Radiative cooling within illuminated layers of dust on (pre)-planetary surfaces and its effect on dust ejection
| Autor: | Gerhard Wurm, Thorben Kelling, Jozef Klačka, Miroslav Kocifaj |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Planetesimal
Materials science Radiative cooling Infrared Astronomy and Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Mechanics Atmosphere of Mars Physik (inkl. Astronomie) Atmospheric sciences Thermal conductivity Space and Planetary Science Heat transfer Thermal Radiative transfer Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Astrophysics::Galaxy Astrophysics |
| Zdroj: | Icarus. 211:832-838 |
| ISSN: | 0019-1035 |
| Popis: | Temperature gradients in dust beds embedded in a low pressure gaseous environment induce a lift of particles under certain conditions. This effect can erode planetesimals and enables entrainment of dust into the martian atmosphere. Here, we consider a numerical model to calculate the temperature profile in a dust bed which is subject to illumination. We consider the situation when the illumination is switched on and heats the dust bed’s surface and when it is switched off again after a certain time. The calculations focus on the heat transfer by infrared radiation within the dust layer. We find that radiative transfer within the dust bed modifies the absolute temperatures and temperature gradients significantly. This is important for effects which are sensitive to absolute temperatures, i.e. ice sublimation or melting of solids. For low thermal conductivity dust beds of 0.001 W m −1 K −1 it determines the temperature structure of the dust. For higher thermal conductivities the modifications are moderate with respect to dust eruptions as the order of magnitude of temperature gradients stays the same. |
| Databáze: | OpenAIRE |
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