613.3 Branch Seminar: Dr. Didier Rault

LARC

The Ozone Mapping and Profiler Suite (OMPS) is scheduled to be launched on NPP in the Fall 2011. This suite of sensors is composed of (1) two Nadir viewing sensors to measure the total ozone column (heritage from TOMS and OMI) and the ozone vertical distribution at relatively low vertical resolution (heritage from SBUV) and (2) a limb viewing sensor (OMPS/LP) to perform high resolution ozone vertical profiling (heritage from SOLSE/LORE, OSIRIS, SAGE III/LS, SCIAMACHY).

While the Nadir instrument techniques and retrieval algorithms are relatively well known and mature, the full potentials of the OMPS limb profiler and its ability to produce ozone data of Climate Data Record (CDR) quality are still being assessed. The presentation will first describe the OMPS/LP mission and define its main goal, namely to produce ozone vertical profiles at a resolution of 1.5-2.5 km, accuracy of less than 10%, precision of 3-5% and a sampling rate of 1 km and 120 km respectively in the vertical and along-track directions. The main concept of the Limb Scatter method will be reviewed, with emphasis placed on both its capabilities (based on past and present on-orbit limb sensors) and its challenges (straylight, height registration, along-track inhomogeneity). While Solar Occultation sensors (SAGE family) are known for their high precision (2%) but poor geographic coverage and low duty cycle (28 events per day), the OMPS/LP sensor is designed to produce CDR quality ozone data at a rate of 6500 events per day with an average revisit time of 4 days, which should provide the science community the necessary data at fine temporal/spatial scales required to assess the global stratospheric ozone recovery.