Global Daily Sea Surface Temperature Analysis from Satellite and In-Situ Data

GHRSST Level 4 data provides a daily, optimally interpolated global sea surface temperature field on a 0.25-degree grid. The dataset is produced by NOAA National Centers for Environmental Information (NCEI), blending observations from AVHRR satellites, ships, buoys, and Argo floats. A preliminary version is available with a 1-day latency, replaced by a final version after two weeks.

Use Cases

• Analyzing daily SST anomaly patterns using the gridded temperature field to monitor events like El Niño.
• Correcting satellite SST biases by incorporating in-situ buoy and Argo float data referenced in the methodology.
• Modeling Arctic ocean heat content using SST values derived from sea-ice concentration conversion for regions above 30% ice.
• Validating climate model outputs against the long-term, globally complete temperature field produced since 1982.
• Studying the impact of data source updates, such as the switch from METOP-A/NOAA-19 to METOP-A/METOP-B inputs after 2016.

Strengths

• Global coverage on a consistent 0.25-degree spatial grid.
• Blends multiple observation sources (satellite AVHRR, ships, buoys, Argo floats) for bias correction.
• Version 2.1 includes major improvements for data after January 1, 2016, such as revised sea-ice-to-SST conversion to remove Arctic warm biases.

Limitations

• Data prior to 2016 remains from version 2.0 with known issues in in-situ data ingest and bias correction, pending a planned update.
• The description notes regions with high sea-ice concentration use proxy SSTs, which may introduce specific artifacts.
• Specific row counts, file sizes, and complete temporal coverage details are not provided in the input.

Provenance

Source

NOAA National Centers for Environmental Information (NCEI) via the GHRSST project.

Collection Method

Optimal interpolation (OI) of SST observations from AVHRR satellites and in-situ platforms (ships, buoys, Argo floats).

Time Range

Data from 1982 onward, with a version update applying to records after January 1, —2016.

Freshness

Daily production with a 1-day latency for preliminary data and a 2-week latency for final data.

Geography

Global ocean coverage.