Diagnostic calculations of the circulation in the Martian atmosphere

Details Diagnostic calculations of the circulation in the Martian atmosphere Diagnostic calculations of the circulation in the Martian atmosphere

Mar 1995

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1995jgr...100.5465s&link_type=abstract

Journal of Geophysical Research (ISSN 0148-0227), Vol. 100, no. E3, p. 5465-5484

Physics

11

Atmospheric Circulation, Convection Cells, Mars Atmosphere, Mathematical Models, Radiative Transfer, Wind (Meteorology), Diurnal Variations, Dust, Opacity, Stream Functions (Fluids), Temperature Gradients

Scientific paper

The circulation of the Martian atmosphere during late southern summer is derived from atmospheric temperature and dust distributions retrieved from a subset of the Mariner 9 infrared interferometer spectrometer (IRIS) thermal emission spectra (LS = 343-348 deg) (Santee and Crisp, 1933). Zonal-mean zonal winds are calculated by assuming gradient wind balance and zero surface zonal wind. Both hemispheres have intense midlatitude westerly jets with velocities of 80-90 m/s near 50 km; in the southern tropics the winds are easterly with velocities of 40 m/s near 50 km. The net effect of the zonal-mean meridional circulation and large-scale waves can be approximated by the diabatic ciculation, which is defined from the atmospheric thermal structure and net radiative heating rates. The radiative transfer model described by Crisp (1990) and Santee (1993) is used to compute solar heating and thermal cooling rates from diurnal averages of the retrieved IRIS temperature and dust distributions. At pressures below 4 mbar, there are large net radiative heating rates (up to 5 K/d) in the equatorial region and large net radiative cooling rates (up to 12 K/d) in the polar regions. These net radiative heating rates are used in a diagnostic stream function model which solves for the meridonal and vertical components of the diabatic circulation simultaneously. We find a two cell circulation, with rising motion over the equator, poleward flow in both hemispheres, sinking motion over both polar regions, and return flow in the lowest atmospheric levels. The maximum poleward velocity is 3 m/s in the tropics at approximately 55 km altitude, and the maximum vertical velocity is 2.5 cm/s downward over the north pole at approximately 60 km altitude. If these large transport rates are sustained for an entire season, the Martian atmosphere above the 1-mbar level is overturned in about 38 days. This diabatic circulation is qualitatively similar to the terrestial diabatic circulation at the comparable season, but is more vigorous.

Affiliated with

Also associated with

No associations

Rating

Diagnostic calculations of the circulation in the Martian atmosphere 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 Diagnostic calculations of the circulation in the Martian atmosphere, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Diagnostic calculations of the circulation in the Martian atmosphere will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-844994