HOP 0420

abstract of observational proposal

Main Objective: Examine the effect of the waves propagating in the lower solar atmosphere on the abundance variation (First Ionization Potential (FIP) fractionation)

Scientific Justification: The various structures in solar atmosphere have different solar abundances, photospheric or coronal. Our goal is to understand how the solar abundances changes in different plasma structures along the solar atmosphere. So far, several theoretical models propose that the waves in the lower solar atmosphere preferentially effect on the ionized particles more than neutral ones depending on their magnetic field configurations and environmental plasma characteristics, which are the main causes for the abundance variations (Laming 2012, 2017).

To examine the effect of the waves and characteristics of the environmental plasma on the elemental abundance variation, we propose to observe the elemental abundances and chromospheric waves in various solar structures (quiet and active regions) using the Hinode/EIS coordinating with IRIS and BBSO/GST. The abundance variation can be measured from the FIP bias factor observed by EIS (Brooks et al. 2015, Lee et al. 2015, Doschek et al. 2018, Doschek & Warren 2019, Baker et al. 2020). However, the connections between abundances and wave characteristics are uncertain due to the difficulties of detecting waves. The higher spatial and temporal resolutions of FISS observations and the analysis method provides a capability to investigate wave characteristics. Recent work by Chae et al. (ApJL, accepted) detected the Alfven waves in the chromosphere at the sunspot penumbra from the FISS (Fast Imaging Solar Spectrograph) data. By taking advantage of the coordinate observations with FISS/GST and IRIS, we will investigate the effect of the waves on the abundance variation (FIP bias factor observed by EIS) in the corona.

Reference
Baker et al., 2020, ApJ, 894, 35
Brooks et al., 2015, NatCO, 6, 5947
Doschek et al., 2015, ApJ, 808, 7
Doschek & Warren, 2019, ApJ, 884, 158
Laming, 2012, ApJ, 744, 115
Laming, 2017, ApJ, 844, 153
Lee et al. 2015, ApJ, 809, 114
Chae et al., accepted, ApJL

request to EIS

EIS is the primary instrument. EIS observation is required.

The main target is an active region. But if there is not an appropriate sunspot, we request a quiet sun or equatorial coronal hole observations. Depending on the target, we request different EIS studies as below.

1. For an active region:
We request the observation set consisting of context image, raster scanning, and sit and stare obs. with high time cadence. The total observation time is 3-4 hours.

Context obs. - Study: PRY_slot_contextLIQS (ID: 577) x 1 time run (5 min)
Scanning obs. - Study: HPW021VEL120x512v2_b (ID:521) x 1 time run (45 min)
Sit & Stare obs. - Study: HPW021VEL001x512v2 (ID:584) x 2 times run (~ 1 hour 40 min)
Scanning obs. - Study: HPW021V HPW021VEL120x512v2_b (ID:521) x 1 time run. (45 min, if telemetry allows)

2. For a quiet sun or coronal hole:
Context obs. - Study: PRY_slot_contextLIQS (ID: 577) x 1 time run (5 min)
Scanning obs. - Study: dhb_atlas_30x512 (ID: 586) x 1 time run (1 hour)
Sit & Stare obs. - Study: HPW021VEL001x512v1_b (ID: 519) x 2 or 3 times run (2 ~ 3 hours)The target and pointing will be chosen in advance by the proposers, Hannah Kwak (hannahk@astro.snu.ac.kr, period of June 30 - July 6) and Kyoung-Sun Lee (lksun@astro.snu.ac.kr, period of July 17 - 23) and communicated to the COs.

other participating instruments

IRIS:
IRIS will observe well-developed sunspots or quiet sun. In the case of sunspots, the observations will be done with “Large coarse 4-step raster (OBS-ID: 3630106023)” and in the case of quiet sun, with “Large sit-and-stare (3604010103)” during the time window of 17-21 UT.

OBS-ID:

1. Sunspots
*High data rate version
3630106023 | Large coarse 4-step raster 6x120 4s Deep x 4 Spatial x 2, Spectralx | 20.65 | 15.85 | 0.89 | 5.2+/-0.1 | 20.7+/-0.1 | 20.7+/-0.0 | 20.7+/-0.0 | 20.7+/-0.0 |20.7+/-0.0

*Low data rate version
3620106023 | Large coarse 4-step raster 6x120 4s Deep x 4 Spatial x 2, Spectralx | 20.65 | 15.85 | 0.52 | 5.2+/-0.1 | 20.7+/-0.1 | 20.7+/-0.0 | 20.7+/-0.0 | 20.7+/-0.0 |20.7+/-0.0

2. Quiet regions and coronal holes
*High data rate version
3604010103 | Large sit-and-stare 0.3x120 1s C II Si IV Mg II h/k Mg II w s D | 200.03 | 233.51 | 0.80 | 16.7+/-0.1 | 16.7+/-0.1 | 70.0+/-27.4 | 50.0+/-0.1 | 50.0+/-0.1 |200.0+/-0.0

*Low data rate version
3624010103 | Large sit-and-stare 0.3x120 1s C II Si IV Mg II h/k Mg II w s D | 198.59 | 190.10 | 0.65 | 16.6+/-0.1 | 16.6+/-0.1 | 69.5+/-27.3 | 49.6+/-0.1 | 49.6+/-0.1 |198.6+/-0.0

BBSO/GST: FISS, BFI and NIRIS

remarks

Dates: We request two observing periods coordinating with BBSO/GST and IRIS, 2021/06/30 － 2021/07/06 and 2021/07/17-2021/07/23.
During the period, FISS, BFI, and NIRIS of GST and IRIS will mainly observe sunspots with a high cadence mode to investigate the waves in the chromosphere. It is not necessary for observations to be on consecutive days, but at least, two days of coordinate observations for each period are desired.

Time window: 17-21 UT coordinated with IRIS and BBSO/GST.

Target(s) of interest: We are interested in various solar features, sunspots, quiet regions, and equatorial coronal holes. The main target is a sunspot (strong magnetic patch) near disk center. If there is not an appropriate sunspot, we request a quiet sun or equatorial coronal hole near disk center for accurate measurements of the line-of-sight Doppler velocity and magnetic field strength.

Previous HOPs: None