NATIONAL POLAR-ORBITING PARTNERSHIP VERIFICATION AND EARLY OPERATIONS FOR

NATIONAL POLAR-ORBITING PARTNERSHIP VERIFICATION AND EARLY OPERATIONS FOR THE OZONE MAPPING AND PROFILE SUITE OMPS IGARSS, Munich DR Lawrence Flynn, Didier Rault, Glen Jaross, Irina Petropablovskikh, Craig Long, Colin Seftor, Eric Beach, Wei Yu, Jianguo Niu, Dustin Swales, Chunhui Pan, Xiangqian Wu, Zhihua Zhang, Yan Hao Session: MO 4. 13: Suomi National Polar-orbiting Partnership (NPP) Monday, July 23, 15: 40 - 17: 20 Paper Code: MO 4. 13. 1, Paper Number: 1746 See posters in the next session: MOP. P. 6 and MOP. P. 7

Short Abstract • • NOAA, through the Joint Polar Satellite System (JPSS) program, in partnership with National Aeronautical Space Administration (NASA), launched the Suomi National Polar-orbiting Partnership (Suomi NPP) satellite on October 28, 2011. The JPSS program is executing the NPP Calibration and Validation (Cal/Val) program to ensure the data products comply with the requirements of the sponsoring agencies. The Ozone Mapping and Profiler Suite (OMPS) consists of two telescopes feeding three detectors measuring solar radiance scattered by the Earth's atmosphere and surface, and solar irradiance by using diffusers [1]. The measurements are used to generate estimates of total column ozone and vertical ozone profiles. The validation efforts make use of external resources, in the form of ground-based and satellite- based measurements for comparisons, and apply internal consistency methods developed over the last thirty years. This paper provides information on the state of the execution of the OMPS Cal/Val Plan with emphasis on the measures of the instrument performance from internal consistency analysis techniques and comparisons to other satellite instrument products for the validation of the NPP OMPS environmental data products. [1] Juan V. Rodriguez, et al. , “An overview of the nadir sensor and algorithms for the NPOESS ozone mapping and profiler suite (OMPS), ” Proc. SPIE, 4891, April 2003, DOI: 10. 1117/12. 467525.

Outline • Brief instrument / product overview • Cal/Val Team and Others • Examples of OMPS Performance – Solar irradiance measurements – Radiance measurements • • • Signal to Noise Geolocation / Reflectivity South Atlantic Anomaly Wavelength Scale and Ring Effect Initial residuals for the Nadir Profiler – Products • • Limb Ozone Profile Retrievals Total Column Ozone Maps Cross-track Bias in Total Ozone Aerosol Index

OMPS Instrument Design Nadir Mapper UV Backscatter, grating spectrometer, 2 -D CCD TOMS, SBUV(/2), GOME(-2), OMI 110 deg. cross track, 300 to 380 nm spectral, 1. 1 nm FWHM bandpass Total Column Ozone, UV Effective Reflectivity, and Aerosol Index Daily Maps Nadir Profiler UV Backscatter, grating spectrometer, 2 -D CCD SBUV(/2), GOME(-2), OMI Nadir view, 250 km cross track, 270 to 310 nm spectral, 1. 1 nm FWHM bandpass Ozone Vertical Profile, 7 to 10 KM resolution Limb Profiler UV/Visible Limb Scatter, prism, 2 -D CCD array SOLSE/LORE, OSIRIS, SAGE III, SCIAMACHY Three 100 -KM vertical slits, 290 to 1000 nm spectral Ozone Vertical Profile, 3 KM vertical resolution The calibration concepts use working and reference solar diffusers. Instrument and FOV Graphics from BATC

Ozone Calibration and Validation Team Members’ Roles & Responsibilities Area Name Organization Funding Agency Task Validation and Comparisons L. Flynn NOAA/NESDIS JPSS Internal and Satellites Ground-based Data I. Petropavlovskikh NOAA/ESRL JPSS Dobson and Umkehr Applications C. Long NOAA/NCEP JPSS/JCSDA Assimilation Limb P. K. . Bhartia NASA GSFC NASA NPP R&D Climate R. Mc. Peters L. Flynn NASA GSFC NOAA/NESDIS NASA NOAA/NCDC CDR & Reprocessing Instrument S. Janz B. Sen G. Jaross X. Wu NASA GSFC NGAS NASA (SSAI) NOAA/NESDIS NASA/JPSS RDR and SDR 6

OMPS Nadir Mapper Spectra • The plot at the top of the following slide shows a sample OMPS Nadir Mapper solar spectrum measured in January. The initial calibration, goniometry and wavelengths scales have been applied. Notice the Fraunhofer lines, e. g. , a deep one near 360 nm. • The plot in the middle shows a sample spectrum for the Earth View data for the nadir field-of view. • The plot on the bottom shows the ratio of the first two spectra. Notice that much of the structure in the solar spectrum cancels out in the ration. Also notice the variations between 320 and 330 nm produced by differential ozone absorption with wavelength. • After further analysis, the wavelength scales have been revised with shifts on the order of 1Å.

