The latest version of Aura MLS Level 2 data, Version 3.3 (v3.3), have been released to the public. MLS data spanning the entire mission, beginning August 2004 and extending to the present, are available.
This data release includes important improvements over the earlier Version 2.2 (v2.2) data. Significant biases in the v2.2 CO and HNO3 products at 215 hPa* (and partly at 146 hPa) have been ameliorated. Biases in lower stratospheric ClO have been reduced, and anomalous structure in mid-stratospheric water vapor has been eliminated.
Ozone profiles are now reported on a vertical grid in the upper troposphere and stratosphere with a resolution twice as fine as earlier versions; useful data for this product now extend down to 261 hPa. Also, the vertical grid for H2O, temperature, geopotential height (GPH), and relative humidity with respect to ice (RHI) now follow the same fine grid as the ozone retrievals through the upper troposphere and stratosphere.
A new product – methyl chloride (CH3Cl) – was added in this release. Interested users should review the new 'Version 3.3 Level 2 Data Quality Description Document" (PDF, 9.42 MB) for full details about each product, including new screening rules to eliminate occasional spikes and oscillations in the presence of thick cloud. The previous v2.2 data are still available from the GES DISC, and incoming data will continue to be processed with v2.2 algorithms, in addition to the new v3.3 algorithms, for at least the next six months, i.e., at least through July 2011.
Link: Aura Microwave Limb Sounder Web site (Jet Propulsion Laboratory)
*hPa stands for hectopascals, which are units of atmospheric pressure. [A link to a commercial Web site does not constitute endorsement by NASA or its affiliates.]