Probing Venus's cloud structure with Galileo NIMS

Astronomy and Astrophysics – Astronomy

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

49

Infrared Spectra, Limb Darkening, Near Infrared Radiation, Opacity, Optical Thickness, Venus (Planet), Venus Clouds, Astronomical Spectroscopy, Galileo Spacecraft, Infrared Spectroscopy, Pioneer Venus 1 Spacecraft, Radiative Heat Transfer, Spaceborne Astronomy

Scientific paper

The spectral image cubes obtained by the Near-Infrared Mapping Spectrometer (NIMS) on Galileo as it flew by Venus have been analyzed to constrain the vertical structure of the clouds, the nature of the aerosol particles, and the location and particle properties of the opacity variations responsible for high-contrast features observed in the near-infrared windows at 1.7 and 2.3 micrometers. A radiative transfer program was used to simulate mid-latitude curves of limb darkening at 3.7 micrometers. Best-fit models to these curves demonstrate that the upper clouds are dominated by mode 2 particles (r-bar = 1.0 micrometers), with a contribution of approximately 15% of opacity from mode 1 particles (r-bar = 0.3 micrometers). The low-latitude upper cloud is well represented by a dual scale-height model, with a particle scale height of approximately 1 km from an altitude of 61-63 km, and a scale height of approximately 6 km above this, up to the level where tau = 1 at approximately 71 km. This model also successfully simulates limb-darkening curves at 11.5 micrometers from the Pioneer Venus Orbiter Infrared Radiometer. Successful simulations of correlation plots of 1.7 vs 2.3 micrometers intensities reveal that mode 3 particles (r-bar = 3.65 micrometers) represent the dominant source of opacity in the lower and middle clouds, and that variation in total cloud opacity reflects chiefly the addition and removal of mode 3 particles near the cloud base. We find that the full spectrum of brightnesses at 1.7 and 2.3 micrometers implies that the total cloud optical depth varies from approximately 25 to approximately 40.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Probing Venus's cloud structure with Galileo NIMS 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 Probing Venus's cloud structure with Galileo NIMS, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Probing Venus's cloud structure with Galileo NIMS will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1073965

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.