Daily Zonal Hydroxyl Mixing Ratios from Aura Satellite

MLS/Aura Level 3 data provides daily binned hydroxyl (OH) mixing ratios from August 2005 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 are near-global, spanning -82 to +82 degrees latitude at 4-degree increments and a vertical range from 31.6 to 0.00316 hPa.

Use Cases

• Analyze OH lat vs pressure zonal mean fields to study the global distribution and seasonal cycles of hydroxyl radicals.
• Compare ascending orbit and descending orbit profile groups to investigate diurnal variations in atmospheric chemistry.
• Use the equivalent latitude vs potential temperature zonal mean groups to examine polar vortex dynamics and its impact on OH concentrations.
• Leverage the vortex average vs potential temperature data for focused studies on chemical processes within the Antarctic or Arctic vortex.
• Apply statistical fields (average, min, max, std dev, rms) within each profile group to quantify uncertainty and variability in OH measurements for model evaluation.

Strengths

• Continuous daily coverage from August 2005 to December 2009, providing over 4 years of consistent data.
• Near-global spatial coverage from -82 to +82 degrees latitude at 4-degree zonal increments.
• Data is subdivided into specific observational conditions (all valid, ascending/descending orbit, day/night) for detailed analysis.
• Each data group includes multiple statistical measures (average, min, max, std dev, rms) for robust analysis.

Limitations

• Primary data collection ended in December 2009; post-2009 data is limited to approximately 30-day campaigns in 2011-2014.
• The vertical resolution is coarse at about 3 km, which may limit fine-scale atmospheric layer analysis.
• Data files contain one year of data per file, requiring multiple file downloads for full temporal analysis.

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 Microwave Limb Sounder (MLS) satellite instrument.

Time Range

August 2, 2005 to December 12, 2009 (continuous), with intermittent 30-day periods in August/September of 2011, 2012, 2013, and 2014.

Freshness

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

Geography

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