Decade-long Ozone Profile Record from Suomi NPP OMPS Limb Profiler:
Assessment of Version 2.6 Data
Abstract
We evaluate a decadal ozone profile record derived from the Suomi
National Polar-orbiting Partnership (SNPP) Ozone Mapping and Profiler
Suite (OMPS) Limb Profiler (LP) satellite instrument. In 2023, the OMPS
LP data were re-processed with the new version 2.6 retrieval algorithm
that combines measurements from the ultraviolet (UV) and visible (VIS)
parts of the spectra and employs the second order Tikhonov
regularization to retrieve a single vertical ozone profile between 12.5
km (or cloud tops) and 57.5 km with the vertical resolution of about 1.9
- 2.5 km between 20-55 km. The algorithm uses radiances measured at six
UV ozone-sensitive wavelengths (295, 302, 306, 312, 317 and 322 nm)
paired with 353 nm, and one VIS wavelength at 606 nm combined with 510
nm and 675 nm to form a triplet. Each wavelength pair or triplet is used
over a limited range of tangent altitudes where the sensitivity to ozone
changes are strongest. A new implemented aerosol correction scheme is
based on a gamma-function particle size distribution. Numerous
calibration changes that affected ozone retrievals were also applied to
measured LP radiances, including updates in altitude registration,
radiometric calibration, stray light, and spectral registration. The key
version 2.6 improvement is the reduction in relative drifts between LP
ozone and correlative measurements, linked previously to a drift in the
version 2.5 LP altitude registration. We compare LP ozone profiles with
those from Aura Microwave Limb Sensor (MLS) to quantify ozone changes in
version 2.6.