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Description

The H09-AHI-L2P-ACSPO-v2.90 dataset contains the Subskin Sea Surface Temperature (SST) produced by the NOAA ACSPO system from the Advanced Himawari Imager (AHI; largely identical to GOES-R/ABI) onboard the Himawari-9 (H09) satellite. The H09 is a Japanese weather satellite, the 9th of the Himawari geostationary weather satellite operated by the Japan Meteorological Agency. It was launched on November 2, 2016 into its nominal position at 140.7-deg E, and declared operational on December 13, 2022, replacing the Himawari-8. The AHI is the primary instrument on the Himawari Series for imaging Earth’s weather, oceans, and environment with high temporal and spatial resolutions. <br><br>
The H08/AHI maps SST in a Full Disk (FD) area from 80E-160W and 60S-60N, with spatial resolution 2km at nadir to 15km/VZA (view zenith angle) 67-deg, and 10-min temporal sampling. The 10-min FD data are subsequently collated in time, to produce the 1-hr product, with improved coverage and reduced cloud leakages and image noise. The L2P data is produced in GHRSST compliant netCDF4 GDS2 format, with 24 granules per day, and a total data volume 1.2 GB/day. The near-real time (NRT) data are updated hourly, with several hours latency. The NRT files are replaced with Delayed Mode (DM) files, with a latency of approximately 2-months. File names remain unchanged, and DM vs NRT can be identified by different time stamps and global attributes inside the files (MERRA instead of GFS for atmospheric profiles, and same day CMC L4 analyses in DM instead of one-day delayed in NRT processing). <br><br>
Pixel earth locations are not reported in the granules, as they remain unchanged from granule to granule. Pixel locations can be obtained using a flat lat/lon file or a Python script available via Documents tab from the dataset landing page. Climate and Forecast (CF) metadata aware software (e.g., Panoply, xarray) can detect and map the data as is via the granule CF projection attributes and variables. The ACSPO H09 HAI SSTs are validated against quality controlled in situ data from the NOAA iQuam system (Xu and Ignatov, 2014) and continuously monitored in the NOAA SQUAM system (Dash et al, 2010). A 0.02-deg equal-angle gridded L3C product 0.7GB/day) is available at https://podaac.jpl.nasa.gov/dataset/H09-AHI-L3C-ACSPO-v2.90

Product Summary

Platforms
Himawari-9
Instruments
AHI
Spatial Extent

N: 60 S: -60 E: -160 W: 80

Spatial Resolution
2000 Meters x 2000 Meters
Geographic Region
PACIFIC OCEAN
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2022-10-22
Data Partner
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC) ,
Center for Satellite Applications and Research, NESDIS, NOAA, U.S. Department of Commerce (DOC/NOAA/NESDIS/STAR)
Concept ID
C2744808497-POCLOUD
Data State
ACTIVE
Number of Files/Granules
26462
Processing Level
2P
Published
Updated
Science Keywords
SEA SURFACE SUBSKIN TEMPERATURE

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

NASA/JPL. (2023). GHRSST L2P NOAA/ACSPO Himawari-09 AHI Pacific Ocean Region Sea Surface Temperature v2.90 dataset [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/GHH09-2P290 Date Accessed: 2025-12-14

Documents

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
brightness_temperature_08um6 non L2P core field; brightness temperature for 8.6 um channel ABI Ch. 11 kelvin short -32768 -32767 to 32767 0.01
brightness_temperature_10um4 non L2P core field; brightness temperature for 10.4 um channel ABI Ch. 13 kelvin short -32768 -32767 to 32767 0.01
brightness_temperature_11um2 non L2P core field; brightness temperature for 11.2 um channel ABI Ch. 14 kelvin short -32768 -32767 to 32767 0.01
brightness_temperature_12um3 non L2P core field; brightness temperature for 12.3 um channel ABI Ch. 15 kelvin short -32768 -32767 to 32767 0.01
dt_analysis Deviation from reference SST, i.e., dt_analysis = SST - reference SST kelvin short -32768 -32767 to 32767 0.01
geostationary geostationary projection N/A int N/A N/A 1
l2p_flags L2P common flags in bits 1-3 and data provider flags (from ACSPO mask) in bits 8-16. For backwards compatibility with legacy reader software, the data provider flags (last 9 bits) contain redundant land and ice information that is also available in bits 2 and 3, respectively. Description of individual bits: bit01 (0=IR: 1=microwave); bit02 (0=not_land; 1=land (from land-sea mask)); bit03 (0=not_ice; 1=ice (from first-guess L4 SST)); bits04-08 (reserved,set to 0); bit08 (0=anti-solar; 1=solar); bit09 (0=valid_radiance; 1=invalid_radiance); bit10 (0=nighttime; 1=daytime); bit11 (0=not_land; 1=land (identical to bit02)); bit12 (0=good quality data; 1=twilight_degradation (degraded quality data due to &quot;twilight&quot; region)); bit13 (0=not_sunglint; 1=sunglint); bit14 (0=not_ice; 1=ice (identical to bit03)); bit15 (0=sst; 1=SST_not_valid_or_degraded (not_valid or degraded SST w/QL&lt;5)); bit16 (0=water (ocean, lake, river); 1=not_water (land, ice, invalid)) N/A short N/A -32768 to 32767 1
ni x coordinate of projection radians float N/A -0.15366402 to 0.15366402 1
nj y coordinate of projection radians float N/A -0.15366402 to 0.15366402 1
quality_level SST quality levels: 5 corresponds to &quot;clear-sky&quot; pixels and is recommended for operational applications and validation. N/A byte -128 0 to 5 1
satellite_zenith_angle satellite zenith angle degrees short -32768 0 to 7000 0.01
sea_surface_temperature SST obtained by collation algorithm kelvin short -32768 -32767 to 32767 0.01
sses_bias Bias is derived against Piecewise Regression SST produced by local regressions with buoys. Subtracting sses_bias from sea_surface_temperature producess more accurate SST at the depth of buoys Further information at (Petrenko et al., JTECH, 2016; doi:10.1175/JTECH-D-15-0166.1) kelvin byte -128 -127 to 127 0.016
sses_standard_deviation Standard deviation of sea_surface_temperature from SST measured by drifting buoys. Further information at (Petrenko et al., JTECH, 2016; doi:10.1175/JTECH-D-15-0166.1) kelvin byte -128 -127 to 127 0.01
sst_dtime time plus sst_dtime gives seconds since 1981-01-01 00:00:00 UTC seconds short -32768 -32767 to 32767 0.25
sst_front_position Binary indicator of SST front position in the valid SST clear-sky domain: 1 - SST front present, 0 - no front present N/A byte -128 0 to 1 1
sst_gradient_magnitude Gradient magnitude calculated from SST field in all grids with valid SST kelvin/km short -32768 -32767 to 32767 0.001
time Seconds since 1981-01-01 00:00:00 seconds since 1981-01-01 00:00:00 int N/A N/A 1
wind_speed Typically represents surface winds (10 meters above the sea surface) m s-1 byte -128 -127 to 127 0.15
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