Global Nitric Acid Zonal Fourier Coefficients from HIRDLS Satellite Mission

HIRDLS/Aura satellite data provides nitric acid (HNO3) concentrations expressed as zonal Fourier coefficients across 1-degree latitude bands from -64 to 80 degrees. The dataset contains the entire ~3-year mission, processed to 121 pressure levels with about 1 km vertical resolution. NASA's GES DISC produced and published this Level 3 data product in 2008.

Use Cases

• Reconstruct nitric acid concentration fields at any longitude using the provided mean and up to 7 sine/cosine Fourier coefficients.
• Analyze diurnal cycles by comparing data fields for ascending (daytime) and descending (nighttime) orbit nodes.
• Study vertical profiles of HNO3 across the useful range from 215 to 5.1 hPa on the 24-levels-per-decade pressure grid.
• Assess data precision for model validation using the root-mean-square difference fields between estimated and input data.
• Investigate latitudinal distribution from -64 to 80 degrees using the 1-degree band zonal Fourier coefficients.

Strengths

• Covers the entire ~3-year HIRDLS mission, providing complete temporal coverage.
• Offers high vertical resolution with data on 121 pressure levels, approximately 1 km resolution.
• Provides separate data fields for ascending, descending, and combined orbits for diurnal analysis.

Limitations

• Data is temporally stale, with the last update in March 2008, limiting analysis of recent atmospheric changes.
• Latitudinal coverage is incomplete, missing polar regions above 80 degrees and below -64 degrees.
• The HDF-EOS5 format requires specialized libraries for data access and processing.

Provenance

Source

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

Collection Method

Derived from HIRDDS 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 from -64 to 80 degrees latitude, with zonal bands at 1-degree resolution.