Insights into Ozone from SHADOZ: Strategic Design, Variability & Role in Model-Observing Systems Dr Anne Thompson NASA/Goddard & SHADOZ Team CMM-U Chile, Nov 04

Presentation Review O 3 “Science Questions,” Definitions Interaction of Models & Observations Design of SHADOZ Network and Key Discoveries = Challenges for Models! > Match Science Questions & Sampling (1998->) Comparison with Satellite Ozone Solve “Wave-one Mystery” Variability in tropospheric ozone (classification need) “Atlantic Paradox”  complexity of processes > Review Science Questions & Modify Network (2004) Preview Integrated Approach: Sondes-Models-Aircraft-Satellites

Issues: - Ozone and Aerosols – Climate, Oxidation, Pollution on Global-Regional-Urban scales - Need predictive capability (models)

Basic Tropospheric Chemistry Initiation: R1:O 3 + h  O( 1 D) + O 2 R2:O( 1 D) + H 2 O  2OH Chain propagation: R3:CO + OH + O 2  HO 2 + CO 2 R4a:HO 2 + NO  NO 2 + OH R4b: HO 2 + O 3  OH + 2O 2 R5:NO 2 + O 2 + h  NO + O 3 Termination: R6:OH + NO 2 + M  HNO 3 + M R7: HO 2 + HO 2  H 2 O 2 + O 2 Net (R1 – R5): R8:O 3 + H 2 O + mCO + (2m 1 -m 2 -1)O 2  mCO 2 + 2OH + (m 1 -m 2 )O 3 m m1m1 m2m2 m1m1 Net Production of O 3 :m 1 > m 2 +1 O 3 neutral: m 1 = m 2 +1 Net destruction of O 3 :m 1  m 2 m = m 1 + m 2 Multipliers

INTERACTION OF OBSERVATIONS & MODELS: Can O 3 Pollution Formation & Transport be: Measured from Satellite, Ground, Sondes? Quantified? Predicted?

Lifetime, Scientific Issue Define Observing Requirement “Junge” diagram - key species in long-range pollution transport, radiation-climate have days-weeks lifetime: ozone, aerosols, CO Require vertical profiles, weekly frequency or higher, depending on scale of phenomenon in question

TROPOSPHERIC OZONE UNITS Mixing ratio, ppbv; pollution > 40 ppbv, 0 km Column-integrated, DU; pollution > DU  “Good ozone” in stratosphere  “Bad ozone” in troposphere

QUESTIONS MOTIVATING SHADOZ O 3 & Measurement Strategy Begun in 1998 > Tropical Questions  SHADOZ network 1. Are ozone satellite columns accurate? √ High resolution, stratosphere and troposphere i.e. Soundings 2. Where is wave-one pattern observed in total equatorial ozone [Shiotani, 1992]? √ 3. Which chemical-meteorological interactions govern ozone variability? Burning? Lightning? Urban? STE? Long-range transport? Time scale? √

Ozonesonde Instrument: Preparation & Packaging with Radiosonde

Design of Tropical Ozone Network What causes zonal wave-one pattern observed in total equatorial ozone [Shiotani, 1992]? Full longitudinal coverage – selected 9 operational stations in 1998 (now 12) Which chemical-meteorological interactions govern tropospheric ozone variability? Time scale? Practicality (cost, personnel) => weekly soundings

SHADOZ PROJECT (Southern Hemisphere Additional Ozonesondes) Operations in southern hemisphere (1998), then add two NH Now > 2200 ozone profiles: Refer to Thompson et al, JGR, 108, 8238, doi: / 2001JD000967, 2003http://croc.gsfc.nasa.gov/shadoz

Tropical Ozone Answers from SHADOZ Are ozone satellite columns accurate? √ Good Agreement at Nairobi

SHADOZ SAMOA, TOMS, DOBSON 1)TOMS comparisons valid )v 7 TOMS, v8 ozone > sonde, Dobson - left 3)TOMS overestimate at low-tropo.-O 3 sites, (eg Samoa, Fiji) - below

√ Wave-One in Tropospheric Ozone, Stratospheric Ozone Longitudinally Invariant – Interaction of General Circulation, Convection + O 3 from Fires, Lightning (via NO) Unique SHADOZ view shows wave present all year (Thompson et al, JGR, 108, D2, JD002241, 2003). Convective influence over western Pacific, subsidence over Atlantic

√ Week-to-week variability, Nairobi: Low ozone in free troposphere (left, blue) coincides with convection & Indian Ocean Transport (higher humidity, right, red). Wavelet, other statistics (Thompson, Chatfield) show distinct 3- 7-day periodicity from convection, advection

Nairobi, Seasonal “Means?” Tropospheric column ozone is higher in S-O-N than M-A-M, but extremes are similar  “Meaningless means” From Thompson et al [Bull. Am. Meteor. Soc., 2004] - Cf Variability defined by synoptic regime [Diab et al., Atmos. Chem. Phys., 2003; JGR, 2004].