Typical spectra from 310 to 380 nm for OMPS Nadir Mapper Solar Irradiance Fraunhoferlinien Earth Radiance Ozone Absorption Features Radiance/Irradiance Ratio 310 Wavelength, nm 380

EOF/SNR analysis for six orbits (~1800 scans) OMPS NM on 1/28/2012 using three wavelength ranges (305 -325, 320 -345, 340 -380) for 35 CT 0. 1 is equivalent to an average SNR of 1000: 1.

OMPS Geolocation This image shows the effective reflectivity (0% to 30% for the 380 -nm Channel for part of an orbit of small Field-of-View (5 KM X 10 KM at Nadir) measurements made by the OMPS Nadir Mapper in a special diagnostic mode on January 26, 2012. The Qatar peninsula sticking into the Persian Gulf in the middle of the picture lies along the nadir view of the orbital track and gives a preliminary assurance of the geolocation at better the 5 KM.

Examination of South Atlantic Anomaly (SAA) effects and product flagging. The noise/spikes below show the expected increases when an orbital path falls within the SAA but return to normal levels after passing through it. The OMPS was designed to use the OMPS Limb Profiler retrievals in the SAA where the OMPS Nadir Profiler is so greatly affected by charged particles that it cannot be used to produce ozone profiles. Map of South Atlantic Anomaly effects on OMPS NM closed-door dark current measurements in December and November 2011, overlaid with OMPS NP SAA Flags (0 to 8) for 3/5 -6/2012

Wavelength Shift and Ring Effect/Stray Light * EOF pattern –– 0. 02 -nm shift * EOF pattern 0. 5% –– ∝ (1/Avg-poly) 0. 5%

Time series of initial V 8 PRO residuals for OMPS NP February through June Initial Measurement Residuals for the OMPS NP V 8 Profile Product: The nine figures show the initial residuals for profile wavelengths [252, 274, 283, 288, 292, 298, 302, 306 and 313 nm, (a) to (i), respectively] for the V 8 PRO product from OMPS compared to the same product for the operational NOAA-18 and NOAA -19 SBUV/2 for the equatorial daily zonal means (20 N to 20 S) with 0 -90 W removed to avoid the SAA. The residuals are in N-values (1 N ~ 2. 3%). The time period is the first six months of this year (February to May for OMPS). Notice that the residuals for OMPS, have maintained a persistent bias relative to the SBUV/2 residuals.

OMPS Limb Profiler These curtains represent the ozone profile in vertical slices through the atmosphere along the three paths shown above. They demonstrate the ability of the research retrieval algorithm for the OMPS Limb Profiler in use at the NASA Ozone PEATE. The gaps at the top in the middle of the plots occur when the satellite encounters charged particles as it passes through the South Atlantic Anomaly; these are consistent with the modeled effects. The profiles regularly extend down below 15 KM in altitude. D. Rault, NASA La. RC

(a) (c) (b) DU 100 300 500 Daily Total Column Ozone map comparisons between (a) IDPS OMPS First Guess Multiple Triplet product, (b) NOAA OMPS V 8 product, and (c ) NASA OMI V 8. 6 product for March 30, 2012. Cross-track features in OMPS products are related to the use of preliminary calibration values.

February weekly-mean total column ozone as a function of the cross-track view angle for the Equatorial Pacific region defined by 20°S to 20°N Latitude, 100°W to 180°W Longitude.

OMPS Aerosol Index shown over VIIRS RGB image for July 4, 2012

Summary & Information • The OMPS instruments are performing well and the retrieval algorithms are producing reasonable products. • Instrument characterization and product validation are proceeding and will produce shifts in the product quality. • OMPS Nadir Mapper and Nadir Profiler Products will be released at “Beta” maturity levels this week and become available at CLASS: http: //www. nsof. class. noaa. gov /saa/products/search? datatype_family=OMPS • OMPS Limb Profiler Products will be released starting this November through the NASA GES DISC • Monitoring plots are provided at the ICVS: http: //www. star. nesdis. noaa. gov /icvs/PROD/pro. OMPSbeta. TOZ_INCTO. php

