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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0107

Slow Solar Wind Sources

plan term


@ @


 name : Landi, Miralles @  e-mail : enrico.landi[at]nrl.navy.mil

contact person in HINODE team

 name : Mariska @  e-mail : mariska[at]nrl.navy.mil

 abstract of observational proposal
In a recent work, Landi & Cranmer (2009) measured the ion temperatures fromb the line widths of many ions observed by SUMER in a polar coronal hole. The measurements were done as a function of distance from the limb in the 1.02-1.17 solar radii range. Their study aimed at characterizing the region of acceleration of the fast solar wind by measuring the presence and effectiveness of the ion-cyclotron waves in accelerating the solar wind. They were looking for
a relation between ion temperatures and charge-to-mass ratio Z/A as a signature of ion-cyclotron wave action. They found that ion temperatures did depend on the Z/A ratio, but in a different way than predicted by models; at high Z/A values the ion temperature showed an upturn that could be explained by no theoretical model; these results were the same at all heights, meaining that ion cyclotron waves, if present, were active already at 0.02 solar radii from the photosphere. Landi & Cranmer (2009) used a sit'n'stare SUMER full spectrum observation, but many of the lines they used were weak and noisy, so they could only reach up to 1.17 solar radii, and also they could not relate their measurements to either polar plume or inter-plume plasma.
We propose to carry out joint deep exposure SUMER/EIS/UVCS observations of a polar coronal hole in order to measure ion temperatures versus Z/A, improving over Landi & Cranmer 2009 by carrying out measurements
1) for many more ions
2) for a larger height range
3) for a 60"x512" or (if possible) 120"x512" section of a coronal hole
4) linking the results to coronal hole structures on the disk
5) linking the results to UVCS ion temperatures at 1.9 solar radii.

 request to SOT

 request to XRT
Observations in two (or more) filters whose ratio is sensitive to low temperature plasma.

Cadence is not important, long exposures are preferred to minimize noise

 request to EIS
Study: LANDI_FULLCCD_SCAN1 (to be verified)
      LANDI_FULLCCD_SCAN2 (to be verified)
      LANDI_SCAN_CH is validated and on the database.

All studies to be pointed at polar coronal hole. The two SCAN studies are interchangeable (smaller data volume being the only difference); the SINGLE study is a ultra-deep sit'n'stare with full CCD range.

 other participating instruments

This HOP is intended to be run during the SUMER/EIS campaign. EIS  observations should require less than 4 hours; the duration of the SUMER observations depends on the type of full reference spectrum being run, but should last less than 6 hours. UVCS will operate with its own schedule continuously for several days. Target will be a polar coronal hole for each run, and it will be selected 1-2 days in advance.

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