An upper limit to the solar wind mass loading by X-ray polar jets

Hinode observations of polar coronal holes revealed a larger population of X-ray jets than previously reported. Some of these comply with the standard reconnection model suggested by Shibata et al. (1992), others, likely analogous to CME eruptions and referred to as blow-out jets (e.g. Moore et al., 2010), show a more structured morphology. We present here two events, representative of the two jet categories, that have been observed by HINODE and STEREO in polar coronal holes. Their outward speed has been evaluated from high resolution images; also, because the jets have been observed in multiple filters, we have been able to derive, via spectroscopic techniques, their temperature and density evolution, both along the jets and in time. Knowledge of these parameters allows us to estimate the mass flux that jets of the two types transport to the solar wind and, assuming a given frequency of events, to infer a value for the wind mass loading contributed by polar jets. Because there are insufficient data to establish the percentage of ejections which eventually fall back to the Sun and because the jets we analyzed are probably among the more energetic within their respective class of events, the estimate we give is an upper limit to the jet wind mass loading.