An axisymmetric limit for the width of the Hadley cell on planets with large obliquity and long seasonality

Abstract

Hadley cells dominate the meridional circulation of terrestrial atmospheres. The Solar System terrestrial atmospheres, Venus, Earth, Mars and Titan, exhibit a large variety in the strength, width and seasonality of their Hadley circulation. Despite the Hadley cell being thermally driven, in all planets, the ascending branch does not coincide with the warmest latitude, even in cases with very long seasonality (e.g., Titan) or very small thermal inertia (e.g., Mars). In order to understand the characteristics of the Hadley circulation in case of extreme planetary characteristics, we show both theoretically, using axisymmetric theory, and numerically, using a set of idealized GCM simulations, that the thermal Rossby number dictates the character of the circulation. Given the possible variation of thermal Rossby number parameters, the rotation rate is found to be the most critical factor controlling the circulation characteristics. The results also explain the location of the ascending branch on Mars and Titan.

References in corpus (4)

• Titan's Atmosphere and Climate
• Atmospheric dynamics of terrestrial exoplanets over a wide range of orbital and atmospheric parameters
• GCM simulations of Titan's middle and lower atmosphere and comparison to observations
• Climate of Earth-like planets with high obliquity and eccentric orbits: implications for habitability conditions

Cited by in corpus (7)

• THOR 2.0: Major Improvements to the Open-Source General Circulation Model
• Atmospheric Dynamics on Terrestrial Planets: The Seasonal Response to changes in Orbital, Rotational and Radiative Timescales
• Axisymmetric constraints on cross-equatorial Hadley cell extent
• Atmospheric dynamics on terrestrial planets with eccentric orbits
• Toward a unified theory for the Hadley cell descending and ascending edges
• The Key Factors Controlling the Seasonality of Planetary Climate
• The emergence of a summer hemisphere jet in planetary atmospheres