SAMSN7L3ZMTG: Nimbus-7 Stratospheric Gas Zonal Averages

SAMSN7L3ZMTG contains Level 3 zonal mean mixing ratios of nitrous oxide (N2O) and methane (CH4) from the Nimbus-7 Stratospheric and Mesospheric Sounder (SAMS). Data are averaged over day and night across 31 pressure levels from 50 to 0.125 mbar and 2.5-degree latitudinal zones from 50°S to 67.5°N. The dataset covers the period from 1 January 1979 through 30 December 1981, with only one gas measured per day due to instrument constraints.

Use Cases

• Analyzing historical stratospheric methane and nitrous oxide distributions based on zonal and vertical pressure level averages.
• Studying trace gas transport and variability in the 1979-1981 period using the provided temporal coverage.
• Validating reanalysis products or model simulations of the middle atmosphere against satellite-derived mixing ratios.
• Investigating latitudinal gradients of greenhouse gases in the stratosphere using the 2.5-degree zonal binning.

Strengths

• Provides a specific historical record from a key satellite mission (Nimbus-7 SAMS) from 1979 to 1981.
• Includes vertical profiling across 31 pressure levels and error estimates for the retrieved mixing ratios.
• Data has been preserved and migrated from original magnetic tapes to an online format.

Limitations

• Metadata completeness is low: column names, row counts, and file size are unknown across all sources.
• Data is stored in a single proprietary binary (BIN) format, which may hinder immediate analysis.
• Conflicting 'last updated' dates (1981 vs. 2026) create uncertainty about metadata maintenance.

Provenance

Source

National Aeronautics and Space Administration (NASA); Principal Investigators Prof. John T. Houghton and Dr. Fredric W. Taylor from Oxford University.

Collection Method

Retrieved from the Nimbus-7 SAMS instrument, averaged into zonal means, and recovered from original magnetic tapes.

Time Range

1979-01-01 to 1981-12-30

Freshness

2026-04-09 22:17:26.304290

Geography

Global, latitudinal zones from 50° South to 67.5° North.