Mathematics
Scientific paper
May 1990
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1990awml.book.....g&link_type=abstract
Absolute wind measurements in the lower thermosphere of Venus using infrared heterodyne spectroscopy NASA
Mathematics
1
Cloud Height Indicators, Heterodyning, Infrared Spectrometers, Infrared Spectroscopy, Qualitative Analysis, Thermosphere, Venus (Planet), Wind Measurement, Wind Velocity, Calibrating, Displacement, Frequencies, Images, Lasers, Line Of Sight, Spatial Resolution, Stabilization, Telescopes, Velocity Distribution
Scientific paper
The first absolute wind velocities above the Venusian cloud-tops were obtained using NASA/Goddard infrared heterodyne spectrometers at the NASA Infrared Telescope Facility (IRTF) and the McMath Solar Telescope. Beam-integrated Doppler displacements in the non-thermal emission core of (12)C(16)O2 10.33 micron R(8) sampled the line of sight projection of the lower thermospheric wind field (100 to 120 km). A field-usable Lamb-dip laser stabilization system, developed for spectrometer absolute frequency calibration to less than + or - 0.1 MHz, allowed S/N-limited line of sight velocity resolution at the 1 m/s level. The spectrometer's diffraction-limited beam (1.7 arc-second HPBW at McMath, 0.9 arc-second HPBW at IRTF), and 1 to 2 arc-second seeing, provided the spatial resolution necessary for circulation model discrimination. Qualitative analysis of beam-integrated winds provided definitive evidence of a dominant subsolar-antisolar circulation in the lower thermosphere. Beam-integrated winds were modelled with a 100x100 grid over the beam, incorporating beam spatial rolloff and across-the-beam gradients in non-thermal emission intensity, line of sight projection geometry, and horizontal wind velocity. Horizontal wind velocity was derived from a 2-parameter model wind field comprised of subsolar-antisolar and zonal components. Best-fit models indicated a dominant subsolar-antisolar flow with 120 m/s cross-terminator winds and a retrograde zonal component with a 25 m/s equatorial velocity. A review of all dynamical indicators above the cloud-tops allowed development of an integrated and self-consistent picture of circulation in the 70 to 200 km range.
No associations
LandOfFree
Absolute wind measurements in the lower thermosphere of Venus using infrared heterodyne spectroscopy 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 Absolute wind measurements in the lower thermosphere of Venus using infrared heterodyne spectroscopy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Absolute wind measurements in the lower thermosphere of Venus using infrared heterodyne spectroscopy will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-780053