1. A Plan for Publication of a Magnetic Cloud List As a Long-Term Database K. Marubashi 1, K.-S. Cho 1, K.-C. Coi 1,2, J.-H. Baek 1, and S.-H. Choi 1 1 Korea Astron. & Space Sci. Inst. (KASI) 2 Chungbuk National University BSS & IHY Workshop, Daejeon, Sept. 2009

2. Outline of Presentation 1. Introduction Why a new MC list is needed? 2. Some Examples A torus model: Advantages and Necessity 3. Overview of WEB Preparation 4. Summary: Results of a Survey of 1999 Data Comparison with Existing MC Lists

3. Schematics of Magnetic Cloud Globally: a loop of a flux rope Internal Structure: consisting of nested helices with changing pitch angles

4. Introduction 1. Importance of Magnetic Clouds (MCs) (1) Physical links to CMEs (2) Strong Bz to produce geomagnetic storms 2. Problems in Existing MC-Lists (1) Survey is still NOT satisfactory. (2) Some lists contain Non-MC events. 3. Our purpose and Advantage (1) To create the most reliable MC List (2) A torus model: a new tool for identifying MCs

5. Example 1: An MC explained ONLY by Torus Magnetic field: rotation > 300° In Principle, a cylinder Model CANNOT explain such large angle rotation.

6. Example 2: Deviation MC-axis from Filament? 12 May 1977 Eruption MC observed on 16 May (WIND)  NO This event is referred to in many papers, as evidence for rotation of MC axis during propagation. However, the MC-axis direction obtained by a torus-model fitting is found to be parallel to the neutral line. (See Next slide)

7. Our torus fitting gives MC direction consistent with the filament.

8. WEB Page Outlook Events (> 7 hours) are listed. The list consists of yearly table, for the cylinder and torus models, separately.

13. Result of Surveying 1999 Data Huttunen et al. (2005): 9 MCs (1 duration < 7hrs, 1 problematic selection) Lepping et al. (2006): 4 MCs (1 unsuccessful fitting) & 16 MC-like structures (7 MCs from our fitting) Lynch et al. (2005): 14 MCs (1 problematic selection, 1 unsuccessful fitting, 3 MC-like structures identified to be MCs) Present Survey: 23 MCs (13 MCs + 4 MC-like + 6 “new”)

14. Concluding Remarks We have confirmed the necessity for a new MC list. (1) The list we are preparing is unique in that fitting results with a torus model are included when necessary. (2) The WEB page is under construction, the schedule for making public possibly within 2009, at least partly. (3) It is more advisable to use the list with communication, because further refinement may be needed in some cases, unfortunately.

15. Thank you very much for your attention!

16. Super storm of November 20, 2003