Daily Zonal Mean Hypochlorous Acid Mixing Ratios from Aura MLS Satellite

MLS/Aura Level 3 data provides daily binned, near-global measurements of hypochlorous acid (HOCl) mixing ratios. The dataset is produced by the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) from Microwave Limb Sounder radiances, with files containing one year of data each. Spatial coverage spans from -82 to +82 degrees latitude at 4-degree zonal increments.

Use Cases

• Analyze lat vs pressure zonal mean HOCl to study its vertical and meridional distribution in the stratosphere.
• Compare daytime (SZA < 90) and nighttime (SZA > 110) profile groups to investigate diurnal variations in chlorine chemistry.
• Use the equivalent latitude vs potential temperature zonal mean groups to examine HOCl distribution relative to the polar vortex.
• Employ the statistical fields (average, min, max, std dev, rms) within each group to quantify measurement uncertainty and variability.

Strengths

• Near-global spatial coverage from -82 to +82 degrees latitude.
• Recommended useful vertical range from 10 to 2.15 hPa with about 6 km vertical resolution.
• Data is subdivided into specific orbit and solar illumination profiles (ascending, descending, daytime, nighttime) for targeted analysis.

Limitations

• The dataset's temporal coverage for individual files is one year, requiring multiple files for long-term trend analysis.
• Useful data is constrained to the 10 to 2.15 hPa pressure range, limiting analysis of HOCl outside this stratospheric layer.
• Specific row counts, sample sizes, and data completeness metrics are not provided in the description.

Provenance

Source

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

Collection Method

Derived from radiances measured primarily by the 640 GHz radiometer on the EOS Aura Microwave Limb Sounder (MLS).

Time Range

Data files contain one year of data each; specific years not stated.

Geography

Near-global, from -82 to +82 degrees latitude at 4-degree latitude zonal increments.