NOAA ACSPO v2.70 GOES-16/East ABI L2P SST

GOES-16 (G16) is the first satellite in the US NOAA 3rd generation of GOES, aka GOES-R series (which also includes GOES-S/17, -T/18, and -U/19). G16 was launched on 19 Nov 2016, moved to its permanent position at 75.2W in Dec 2017, and declared NOAA operational GOES-East on 18 Dec 2017.

The improved ABI capability over the heritage GOES-I/P Imager stems from the availability of five narrow SST bands at 3.9, 8.4, 10.3, 11.2, and 12.3 um, accurate sensor calibration, image navigation and co-registration, and sophisticated pre-processing (geo-rectification, radiance equalization, and mapping). From a 35,800km altitude, the G16/ABI accurately maps SST in a Full Disk (FD) US East domain, with spatial resolution 2km at nadir and temporal sampling of 10min (15min prior to 2 Apr 2019). The US ACSPO first processes every 10min FD data using its clear-sky mask (ACSM; Petrenko et al., 2010) and Non-Linear SST (NLSST) algorithm (Petrenko et al., 2014) applied to 4 longwave bands centered at 8.4, 10.3, 11.2, and 12.3. (The 3.9 band is currently excluded, to minimize possible discontinuities in the diurnal cycle.) The regression is tuned against quality controlled in situ SSTs from drifting and tropical mooring buoys provided by the NOAA iQuam system ( https://www.star.nesdis.noaa.gov/socd/sst/iquam ). The 10min FD data are subsequently collated in time, to produce 1hr L2P product, with improved coverage, reduced cloud leakages and image noise, compared to individual 10min images.

In the collated L2P, SSTs are only reported in clear-sky water pixels (defined as ocean, sea, lake or river, and up to 5 km inland) and fill values elsewhere. The L2P is reported in netCDF4 GHRSST Data Specification v2 (GDS2) format, 24 granules per day, with a total data volume of 0.6GB/day. The l2p_flags layer includes day/night, land, ice, twilight, and glint flags. Other variables include NCEP wind speed and ACSPO SST minus reference SST (Canadian Met Centre 0.1deg L4 SST; available at https://podaac.jpl.nasa.gov/dataset/CMC0.1deg-CMC-L4-GLOB-v3.0 ). Pixel-level earth locations are not reported in the granules, as they remain unchanged from granule to granule. To obtain those, user has a choice of using a flat lat-lon file, or a Python script, both available at https://www.star.nesdis.noaa.gov/pub/socd4/coastwatch/sst/nrt/abi/nav . Per GDS2 specifications, two additional Sensor-Specific Error Statistics layers (SSES bias and standard deviation) are reported in each pixel.

The ACSPO ABI L2P product is monitored and validated against iQuam in situ data in the NOAA SQUAM system https://www.star.nesdis.noaa.gov/socd/sst/squam . Quality of SST imagery and clear-sky mask is evaluated in the NOAA ARMS system https://www.star.nesdis.noaa.gov/socd/sst/arms . A reduced size (0.2GB/day), equal-angle gridded (0.02-deg resolution), ACSPO L3C product is also available at https://podaac.jpl.nasa.gov/dataset/ABI_G16-STAR-L3C-v2.70 , where gridded L2P SSTs are reported.