Left: schematic showing FIP fractionation in open and closed field regions. In both cases, waves impinge on footpoints from below, but the closed field can also have wave generation within the corona. Right: model element fractionation in open (top, shifted up by 0.5 for clarity) and closed field (bottom). The result shown here is for model 1 (see Table 1). Short green dashed lines show ponderomotive acceleration only; long purple dashed lines show the combined effect of ponderomotive acceleration and adiabatic invariant conservation. The inset shows the region around H, O, Kr, and N in more detail, for fast wind (top) and slow wind (bottom), for the combined model only. Note that the fractionation ratio O/H ﹩\gt 1﹩ in the slow wind, but is ﹩\lt 1﹩ in the fast wind.