HIRDLS/Aura Nitrous Oxide Zonal Fourier Coefficients for Entire Mission

HIRDLS/Aura Level 3 Nitrous Oxide (N2O) zonal Fourier coefficients version 7 data product contains the entire mission (~3 years) of satellite data. The coefficients are computed from Level 2 profiles using a Kalman filter approach and are expressed as mean and up to 7 sine and cosine coefficients. The data are provided by NASA on a pressure grid with 24 levels per decade, covering latitudes from -64 to 80 degrees.

Use Cases

• Model global atmospheric nitrous oxide distribution based on zonal Fourier coefficients.
• Analyze seasonal or longitudinal variations in N2O concentration based on ascending and descending orbit node data.
• Study vertical profiles of nitrous oxide from 100 to 5.1 hPa pressure levels.
• Reconstruct atmospheric values at any longitude using the provided sine and cosine coefficients.

Strengths

• Contains the entire mission (~3 years) of HIRDLS data.
• Provides data on 121 pressure levels with about 1 km vertical resolution.
• Includes separate data fields for ascending (daytime), descending (nighttime), and combined orbit nodes.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• Row count is unknown, which may limit suitability assessment.
• The useful vertical range is limited to 100 to 5.1 hPa.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Coefficients computed from HIRDLS Level 2 profiles with a Kalman filter approach using both forward and backward passes in time.

Time Range

Entire mission (~3 years)

Geography

Zonal data in 1 degree latitude bands from -64 to 80 degrees.