Figure 7. Simulated changes in Saharan vegetation coverage for the last 125,000 years (green curve, upper part). The thin black line indicates the changes in the Rossignol-Strick (1985) monsoon index M normalized to its maximum and minimum value during this period, where M is approximated by M = 2 I(23)–I(0), I(23) and I(0), being the insolation during June, July, August at the latitude 23°N and 0°, respectively. The lower part of the figure shows the variations of the continental humidity index (ratio of nonaeolian and aeolian sediment). (Redrawn from Tjallingii et al., 2008).