SMMRN7IM: Nimbus-7 Microwave Radiometer Color Images of Ocean and Ice

Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) data provides global coverage from 64°S to 64°N in Mercator projection and polar stereographic projections for the poles. The dataset consists of color images scanned from original prints, containing parameters like sea surface temperature, winds, atmospheric water vapor, and sea ice concentration. Data is available as 3-day, 6-day, and 1-month composite averages from October 30, 1978, to November 2, 1983.

Use Cases

• Analyzing historical sea ice extent and concentration trends based on polar stereographic image composites.
• Studying decadal changes in sea surface temperature and wind patterns from 6-day Mercator projections.
• Investigating atmospheric water vapor and liquid water content over oceans from brightness temperature parameters.
• Calibrating or validating newer satellite microwave data against this early instrument record.

Strengths

• Provides a continuous five-year historical record from 1978 to 1983, a key early period for satellite microwave observation.
• Data is processed into standardized temporal composites (3-day, 6-day, 1-month) facilitating time-series analysis.
• Cross-platform presence on NASA EarthData and Data.gov signals its importance and curation within official archives.

Limitations

• Core metadata is sparse: column names, row counts, and exact file sizes are unknown across all sources.
• Source freshness metadata conflicts: one lists an update in 2026, another lists the end date in 1983.
• Data is derived from scanned physical prints (JPEG-2000), not raw digital measurements, which may limit precision.

Provenance

Source

NASA GSFC; Principal Investigator Dr. Per Gloersen. Previously archived at NSSDC under multiple ESAD IDs.

Collection Method

Scanned from 17" x 15" color prints of original SMMR instrument data.

Time Range

1978-10 30 to 1983-11-02

Freshness

2026-04-09 22:52:15.713337

Geography

Global, with Mercator projection from 64°S to 64°N and polar stereographic projections for the Arctic and Antarctic.