首页|Thermodynamic simulation of the seasonal cycle of temperature, pressure and ice caps on Mars

Thermodynamic simulation of the seasonal cycle of temperature, pressure and ice caps on Mars

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We present a thermodynamic model to simulate the atmospheric temperature and pressure, the regolith temperature and the polar CO_2 ice caps vertical thickness and horizontal extent of Mars. This is done using the temperatures of the atmosphere and regolith for each Martian day of the year, determined from the thermodynamic equation. Assuming a CO_2 atmosphere, we calculate its emission spectrum using the spectral calculator E-Trans with the HITRAN database (E-Trans/HITRAN), resulting in only a band at 15 mm and the rest transparent, through which the radiation emitted by the regolith and ice caps (considered as black bodies) goes toward space. We also include the solar radiation extinction and longwave emission of atmospheric dust. The equation calculates the energy balance between the absorbed solar radiation and the outgoing longwave radiation, incorporating also the latent heat released by CO_2 condensation, the sensible heat flux from the surface to the atmosphere, the latent heat flux due to the CO_2 ice sublimation and the heat exchange between the surface regolith layer and its lower layers. The atmospheric planetary scale horizontal turbulent heat transport is parameterized with an exchange coefficient, which is an order of magnitude smaller than that employed in the terrestrial troposphere. Considering a long-time average, the regolith vertical temperature profile is explicitly found using the thermal inertia including conductivity; its temperature regulation is achieved through the thermal conduction from the surface during the warm season. This stored energy goes back to the surface during the cold season. Our model simulates the seasonal variation ofthe polar ice caps and consequently of the surface atmospheric pressure through the CO_2 mass balance between them. Finally, it is explicitly shown that the amplitude of the global seasonal pressure cycle is modulated by a local thermal-orographic effect, which increases (decreases) this amplitude in the low

Marsthermodynamic simulationCO_2 ice-polar capseasonal climate cycle

Victor M. MENDOZA、Blanca MENDOZA、Rene GARDUNO、Guadalupe CORDERO、Marni PAZOS、Sandro CERVANTES、Karina CERVANTES

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Centro de Ciencias de la Atm?sfera,Universidad Nacional Aut?noma de Mexico, Ciudad Universitaria, 04510 Ciudad de Mexico, Mexico

Instituto de Geofisica, Universidad Nacional Aut?noma de Mexico, Ciudad Universitaria, 04510 Ciudad de Mexico, Mexico

Posgrado en Ciencias de la Tierra, Universidad Nacional Aut?noma de Mexico, Ciudad Universitaria, 04510 Ciudad de Mexico, Mexico

Facultad de Ciencias, Universidad Nacional Aut?noma de Mexico, Ciudad Universitaria, 04510 Ciudad de Mexico, Mexico

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2021

Atmosfera

Atmosfera

SCI
ISSN:0187-6236
年,卷(期):2021.34(1)
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