Skip to main content

Description

A global Group for High Resolution Sea Surface Temperature (GHRSST) Level 2P dataset based on multi-channel sea surface temperature (SST) retrievals generated in real-time from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-18 platform (launched 20 May 2005) produced and used operationally in oceanographic analyses and forecasts by the US Naval Oceanographic Office (NAVO). The AVHRR is a space-borne scanning sensor on the National Oceanic and Atmospheric Administration (NOAA) family of Polar Orbiting Environmental Satellites (POES) having a operational legacy that traces back to the Television Infrared Observation Satellite-N (TIROS-N) launched in 1978. AVHRR instruments measure the radiance of the Earth in 5 (or 6) relatively wide spectral bands. The first two are centered around the red (0.6 micrometer) and near-infrared (0.9 micrometer) regions, the third one is located around 3.5 micrometer, and the last two sample the emitted thermal radiation, around 11 and 12 micrometers, respectively. The legacy 5 band instrument is known as AVHRR/2 while the more recent version, the AVHRR/3 (first carried on the NOAA-15 platform), acquires data in a 6th channel located at 1.6 micrometer. Typically the 11 and 12 micron channels are used to derive SST sometimes in combination with the 3.5 micron channel. The NOAA platforms are sun synchronous generally viewing the same earth location twice a day (latitude dependent) due to the relatively large AVHRR swath of approximately 2400 km. The highest ground resolution that can be obtained from the current AVHRR instruments is 1.1 km at nadir. AVHRR data are acquired in three formats: High Resolution Picture Transmission (HRPT), Local Area Coverage (LAC), and Global Area Coverage (GAC). HRPT data are full resolution image data transmitted to a ground stations as they are collected. LAC are also full resolution data, but the acquisition is prescheduled and recorded with an on-board tape recorder for subsequent transmission during a station overpass. This particular dataset is produced from GAC data that are derived from an on-board sample averaging of the full resolution global AVHRR data. Four out of every five samples along the scan line are used to compute on average value and the data from only every third scan line are processed, yielding an effective 4 km resolution at nadir. Further binning and averaging of these pixels results in a final dataset resolution of 8.8 km.

Product Summary

Platforms
NOAA-19
Instruments
AVHRR-3
Spatial Extent

N: 80 S: -70 E: 180 W: -180

Spatial Resolution
8800 Meters x 8800 Meters
Geographic Region
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
CARTESIAN
Temporal Extent
2013-09-24 to 2018-05-14
Data Partner
Naval Oceanographic Office, U.S. Navy, U.S. Department of Defense (DOD/USNAVY/NAVOCEANO) ,
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC)
Concept ID
C2499940513-POCLOUD
Data State
COMPLETE
Number of Files/Granules
23756
Processing Level
2P
Published
Updated
Science Keywords
Sea Surface 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 Jet Propulsion Laboratory (JPL). (2014). GHRSST Level 2P Global 1m Sea Surface Temperature from the Advanced Very High Resolution Radiometer (AVHRR) on the NOAA-18 satellite produced by NAVO [Data set]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/GH18G-2PN02 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
adi_dtime_from_sst time difference with NAAPS forecast hour byte -128 -127 to 127 0.1
aerosol_dynamic_indicator Aerosol optical depth provided from the Navy Aerosol Analysis and Prediction System (NAAPS) global aerosol prediction system. count byte -128 -127 to 127 0.006
brightness_temperature_4um non L2P core field; brightness temperature for 3.7 um channel AVHRR channel 3 kelvin short -32768 -5000 to 5000 0.01
brightness_temperature_11um non L2P core field; brightness temperature for 10.8 um channel AVHRR channel 4 kelvin short -32768 -5000 to 5000 0.01
brightness_temperature_12um non L2P core field; brightness temperature for 12.0 um channel AVHRR channel 5 kelvin short -32768 -5000 to 5000 0.01
dt_analysis Deviation from NAVOCEANO 10-km SST gridded field (K10) kelvin byte -128 -127 to 127 0.1
l2p_flags no retrieval made on land or ice. SST over lakes and river are not identified N/A short 2048 0 to 2047 1
lat Latitude of retrievals degrees_north float N/A -90 to 90 1
lon Longitude of retrievals degrees_east float N/A -180 to 180 1
quality_level Based on NAVOCEANO reliability estimates N/A byte 0 0 to 5 1
satellite_zenith_angle satellite zenith angle angular degree byte -128 -127 to 127 1
sea_surface_temperature SST obtained by regression from buoy measurements at 1 m depth kelvin short -32768 -5000 to 5000 0.01
sses_bias Updated daily based on previous month match-ups kelvin byte -128 -127 to 127 0.01
sses_standard_deviation Updated daily based on previous month match-ups kelvin byte -128 -127 to 127 0.01
sst_dtime none second short -32768 -32767 to -32767 0.25
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 wind speed is not available m s-1 byte -128 -127 to 127 0.15
You're viewing 17 of 17