WSM3 FLARE TOPOLOGY WORKING GROUP

CONTENTS

PREPARATIONS

Goals & Approach
Flare List
Overview of the sigmoid region (AR8668), its evolution, flaring
Advance Data Preparations
Quick Look Movies
Tentative FTWG agenda
FTWG Participants -- Role and Responsibility

REPORT FROM THE WORKSHOP

Report from the Workshop
Plans for after the Workshop


CO-ALIGNED DATA MOVIES

Co-Aligned Data Movies

GOALS & APPROACH

In this WSM3 working group our goal will be to learn something about the topology of the magnetic field of the sigmoid in AR 8668 through observations of flares that occurred in this active region.  The working assumptions here are that: We will co-align digital flare images and magnetograms obtained before and during the Max Millennium observing campaign MM002: Eruptive Flares Associated with Sigmoids during WSM3 and compare them to inferences from the topological model of Titov and Demoulin, A&A 351, 707 (1999) (gzipped PostScript file)

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OVERVIEW OF THE SIGMOID REGION (AR8668), EVOLUTION, FLARING

We will study AR8668 flares observed only on 16-Aug and 17-Aug (the period during which several flares occured, yet the region is not too close to the limb).  An overview of these two days comes from Sam Freeland's SXT movies and Barbara Thompson's EIT movies

FLARE LIST

Only 6 flares of GOES B class and above occurred in AR 8668 on August 16th and 17th:

    Date     DOY      Start    End      Max

  • 990816    228      0018    0048    0034    N19E50SF   C 1.3    GOES 2.1E-03  8668
  • 990816    228      1637    1653    1642    N24E47SF   B 8.1    GOES 6.8E-04  8668(see David Alexander's web page)
  • 990816    228      2023    2035    2029    N24E40SF  C 1.2    GOES 7.7E-04  8668

    •  
  • 990817    229      0318    0347    0334    N23E42SF   B 9.5    GOES 1.4E-03  8668 (see Kuniko Hori's web page or second web page)
  • 990817    229      1232    1357    1323    N26E35SF   C 2.6    GOES 1.1E-02  8668 (see David Alexander's web pag)
  • 990817    229      1428    1754    1602                         C 5.9    GOES 5.2E-02  8668 (see Narkiaki Nitta's Nugget.)

    •  

     

    The second, fifth and sixth flares on this list are best observed, and should be given priority if there is not time to study all six of the events.  Further details of which observatories have observations of which flares, and "Context Data" such as magnetograms, is listed in my table FLARES IN NOAA AR 8668 DURING MMOC002 "SIGMOIDS" CAMPAIGN.

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    ADVANCE DATA PREPARATIONS

    Please prepare your digital data in FITS format following the guidelines given on the web page SSW FITS Keywords Standards. Once you have done that, it will be straightforward to overlay your data with those of other observatories using Dominic Zarro's mapping software.  If, for some reason, you can't get your data in FITS format with the right keywords, you must identify UT date and time, image coordinates of solar disk center, image pixel angular size, and image orientation to enough accuracy to be able to align the image to a few arc seconds.

    To get your data to Goddard, use the following procedure:

    ftp orpheus.nascom.nasa.gov
    login: guest
    passwd: Workshop
    This will take you to a 'pub' directory. Use 'mkdir' to create a directory
    using your last name (e.g. 'mkdir zarro'). Move to that directory
    (e.g. 'cd zarro') and 'mput' your files.

    Some tips:

    (1) Don't forget to set 'binary' for binary file copies.
    (2) Use FITS files for easy IDL reading
    (3) Send GIF or JPEG files for Web display at the workshop
    (4) Create subdirectories within your user directory to organize different
        file or data types.

    To see the current contents of the directory at Goddard using a web browser, use http://orpheus.nascom.nasa.gov/wsm

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    QUICK LOOK MOVIES

    Before we can start to overlay flare images on magnetograms, we need to have some quick-look movies in order to decide which times are most interesting.  Presumably we will want to overlay images early in the flares, but there will be other constraints, as well, so we really need to look at movies of each flare from each instrument to make a decision.

    I therefore request that everybody who is contributing data prepare one or more simple MPEG movies of their data to show everybody in a quick way what observations they have, which can readily be run without significant setup time.  For each flare, the appropriate time frame of such a moviemight be from about 20 minutes before the GOES start time until the GOES end time.  For some datasets (e.g. SXT full-disk), it might make more sense to make a continuous movie covering at least two days, perhaps more if needed by other working groups.  Please ftp these movies to Goddard, in the directory discussed in the paragraph above.

    It may also be OK to use quicktime movies, rather than MPEG -- that is still to be determined.

    Let's plan to use the first day of the meeting to show such movies.

