1 Study of Air Quality by Ultraviolet Satellite Instruments Pawan K Bhartia NASA Goddard Space Flight Center, Greenbelt, MD, USA Split Antarctic O 3 Hole Mapped by EP/TOMS Presented at U. of Toronto on Jan 11, 2006

2 40 Years of BUV Observations NOAA-9 SBUV-2 NOAA-11 NOAA-14 Nimbus-4 BUV Nimbus-7 SBUV Nimbus-7 TOMS Meteor-3 TOMS NOAA-16 Earth Probe TOMS EOS Aura OMI SCIAMACHY GOME-2 GOME OMPS

3 Impact of satellite maps Visually Compelling Visually Compelling Raises awareness of the issuesRaises awareness of the issues Motivating Motivating Spurs further researchSpurs further research Provides data for model selection & Validation Provides data for model selection & Validation generates confidence in model predictionsgenerates confidence in model predictions

4 A selection of “visually compelling” images from BUV instruments

5

6 Western Fires June 25, 2002 Earth-Probe/TOMS: Aerosol Index

7 Alaska Fires, June 25-27, 2004 SeaWiFS June 27, 2004 TOMS Aerosol Index

8 Smoke from Alaska Fires

Mean trop NO 2 from SCIAMACHY

10 OMI Tropospheric NO 2 Aug 22, 2005 assuming 1.5 km BL Gleason/GSFC ppbv

11 OMI HCHO Chance & Kuruso MODIS Fire Counts

12 Results that have motivated aircraft campaigns, ground- based observations and modeling.

13 Evolution of Polar Ozone

14 Trop O 3 Column from Cloud Slicing

15 Tropospheric Column O 3 from OMI/MLS Total O 3 - Strat Column O 3 October 2004 July 2005

16 SO 2 from explosive eruptions

17 SO 2 concentrations in China 70% of China’s energy is derived from coal burning SO2 emissions increased at a rate 35%/decade in China’s sulfate aerosol loading has increased by 17%/decade in [Massie, Torres and Smith 2004] 65,000 SO 2 tons/day emitted in 1995 [Streets & Waldhof, 2000] OMI 12/24/04

18 Aerosol abs. opt. thickness time Series

19 Extinction Optical Depth Aqua-MODIS RGB Absorption Optical Depth Single Scattering Albedo no abs ext Smoke over Alaska (Aug 21, 2004)

20 Model Validation using BUV data

21 Comparison with Goddard Coupled Chemistry GCM model measurement

22 OMI/MLS and GMI model comparisons OMI/MLS Sept ‘04-Aug ‘05GMI 5-year average

23 Future Operational Missions MetOp (from European EUMETSAT) Polar orbiting Satellite Series MetOp (from European EUMETSAT) Polar orbiting Satellite Series GOME-2 (TOMS-like horizontal res., GOME-like spectral res.)GOME-2 (TOMS-like horizontal res., GOME-like spectral res.) IASI (AIRS-like)IASI (AIRS-like) NPP & NPOESS (NASA/NOAA/DOD) NPP & NPOESS (NASA/NOAA/DOD) OMPS (SBUV & TOMS replacement plus limb scattering)OMPS (SBUV & TOMS replacement plus limb scattering) CRIS (AIRS-like)CRIS (AIRS-like) Must consider these capabilities in future mission planning

24 New Mission Requirements Stratosphere & Upper Troposphere Stratosphere & Upper Troposphere Large no of chemical species, high vert. res., limited spatial/temporal res.Large no of chemical species, high vert. res., limited spatial/temporal res. Solar (or stellar) occultation in VIS (like SAGE, POAM, MAESTRO) and FTIR (like ACE) Solar (or stellar) occultation in VIS (like SAGE, POAM, MAESTRO) and FTIR (like ACE) wave limb sounder wave limb sounder Lower Troposphere Lower Troposphere High spatial/temporal res. ???High spatial/temporal res. ??? Geostationary or higher altitudes Geostationary or higher altitudes

