Weekly averages of the maximum and minimum (blue and red lines, respectively) absolute ionospheric Faraday depth | φ_ion | from April 1998–2012, as modeled by ionFR. The absolute value is shown because the ionospheric Faraday depth is positive or negative if observing from the northern or southern hemisphere, respectively. The dashed vertical lines represent the end of Solar Cycle 23 (December 2008) and beginning of the current Solar Cycle 24. Left: toward CasA, as viewed from LOFAR. Right: toward Eta Carinae, as viewed from an average of the SKA core sites in Western Australia and South Africa.