  Observations of Halpha emission measures and pulsar dispersion measures at
high Galactic latitude (|b| > 10 deg) provide information about the density and
distribution of the diffuse warm ionized medium (WIM). The diffuse WIM has a
lognormal distribution of EM sin |b|, which is consistent with a density
structure established by isothermal turbulence. The H+ responsible for most of
the emission along high-EM sin |b| sightlines is clumped in high density (> 0.1
cm^{-3}) regions that occupy only a few parsecs along the line of sight, while
the H+ along low-EM sightlines occupies hundreds of parsecs with considerably
lower densities.
