Aura Validation

1. Aura Validation

2. Aura Validation • Five major aircraft validation missions - completed • Houston Ave I (Oct. ‘04) • PAVE (‘05) • Houston AVE II (June ‘05) • CRAVE (Jan-Feb. ‘06) • Intex-B (April - May ‘06) • Remaining Aircraft Validation & Science Missions • TC4 Summer (Summer ‘07) • UAV (TBD) • POLARCAT (‘08) • TC4 Winter (Winter ‘09??) • Stratospheric Balloon Launches • Polar launch ‘07 partially successful • Sonde Campaigns • 3 Ticosonde campaigns (July ‘05 & Jan.‘06 & Jan. ‘07) • Sauna I & II(‘06,’07), WAVES (‘06), IONS (‘06) • Non-Aura sponsored campaigns (TexAQS, MONA, Dandelions…) • Aura Validation Data Center (AVDC) • Clearing house for Aura provisional data and non-US satellite data

3. INTEX-B(CO, O3, HCHO, NO2, HNO3, H2O, HCN, Aerosol) Anchorage Houston Hawaii 145 DC-8 Flight hours

4. HIRDLS Validation • Data from sondes, AVE, INTEX B, HALOE, ACE, SAGE II and III, POAM 3, MIPAS, GMAO, and MLS • Validation of temperature and ozone showed agreement with small vertical scale structures, verifying high resolution of results • DC-8 along track ozone and temperature profiles were very useful • Validation reveals low biases in the radiances at Level 1; the source of this is being investigated and corrections applied • Data from CRAVE used to test and confirm data in aerosol channels has good information on aerosol extinction coefficients • Validation is currently with V2.02, newest algorithm V 2.03, working on V 2.1 • Full reprocessing under V2.03 and later under V 2.1 • TC4 will be used to validate and refine our cloud and aerosol results

5. AROTAL-HIRDLS comparison T (K) HIRDLS AROTAL 10 UT DC-8 Transit Flight: 2006Apr30 [UT: 2006May01/04:10-13:22] O3 (PPBV) HIRDLS AROTAL 10 UT Courtesy Laurence Twigg & PI: Tom McGee HIRDLS v2.02

6. Comparisons with other satellites, balloons and aircraft indicate generally good performance for stratospheric products (e.g., often better than 5-10% for ozone) Campaign data indicate for version 1.5 data: some vertical oscillations in UTLS H2O, factor of ~2 high bias in upper tropospheric CO data (model/climatologies concur) These issues are improved in version 2 algorithms TC4 will add more UT CO/O3 and cloud observations Cloud validation to benefit from close collaboration with the CloudSat science team MLS Validation

7. = 146 hPa, = 215 hPa, Use of INTEX-B Upper Troposphere data for MLS validation • INTEX-B is a useful source of information for validation of Aura MLS upper trop. measurements • O3, CO, HNO3 (also H2O, Temperature and cloud ice) • Interpretation is complicated by • Noise on individual MLS measurements • Relating high resolution in situ observations to ‘box average’ measurements from MLS • ~200 x 7 x 3 km (L x W x H) • Example compares MLS O3 to DIAL/FASTOZ for 3 flights • See Nathaniel Livesey’s talk this afternoon for more details Plot compares MLS O3 (y-axis) to DIAL/FASTOZ interpolated to the MLS grid (x-axis). Correlation coefficient is 0.94

8. DC-8 & MLS: sample of correlative observations in INTEX-B (PRELIMINARY DATA) MLS CO DC-8 CO • MLS v1.51 CO data have known high (factor ~2 bias) in 200 hPa region • Later versions of MLS processing will address this issue • INTEX flight above confirms this and will be useful comparison dataset • Encouraging agreement on CO morphology despite bias, given MLS resolution

9. Ground validation Comparison with a network of 92 Dobson/Brewer stations shows OMI total ozone is about as accurate as TOMS and SBUV. SAUNA campaign (high ozone, high latitude conditions) showed large differences between various ground-based instruments. OMI ozone retrievals agree well with the best instruments (double Brewers). Aircraft validation(participated in AVE and INTEX-B campaigns) Ozone: lidar used to check OMI tropospheric ozone retrieval; CAFS used to validate column above aircraft measured by MLS. Cloud height: significant cloud height errors identified in MODIS and OMI-derived cloud heights for cirrus, and multi-layer cloud conditions - TC4. NO2: limited boundary layer comparisons; good agreement between standard product and DC-8 profiles Remaining Issues Need to understand the influence of thin and multi-layer clouds on retrievals - TC4. OMI Validation

10. Validation of OMI Tropospheric NO2 During INTEX-B OMI avg = 2.10 OMI std = 1.24 in-situ = 1.96 in-situ err = 0.68 DC-8 NO2 Profiles

11. OMI Lidar Cloud Height Comparison during Intex- B DIAL MODIS cloud height OMI Raman OMI O2-O2

12. Validation efforts have relied on ozonesondes, radiosondes (temperature and water vapor), aircraft campaigns (O3, CO, HNO3, radiance), and other satellite datasets (O3, T, H2O, HNO3, CO, clouds) The validation activities revealed a bias in the TES upper tropospheric ozone and temperature which will be addressed in the upcoming algorithm version. Radiance validation activities directly impacted changes made to the calibration algorithms last year. We are actively working with the INTEX-B nitric acid investigators to verify changes to the limb retrievals in the upcoming algorithm version. TES Validation

13. Houston Honolulu Anchorage Comparisons of TES to DIAL Lidar • Comparison of TES profiles to DIAL lidar (percentage difference) • TES is biased high with respect to DIAL through most of the troposphere • Similar bias seen when TES is compared to ozonesondes • TES low bias in upper trop is under investigation

14. Comparisons of TES to DACOM CO Honolulu Houston • Comparisons between TES profiles and DACOM for Houston flights encouraging • TES lower than DACOM by up to 10% in the middle and upper troposphere • The comparisons of profiles taken during the Pacific flights show poorer agreement due to the large variability of CO in the observed air masses • Comparisons between TES and in situ O3 and CO both show best agreement in less polluted air masses

15. Summary • INTEX-B was one of the most successful validation campaigns from an Aura perspective • New versions of MLS, TES, OMI and HIRDLS will be coming soon to a DAAC near you.