The hydrogen ortho-to-para ratio in the stratospheres of the giant planets

Details The hydrogen ortho-to-para ratio in the stratospheres of the giant planets The hydrogen ortho-to-para ratio in the stratospheres of the giant planets

Jan 2003

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2003icar..161..127f&link_type=abstract

Icarus, Volume 161, Issue 1, p. 127-143.

Computer Science

15

Scientific paper

Observations of the H2 S(0) and S(1) quadrupole lines in the four giant planets by the short-wavelength spectrometer of the Infrared Space Observatory are analyzed. These lines probe pressure levels located between 10 and 1 mbar and allow us to determine the stratospheric hydrogen para fraction for the first time. In Jupiter and Saturn, the stratospheric para fraction is close to its tropopause value. In the stratosphere of these planets as well as in Neptune's, the para fraction presents a significant departure from thermodynamic equilibrium. This situation results from a lagged conversion between the ortho and the para states as molecular hydrogen is transported upward under the influence of turbulent eddy diffusion. In contrast, the uranian stratosphere lies close to thermodynamic equilibrium. The magnitude of the departure from thermodynamic equilibrium appears to be anti-correlated with the amount of stratospheric aerosols. To validate this assumption, we estimate the hydrogen equilibration time with a one-dimensional diffusion model for different conversion processes in the gas phase or on aerosols. The comparison between our results and the tropospheric estimates from , Icarus, 135, 501-517) shows that paramagnetic conversion on aerosols matches the estimated tropospheric and stratospheric relaxation times in the four giant planets. In contrast, paramagnetic conversion in the gas phase can only explain the relaxation times measured in Jupiter and Saturn atmospheres. This situation provides quantitative evidence for an equilibration mechanism dominated by conversion on aerosols.

Affiliated with

Also associated with

No associations

Rating

The hydrogen ortho-to-para ratio in the stratospheres of the giant planets 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 The hydrogen ortho-to-para ratio in the stratospheres of the giant planets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The hydrogen ortho-to-para ratio in the stratospheres of the giant planets will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1529649