Coronal Hole Boundary Working Group

To:      E. Antonucci, J. Geiss, J. Raymond, P. Riley, R. von Steiger

CC:      L.A. Fisk, G. Gloeckler, J. Kohl

From:  Thomas Zurbuchen

Date: 30.06.00

Re:      1st meeting in Bern, June 26-28

Dear colleagues,

The time is coming closer when we will meet at ISSI for our first meeting of the working group. This group should facilitates a very natural combination of UVCS and SWICS data, comparing composition in the corona and in interplanetary space.

            During the CME workshop in Elmau, where most of you participated, we finally decided to attack this problem. The idea was to have a very small group starting in mid-June and get much of the work done. ISSI seemed like the perfect place for this. Many of us either work there or happen to be there differnent reasons. Only Pete will not be able to join the first meeting of this core-group, he will participate remotely.

            I was thinking during this weekend about how to perform this work. Here are my first thoughts, questions and planning. Please add and comment as you like. Ruedi and I will then sit together and include your comments and suggestions. The enclosed program is meant to be a start point for discussions. Do not over-interpret what is in there…

With best regards - see you in Bern !

            Thomas Zurbuchen


June ISSI Meeting

Scientific Rationale:

It is the purpose of this working group to address the following questions:

1.      What is the nature of coronal hole boundaries and what is their structure from the photosphere to the corona?

2.      Are these boundaries associated with tangential or rotational discontinuities ?

3.      Are there non-ambiguous signatures of super-radial expansion ?

Scientific method:

These questions will be addressed using a combination of composition data in the corona and the solar wind. Coronal data will be provided by UVCS, solar wind data by Ulysses (and ACE) SWICS. We will use a 3D-MHD model of the corona to relate these two sets of data. The code will also allow to "order" solar wind data according to their distance from the coronal hole boundary. Over-expansion signatures should therefore be detected using a super-posed epoch analysis.

 

Work Plan:

This working group will meet June 26-28. The work will contain the following three steps:

a)      define and specify scientific plan,

b)      know the details of the methods involved (UVCS, SWICS, MHD),

c)      perform one example of a combined data-analysis for CR 1914.

Note that c) implies the availability of data on a portable computer or the WWW. Also, bring some information to perform tasks a) and b).

            Here is a preliminary program (times are only to give order of magnitude estimates):

When

Who

What

Day 1:

 

 

9:00-9:30

All

Coffee at ISSI

9:30-9:45

Von Steiger

Welcome, ISSI Specific information

9:45-10:30

Geiss

Scientific Introduction

10:30-10:50

Raymond

UVCS Point of view: Open issues

10:50-11:10

Antonucci

UVCS Point of view: Open issues

10:50-11:10

Zurbuchen

SWICS Work performed, open questions

11:10-11:30

Von Steiger

SWICS Work performed, open questions

11:30-11:50

Riley (Zurbuchen)

MHD Code: Performance and limitations

13:30-16:00

All

Discussion and definition of Tasks a), b)

17:00-18:00

(8 am for Pete)

All & Riley

Telecon: Summary of the day,
Questions to Pete

 

 

 

Day 2:

 

 

9:00-9:30

All

Coffee at ISSI

9:30-10:00

Zurbuchen, von Steiger

Recap first day

10:00-11:00

All

Finalize tasks a) & b)

11:00-12:00

All

Agree on time-periods

13:30-14:00

All

Plot/Share data

14:00-16:00

All

Present, discuss data and problems
assoc. with them. Agree on Detailed task list
and schedule

17:00-18:00

All & Pete

Telecon: Summary of the day,
Questions to Pete