Non-Local Thermodynamic Equilibrium in Cloudy Planetary Atmospheres.

Astronomy and Astrophysics – Astrophysics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

2

Scientific paper

This study is restricted to an assessment of the degree to which non-local thermodynamic equilibrium (non-LTE) is important in cloudy planetary atmospheres, although the formalism is developed in a fashion general enough to serve as a guide for similar studies involving various low-density systems of astrophysical interest. The atmosphere is assumed to be plane-parallel, semi-infinite and vertically homogeneous, and is considered to consist of conceptually separate but spatially coexistent cloud and gas subsystems. Certain physical requirements are imposed: 1) the cloud subsystem opacity is made consistent with the Mie theory; 2) the gas subsystem opacity is restricted to be gray over the visible spectrum and to obey a modified picket fence model in the thermal infrared; and 3) the restriction of LTE is relaxed.Various microscale heating and cooling mechanisms are then considered. Radiative and conductive heat transfer processes are examined in detail, whereas heat transfer processes by convection and advection are found to be essentially ignorable in the present context. It is verified a posteriori that the importance of latent heat transfer is negligible. It is found for intermediate time scales that the gas subsystem is thermally inert, and that the cloud subsystem is in a state of radiative-conductive equilibrium.The equation of radiative transfer is solved in the two-stream approximation for two representative models, and the results are tabulated. It is found that departures from LTE fail to be of practical importance by about two orders of magnitude for the cases considered. From scaling arguments it is further concluded that effects due to non-LTE (in the sense under consideration) are of negligible practical concern for cloudy planetary atmospheres under all conditions.

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

Non-Local Thermodynamic Equilibrium in Cloudy Planetary Atmospheres. 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 Non-Local Thermodynamic Equilibrium in Cloudy Planetary Atmospheres., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Non-Local Thermodynamic Equilibrium in Cloudy Planetary Atmospheres. will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-1851405

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