11

Study of Air Quality by Ultraviolet Satellite Instruments

Pawan K BhartiaNASA Goddard Space Flight Center, Greenbelt, MD,

USA

Split Antarctic O3 Hole Mapped by EP/TOMS

Presented at U. of Toronto on Jan 11, 2006

22

40 Years of BUV Observations40 Years of BUV Observations

20101970 1980 1990 2000

NOAA-9 SBUV-2NOAA-11

NOAA-14

Nimbus-4 BUVNimbus-7 SBUVNimbus-7 TOMS

Meteor-3 TOMS

NOAA-16Earth Probe TOMS

EOS Aura OMISCIAMACHY

GOME-2

GOME

OMPS

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Impact of satellite mapsImpact of satellite maps

Visually Compelling Visually Compelling • Raises awareness of the issuesRaises awareness of the issues

MotivatingMotivating• Spurs further researchSpurs further research

Provides data for model selection & Provides data for model selection & ValidationValidation• generates confidence in model generates confidence in model

predictionspredictions

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A selection of “visually A selection of “visually compelling” images from compelling” images from

BUV instrumentsBUV instruments

55

66

Western Fires June 25, 2002

Earth-Probe/TOMS: Aerosol Index

77

Alaska Fires, June 25-27, 2004Alaska Fires, June 25-27, 2004

SeaWiFS June 27, 2004TOMS Aerosol Index

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Smoke from Alaska FiresSmoke from Alaska Fires

QuickTime™ and aYUV420 codec decompressor

are needed to see this picture.

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2003 Mean trop NO2003 Mean trop NO22 from SCIAMACHY from SCIAMACHY

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OMI Tropospheric NOOMI Tropospheric NO22

Aug 22, 2005

assuming 1.5 km BL

Gleason/GSFC

5.62.8ppbv

1111

OMI HCHO OMI HCHO Chance & Kuruso

MODIS Fire Counts MODIS Fire Counts

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Results that have motivated Results that have motivated aircraft campaigns, ground-aircraft campaigns, ground-

based observations and based observations and modeling. modeling.

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Evolution of Polar OzoneEvolution of Polar Ozone

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Trop OTrop O33 Column from Cloud Slicing Column from Cloud SlicingTrop OTrop O33 Column from Cloud Slicing Column from Cloud Slicing

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Tropospheric Column OTropospheric Column O33 from OMI/MLS from OMI/MLS

Total O3 - Strat Column O3

October 2004

July 2005

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SOSO22 from explosive eruptions from explosive eruptions

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SOSO22 concentrations concentrations in Chinain China

• 70% of China’s energy is derived from coal burning

• SO2 emissions increased at a rate 35%/decade in 1979-2000

• China’s sulfate aerosol loading has increased by 17%/decade in 1979-2000 [Massie, Torres and Smith 2004]

• 65,000 SO2 tons/day emitted in 1995 [Streets & Waldhof, 2000]

OMI 12/24/04

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Aerosol abs. opt. thickness time SeriesAerosol abs. opt. thickness time Series

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Extinction Optical Depth Aqua-MODIS RGB

Absorption Optical Depth Single Scattering Albedo

no abs

ext

Smoke over Alaska (Aug 21, 2004)

2020

Model Validation using Model Validation using BUV dataBUV data

2121

Comparison with Goddard Coupled Chemistry GCM

model

measurement

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OMI/MLS and GMI model comparisonsOMI/MLS and GMI model comparisons

OMI/MLS Sept ‘04-Aug ‘05 GMI 5-year average

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Future Operational MissionsFuture Operational Missions

MetOp (from European EUMETSAT) Polar MetOp (from European EUMETSAT) Polar orbiting Satellite Seriesorbiting Satellite Series• GOME-2 (TOMS-like horizontal res., GOME-like GOME-2 (TOMS-like horizontal res., GOME-like

spectral res.) spectral res.) • IASI (AIRS-like)IASI (AIRS-like)

NPP & NPOESS (NASA/NOAA/DOD)NPP & NPOESS (NASA/NOAA/DOD)• OMPS (SBUV & TOMS replacement plus limb OMPS (SBUV & TOMS replacement plus limb

scattering)scattering)• CRIS (AIRS-like)CRIS (AIRS-like)

Must consider these capabilities in future mission planning

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New Mission RequirementsNew Mission Requirements

Stratosphere & Upper TroposphereStratosphere & Upper Troposphere• Large no of chemical species, high vert. Large no of chemical species, high vert.

res., limited spatial/temporal res.res., limited spatial/temporal res. Solar (or stellar) occultation in VIS (like Solar (or stellar) occultation in VIS (like

SAGE, POAM, MAESTRO) and FTIR (like ACE)SAGE, POAM, MAESTRO) and FTIR (like ACE) wave limb sounder wave limb sounder

Lower TroposphereLower Troposphere• High spatial/temporal res. ???High spatial/temporal res. ???

Geostationary or higher altitudes Geostationary or higher altitudes

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Case for Geostationary Case for Geostationary and other High Altitude and other High Altitude

OrbitsOrbits•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

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Effects of spatial resolutionEffects of spatial resolution

Maximum values

GOME 7x1015 mol/cm2

SCIA 17x1015 mol/cm2

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Why do we need time resolution?Why do we need time resolution?

