SAGE II Version 6.3: Improved ozone and water vapor data products

A new version for the Stratospheric Aerosol and Gas Experiment (SAGE II) data products has been developed and is in the process of being released. This version incorporates the transmission refinements developed for SAGE III Version 4 that reduces uncertainty in the multi-wavelength line-of-sight transmission data. The transmission profiles form the backbone of the SAGE II retrievals of ozone, NO₂, water vapor, and multi-wavelength aerosol extinction. In addition, we have updated the SAGE II ozone and NO₂ spectroscopic data to match those used in the SAGE III retrievals. The change in spectroscopy, required a reassessment of the spectral characteristics of the water vapor channel located near 940 nm with an end result that SAGE II water vapor is in much better agreement with MLS and SAGE III than in version 6.2 and remains so over a larger altitude range than was previously noted. Finally, we have reassessed the estimation of dark current in SAGE II data stream with an outcome that the well-known bias in SAGE II ozone in the troposphere is significantly reduced.