\begin{table}%t5 \par \caption{\label{tab5}Initial value of the parameters defining the two cases.} %\centering \par \begin{tabular}{l c c} \hline \hline & Case 1 & Case 2\\ \hline Dust/ice & 1 & 1 \\ Initial temperature (K) & 25 & 25 \\ Surface albedo & 0.04 & 0.04 \\ Surface emissivity & 0.96 & 0.96 \\ Spin period (h) & 10 & 10 \\ Initial pore radius (m) & 10$^{-4}$ & 10$^{-4}$ \\ Initial porosity & 0.7 & 0.7 \\ Initial radius (km) & 10 & 10 \\ CO$_2$/H$_2$O & 0.03 & 0.1 \\ CO/H$_2$O & 0.2 & 0 \\ Trapped CO & 0.1 & 0 \\ Dust size classes & 6 & 6 \\ Dust size ranges (m) & 10$^{-6}$--10$^{-1}$ & 10$^{-6}$--10$^{-1}$ \\ Dust density (kg $\;$ m $^{-3}$) & $2.5 \times 10^{3}$ & $2.5 \times 10^{3}$ \\ Dust conductivity (K $\;$ kg$^{-1} \;$ m$^{-3}$) & 2 & 2 \\ \hline \end{tabular} \end{table}