Preferred conductivity profile. Using only physical SH coefficients for the two time series of 210 days of proxy-MGS. The shaded area denotes the domain of acceptable values determined from the sensitivity analysis. Below 1,300-km depth, data are insensitive to conductivity structure (dashed line). Dark gray areas denote the range of theoretical conductivity models obtained by Mocquet and Menvielle (2000), while light gray area denotes the model constructed by Vacher and Verhoeven (2007).