OMI Science Team Meeting KNMI, De Bilt, the Netherlands March 12, 2014 Results from the OMPS Nadir Instruments on Suomi NPP Satellite Richard McPeters NASA GSFC
Dec 18, 2015
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 resolution
Nadir 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 98 100
Percent
80 82 84 86 88 90 92 94 96 98 100
Percent
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
Pre
ssure
(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