Air Quality changes during the day.

Boston Morning Boston Afternoon

2828

Why 1hr time resolution?Why 1hr time resolution?

O3, aerosols, &

precursors

change rapidly

during the day.

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GOME Data from U of Heidelberg Bierle Atmos. Chem. Phys. Discuss, 2003

Time Resolution: Remote Sensing of the Sabbath

Sun Sun Fri

NO2 is produced by combustion.There is less combustion (energy production) on the “Days of Rest.”

Sat

3030

PPassive degassing of volcanic SOassive degassing of volcanic SO22

observed by OMIobserved by OMI

Ambrym volcano, Vanuatu (16.25ºS, 168.12ºE) on February 20, 2005.

3131

Evolution of NOEvolution of NO22 column over 3 Days column over 3 Days

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

0.1 = 1.0x1015 mols/cm2

QuickTime™ and aYUV420 codec decompressor

are needed to see this picture.

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Tracking plumesTracking plumes

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Smoke from S. California FireSmoke from S. California Fire

QuickTime™ and aYUV420 codec decompressor

are needed to see this picture.

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Cloud SlicingCloud Slicing

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OO33 Above Deep Convective Clouds in Above Deep Convective Clouds in

PacificPacific

OO33 Above Deep Convective Clouds in Above Deep Convective Clouds in

PacificPacificFrom: Observation of near-zero O3 concentrations over the convective Pacific: Effects on air chemistry, Kley et al., Science, Oct 1996.

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Strat Column OStrat Column O33 from TOMS and SAGE from TOMS and SAGEStrat Column OStrat Column O33 from TOMS and SAGE from TOMS and SAGE

3737

SeaWiFS True ColorTOMS Aerosol Index

Laos

Thailand

Vietnam

Southern China

Taiwan

21 March 1999

A Frequent Flyer+: the typical pathway

Cambodia

Detection of Smoke Embedded in CloudsDetection of Smoke Embedded in CloudsFrom: Christina Hsu, UMBCFrom: Christina Hsu, UMBC

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Aerosol Detection in presence of Aerosol Detection in presence of cloudsclouds

OMI Aerosol Index (color)OMI reflectivity (B/W)

3939

Mission ConceptsMission Concepts

4040

Geostationary Mission Concept

• Tropospheric columns of chemically linked gases

• O3, aerosols, CO, CH2O, NO2, & SO2;

• 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.

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International CooperationInternational CooperationComplementary Coverage

NASA ESANASDA

China?

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Lagrange Points

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Advantages of L1 ViewpointAdvantages 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)

DisadvantagesDisadvantages• Large aperture- too large for IR

• Communication problems when Sun is behind the satellite

• Infrequent downlink- large storage needed

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Orbit Altitude Tradeoffs Orbit Altitude Tradeoffs

Many options availableMany options available• 500-1000 km (LEO), 500-1000 km (LEO), • 1000-40,000 km (MEO)1000-40,000 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 (following spreadsheet shows comparison of 4 representative scenarios.) 4 representative scenarios.)

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Orbit ScenariosOrbit ScenariosLEO MEO GEO L1

Altitude (km) 564 20,187 35,784 1,600,000

No. of orbits/day 15 2 1 0

Earth's rel motion (/orbit) 24˚ -360˚ 0 360˚

Max scan angle (sat za=70˚) 59.7 13.0 8.2 0.2

Swath (km) 2,293 12,662 13,742 15,508

Obs. Time (hr/pixel)- TIR 0.09 7.6 24.0 9.3

Obs. Time (hr/pixel)- UV/VIS/NIR 0.09 5.7 12.0 9.3

Daily Spatial Coverage global global 13,742 km global

Sun-glint obs all lats sub-solar lats sub-solar lats sub-solar lats

Multi-angle obs all lats tropics No tropics

Aperture in cm (2000:1 S/N) 1 36 63 2,837( 5 km pixel, 0.5 sec integ time)

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Orbit SummaryOrbit Summary

20K km alt equatorial orbit provides daily 20K km alt equatorial orbit provides daily global coverage, 4-8 hr/pixel temporal global coverage, 4-8 hr/pixel temporal coverage, with reasonable aperture size.coverage, with reasonable aperture size.

L1 provides daily global coverage, 9+ L1 provides daily global coverage, 9+ hr/pixel of temporal coverage, but requires hr/pixel of temporal coverage, but requires very large apertures, particularly for TIR very large apertures, particularly for TIR measurements.measurements.

GEO provides max temporal coverage, but GEO provides max temporal coverage, but with 1/3rd global coverage.with 1/3rd global coverage.

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Overall SummaryOverall Summary

Geo or high altitude orbits can provide Geo or high altitude orbits can provide high spatial and temporal measurements high spatial and temporal measurements of many species important for AQ.of many species important for AQ.

Lack of vertical resolution is an issue, but Lack of vertical resolution is an issue, but cloud slicing and plume tracking can cloud slicing and plume tracking can provide important information.provide important information.

Sensors in polar orbit, UAV, and ground, Sensors in polar orbit, UAV, and ground, along with a high res. chemical data along with a high res. chemical data assimilation system, are necessary assimilation system, are necessary components of a complete mission. components of a complete mission.