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R.E. Novak (Iona College), M.J. Mumma (NASA-Goddard Space Flight Center), M.A. DiSanti, N Dello Russo (GSFC, Catholic University of America), K. Magee-Sauer (Rowan University)
Photolysis of ozone in Mars' atmosphere by UV sunlight (Hartley bands) produces the singlet Delta state of O2; emissions from this state (1.27 micron band) are used as a tracer for atmospheric ozone. Quenching of the singlet Delta state by carbon dioxide is dominant at low altitudes so that the measured ozone comes from altitudes above ~20 km. We used CSHELL (0.5 arc-sec slit width, resolving power ~ 40,000) at IRTF to observe the 1.27 micron band of O2 (singlet Delta - triplet Sigma, magnetic dipole transition) on Jan. 14, 2001 (Ls = 103 deg.) and Mar. 20, 2001 (Ls = 133 deg). On both dates, the slit was oriented north-south on Mars and it was stepped east-west at one arc-sec intervals. On Mar. 21, 2001, the slit was oriented east-west on Mars. HDO bands measured near 3.67 micron provided maps for water column burdens. Ozone maps for Ls=103 deg along the meridian indicate a considerable reduction in ozone column density in the northern latitudes when compared to a similar map for Ls=67 deg. during the 1997 apparition. A map taken for Ls=133 deg. indicates a further reduction of ozone in the northern hemisphere with a concentration of ozone in the southern hemisphere. These data will be presented along with near simultaneous measurements of water column burdens retrieved from the HDO bands. Diurnal variation of the 1.27 micron emission will also be presented. Project was partially funded through a faculty grant from Iona College.