DOI: 10.6084/m9.figshare.14180039
title: Data Tables Buhler Piqueux JGR 2021

description: <b><i>We have provided data tables for figures 3-6 and model routines used in Buhler and Piqueux (2021), JGR.</i></b><b><i><br></i></b><b><i>Figures 3 and 6</i></b><br>We have provided ten data tables: as_zreg.txt, matm.txt, mcap.txt, mreg.txt, matm_hist.txt, mcap_hist.txt, mreg_hist.txt, obl.txt, obl_hist.txt, and t_hist.txt. These tables contain the information shown in Fig. 3 and Fig. 6 in the text. <b>as_zreg.txt</b> is a 1-dimensional array of length 7 that contains the product of the specific surface area and regolith thickness z<sub>reg</sub> used in each of the seven model outputs, corresponding to the caption in Fig. 3 and Fig. 6. <b>The data for Fig 3 </b>is contained in: matm.txt, mcap.txt, mreg.txt, and obl.txt. obl.txt is a 1-dimensional array of length 91, spanning 0 to 90, that contains obliquity values in degrees. matm.txt, mcap.txt, and mreg.txt are each 2-dimensional arrays of shape (7, 91) that provide our model output solution for atmosphere mass (matm.txt), cap mass (mcap.txt), and adsorbed CO<sub>2</sub> mass (mreg.txt) in kilograms as a function of obliquity (along the axis of length 91; corresponding to obl.txt) and regolith thickness (along the axis of length 7; corresponding to zreg.txt). All values were calculated assuming regolith thermal conductivity k<sub>reg</sub> = 1.0 W m<sup>-1</sup> K<sup>-1</sup> and regolith albedo A<sub>reg</sub> = 0.25. <b>The data for Fig. 6 </b>is contained in: matm_hist.txt, mcap_hist.txt, mreg_hist.txt, obl_hist.txt, and t_hist.txt. t_hist.txt is a 1-dimensional array of length 1000 with values of time referenced to J2000 in units of 1000 years. obl_hist.txt is a 1-dimensional array of length 1000 with values of obliquity in units of degrees from Laskar et al. (2004). matm_hist.txt, mcap_hist.txt, and mreg_hist.txt are each 2-dimensional arrays of shape (7, 1000) that provide our model output solution for atmosphere mass (matm.txt), cap mass (mcap.txt), and adsorbed CO<sub>2</sub> mass (mreg.txt) in kilograms as a function of time (along the axis of length 1000; corresponding to t_hist.txt) and regolith thickness (along the axis of length 7; corresponding to as_zreg.txt). All values were calculated assuming regolith thermal conductivity k<sub>reg</sub> = 1.0 W m<sup>-1</sup> K<sup>-1</sup> and regolith albedo A<sub>reg</sub> = 0.25.<br><b><i>Figure 4</i></b><b><i><br></i></b><b>MCMC_chains.txt</b> is a table of size 3 x 1e7. The axis of length 1e7 correspond to steps in the MCMC simulation. Values in the first row are the regolith thermal conductivity (k; W m<sup>-1</sup> K<sup>-1</sup>) value, values in the second row are the regolith thickness (z_reg; m) value, and values in the third row are the regolith specific surface area (a_S; m<sup>2</sup> kg<sup>-1</sup>) value at each timestep. <b><i>Figure 5</i></b><b><i><br></i></b><b>mtothistx.txt</b> is a table of size 1 x 100 containing the bin value total obliquity-timescale exchangeable inventory (kg).<b>mtothisty_norm</b> is a table of size 1 x 100 containing the normalized probability density (unitless) for the corresponding mass bin index. <b><i>Figure 7</i></b><b><i><br></i></b>Figure 7 comprises an ensemble of 5e6 draws of model results for MCID bounding layer elevations and total obliquity-timescale exchangeable CO2 reservoirs taken from the model input parameter probability distributions shown in Figure 4.<b>elevs0.txt</b> is a table of size 1 x 5e6 containing the fraction of the MCID modeled to be below the topmost bounding layer of water ice (unitless).<b>elevs1.txt</b> is a table of size 1 x 5e6 containing the fraction of the MCID modeled to be below the second topmost bounding layer of water ice.<b>elevs2.txt </b>is a table of size 1 x 5e6 containing the fraction of the MCID modeled to be below the third topmost bounding layer of water ice.<b>elevs3.txt</b> is a table of size 1 x 5e6 containing the fraction of the MCID modeled to be below the bottommost bounding layer of water ice. <b>mtots.txt</b> is a table of size 1 x 5e6 containing the total obliquity-timescale exchangeable CO2 reservoir corresponding to elevation indices in elevs0.txt, elevs1.txt, elevs2.txt, and elevs3.txt.<br><b><i>Model Routines</i></b><b><i><br></i></b><b>Construct Subsurface Temperature Arrays.py</b> is a 1d thermal diffusion model that constructs subsurface temperature arrays as a function of latitude, depth, and insolation (based on orbit parameters) in sub-sol time steps.<br><b>Construct mean annual subsurface arrays_v0.3.py</b> creates the mean annual subsurface profile from the output of <b>Construct Subsurface Temperature Arrays.py</b> for more efficient calculation in <b>Pressure_reg_only_iterator_v8.py</b>.<b>Pressure_reg_only_iterator_v8.py</b> is a joint atmosphere-regolith equilibration model (without a CO2 ice cap) that calculates the atmospheric pressure in equilibrium with a regolith of given defined properties as a function of orbit parameters, using as input the mean annual temperature profiles output from <b>Construct Subsurface Temperature Arrays.py</b>. These equilibrium solutions are an input that improves numerical stability for <b>Pressure_MCID_reg_iterator_v8.py</b>.<br><b>Pressure_MCID_reg_iterator_v8.py </b>is the full joint cap-atmosphere-regolith equilibration model that calculates the equilibrium atmospheric pressure, cap mass, and adsorbed CO2 as a function of orbit parameters, using as input the mean annual temperature profiles output from <b>Construct Subsurface Temperature Arrays.py </b>and regolith-atmosphere equilibrium solutions from <b>Pressure_reg_only_iterator_v8.py. </b>The difference in cap mass at each of the previous obliquity maxima can then be used to find the model-predicted layer thicknesses of the MCID as input to <b>MCMC.py</b>.<br> <b>MCMC.py</b> is the Markov Chain Monte Carlo model that compares modeled stratigraphy to the observed stratigraphy of the MCID.<br> <b><i>References</i></b> Laskar, J., Correia, A.C.M., Gastineau, M., Joutel, F., Levrard, B., Robutel, P., 2004. Long term evolution and chaotic diffusion of the insolation quantities of Mars. Icarus <b>170</b>, 343–364