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HINODE Operation Plan (HOP)

accepted on


 HOP No.

 HOP title

HOP 0159

CORE: Chromosphere-Corona connection

plan term


@ @


 name : De Pontieu @  e-mail : bdp[at]lmsal.com

contact person in HINODE team

 name : De Pontieu @  e-mail : bdp[at]lmsal.com

 abstract of observational proposal
We aim to investigate the connection between chromospheric and coronal dynamics by exploiting recent observations and analysis that have revealed the presence of ubiquitous rapid upflows with velocities of order 50-150 km/s in the lower solar atmosphere (De Pontieu et al., 2009a, McIntosh & De Pontieu, 2009a,b). We observed signatures of these events with a broad range of imaging and spectroscopic instruments (SOHO/SUMER, Hinode/SOT-EIS-XRT, and Swedish Solar Telescope, SST) in the chromosphere (in the form of spicules or RBEs -- rapid blue-shifted events, De Pontieu et al., 2009a, Rouppe van der Voort et al., 2009) and in the transition region (TR) and corona (in the form of blueward asymmetries of TR/coronal spectral line profiles, and propagating disturbances in coronal imaging). Preliminary analysis suggests that these upflows are part of a previously undetected, but relentless transfer of mass between the dense lower atmosphere and tenuous corona in which a potentially significant amount of plasma may be heated to coronal temperatures at very low heights, in the upper chromosphere, TR and low corona.

We propose to obtain coordinated measurements with SOT, EIS, XRT and SDO to address a variety of unresolved issues:

- Do these occur at the footpoint regions of loops across whole active regions, or only at the edges?

- How do the upflow speeds vary with temperature?

- How well correlated are the chromospheric upflow events (observed as Doppler shifts in H-alpha) to the faint upflowing signals observed in the TR and corona?

- How ubiquitous is the apparently sometimes quasi-periodic recurrence of these events, and on what timescale do they recur? Have these upflow events previously been interpreted as a signature of propagating slow-mode magnetoacoustic waves in coronal loops?

- How are these upflow events correlated with changes in the photospheric vector magnetic field?

 request to SOT
Before: NFI: Na IVDG, 40x164", 2x2 binned (this is to obtain context magnetograms) for 5 minutes

High-cadence run: SP : fast raster (dynamics), 4.8"x60" at 1 min cadence
                 NFI: H-alpha sequence: H-alpha at -2.1A, at -1.28A and
                      -0.87A, 30"x82", 2x2 rebinned, at 13 s cadence
                 BFI: Ca II H, 38"x88", 2x2 rebinned, exposure time
                      of >0.6s, at 13 s cadence

The high cadence part should run for 1 hour. The Na IVDG should be run before the high cadence run for about 5 minutes for co-alignment.

The high cadence run combines properties of two programs that were run in september 2009, one on 14-sep-2009 from 07:24-07:56, and one on 17-sep-2009 from 16:21-16:45.

Telemetry rate:  XX Mbits/hour

 request to XRT
Images with Al poly filter configuration at 30 s cadence with AEC exposure for a FOV of 384"x384". This data will allow us to track propagating disturbances in the corona. We will investigate the correlation between these "blobs" with the line asymmetries observed with the EIS fast raster. This XRT program should be run during the high cadence SOT-NFI/SP program for one hour.

Telemetry rate:  XX Mbits/hour

 request to EIS
EIS study 373 (VHH_SlowAR_2h20_DPCM), which rasters a 256"x256" region with 60s exposure time for a range of lines that allow study of line asymmetries for a range of temperatures. Many of these lines have been selected to allow clean measurements of the blueward asymmetries associated with the upflow events (i.e., no known blends, or weak blends).

EIS study 387 (VHH_HI_BRT_SCAN), which rasters a 5"x256" region with 60s exposure time for the same lines as the large raster.

EIS study 373 should be run before (and ideally after as well) the high cadence SOT-NFI/SP program.

EIS study 387 should be run simultaneously, and co-pointed with the high cadence SOT-NFI/SP program. This should be run for 1 hour minimum.

Telemetry rate:  XX Mbits/hour

 other participating instruments
- Target: AR plage
- We'd like to run this program on an active region as it passes from the limb to disk center, essentially every day for 1 hour (for 7 days). This is to investigate the effect of the changing viewing angle on the visibility of the upflows. For the observations close to the limb, the SP fast raster maps can be dropped (for \mu < 0.3 or so).
- Minimum number of observations days: 7 days
- Continuity of observations: not required from day to day
- Time window in day: we are hoping to get STEREO high cadence data, which means that it would be best if the Hinode 1 hour run was started at the beginning of the hour (STEREO high cadence programs run in blocks starting at the even hours: e.g., 6 to 8 UTC)
- Time frame: we need a nice active region, and are hoping to use SDO/AIA data as well, so ideally this program would run from the middle of april onward.

TOTAL HOP Telemetry rate = XXX Mbits/hour

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