N2O5 Zonal Fourier Coefficients from HIRDLS Satellite Mission

HIRDLS/Aura satellite data provides dinitrogen pentoxide (N2O5) measurements expressed as zonal Fourier coefficients for the entire ~3-year mission. Coefficients represent the mean and up to 7 sine/cosine terms across 1-degree latitude bands from -64 to 80 degrees at 121 pressure levels. The NASA GES DISC published this Level 3 data product, with files last updated in March 2008.

Use Cases

• Reconstruct global N2O5 fields at any longitude using the stored mean and 7 sine/cosine Fourier coefficients.
• Analyze diurnal cycles by comparing ascending (daytime) and descending (nighttime) orbit node data fields.
• Study vertical distribution of N2O5 across the 121 pressure levels, from 82.5 hPa to 1.0 hPa.
• Validate chemical transport models using precision values derived from root-mean-square differences between estimated fields and input data.
• Investigate latitudinal gradients from -64 to 80 degrees using the 1-degree latitude band zonal structure.

Strengths

• Covers the entire ~3-year HIRDLS mission, providing complete temporal coverage.
• Data provided on a detailed grid of 121 pressure levels with about 1 km vertical resolution.
• Coefficients allow longitudinal reconstruction without storing every longitude, reducing data volume.

Limitations

• Data is temporally stale, with last update in 2008, limiting analysis of recent atmospheric trends.
• Useful vertical range is restricted to 82.5 to 1.0 hPa, excluding the lower troposphere.
• Latitude coverage is from -64 to 80 degrees, omitting polar regions above 80 degrees.

Provenance

Source

NASA Goddard Earth Sciences Data and Information Services Center (GES DISC).

Collection Method

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

Time Range

Covers the entire HIRDLS mission, approximately 3 years up to 2008.

Freshness

null

Geography

Global coverage in 1-degree latitude bands from -64 to 80 degrees.