Figure 3From: Electrical conductivity of the mantle of Mars from MGS magnetic observationsSpectrograms of external (upper part) and internal (lower part) SH magnetic potential coefficients α l m and β l m , respectively. Each panel presents the spectrum obtained for the two proxies, proxy-MGS-2 (left) and proxy-ACE (right). The values are presented in logarithm of energy as a function of degree and order (abscissa) and period in days (ordinate).Back to article page