SCAMS/Nimbus-6: Microwave-Derived Atmospheric Profiles

SCAMS/Nimbus-6 Level 2 data provides historical atmospheric profiles from a pioneering microwave spectrometer. The instrument monitored five frequencies to derive tropospheric temperature profiles, water vapor abundance, and cloud water content over oceans, enabling weather prediction through cloud cover. Data from June 15, 1975, to May 31, 1976, are archived in their original IBM 32-bit binary format recovered from 9-track magnetic tapes.

Use Cases

• Analyzing historical tropospheric temperature profiles derived from 52.85, 53.85, and 55.45 GHz oxygen absorption channels.
• Estimating historical water vapor and cloud water content over calm oceans using 22.235 and 31.65 GHz channels.
• Calibrating or validating climate reanalysis models with microwave brightness temperature data.
• Studying the performance and data recovery of early satellite-based Dicke-superheterodyne microwave instruments.

Strengths

• Provides calibrated atmospheric data with specified instrument accuracy: oxygen channels better than 2 K RMS, water vapor channels better than 1 K RMS.
• Offers a nearly one-year continuous time series from June 1975 to May 1976 for historical climate analysis.
• Data was recovered from original archival media, preserving a unique record from early satellite meteorology.
• Cross-platform presence on NASA Earthdata and Data.gov signals its importance and institutional backing.

Limitations

• Column names and detailed data structure are unknown, complicating direct analysis.
• Data is stored in a legacy IBM 32-bit binary (TAP) format, requiring specialized tools for access and conversion.
• Metadata conflicts: last updated date is listed as both 2026-04-09 and 1976-05 31 across sources.

Provenance

Source

GES DISC, from the Nimbus-6 satellite SCAMS instrument. Principal Investigator was Prof. David H. Staelin from MIT.

Collection Method

Recovered from original 9-track magnetic tapes written on IBM 360 machines.

Time Range

June 15, 1975 to May 31, 1976

Freshness

2026-04-09 22:37:10.590306

Geography

Global, with a focus on measurements over calm oceans.