Backup

331 -nm Channel Radiances for the first eight orbits of OMPS Nadir Mapper measurement (end of 1/26/2012 and start of 1/27/2012). This image shows the expected range of values and variations across the orbital track and with solar zenith angles at the times of the measurements. The white circle around the North Pole is the region of polar night during the Northern Hemisphere Winter. The OMPS needs scattered sunlight to make its measurements, so there are no data there. Effective Reflectivity from the multiple triplet retrieval algorithm in IDPS for the same eight orbits. The quantity represents the UV reflectivity of the clouds and surface in each Field-of-View. Again, the range of values from bright clouds to dark open ocean scenes is as expected. Reflectivity Total Ozone from the multiple triplet retrieval algorithm in IDPS for the same eight orbits for the first pass ozone retrieval (first guess IP product without Cr. IS or VIIRS information). The values show some cross track variations and are offset approximately 5 -10% from other satellite ozone products. These uncertainty levels for preliminary products are consistent with the use of prelaunch calibration parameters and tables in the initial operational system. Figures: J. Niu, NOAA/STAR (ERT) 1/2627/2012

Total Ozone Maps for OMPS INCTO, OMPS V 8, OMI V 8. 6, and GOME-2 V 8 for June 15, 2012

OMPS NP Solar Flux Measurements

Noise and Stray Light for OMPS NP Earth Radiances The % RMSR estimates on the right were computed using EOF analysis on clean data for 230 spectra. A spectral screen detected and removed one deviant value on average from each of the 120 -wavelength spectra. The removal of the second EOF pattern was somewhat arbitrary as it and the third EOF may be stray light patterns. The covariance computation used a 6 th order polynomial for normalization. The scatter plot on the left compares simple three-wavelength Mg II core-to-wing ratio variations (280 nm to the average of 277 nm and 282 nm) with longer wavelength variations at 305 nm. There is no geophysical reason to expect the two to be correlated, and the exposed relationship is symptomatic of out-ofband stray light. The core average is ~0. 4 of wings, so this -0. 5% to 1. 5% variation represents (1. 0/0. 4 – 1 =) 1. 5 times the expected stray light variations in the wings.

Reflectivity, % IINCTO One-Percentile Reflectivity Cross-Track Dependence for March Black Week 1 |Lat|<20 Blue Week 2 Green Week 3 Lon<-100 Red Week 4 Cross-track View Position

Overview of Data Products (2/2) • Total Column Ozone – Global coverage of atmospheric ozone column • Operational Assimilation (Weather and UV forecast) • Daily Maps (Ozone Hole/Layer monitoring) • Climate Data Records (Ozone Layer assessments) – UV Effective reflectivity IP – UV Aerosol Index IP • Ozone Vertical Profile – Nadir Profiler Layer amounts and mixing ratios – Mg II Solar Index – Limb Profiler Number density and mixing ratios • Cr. IS IR Ozone – Ozone total column and profile 27

Schedule of Major Task Categories • Pre-Launch Phase (L-24 M to L) – – Improve Ground-based assets operations and access Develop Match-up and statistical analysis tools and readers Implement and exercise forward models for radiative transfer Create and manipulate sample, synthetic, and proxy SDR (Level 1), EDR (Level 2), and DIP data sets – Collect and exercise calibration parameters and instrument models – Implement alternative/heritage algorithms • Early Orbit Check Out Phase (L to L+3 M) – – Check parameters and instrument behavior Perform internal consistency checks Provide feedback to SDR Team Test tools and alternate algorithms with real data • Intensive Cal/Val Phase (L+3 M to L+24 M) – – – Perform external comparisons to satellite products Perform sub-orbital comparison/validation Provide feedback to IPO and NGAS Evaluate product applications Begin trending and automated monitoring • Transition to regular operations and long-term monitoring

How much data do you need? What can it tell you? How can you accentuate different effects? • Internal Measurements – Dark Current and non-Linearity estimates, and Charged Particle effects • Single set of Solar measurements – Goniometry, Irradiance Calibration, Wavelength Scale, SNR, Flat Fielding, Bandpass check (Comparisons to reference, contemporaneous, and high-resolution spectra) • Single Orbit of Earth-view data – Wavelength Scale variations, SNR, Rough Radiance/Irradiance Calibration, Triplet/Pair consistency (Absorbing, reflectivity, and aerosol channels), Cross-track consistency • Single Day – Total Ozone versus other mappers, Zonal Means, Stray Light (Profile Wavelengths), better orbital analysis, and start of performance monitoring • Single Week – Cross-track consistency, Absolute calibration of reflectivity channels, calibration biases compared to other space-based mappers and profilers – transfer, and better daily analysis. • Single Month – Ground based total ozone validation data points (assisted by transfer), Starting points for trending of instrument degradation and solar diffuser changes, and better weekly analysis – trending of consistency results. • Single Year – Ground-based ozone profile validation, evaluation of long-term characterization, better monthly analysis, and start of ice radiance trending.