Aura Satellite Daily Hydroxyl Mixing Ratio on Zonal Grids

MLS/Aura Level 3 data provides daily binned hydroxyl (OH) mixing ratios from August 2004 to December 2009, with intermittent data through 2014. The dataset is produced by the NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) from the Microwave Limb Sounder instrument. Measurements offer near-global coverage from -82 to +82 degrees latitude at 4-degree increments and a vertical range from 31.6 to 0.00316 hPa.

Use Cases

• Analyze trends in hydroxyl (OH) zonal means versus pressure to study stratospheric chemistry changes over the 2004-2009 period.
• Compare daytime (SZA < 90) and nighttime (SZA > 110) average OH profiles to investigate diurnal variations in atmospheric composition.
• Map hydroxyl mixing ratios by equivalent latitude versus potential temperature to examine transport processes within the polar vortex.
• Use the standard deviation and RMS fields within each binned group to quantify measurement uncertainty for model validation.

Strengths

• Continuous primary data coverage spans over 5 years from August 2004 to December 2009.
• Provides data binned into specific profiles: all valid, ascending/descending orbit, and day/night, enabling targeted analysis.
• Near-global spatial coverage from -82 to +82 degrees latitude at 4-degree zonal increments.

Limitations

• Primary continuous data collection ended in December 2009, with only 30-day snapshots available in subsequent years up to 2014, limiting recent trend analysis.
• The vertical resolution of about 3 km may be coarse for studying fine-scale atmospheric processes.
• Data is aggregated into yearly netCDF4 files with complex internal group structures, requiring specialized knowledge for access and interpretation.

Provenance

Source

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

Collection Method

Derived from radiances measured by the THz radiometer on the EOS Aura satellite's Microwave Limb Sounder (MLS) instrument.

Time Range

August 2004 to December 2009 (continuous), with intermittent 30-day periods in 2011-2014.

Freshness

Data collection ended in 2014; the dataset is archived and not updated.

Geography

Near-global, -82 to +82 degrees latitude.