1. Envisat for the chemistry in our atmosphere John Burrows University of Bremen, Germany

2. Atmospheric Chemistry on Envisat Contents • Atmospheric Chemistry & Climate • Motivation for satellite borne experiments • Global Atmospheric Scientific and Policy Issues for the Next Decade • The European Response to Global Atmospheric Chemistry Needs • Atmospheric Chemistry missions on Envisat • Targeted Scientific Products from ENVISAT • Conclusions

3. Ozone is the most important trace atmospheric gas, determining the UV flux at the Earth’s surface, the height of the tropopause (thereby the weather), initiating the tropospheric oxidation of anthropogenic and natural emissions etc. Atmospheric Chemistry & Climate (1) The earth’s atmosphere is a complex system. Chemical, physical and biological processes determine the climate. Conditions at the Earth’s surface are determined by the chemical composition of the atmosphere.

4. Atmospheric Chemistry & Climate (2) The reduction in stratospheric ozone over Europe and the entire globe is the direct result of anthropogenic emissions of Chlorofluorcarbon compounds CFCs. The phenomena known as the stratospheric ozone hole results from CFC emissions. Conversely, pollution at the Earth’s surface has led to summer smog and increased tropospheric ozone amounts. Tropopsheric Ozone is both a greenhouse gas and toxic.

5. Atmospheric Chemistry & Climate (3) bio-mass burning fossil fuel burning (industry) volcanic eruptions HCHO, NO2, Aerosol and SO2 are tracers for:

6. Atmospheric Chemistry & Climate (4) The Greenhouse Effect causes Global warming of the troposphere due to absorption of the Earth’s infrared radiation by Greenhouse gases. IPCC recommends (2001): Sustain and expand the observational foundation for climate studies by providing accurate, long-term, consistent data including implementation of a strategy for integrated global observations. The amounts of radiatively active gases CO2, CH4, N2O and CFCs etc. are being modified directly and indirectly by anthropogenic activity and natural phenomena e.g. volcanic eruptions.

7. Global Atmospheric Scientific and Policy Issues for the Next Decade 1 The response of Stratospheric Ozone to the limits imposed by the Montreal Protocol and its amendments. 2 The role of Anthropogenic Emissions (Industrial Pollution and biomass/biofuel burning) and their impact on tropospheric Chemistry and Global Climate Change. In particular in the Tropics and sub Tropics!! 3 The coupling of Global Warming, tropopause height and stratospheric chemistry - tropospheric -stratospheric coupling 4 Natural Phenomena (Volcanic Eruptions, Solar Proton Events) and their Impact on the Atmosphere.

8. Coverage: The atmosphere is a global phenomenon, thus the measurement of key species and parameters are required on a global scale. Continuity of Data-sets: Long time series are required to establish trends and changes in trends e.g. ozone measurements from ESA-ERS-2-GOME and NASA-TOMS. Key Components: Measurements of key species and parameters are required to constrain and improve the prediction of atmospheric models. Policy and Policymaking: To monitor compliance with international and European treaties designed to limit anthropogenic emissions (Montreal, Kyoto, EU directives etc.) Motivation for satellite borne experiments

9. The European Response to Global Atmospheric Chemistry Needs ESA began its measurements of significance for Global Atmospheric Chemistry with GOME (Global Ozone Monitoring Experiment) on ERS-2, launched in 1995. GOME is a small scale version of SCIAMACHY - proof of concept The ENVISAT is the first large European Space Mission to have a focus on Measurements relevant to global Atmospheric Chemistry Research. Its instrumentation aims to initiate the long term measurements of critical constituents and parameters. The ENVISAT instrumentation represents a unique opportunity for a generation of atmospheric scientists.

10. GOMOS: Global Ozone Monitoring by Occultation of Stars MIPAS: Michelson Interferometer for Passive Atmospheric Sounding SCIAMACHY: Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (AO Instrument, provided to ESA by Germany, The Netherlands and Belgium.) Envisat MIPAS SCIAMACHY GOMOS Atmospheric chemistry missions on Envisat (1)

11. F(zi) T(zi) = Intensity Intensity Fo F(z1) F(zi) Intensity Transmission Fo Wavelength Wavelength Wavelength Wavelength Atmospheric chemistry missions on Envisat (2) The Envisat atmospheric chemistry mission are complementary: GOMOS will primarily provide highly accurate profiles of stratospheric ozone, preferably at altitudes above 15 km. Additional profiles: NO2, NO3, H2O and Temperature. Fo 60 Km z 40 Km F(z) 20 Km

12. Atmospheric chemistry missions on Envisat (3) MIPAS, operating in the mid-infrared, will provide highly accurate temperature profiles and a number of key species including most of the NOx family. Making emission measurements it observes both by day and by night .

13. Atmospheric chemistry missions on Envisat (4) SCIAMACHY will make unique measurements for its target constituents (profiles and total columns) throughout the stratosphere and troposphere. It will thereby yield the amounts and distributions of trace gas and aerosol in the troposphere.

14. tropospheric O3 and its precursors (NOx, CO, H2O, CH4, UVA, UVB...) stratospheric ozone production and destruction cycles the dynamics of the stratosphere. tropospheric / stratospheric exchange processes Atmospheric chemistry missions on Envisat (5) The atmospheric instruments will be used to investigate:

15. the global distribution of many important greenhouse gases (H2O, CO2, CH4, N2O, CFCs...) in the lower atmosphere and thereby investigate their impact on global climate change the physics and chemistry of the mesosphere the improvement of the accuracy of numerical weather prediction, using the global measurements of pressure, temperature fields, H2O and O3 made in near real time. Atmospheric chemistry missions on Envisat (6)

16. Atmospheric chemistry missions on Envisat (7) 03 H20 NO2 NO3 N2O CH4 HNO3 CO CO2 BrO p,T Aerosol 100 90 80 70 60 50 40 30 20 10 0 Thermosphere. Mesosphere. Altitude (Km) Stratosphere. O3layer Stratosphere. Troposphere. GOMOS MIPAS SCIAMACHY Operational routine products from GOMOS, MIPAS and SCIAMACHY

17. Targeted Scientific Products from ENVISAT Clear colours:operational Shaded colours: further scientific targets GOMOS: Stratosph. MIPAS: upper Troposph. - lower Mesosphere SCIA:Troposph. - lower Mesosph.

18. Conclusions ENVISAT is a unique scientific platform, which will • improve our understanding of • the chemistry and physics of the atmosphere • global climate change • the coupling of global warming with stratospheric chemistry. • increase the accuracy of numerical weather forecasting by the provision of simultaneous measurements of key constituents in NRT. • Facilitate the monitoring of international environmental agreements (Montreal, Kyoto, EU directives etc.) and assist policymakers.