Results from the OMPS Nadir Instruments on Suomi NPP Satellite Richard McPeters NASA GSFC OMI Science Team Meeting KNMI, De Bilt, the Netherlands March 12, 2014

OMPS Sensor Views OMPS consists of suite and ground processing algorithms Two sensors, Limb and Nadir, provide Limb Profile, Nadir Total Column, and Nadir Profile Raw Data Records Main Electronics Boxes provide data processing, provide spacecraft electrical interfaces, and controls on-orbit operations SDR and EDR algorithms process RDRs into SDR and EDR products 110° nadir cross-track field of view (FOV) and 3 limb FOVs provide required coverage 2.23° limb vertical FOV provides sampling from tropopause to 60 km NM

OMPS Sensor Views OMPS consists of suite and ground processing algorithms Two sensors, Limb and Nadir, provide Limb Profile, Nadir Total Column, and Nadir Profile Raw Data Records Main Electronics Boxes provide data processing, provide spacecraft electrical interfaces, and controls on-orbit operations SDR and EDR algorithms process RDRs into SDR and EDR products 110° nadir cross-track field of view (FOV) and 3 limb FOVs provide required coverage 2.23° limb vertical FOV provides sampling from tropopause to 60 km NP

OMPS Sensor Views LP OMPS consists of suite and ground processing algorithms Two sensors, Limb and Nadir, provide Limb Profile, Nadir Total Column, and Nadir Profile Raw Data Records Main Electronics Boxes provide data processing, provide spacecraft electrical interfaces, and controls on-orbit operations SDR and EDR algorithms process RDRs into SDR and EDR products 110° nadir cross-track field of view (FOV) and 3 limb FOVs provide required coverage 2.23° limb vertical FOV provides sampling from tropopause to 60 km

Nadir Sensor Consists of a Mapper and a Co-Boresighted Profiler 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 Telescope Total Column Spectrometer Profile Spectrometer Nadir total column mapper: 300-380 nm @1 nm resolution Nadir profiler: 250-310 nm @1 nm resolution Note wavelength ranges

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 NM product 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 Note 2 products

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

We propose to process NPP mapper data with PK’s v9 algorithm NM ozone map for February 21, 2013 Map 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

The OMPS NM and OMI benefit each other

OMI reveals issues with OMPS calibration Why does OMPS – OMI Ozone difference switch sign over high southern latitudes? This is an ozone difference plot -8 -7 -6 -5 -4 -3 -2 -1 1 2 3 4 5 6 7 8 Dobson Units Dobson Units

OMPS reflectivity (over snow/ice) too high 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 1 2 3 4 5 6 7 Percent

OMPS NP Product NOAA’s operational NP product Pressure (hPa) Dobson Units 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 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 Not e 2 products

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

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 High energy particles in the South Atlantic Anomaly (SAA) affect imaging sensors. 252 nm radiance NP flags give the stripes Radiance map C. Seftor, SSAI, Flag map Y. Hao, IMSG Radiance Line Plots J. Niu, ERT 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)

Ozone % difference – Nadir Profiler vs NOAA 19 1.0 – 1.6 hPa Compare profile from NOAA 19 SBUV/2 with the NP profile

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

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