ACSPO Global SST from AHI

The AHI SST data are produced from Himawari-9 (Himawari-8 before 2022-Dec-13) geostationary satellite using the NOAA Advanced Clear-Sky Processor for Ocean (ACSPO) v2.90 enterprise system,(ACSPO v2.70 was used for Himawari-8). Currently, only near-real time (NRT) data are produced at STAR, with a 2-6 hour latency (typically closer to 2 hours). The data are available in NetCDF4 format, compliant with the GHRSST Data Specifications v2 (GDS2). The data for Himawari-8  was archived with PO.DAAC with start date 2019-Oct-16 and end date 2022-Dec-13. The  PO.DAAC archival of the Himawari-9 will start soon. The data is also available at this Coast Watch page as a 2week rotated buffer. There is a plan to reprocess the AHI data, for the full Himawari-8 and -9 missions.

    Data Access
    HTTPS
    THREDDS
    PO.DAAC Archive
    NCEI Archive
    Sample Filenames

    L2P: 20191016000000-STAR-L2P_GHRSST-SSTsubskin-AHI_H08-ACSPO_V2.70-v02.0-fv01.0.nc
    L3C: 20191016000000-STAR-L3C_GHRSST-SSTsubskin-AHI_H08-ACSPO_V2.70-v02.0-fv01.0.nc

    Global map projection of sea surface temperature data

    The AHI SST data are produced from Himawari-9 (Himawari-8 before 2022-Dec-13 ) geostationary satellite using the NOAA Advanced Clear-Sky Processor for Ocean (ACSPO) v2.90 enterprise system  (ACSPO v2.70 was used for Himawari-8). Currently, only near-real time (NRT) data are produced at STAR, with a 2-6 hour latency (typically closer to 2 hours). The data are available in NetCDF4 format, compliant with the GHRSST Data Specifications v2 (GDS2). The data for Himawari-8 was archived with PO.DAAC with start date 2019-Oct-16 and end date 2022-Dec-13. The PO.DAAC archival for Himawari-9 will start soon.  The data is also available at this Coast Watch page as a 2week rotated buffer. There is a plan to reprocess the AHI data, for the full Himawari-8 and -9 missions.

    The data are reported hourly, in AHI Full Disk (FD), for view zenith angle not exceeding 68¬į, both in swath projection (L2P) and as a 0.02¬į gridded L3C. There are 24 FDs per day, with a total data volume of 6.3GB/day for L2P and 0.6GB/day for L3C, respectively. For data assimilation applications (such as production of L4 analyses, especially those that blend satellite and in situ data), correction for the Sensor-Specific Error Statistics (SSES; reported in ACSPO files; Petrenko et al., 2016) biases is strongly recommended.

    In each valid water pixel (defined as ocean, sea, lake or river, up to 5km inland; note that in "invalid" pixels, defined as those with >5km inland, fill values are reported), the following layers are reported in both L2P and L3C: SSTs derived using multi-channel SST (MCSST; night) and Non-Linear SST (NLSST; day) algorithms (Petrenko et al., 2014); ACSPO clear-sky mask (ACSM; provided in each pixel as part of l2p_flags; Petrenko et al., 2010); SSES bias and standard deviation (Petrenko et al., 2016); NCEP wind speed; and ACSPO SST minus reference (Canadian Met Centre L4 SST). For L2P, brightness temperatures (BTs) in 3.9, 8.6, 10, 11, and 12 ¬Ķm bands are also reported, for those users interested in direct radiance assimilation (e.g., NOAA NCEP, NASA GMAO).

    Only ACSM "confidently clear" pixels (equivalent to GDS2 "quality level"=5; also reported for each pixel) should be used. The ACSM also provides day/night, land, ice, twilight, and glint flags. Note that users of ACSPO data have the flexibility to ignore the ACSM, derive their own clear-sky mask, and use BTs and SSTs in those pixels. They may also ignore ACSPO SST, and derive their own SSTs from the original BTs.

    Both L2P and L3C SSTs are monitored and validated against in situ data (Xu and Ignatov, 2014) in SQUAM (Dash et al., 2010) and ARMS (Ding et al., 2017) systems, and BTs are monitored in MICROS (Liang and Ignatov, 2011).

    Short Names
    AHI_H08-STAR-L2P-v2.70
    AHI_H08-STAR-L3C-v2.70
    H09-AHI-L2P-ACSPO-v2.90
    H09-AHI-L3C-ACSPO-v2.90
    Temporal Start Date
    October 16, 2019
    Product Families
    Sea Surface Temperature
    Measurements
    Sea Surface Temperature - Geostationary
    Processing Levels
    Level 2
    Level 3
    Latency Groups
    0 Hours <= 24 Hours (NRT)
    Latency Details

    2-6 hours (typically closer to 2 hours)

    Spatial Resolution Groups
    2km+
    Spatial Resolution Details

    L2P: From 2km@Nadir(link sends e-mail) to ~12km @VZA=68¬į
    L3C: 0.02¬į

    Data Providers
    JMA
    NOAA
    NESDIS
    STAR
    Spatial Coverage

    East Asia & Western Pacific

    Description

    80E-160W
    90N-90S

    ACSPO

    Description

     Advanced Clear Sky Processor for Ocean (ACSPO) is the NOAA Enterprise SST system

    Himawari

    Description

    Himawari

    Platform Type
    Geostationary Earth Orbit Satellite (GEO)
    Instruments
    Organizations
    JMA
    Orbital Longitude
    140.7¬į E
    Orbital Altitude
    35786 km

    AHI

    Description

    Advanced Himawari Imager

    Platforms
    Instrument Types
    Imager
    Organizations
    JMA

    Algorithms:

     

    Monitoring:

    The ACSPO AHI SST data are provided by NOAA STAR. We strongly recommend contacting NOAA SST team led by A. Ignatov before the data are used for any publication or presentation.

    ** When you use our data, please reference the product citation (if available) and acknowledge "NOAA CoastWatch" **