OMI Science Team Meeting KNMI, De Bilt, the Netherlands March 12, 2014

Results from the OMPS Nadir

Instruments on Suomi NPP Satellite

Richard McPetersNASA GSFC

OMPS Sensor Views

NM

OMPS Sensor Views

NP

OMPS Sensor Views

LP

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

TelescopeTotal Column Spectrometer

Profile Spectrometer

Nadir total column mapper: 300-380 nm @1 nm resolutionNadir profiler: 250-310 nm @1 nm resolution

OMPS Nadir Mapper Status► 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/o

mps

Ozone ST & PEATE

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• 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

NM ozone map for February 21, 2013

The OMPS NM and OMI benefit each other

OMI OMPS NM

OMI reveals issues with OMPS calibration

Why does OMPS – OMI Ozonedifference switch sign over highsouthern latitudes?

Dobson Units-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8

Dobson Units

OMPS reflectivity (over snow/ice) too high

OMPS OMI

Percent-8 -7-6 -5 -3 -2 -1 0 1 2 3 4 5 6 7-4

80 82 84 86 88 90 92 94 96 98 100Percent

80 82 84 86 88 90 92 94 96 98 100Percent

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/o

mps

Pres

sure

(hPa

)

Dobson Units

Comparison of average OMPS NPresearch product profile to average MLS profile for 23 June, 2012(-20 < Latitude < 20 degrees)Sum of MLS profile = 235.7 DUSum of OMPS profile = 236.7 DU

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

High energy particles in the South Atlantic Anomaly (SAA) affect imaging sensors.

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

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)

Ozone % difference – Nadir Profiler vs NOAA 191.0 – 1.6 hPa

Ozone % difference – Nadir Profiler vs NOAA 194.0 – 6.3 hPa

► 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

Conclusions