HOP 0406

abstract of observational proposal

Main Objective: Examine the evolution of mass and energy through the Chromosphere/Transition region/Corona on both spatial and temporal scales

Scientific Justification: First Ionisation Potential (FIP) is a powerful tool for investigating the relationship between different parts of the solar atmosphere and quantifying the evolution of mass and energy from the Sun through its atmosphere into the heliosphere. However, the process by which elemental abundance is fractionated in the solar atmosphere remains uncertain. Recent work by To et al. (2020, in prep), Stangalini et al. (2020, submitted), Baker et al. (2020, in prep) has found evidence of strong FIP bias associated with waves propagating along strong magnetic fields within active regions and sunspots. However, this work has been limited to observations of the corona (using AIA and EIS) and the photosphere/chromosphere (using IBIS), with no supporting observations in the transition region.

We propose a joint observing campaign using both Hinode/EIS and IRIS to probe the interface region of the solar atmosphere from the chromosphere to the corona. This will enable a systematic examination of the evolution of mass and energy through the different layers of the solar atmosphere on both spatial and temporal scales. Hinode/EIS will provide observations of elemental abundance variation in the corona, while the higher spatial and temporal resolution of IRIS will be used to identify signatures of wave propagation associated with these elemental abundance variations. Hinode/SOT offers spectropolarimetric observations which can provide a constraint on the associated magnetic field. Hinode/XRT will provide higher temperature constraints on the plasma which will be vital when constructing the associated DEMs.

request to EIS

We request that EIS study 577 (PRY_slot_contextLIQS) be run first to provide context of the active region and enable co-alignment with SDO. We then request EIS study 437 (HPW021_VEL_240x512v1) to provide a large field of view raster of the target active region, followed by EIS study 405 (Atlas_120), which should then be run repeatedly throughout the observing window (3-5 times).

other participating instruments

IRIS requests:
3600107404 | Very large sit-and-stare 0.3x175 1s Si IV Mg II h/k Deep x 4 Spatia | 10.50 | 15.48 | 1.00 | 5.3+/-0.2 | 5.3+/-0.2 | 0.0+/-0.0 | 10.5+/-0.0 | 10.5+/-0.0 | 0.0+/-0.0

Run the sit and stare for 2 hours to match the duration of EIS study 437 (HPW021_VEL_240x512v1).

3600009176 | Large dense 320-step raster 105.3x120 320s C II Si IV Mg II h/k D | 3092.08 | 5898.24 | 1.30 | 9.7+/-0.2 | 3092+/-0 | 38.7+/-0.0 | 38.7+/-0.0 | 38.7+/-0.0 | 0.0+/-0.0

The large dense 320-step raster should be run 3-5 times within the observing window to match EIS study 405 as closely as possible.

remarks

Dates: ToO that requires an active region. If possible, to be carried out during the first 2 weeks of October, while David Long is IRIS science planner.

Target(s) of interest: The primary target is an active region, preferably one with a clear sunspot and associated strong magnetic field. The target and pointing will be chosen in advance by the proposer and communicated to the COs in a timely manner to ensure observation. Once a target has been identified, we would like to repeat the IHOP preferably once per day for several days (with a minimum of one observation every other day) to track the evolution of the active region.