EUV observations of solar coronal outflows
Five sounding rocket experiments have been conducted between June 1979 and June 1984 using a new high-resolution spectrometer with a CODACON array detector to make velocity measurements in the solar corona and transition region. Polar coronal holes, low latitude holes and compact holes closely associated with active regions have been observed. In each case we have found strong evidence for systematic outflows relative to the quiet Sun. The largest observed Doppler shifts correspond to 7 km/sec in λ629 OV (T-105.4K) and 12 km/sec in λ625 MgX (T-106.15K). In those coronal holes where both the MgX and OV lines are well measurable, the apparent outflow is larger in the coronal line, suggesting an increase in velocity with temperature and perhaps height.
KeywordsSolar Wind Coronal Hole Polar Coronal Hole High Speed Solar Wind Stream Open Magnetic Field
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