The Dust Planet Clarified: Modelling Martian MY29 Atmospheric Data using the Dynamic-Atmosphere Energy-Transport (DAET) Climate Model
Abstract
The Dynamic Atmosphere Energy Transport (DAET) climate model, a mathematical model previously applied to a study of Earth’s climate, has been adapted to study the climatic features in the low-pressure, dust-prone atmosphere of the planet Mars. Using satellite data observed for Martian Year 29 (MY29), temperature profiles are presented here that confirm the studies of prior authors of the existence on Mars of a tropical solar-energy driven zone of daytime atmospheric warming, that both diurnally lifts the tropopause and follows the annual latitudinal cycle of the solar zenith. This tropical limb of ascending convection is dynamically linked to polar zones of descending air, the seasonal focus of which is concentrated over each respective hemisphere’s polar winter cap of continuous darkness. An analysis of the MY29 temperature data was performed to generate an annual average surface temperature metric that was then used to both inform the design of and to constrain the computation of the DAET climate model. The modelling analysis suggests that the Martian atmosphere is fully transparent to surface emitted thermal radiant energy. The role of lit hemisphere surface reflectance provides an energy boost to the dust-prone surface boundary layer at grazing-angle latitudes. This backlighting process of quenched solar energy capture ensures that the Martian climate operates as a black-body system. The high emissivity solar illuminated hemispheric surface heats the atmosphere by direct thermal conduction followed by a process of adiabatic convection across the planetary surface. It is the non-lossy process of adiabatic convection that results in the development and maintenance of a flux-enhanced atmospheric energy reservoir which accounts for the 2 Kelvin Atmospheric Thermal Effect in the Martian troposphere.