Future Stratosphere/Troposphere Research with Suborbital Platforms

1. Future Stratosphere/Troposphere Research with Suborbital Platforms David Fahey NOAA Earth System Research Laboratory Boulder, CO and Elliot Weinstock Thomas Hanisco Harvard University Cambridge, MA NASA Future Suborbital Activities Meeting Virginia Beach, VA March 8-9, 2007

2. Stratosphere/Troposphere Research with Suborbital Platforms • How will UT/S ozone and surface UV respond to climate variability and change? Major science question Unifying theme for UT/S measurements from orbital and suborbital platforms Unifying theme for 2-D, CTM and CCM modeling efforts • Future UT/S ozone amounts are the bellwether of UT/S climate change. Developing skill for ozone changes will require understanding of a broad range of processes.

3. NASA Future Suborbital Activities Meeting, VA Beach, March 2007

4. Figure SPM-2 IPCC Summary for Policymakers, AR4, 2007.

5. Ozone Radiative Heating and Climate Change Sensitivity Portmann et al., GRL, 2007 10 DU/km change 10%/km change Forster and Shine, JGR, 1997

6. Trends in Future Ozone Amounts Year 2000 ozone values (ppbv) • Year 2100-2000 ozone • values (ppbv) • - x 2 CO2 • - STE increases by 80% • PO3 increased by 25% • in troposphere Figure 1. Annual and zonal mean distribution of O3 for 2000 (a); annual and zonal mean changes in O3 (b) between 2000 and 2100 without climate change (B–A); (c) between 2000 and 2100 with a double CO2 climate (C–A); and (d) between 2100 and 2100 with a double CO2 climate (C–B). Units in ppbv. Thick line shown is the contour of 150 ppbv O3, a conventional measure of the chemical tropopause. Zeng and Pyle GRL 2003.

7. ECMWF tropopause height, 00 UTC July 10, 2006, with NLDN lightning flashes overlain. Histogram shows tropopause height above the flashes. Tropopause height above all 11 million NLDN cloud-to-ground lightning flashes during July, 2006 Two recent studies have demonstrated through measurements and modeling that an upper tropospheric ozone maximum exists above the southern USA during summer. Anthropogenic emissions and subsequent free tropospheric ozone production are partly responsible. However most of the enhancement is due to ozone production from lightning NOx emissions that overwhelmingly dominate the upper tropospheric NOx budget in summer. Li et al. (2005), North American pollution outflow and the trapping of convectively lifted pollution by upper-level anticyclone, JGR Cooper et al. (2006), Large upper tropospheric ozone enhancements above midlatitude North America during summer, JGR Average ozone within the troposphere at 10-11 km, August, 2006, contoured from daily IONS ozonesonde measurements. Owen Cooper, 2007

8. Orbital and Suborbital Platforms Glory Satellite: Aerosol Polarimetry Sensor Total Irradiance Monitor (Scheduled for 2008) WB-57F DC-8 ER-2 P3 G-Vs UAS

9. Table 9.2 Status of major climate variables and forcing factors • Total solar irradiance • Earth radiation budget • Surface radiation budget • Tropospheric aerosols • Stratospheric aerosols Earth Science Applications from Space, NRC, 2007

10. Table 9.2 Status of major climate variables and forcing factors • Cloud properties • Ozone: strat and trop • Trace gases controlling ozone • CO2 • CH4 Earth Science Applications from Space, NRC, 2007

11. Human health Climate and its coupling to chemistry, radiation and dynamics Water resources Weather and severe storms Solid Earth hazards Land use, Ecosystems, Airborne and water borne toxicity UV dosage levels Optical properties of the atmosphere and link to climate Regional temperatures, hurricane intensity, optical properties of atmosphere Earthquakes, volcanoes, tsunamis Science priorities driven by societal needs Critical Observations to Specifically Test Forecast Credibility Decision Structures in Service to Society for: Required Forecasts: • Isotopes, radicals, reactive intermediates • Nitrate, sulfate, organics, heavy metal effluents globally • Cloud properties, aerosol composition, size, surface properties Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, National Research Council, 2007

12. Transport and dynamics of water vapor and trace species Mechanisms describing the exchange between the troposphere and stratosphere must be quantified using a combination of isotopes, long-lived tracers, and reactive intermediates.

13. Stratospheric water vapor Discrepancies between in situ, frost point, and remote observations must be resolved. How will the irreversible flux of water vapor into the stratosphere change given increased forcing of the climate system by CO2, CH4, etc? To what degree is stratospheric water influenced by tropopause temperatures and by deep convection? What controls the relative humidity at which ice particles form, grow, and are maintained? How do these processes influence stratospheric water and cloud radiative properties?

14. TTL photochemistry What short-lived trace species are convected to the TTL? H2CO H2O2 (CH3)2CO PAN PNA CH3Br CH3I …? Wennberg et al., 1998 The role of convective injection of short-lived compounds through the tropical tropopause and at midlatitude continental sites must be established.

15. Salawitch, et al., (2005), GRL Annual mean O3 anomaly (%) UV dosage forecast WMO, 2006 Catalytic destruction of ozone under conditions of low temperature and elevated water vapor by halogen radicals must be determined by observing the ClO, BrO and IO concentrations in the lower stratosphere in the presence of elevated water vapor concentrations.

16. Recommended Satellite Observations:Collaborative science requires a sophisticated airborne payload Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, National Research Council, 2007