HIRDLS/Aura: Aerosol Extinction Zonal Fourier Coefficients

HIRDLS/Aura Level 3 data expresses the entire mission (~3 years) of aerosol extinction measurements as zonal Fourier coefficients. The coefficients, computed with a Kalman filter, allow calculation of values at any longitude across 1-degree latitude bands from -64 to 80 degrees. NASA provides this data on a pressure grid with about 1 km vertical resolution between 215 and 20 hPa.

Use Cases

• Modeling global aerosol distribution patterns based on zonal Fourier coefficients.
• Analyzing vertical aerosol extinction profiles based on the 121 pressure level grid.
• Studying diurnal aerosol variations based on separate ascending (daytime) and descending (nighttime) orbit node data.
• Reconstructing atmospheric extinction values at any longitude based on the sine and cosine coefficients.

Strengths

• Provides data for the entire HIRDLS mission (~3 years).
• Offers high vertical resolution with 121 pressure levels, corresponding to about 1 km.
• Separates data fields for ascending (daytime), descending (nighttime), and combined orbit nodes.

Limitations

• Column-level documentation is absent; field semantics must be inferred after download.
• The useful vertical range is limited to 215 to 20 hPa.
• Row count is unknown, which may limit suitability assessment.

Provenance

Source

National Aeronautics and Space Administration

Collection Method

Coefficients computed from HIRDLS Level 2 profiles with a Kalman filter approach.

Time Range

The entire HIRDLS mission (~3 years).

Freshness

Last updated 2026-03-13 01:39:43.922842; freshness should be verified.

Geography

Global coverage from -64 to 80 degrees latitude.