Red vertical lines represent the midpoints of the last seven ice ages (Shaviv 2003) showing the reported 140 Myr climatic cycle, and red ×'s mark the intersections of the solar system with spiral arms found in previous work (Svensmark 2006). They assumed the spiral-arm crossings to extend in a 140 Myr periodic pattern. Intersections of our solar system with the spiral arms of the Milky Way computed from the current model are plotted in blue squares, with upper bounds of pattern speed plotted in black triangles and lower bounds of pattern speed giving the intersections plotted in black diamonds, showing lack of correlation to the ice-age epochs within the given pattern-speed range. Error bars on intersection points represent combined error of ice-age epoch time and spiral-arm intersection uncertainty of 20 Myr. Horizontal bars represent the extended intersection time for grazing events. Angles are taken in degrees from current location, increasing with time into the past.