Properties of the Solar Corona above a Polar Coronal Hole during the Recent Solar Minimum

Recent observations have shown that the latest solar minimum differs from the previous one in 1996-1997. Here we present the analysis of EUV spectra of the north polar coronal hole observed in November 2007, during the current minimum. The data were taken using the Extreme Ultraviolet Imaging Spectrometer (EIS) on Hinode. Five observations span the coronal hole in the longitudinal direction from the center to the boundary with the quiet sun corona and extend radially from the solar disk to about 1.2 solar radii to. We use the geometric mean emission measure (GEM) approach to determine the plasma emission measure (EM) and electron temperature. From the EM we estimate the relative elemental abundances. We also determine upper and lower bounds on the ion temperature using measured line widths. We then compare our results to spectroscopic measurements of polar coronal holes obtained from observations carried out during the previous solar minimum in 1996-1997.