Recently, we performed an analysis of line width data based on  observations of the polar corona by the SUMER/SOHO spectrometer at  heights of 57 arcsecond  and 102 arcsecond. We found, for the first time, that there exists a  strong strongly linear correlation between the square of line width  relative to the wavelength and the inverse ion mass. The Pearson  product-moment correlation coefficients exceed 0.9. This finding may be  interesting because it implies that the ions from a given height of  polar corona have a common temperature and a common non-thermal  velocity. Consequently, we directly obtained the temperature and  non-thermal velocity using linear least-square fit,. The results is  shown in Figure 1. One can find that the temperature is around 2.8 MK at  heights of 57 arcsecond and 102 arcsecond. The non-thermal velocity is  21.6 km s⁻¹ at height of 57 arcsecond and 25.2 km s⁻¹ at height of 102 arcsecond, with standard deviations of 1.5 km s⁻¹ and 1.6 km s⁻¹, respectively.