atmosphere started to be seen as a chemically dynamic system • New analytic instrumentation • New measurements of chemical rate constants • Simple atmospheric models

7. 1970’s • Stratospheric ozone became a major scientific issue • Aircraft NOx • Industrially manufactured CFCs • Photochemistry of tropospheric ozone started to be investigated at the global scale.

8. 1980’s • Discovery of the stratospheric ozone hole and role of heterogeneous chemistry • Potential importance of greenhouse gases other than CO2 in the climate system • Recognition that air pollution is becoming a global issue

9. The Antarctic Ozone Hole 1970-1997

10. The atmospheric concentration of greenhouse gases (CO2, CH4, N2O) is increasing in response to human activities

11. Air Pollution becomes a global problem

12. 1990’s Role of the biosphere for the chemistry of the troposphere (e.g., biogenic hydrocarbons) • Role of chemical compounds (including aerosols) in the climate system • Aerosols and cloud microphysics

14. The Chemical Reactor in the Tropics

15. Radiative Forcing (IPCC, 2001)

16. Crystalshattering Evaporation * Crystal collection * * * * * Collection Coalescence SO2 Diffusion SO4- Nucleation Aerosols, cloud condensation nuclei particles, clouds and precipitation Cycle: Vegetation (VOCs) – aerosols- CCN - clouds - precipitation Modified after Hegg 2001

17. 1990’s • New research infrastructure and approaches for tropospheric studies • Spacecraft • Surface networks • Large airborne campaigns • Comprehensive chemical-transport models • International efforts (e.g., IGAC)

18. Integration of Measurements and Modeling Satellites (GOME, MOPITT) Aircraft (MOZAIC, NOXAIR) Lidar, Sondes 3-D Chemistry-Transport Models Export Import Emissions Surface Measurements Deposition USA EUROPE ASIA

20. Towards a Systemic Approach: IGBP

22. IGBP Objective • To describe and understand Earth System dynamics • focusing on the interactive biological, chemical and physical processes • the changes that are occurring in these dynamics • and the role of human activities in these changes

23. Towards IGBP II • IGBP II: • New questions • New structure • New partners • New people

24. Characteristics of the New IGBP • More integrative, more interdisciplinary • Global change versus climate change • Strong base in biogeochemical sciences • More emphasis on issues of societal concern • More emphasis on the regional scale • Strategic partnerships via the Earth System Science Partnership (ESS-P)

25. Structure of the New IGBP

26. Atmosphere: IGAC • What is the role of atmospheric chemistry in amplifying or damping climate change? • What effects do changing emissions and deposition, long-range transport, and transformations have on the chemical composition of the atmosphere and on air quality?

27. Landunder development • What are the drivers and dynamics of variability and change in terrestrial human-environment systems? • How is the provision of environmental goods and services affected by changes in terrestrial human-environment systems? • What are the characteristics and dynamics of vulnerability in terrestrial human-environment systems? New Land Project and LUCC

28. Oceansunder development • 1. How does global change, represented by natural and anthropogenic forcings, impact marine biogeochemical cycles and ecosystem dynamics? • 2. How do these impacts alter the mechanistic relationship between elemental cycling and ecosystem dynamics? • 3. What are the feedback mechanisms to the Earth System from these changes? New Ocean Project and GLOBEC

29. Ocean-Atmosphere: SOLAS • Biogeochemical interactions and feedbacks between ocean and atmosphere • Exchange processes at the air-sea interface and the role of transport and transformation in the atmospheric and ocean boundary layers • Air-sea flux of CO2 and other long-lived radiatively active gases

30. Land-Atmosphere: iLEAPSunder development • Goals: • How do interacting physical, chemical and biological processes transport and transform energy and materials through the land-atmosphere system? • What are the implications for the dynamics of the Earth System? • How are human activities influencing the land-atmosphere system (and vice versa)?

31. Land-Ocean: LOICZ Draft Themes: 44% of the world’s population live within 150km of a coastline • River basins and human dimensions • Coastal development and change: implications of land use and sea use changes • Fate and transformation of materials in coastal and shelf waters • System sustainability and resource management issues • Risk and safety

32. Earth System Science Partnership

33. Fast-track Studies • Fast-track Studies will be initiated by the IGBP-SC to address a specific scientific question in a more integrated fashion than at the Core Project level. • A Fast-track study is established for a defined period (often 2-3 years) and produces a seminal paper or 'milestone' book on the topic, something that really advances the field.

34. Fast-track Studies(Adopted in Punta Arenas, Jan. 2003) • Integrated Fire Study (biological, chemical, societal aspects) • The Global Nitrogen cycle in the Eath System • The Global Iron cycle in the Earth System • Contaminants (e.g., Mercury) in the Earth System

35. Atmosphere Stratospheric Effects PM & Visibility Effects Ozone Effects NOx GH Effects Energy Production N2O Terrestrial Ecosystems NOx NH3 Food Production NHx Agroecosystem Effects Forests & Grassland Crop Animal People (Food; Fiber) Soil Soil Norg NO3 N2O Groundwater Effects Human Activities The Nitrogen Cascade Surface water Effects Ocean Effects Coastal Effects Aquatic Ecosystems --Indicates denitrification potential

36. An IRS must: • assess the influence of regional processes on Earth System functioning (and vice-versa) • be integrative (natural and social sciences, all components of the Earth System, planning to synthesis) • contribute sound scientific understanding in support of sustainable development in the region • be scientifically-driven by scientists in the region, but with global collaboration Integrated Regional Studies

37. Atmospheric Chemistry: Themes for the Future

38. Research Themes • Oxidizing Power of the Atmosphere • Chemistry-Climate Interactions • Long-Range Transport of Pollutants • Stratospheric Ozone Recovery

39. Theme 1 Oxidizing Power of the Atmosphere

40. Stratospheric ozone Wet removal Stratosphere-troposphere exchange Tropospheric Ozone Temperature humidity Changes in tropospheric ozone production and destruction Transport: Interhemispheric& Synoptic mixing Convection Weather patterns HOx NOx ROx Climate induced changes in emissions: NOx, VOC, DMS, halogens, CH4, mineral dust and seasalt. Lightning NOx emissions SURFACE EMISSIONS DRY DEPOSITION-LAND-USE CHANGES

41. O2 + h O3 O3 + h O(1D) O(1D) + N2O  NO NO  NO2 HNO3 Ozone STE In-situ Chemistry(NOx) Ozone and Precursors Strato-sphere NO Tropo-sphere H2OCONOy H2OCONOy

42. Stratosphere-Troposphere ExchangesLidar Measurements in Garmisch – Partenkirchen (D) Stohl and Trickl, 1999

43. Distribution of OH radicals in the atmosphere:This is where most of the self-cleaning of the atmosphere takes place But note: this is model output and has not yet been experimentally validated

44. Theme 2 Chemistry-Climate Interactions

45. Changes in ozone 1750-1990 January (left) July (right) Surface (upper panel) 500 hPa (middle panel) 200 hPa (upper panel) Hauglustaine and Brasseur (2001)

46. O3 Radiative Forcing 2000 – 2100 Gauss et al., 2002

47. Aerosol-Climate

49. Aerosol Climate Interactions Aerosols Atm Heating Surface Shading Surface Climate Hydrologic Cycle Transport Chemistry J.T. Kiehl