GSICS Telecon July 2012 AVHRR, MODIS, VIIRS Radiance Monitoring in MICROS and GSICS help to SST www.star.nesdis.noaa.gov/sod/sst/micros/ Sasha Ignatov Alex.Ignatov@noaa.gov Xingming Liang Xingming.Liang@noaa.gov NOAA/NESDIS/STAR Specific for nesdis July 2012 GSICS help to SST

M-O Biases and Double Differences (“DD”) Model minus Observation (“M-O”) Biases M (Model) = Community Radiative Transfer Model (CRTM) simulated TOA Brightness Temperatures (w/ Reynolds SST, GFS profiles as input) O (Observation) = Clear-Sky sensor (AVHRR, MODIS, VIIRS) BTs Double Differences (“DD”) for Cross-Platform Consistency “M” used as a “Transfer Standard” DDs cancel out/minimize effect of systematic errors & instabilities in BTs arising from e.g. Errors/Instabilities in Reynolds SST & GFS Missing aerosol Possible systemic biases in CRTM Updates to ACSPO algorithm July 2012 GSICS help to SST

Nighttime DD’s @3.7 µm (Ref=Metop-A GAC) N17 was most consistent with Metop-A (N17 scan motor stalled on 10 Feb 2010). Their equator crossing times (EXT) are very close – 10:00-10:30pm N19 (launch Feb 2009; EXT~1:30am) largely consistent with Metop-A and N17 N18 (launch May 2005; EXT~1:30am): Less consistent N16 (launch Sep 2000; EXT~5am): Most inconsistent July 2012 GSICS help to SST

Nighttime DD’s @11 µm (Ref=Metop-A GAC) N17 was most consistent with Metop-A (N17 scan motor stalled on 10 Feb 2010). Their equator crossing times (EXT) are very close – 10:00-10:30pm N19 (launch Feb 2009; EXT~1:30am) largely consistent with Metop-A and N17 N18 (launch May 2005; EXT~1:30am): Less consistent N16 (launch Sep 2000; EXT~5am): Most inconsistent July 2012 GSICS help to SST

Nighttime DD’s @12 µm (Ref=Metop-A GAC) N17 was most consistent with Metop-A (N17 scan motor stalled on 10 Feb 2010). Their equator crossing times (EXT) are very close – 10:00-10:30pm N19 (launch Feb 2009; EXT~1:30am) largely consistent with Metop-A and N17 N18 (launch May 2005; EXT~1:30am): Less consistent N16 (launch Sep 2000; EXT~5am): Most inconsistent July 2012 GSICS help to SST

Nighttime DD’s SST (Ref=Metop-A GAC) N17 was most consistent with Metop-A (N17 scan motor stalled on 10 Feb 2010). Their equator crossing times (EXT) are very close – 10:00-10:30pm N19 (launch Feb 2009; EXT~1:30am) largely consistent with Metop-A and N17 N18 (launch May 2005; EXT~1:30am): Less consistent N16 (launch Sep 2000; EXT~5am): Most inconsistent July 2012 GSICS help to SST

Summary Observations from MICROS – for BTs and SSTs AVHRRs on Metop-A, N17, N19 form the tightest “family” N18 shows unexplained deviations from the “family” N16 shows largest unexplained “out-of-family” behavior Question 1: Are these MICROS observations consistent with AVHRR trending against spectrometers (AIRS, IASI)? VHRR trending using Simultaneous Nadir Overpasses? Question 2: If they are, then we need GSICS help with Reconciliation of BTs form various AVHRR sensors Doing this from “first principles” (better understanding of sensors, improved cal procedures) rather than “empirical bias corrections” MODIS and VIIRS are also trended in MICROS We do see smaller anomalies for MODIS – need GSICS help, too Specific for nesdis July 2012 GSICS help to SST

Email from Sasha Ignatov 12/06/2012 we do see inconsistencies across various AVHRRs in MICROS we wanted to know if these anomalies are also seen in AVHRR comparisons against multispectral radiances if they are, we need GSICS help with resolving and reconciling radiances we need this reconciliation based on "first principles" rather than any sort of empirical "bias corrections" we do monitor both MODIS instruments, and VIIRS in MICROS, and see some (relatively smaller) inconsistencies for MODIS. we might need help here too … our major message Xingming and I would like to send to the GSICS community: it's time to actually start "walking the walk" towards more stable and cross-platform consistent radiances from various platforms, sensors & bands employed for SST. we expect that the GSICS will respond to this "user's request" and help us improve and reconcile SSTs. July 2012 GSICS help to SST