Results from the OMPS Nadir Instruments on Suomi NPP Satellite

1. Results from the OMPS Nadir Instruments on Suomi NPP Satellite Richard McPeters NASA GSFC

2. OMPS Sensor Views NM

3. OMPS Sensor Views NP

4. OMPS Sensor Views LP

5. Nadir Sensor Consists of a Mapper and a Co-Boresighted Profiler Telescope Total Column Spectrometer Profile Spectrometer Nadir total column mapper: 300-380 nm @1 nm resolution Nadir profiler: 250-310 nm @1 nm resolution • Single pushbroom telescope • Two grating spectrometers • Each spectrometer has a 740x340 pixel CCD detector array • Both sample spectrum at 0.42 nm, 1 nm FWHM end-to-end resolution • Calibration stability maintained by periodic solar observations using dual reflective diffusers

6. OMPS Nadir Mapper Status Ozone ST & PEATE • Launched on Suomi-NPP 28 Oct 2012 • Data available from February 2012 to March 2014 • NOAA’s operational NMproduct • http://www.class.noaa.gov • NASA science team’s research product • Compatible with OMI • Uses the NASA v8 algorithm • Quality consistent with OMI • http://ozoneaq.gsfc.nasa.gov/omps

7. NASA product from NM - 1.4% offset due to use of Brion-Daumont-Malicet ozone cross sections

8. NM ozone map for February 21, 2013 • We propose to process NPP mapper data with PK’s v9 algorithm • very similar accuracy to v8 • accuracy better at high solar zenith angles • will include Joanna’s cloud height retrieval • will give error for each FOV

10. The OMPS NM and OMI benefit each other OMI OMPS NM

11. OMI reveals issues with OMPS calibration Why does OMPS – OMI Ozone difference switch sign over high southern latitudes? -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 Dobson Units Dobson Units

12. OMPS reflectivity (over snow/ice) too high OMPS OMI 80 82 84 86 88 90 92 94 96 98 100 80 82 84 86 88 90 92 94 96 98 100 Percent Percent -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 Percent

13. OMPS NP Product • NOAA’s operational NP product • Based on NASA V6 algorithm • http://www.class.noaa.gov • NASA science team’s NP research product • Based on NASA V8.6 algorithm • Compatible with SBUV/2 long-term record • Formats consistent • http://ozoneaq.gsfc.nasa.gov/omps Comparison of average OMPS NP research product profile to average MLS profile for 23 June, 2012 (-20 < Latitude < 20 degrees) Sum of MLS profile = 235.7 DU Sum of OMPS profile = 236.7 DU Pressure (hPa) Dobson Units

14. Comparison of the average OMPS limb profile with the average nadir profile for September 2013.

15. High energy particles in the South Atlantic Anomaly (SAA) affect imaging sensors. 252 nm radiance The noise / dark current increases when an orbital path falls with within the SAA, mainly affecting short wavelengths in the Nadir Profiler. (252 nm plotted) 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

16. Ozone % difference – Nadir Profiler vs NOAA 19 1.0 – 1.6 hPa

17. Ozone % difference – Nadir Profiler vs NOAA 19 4.0 – 6.3 hPa

18. Conclusions • Performance of OMPS nadir NM & NP sensors is very good can be used to produce high quality ozone retrievals • “Soft calibration” needed, particularly at NM far off-nadir scenes • NASA research product ~1.5% higher than OMI • OMPS data (NP & NM) will be used to extend ozone long-term ozone data records • algorithm consistent with heritage dataset should be used to process data (v9 for TOMS, OMI, and NPP NM) • SAA anomaly affect NP measurement • 10-20% error neear 1 hPa • <2% below 5 hPa • No effect on total column ozone