Computer Science
Scientific paper
Feb 1994
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1994rmus.nasav....l&link_type=abstract
In its Reanalysis of Mariner 9 UV Spectrometer Data for Ozone, Cloud, and Dust Abundances, and Their Interaction Over Climate Ti
Computer Science
Abundance, Annual Variations, Atmospheric Attenuation, Atmospheric Chemistry, Atmospheric Temperature, Dust, Mariner 9 Space Probe, Mars Atmosphere, Ozone, Photochemical Reactions, Radiative Transfer, Spectral Resolution, Ultraviolet Spectra, Ultraviolet Spectrometers, Computerized Simulation, Frost, Reflectance, Surface Temperature, Ultraviolet Spectroscopy, Winter
Scientific paper
Ozone is a key to understanding atmospheric chemistry on Mars. Over 20 photochemical models of the martian atmosphere have been published, and O3 is often used as a benchmark for these models. O3 abundance has been inferred from instrumentation on several spacecraft, with the most complete coverage provided by Mariner 9. The Mariner 9 UV spectrometer scanned from 2100 to 3500 Angstroms with a spectral resolution of 15 Angstroms and an effective field-of-view of approximately 300 sq km. The only atmospheric absorption in the 2000 to 3000 A wavelength region was previously assumed to come from the Hartley band system of ozone, which has an opacity of order unity at winter polar latitudes. Therefore, the amount of ozone was inferred by fitting this absorption feature with laboratory data of ozone absorption. Mars O3 shows strong seasonal and latitudinal variation, with column abundances ranging from 0.2 micron-atm at equatorial latitudes to 60 micron-atm over northern winter polar latitudes (1 micron-atm is a column abundance of 2.689 x 10 exp 15 molecules cm-2). However, the O3 abundance is never great enough to significantly affect atmospheric temperatures or surface temperatures and frost amounts. Some of the previously-inferred O3 abundances are shown. A radiative transfer computer model is used to re-examine the Mariner 9 UV spectra. Assuming a constant mixing ratio for O3 and no chemical or radiative interaction between O3 and clouds/dust, it is shown that when typical amounts of dust and cloud are present that significant underestimation of O3 abundance occurs. A factor of 3 times as much O3 is needed to generate the same spectrum the spacecraft would measure for a cloudy, dusty atmosphere as for a clear atmosphere. If the scattering properties of martian clouds and dust were well known, then their appearance would not be a problem, as a model would be capable of retrieving the O3 abundance. However, these properties are not well known, which raises doubts about the effectiveness of the UV reflectance spectroscopy technique for measuring O3 abundance on Mars.
No associations
LandOfFree
How well was total ozone abundance inferred with Mariner 9? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with How well was total ozone abundance inferred with Mariner 9?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and How well was total ozone abundance inferred with Mariner 9? will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-956163