General description

Relating observed coronal holes and boundaries to the fast solar wind measured in situ.

Science Goal: What are the release mechanisms of the fast solar wind?


  • Link in-situ plasma to specific coronal source regions
  • Identify possible sources of the fast solar wind in coronal holes

Target: Low-latitude (or extended) coronal hole. Typically west of central meridian and observed close to the Sun. Polar coronal hole when at high latitude.

Default SOOP duration: 3 days

Pointing requirements:

  • Low latitude: Off-pointing for specific target pointing or target tracking.
  • High latitude: Centre pointing with Metis for polar coronal holes

Triggers: only IS triggers active (TBC)

Observations requirement (baseline)


PHI_HRT_NOM_0: HRT nominal mode at 1-min cadence

Flush 1-2 hr period (725MB per hour), coordinated with EUI.

Note that FDT, highest spatial resolution (2Kx2K), cadence 6 hours preferred, but certainly ≥ 1 per day may be useful for context beforehand (Earth source as well?).

Model PHI flush with 1550MB after SOOP has completed.


HRI: 1 – 2 hours, at 1-min cadence, e.g. EUV & LYA Coronal hole modes (C) (reduced cadence)

FSI: FSI Synoptic mode (S) (chosen for model) or FSI Reference Synoptic mode (R), at several-hour cadence, both 174 and 304.

≥ 12 hours of much lower-cadence HRI data for context

We downlink 1-2 hours long period at 1min cadence (220MB per hour) based on modelling & LL data from EUI. Coordinated with PHI.

Model EUI flush with 440MB for HRI.  FSI volume based on 2.04kbits/s during whole SOOP, 3 days =>66Mbytes.


If polar CH is target, modes are (see METIS standard modes):
WIND: 2 hours
MAGTOP: ≥ min. 2 hours; repeated each day in available observing windows
FLUCTS: ≥ 1 hour; at perihelion (see METIS special modes)

Rest of the time Metis will need to switch off for off-pointing (TBC)

For SAP v0, we can model the Metis contribution in this SOOP as:

  • 2 hours WIND per day
  • 2 hours MAGTOP per day
  • 1 hour FLUCTS, once in the SOOP (will be scheduled at closest point)
  • Rest of the time Metis off


STIX Normal Mode

SPICE Composition Mapping: 1 repeat (3.2 hours) (low-latitude CH only);

SPICE Dynamics: 14 x 4" slit + 8 x 2" slit = 3.72 hours per day throughout RSW; FOV 8' x 11' (maybe 4' x 11' at poles)

Possible 4-pixel binning in Y

Default FOV in X for both studies is 4'. Will assume that these are just placed side-by-side but with half the time on each position if the CH is large enough to warrant this. Duration is therefore unaffected.

Use observation called SPICE_FAST_WIND in modelling.

SoloHIMode: synoptic + turbulence
Currently modelled as HI_SYN_NEAR + HI_TURB_PER  split to get EID-A rate

RPWDetection Mode

Triggers on

Science objectives

SAP objectiveTargetDuration (milliseconds)Opportunity
(e.g., orbital requirements, solar cycle phase, quadrature ...)

Operational constraints 

Additional comments Low FIP fast wind originsSufficiently wide spatial area across a CH to cover connection to spacecraft.Several hours of RS observations of coronal source, considering time taken for wind to arrive at s/c
  • Pre-perihelion (so, south?) and perihelion parts of RSW
  • low-latitude (to compare with the intermediate speed wind observed at Earth)
  • any phase of the cycle, but more likely during the rising phase (TBC Yannis Zouganelis)
  • Performed on several orbits (preferably; PHI request 10 orbits)
  • EMC quiet for in situ observations 12 hours after the RS observations of the source region
    • can be EMC-noisy during RS observations

Likely to involve pointing away from disc centre ("DC"): difficult to see how Metis can participate at those times.

However, could involve DC pointing, especially between observations of the polar CHs, to look at propagating fluctuations in/near plane of sky (but not connected to s/c) at 1.5–2.9º from DC.

Doppler dimming measurements will not be so useful in these cases, since the fast wind will not have made it out into the Metis FOV (need to check exact distances) from the observed "source region". Origin of the small-scale X-ray and UV jets in polar coronal holesPolar CH with sufficiently wide extension to catch multiple above
  • High-latitude perihelion (preferred, for fastest solar wind)
  • solar minimum or declining phase
as aboveMetis will require repoints to DC after off-centre observations. How does the heliospheric magnetic field disconnect from the Sun?

Instances run / planned

LTP13 (planned)

RSW 10: 8-9 October 2023 (~0.3 AU, low latitude)

RSW 12: 24-26 October 2023 (~0.5 AU, low latitude)

SOOP coordinators: A. James, L. Franci, É. Buchlin, with support from S. Yardley

Science outcomes

Future references of papers using the SOOP data

Original SOOP proposers

C. Owen, A. Giunta, D. Berghmans, D. Spadaro, A. Fludra, L. Harra, D. Baker

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  1. SOOP ID in SOOP Kitchen = LS1