Disparity of ground-based Total Solar eclipse polar plumes and AIA/SDO space mission EUV ray-like jets

Document Type : Research Article


1 Department Of physics

2 Physics


Multi wavelength observations could help discriminate the fundamental differences for the mechanism of the jet-like structures of the hot and cool material in the inner atmosphere. We use the Atmospheric Imaging Assembly (AIA) on-board the Solar Dynamics Observatory (SDO) unprecedented temporal and spatial resolving power for a wide range of wavelengths to increase our knowledge about the origin and the evolution of jets. The dynamical behavior of the jets in polar plumes (PP’s) is considered for the first time based on the simultaneously observed in space EUV hot and cool emission lines also observed in W-L at total eclipses.

At the USA 2017 total solar eclipse, we observed white-light polar plumes (W-L PPs) with an excellent resolution from different sites. We tried several combinations of pictures taken (a) from different sites at the ground, using different image processing, and (b) from space, taken with different coronal filters and time sequences. The resolution of the faint polar regions space images are of low signal/noise (S/N) ratio, and instead of summing pixels of images to reduce the noise of individual images, we found it more efficient to sum a burst of 5 to 10 min. consecutive AIA frames from a sequence taken around the total eclipse time. This should smear images showing fast dynamical events, but the jet part is not significantly smeared, the flow being linear. We also found promising results using the 171 Å filter with temperature sensitivity extended from 0.6 MK to 2 MK due to lines of Fe IX, Fe X and Ni XIV but also performed the analysis with the higher temperature sensitivity filters, at 193 and 211 Å.

The result gives the unprecedented spatial resolution total solar eclipse observations for the very high speed outflows from the interplumes region where the estimated temperature is much higher than plums (20x106 K, Banerjee et al. 2009a), as the plausible sources for the fast solar winds. This achievements should be re-examined by the Multi Element Telescope for Imaging and Spectroscopy (METIS/COR) coronagraph/Solar orbiter particularly during closest approach to the Sun (0.28 AU at the perihelion phase of mission).

Finally, the composite W-L and EUV line-emission diagnostics reveal the noticeable un-correlations between W-L the more global and quasi-stationary structures of polar regions with the EUV more dynamical and shorter life-time rays. Further, the eclipse WL images do more advances that are privileged the best spatial resolutions in both inner and outer parts of corona in the base of a more precise electron density distribution and, accordingly, could permit a better diagnostic about the plausible sources of the fast solar wind. Outline, the connection of WL-PP’s with inner parts off-limb EUV emission lines jets have non-perfect correlations, therefore in some cases, the direct connection was not detectable at all. However, most W-L plumes have counterparts with EUV ray.


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