Profile Classification: Two DJF patterns at Irene, So. Africa *** Search for pattern and order. Multivariate cluster analyses technique Profiles group according to magnitude and altitude of ozone Highlight need to account for temporal variability, I.e. stratification? *** Diab et al., Atmos. Chem. Phys., 3, , 2003

GEOGRAPHICAL VARIABILITY From data: (a) La Reunion – more stratospheric influence; African biomass burning (b)Natal – M-A-M convective influence; SON – biomass burning impact (c)Fiji – pronounced convective in- fluence, SON – imported pollution

Looking Ahead! – Now in Aura Era > What is Aura? Launched 15/7/04, 4 ozone sensors -- Two (OMI/TES) oriented to troposphere > Ozonesonde needs for scientific issues: Processes – Tropical*, Mid-latitude Validation – TOMS/OMI retrievals * Tropical – Re-examine SHADOZ to respond to new findings of “Paradox,” absence of NH wave-one --- TES HIRDLS OMI-- MLS--

NO 2 over South America and the US

Atlantic “Ozone Paradox” “Paradox” (left) – more DJF ozone over southern hemisphere when north tropics (west Africa) burning! Thompson et al. [2000] Mechanisms: Interhemispheric transport, subsidence of ozone over So. Atlantic (middle), lightning (right) How much of each?

Atlantic “Ozone Paradox” Not Seen over Africa Re-evaluate SHADOZ Design – 2004 Over African continent no DJF “Paradox” (Note! NH is at right, SH is left) [Sauvage at al., Thesis, 2004]. Paramaribo (Surinam, 5N) O 3 differs from SH O 3 [Peters et al., 2004] All SHADOZ sites, distinct 3-7-day periodicity  weekly sampling ok; 2/week better; 2/month inadequate

Urban fires cause 30-50% of surface 90 ppbv ozone [Thompson et al., GRL, 29, 1976, doi: /2002GL015399, 2002] Issues: Aerosol interferes with uv ozone satellite retrieval. Algorithms need profile data in regions with smoke Pollution-level surface ozone absent from SHADOZ stations because most are far from sources Need more Polluted Sites SAFARI-2000 Lusaka, Zambia (15S, 28E) (9/2000)

4.Can Ozone in High Pollution be Quantified? Predicted? Test Assimilation √ TOMS satellite ozone in Regional Air Quality Model System (B Pierce, NASA- LaRC) 8 July Ron Brown Sounding & RAQMS Lower tropospheric (LT) ozone and UT/LS not correct Will IONS assimilation improve agreement?  Give better tropospheric ozone from satellite?  Predict pollution transport?

Sounding Strategies in AURA Profile interactively guides satellite (OMI/TES) derivation of tropospheric ozone and assimilation Simultaneously engage other EOS/A-train sensors (eg H2O, AIRS) Full range of radicals, ozone precursors, deposited species (ground-based), plus aircraft/uav data constrain Models, Assimilation Satellite SONDE

Synergism of Ground-based-Models-Balloon-Aircraft Observations with Modeling & Assimilation

Summary O 3 & Measurement Strategy Design > Tropical Questions  SHADOZ network Spatial, temporal resolution in network must match scientific question (for O 3,, scales of dominant meteorological processes) Regional-to-global scale of tropical issues define SHADOZ (~12 global sites, 1/wk) Integrated Observing Strategies Required – Sondes-aircraft-satellite- ground-based Analyses, Predictions require multiple statistical, modeling approaches, all scales!

Thank you for Attention! Thank You L Gallardo (U Chile-CMM) Acknowledgments:  Jacquelyn Witte for Graphics, Analysis  NASA Program Sponsors for SHADOZ  SHADOZ Team – NASA Honor Awards Given in 2004 to > 40 individuals in 20 nations!