25 Case for Geostationary and other High Altitude Orbits Spatial resolution - 10 km or better Temporal resolution- 1 hr or better Less variable FOV- simplifies data interpretation Plume tracking- provides some ht info Cloud avoidance- necessary for BL measurement Cloud slicing- to separate BL from free trop

26 Effects of spatial resolution Maximum values GOME 7x10 15 mol/cm 2 SCIA 17x10 15 mol/cm 2

27 Why do we need time resolution? Air Quality changes during the day. Boston Morning Boston Afternoon

28 Why 1hr time resolution? O 3, aerosols, & precursors change rapidly during the day.

29 GOME Data from U of Heidelberg Bierle Atmos. Chem. Phys. Discuss, 2003 Time Resolution: Remote Sensing of the Sabbath Sun Fri NO 2 is produced by combustion. There is less combustion (energy production) on the “Days of Rest.” Sat

30 Passive degassing of volcanic SO 2 observed by OMI Ambrym volcano, Vanuatu (16.25ºS, ºE) on February 20, 2005.

31 Evolution of NO 2 column over 3 Days 0.1 = 1.0x10 15 mols/cm2

32 Tracking plumes

33 Smoke from S. California Fire

34 Cloud Slicing

35 O 3 Above Deep Convective Clouds in Pacific From: Observation of near-zero O 3 concentrations over the convective Pacific: Effects on air chemistry, Kley et al., Science, Oct 1996.

36 Strat Column O 3 from TOMS and SAGE

37 Detection of Smoke Embedded in Clouds From: Christina Hsu, UMBC

38 Aerosol Detection in presence of clouds OMI Aerosol Index (color) OMI reflectivity (B/W)

39 Mission Concepts

40 Geostationary Mission Concept Tropospheric columns of chemically linked gases O 3, aerosols, CO, CH 2 O, NO 2, & SO 2 ; Simultaneous measurements of non-linear chemistry continental-scale (5000 km x 5000 km, e.g., N. America); ~ 3-5 km resolution; every hour during daylight.

41 International Cooperation Complementary Coverage NASAESANASDA China?

42 Lagrange Points

43 Advantages of L1 Viewpoint Continuous view of the sunlit earth Global coverage at moderate/high spatial/temporal resolution. Benign thermal & radiation environment (except during solar flares) Disadvantages Large aperture- too large for IR Communication problems when Sun is behind the satellite Infrequent downlink- large storage needed

44 Orbit Altitude Tradeoffs Many options available Many options available km (LEO), km (LEO), ,000 km (MEO) ,000 km (MEO) 40,000 (GEO)40,000 (GEO) 0.5 million km (Moon)0.5 million km (Moon) 1.6 million km (L1, L2)1.6 million km (L1, L2) (following spreadsheet shows comparison of 4 representative scenarios.)

45 Orbit Scenarios

46 Orbit Summary 20K km alt equatorial orbit provides daily global coverage, 4-8 hr/pixel temporal coverage, with reasonable aperture size. 20K km alt equatorial orbit provides daily global coverage, 4-8 hr/pixel temporal coverage, with reasonable aperture size. L1 provides daily global coverage, 9+ hr/pixel of temporal coverage, but requires very large apertures, particularly for TIR measurements. L1 provides daily global coverage, 9+ hr/pixel of temporal coverage, but requires very large apertures, particularly for TIR measurements. GEO provides max temporal coverage, but with 1/3rd global coverage. GEO provides max temporal coverage, but with 1/3rd global coverage.

47 Overall Summary Geo or high altitude orbits can provide high spatial and temporal measurements of many species important for AQ. Geo or high altitude orbits can provide high spatial and temporal measurements of many species important for AQ. Lack of vertical resolution is an issue, but cloud slicing and plume tracking can provide important information. Lack of vertical resolution is an issue, but cloud slicing and plume tracking can provide important information. Sensors in polar orbit, UAV, and ground, along with a high res. chemical data assimilation system, are necessary components of a complete mission. Sensors in polar orbit, UAV, and ground, along with a high res. chemical data assimilation system, are necessary components of a complete mission.