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    TENTATIVE FTWG AGENDA

    Wednesday Jan 19

  • Plenary WSM3 presentations -- see WSM3 3rd announcement

    •  
  • Quick Survey of the Observations
  • SXT - Hudson
  • NoRH - Hudson
  • EIT - Thompson
  • BBSO - Qiu
  • HASTA - Canfield
  • Interball - Canfield
  • MLSO - Canfield
  • MDI - Gregory
  • TRACE - Myers
  • Mees - Canfield

    • Thursday Jan 20

    Do preliminary co-registration of each flare on the list above

    Friday Jan 21

    Try to intrerpret preliminary co-registrations in terms of Titov and Demoulin model
    Decide what is worth doing with more care.
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    FTWG PARTICIPANTS - ROLE AND RESPONSIBILITY

    Alexander, David (alexander@lmsal.com) -- SXT and TRACE observations
    Bagala*, Gabriela (gbagala@cds.plasma.mpe-garching.mpg.de) -- HASTA observations
    Burkepile*, Joan (iguana@ucar.edu) -- MLSO observations
    Canfield, Dick (canfield@physics.montana.edu) -- FTWG organization, interpretation of the Titov and Demoulin paper
    Gregory, Sarah (gregory@mdisas.nascom.nasa.gov) -- MDI observations
    Hori*, Kuniko (hori@nro.nao.ac.jp) -- NoRH observations -- see web page
    Hudson, Hugh (hudson@isass0.solar.isas.ac.jp) -- SXT observations
    LaBonte*, Barry (labonte@maile.ifa.hawaii.edu) -- Mees observations
    Liu, Yang (yliu@solar.stanford.edu) -- MDI movie
    Mikic, Zoran (mikic@iris023.saic.com) -- Analysis of vector magnetograms
    Myers, Dawn (dcm@chippewa.nascom.nasa.gov) -- TRACE observations
    Nitta, Nariaki (nitta@sag.lmsal.com) -- co-registered observations of C5.9 flare and associated CME  -- see Nugget
    Qiu, Jiong (qiuj@bbso.njit.edu) -- BBSO observations
    Siarkowski*, Marek (ms@cbk.pan.wroc.pl) -- Interball RF15-I X-ray observations
    Thompson, Barbara (thompson@eitv3.nascom.nasa.gov) -- EIT observations
    Zarro, Dominic (zarro@orpheus.nascom.nasa.gov) -- SOON observations, data organization at Goddard, co-alignment software

    This is an updated list of those who participated at the workshop.

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    REPORT FROM THE WORKSHOP

    Various images and movies, and analyses thereof, are available:
     
    SINGLE INSTRUMENT, VARIOUS EVENTS
  • SXT (Sam Freeland)
  • EIT (Barbara Thompson)
  • MDI (Yang Liu)
  • BBSO 8/13 to 8/26 (Jiong Qiu)
  • BBSO 8/17 only (Jiong Qiu)
    		•  MULTIPLE INSTRUMENTS, VARIOUS EVENTS
  • Nariaki Nitta's Nugget.
  • David Alexander's web page
  • Jiong Qiu's August 16:09 UT overlays
    		•  ANALYSES OF AUGUST 17TH EVENT(S)
  • EIT Aug 17th (Barbara Thompson).
  • Where are the footpoints? (Hugh Hudson)
    		•

    On reviewing the movies, bearing in mind comparison with models, we decided to overlay all available images at one time during each of two flares on August 17th, as follows:

    990817    229      1232    1357    1323    N26E35SF   C 2.6    GOES 1.1E-02  8668


    SXT TRACE EIT MDI SOON HASTA
    12:41:25 12:41:48 12:47:59 12:41:02 12:41:50 12:39:34

    990817    229      1428    1754    1602                         C 5.9    GOES 5.2E-02  8668


    TRACE EIT MDI SOON BBSO MLSO HASTA
    14:53:53 14:47:28 15:01 14:55:20 14:55:30 16:38:40 14:46:08

    We had time to make the following two overlays using Dominic Zarro's map software:
     

      SXT-MDI co-alignment
    This overlay of MDI line of sight magnetic field contours on an SXT image was relatively straightforward once the datasets were in FITS format, since both datasets contain the necessary header information, with the necessary accuracy, to make the maps used for the overlays.
      EIT-TRACE co-alignment
    This overlay of a TRACE flare image on EIT contours demonstrates the ability to take a partial-sun field of view and co-register it with a full disk image. This is important, since the solar coordinates of the TRACE image are not well enough known, whereas those of EIT are.

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    PLANS FOR AFTER THE WORKSHOP

    The basic decision was to make co-aligned movies, rather than simply co-aligned images at certain times.  Each instrument's movie will be at that instrument's own cadence, co-aligned witth respect to co-temporal contours from MDI (which has images very frequently, one per minute), whose pixel coordinates in arc-seconds relative to Sun center are very accurately known.  Let's start by doing the three flares listed in bold font in the table below. -- maybe that will be enough. Optimum start and end times for the movies are given in red:

                             Movie    Movie    GOES  GOES  GOES
         Date      DOY   Start    End        Start    End      Max
     

  • 990816    228     0000   0050       0018    0048    0034    N19E50SF   C 1.3    GOES 2.1E-03  8668
  • 990816    228     1620   1655       1637    1653    1642    N24E47SF   B 8.1    GOES 6.8E-04  8668
  • 990816    228     2000   2040       2023    2035    2029    N24E40SF   C 1.2    GOES 7.7E-04  8668

    •  
  • 990817    229     0300   0400       0318    0347    0334    N23E42SF   B 9.5    GOES 1.4E-03  8668
  • 990817    229     1200   1400       1232    1357    1323    N26E35SF   C 2.6    GOES 1.1E-02  8668
  • 990817    229     1400      1800       1428    1754    1602                       C 5.9    GOES 5.2E-02  8668

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    CO-ALIGNED DATA MOVIES

    Co-aligned data movies are now being produced.  The current ones are available on Dominic Zarro's Co-aligned Data Movies page.

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