Climate model studies of synchronously rotating planets

Astrobiology. 2003 Summer;3(2):415-27. doi: 10.1089/153110703769016488.

Abstract

M stars constitute 75% of main sequence stars though, until recently, their star systems have not been considered suitable places for habitable planets to exist. In this study the climate of a synchronously rotating planet around an M dwarf star is evaluated using a three-dimensional global atmospheric circulation model. The presence of clouds and evaporative cooling at the surface of the planet result in a cooler surface temperature at the subsolar point. Water ice forms at the polar regions and on the dark side, where the minimum temperature lies between -30 degrees C and 0 degrees C. As expected, rainfall is extremely high on the starlit side and extremely low on the dark side. The presence of a dry continent causes higher temperatures on the dayside, and allows accumulation of snow on the nightside. The absence of any oceans leads to higher day-night temperature differences, consistent with previous work. The present study reinforces recent conclusions that synchronously rotating planets within the circumstellar habitable zones of M dwarf stars should be habitable, and therefore M dwarf systems should not be excluded in future searches for exoplanets.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Climate*
  • Models, Theoretical
  • Ozone / analysis
  • Planets*
  • Solar System
  • Temperature
  • Water

Substances

  • Water
  • Ozone