GIANT LOOPS IN THE SOLAR ATMOSPHERE MAY TRIGGER SUN'S MAGNETIC POLES REVERSALS

Analysis of SOHO and Yohkoh data has revealed that giant X-ray loops in the hot solar corona provide important magnetic links between sunspots and the Sun's magnetic poles. These giant loops are about 500,000 miles long and filed with 3,500,000 F hot electrified gas. The loops appear during the growing phase of the 11-year sunspot cycle, and are associated with bursts of the sunspot activity, which come every 1-1.5 years and cause reversal of the magnetic poles around the cycle maximum. It is suggested that these links play an important role in "solar dynamo", the process that generates strong magnetic fields on the Sun and is the source of sunspots, solar flares and mass ejections that affect the Earth space environment.

The results are reported by Elena Benevolenskaya in the paper [#57.12] "Solar Cycle Variations in Corona," at the American Astronomical Society meeting in Albuquerque, NM, on June 5, at 10 a.m. MDT, and published in the June 1 issue of the Astrophysical Journal Letters
(download the paper in the PDF format).

Photos, graphics and videos can be downloaded at
http://soi.stanford.edu/press/aas06-02 (this page).

With the assistance of the Stanford press office the following statement will be released on June 5, 2002 at the American Astronomical Society Meeting in Albuquerque:

Press-release: Solar_Magnet.doc [MS-Word format]; Solar_Magnet.asc [ASCII format]; Solar_Magnet.pdf [PDF format]. The following image and movie show these results.


Topic	Sample Image	Image or Video links	Notes
Giant loops and magnetic coupling (press-release illustration)		TIF(1.5Meg) TIF(3Meg) GIF(0.5Meg) JPEG(0.07Meg) Postscript(2.1Meg)	X-ray image of the solar corona and a scheme of magnetic links (figure caption, ASCII) (figure caption, doc)
Yohkoh movie of the solar corona		AVI (12Meg) MOV (QT)(51Meg) AVI (slower) (6Meg) MOV (slower) (29Meg) MPEG (25Meg)	X-ray loops in the Sun's corona during 7 solar rotations, August 1997 - February 1998.

Additional images and movies.


Topic	Image or Video links	Notes
A short Yohkoh movie of the solar corona	MPG (0.3Meg) AVI (0.4Meg) MOV (QT) (0.9Meg)	X-ray images of the solar corona (showing the same giant loop as in the first figure) during 1 solar rotations, November 1997.
Magnetic "butterfly" diagram showing the polar field reversals.	TIF (0.6Meg) GIF (0.2Meg) JPEG (0.07Meg)	Solar-cycle evolution of the Sun's mean magnetic field at different latitudes. Yellow color shows the positive magnetic polarity, blue color shows the negative polarity. The "butterfly" diagram in the central zone, from -30 degrees to +30 degrees, is formed by sunspots. The reversal of the polar magnetic fields occurs near the time of cycle maximum (when the number of sunspots is near its maximum). The most recent reversal was in 2001. Ref. The Solar Dynamo page.
A movie of synoptic maps of the solar magnetic field	AVI (15Meg) MOV (16Meg) MPG (5Meg)	Magnetic synoptic maps of the Sun, from 0 to 360 degrees in longitudes and from -83 to +83 degrees in latitude for two solar cycles, from 1980 to 2001 (each rectangular frame corresponds to one full solar rotation). Ref. The Solar Dynamo page.
A movie of synoptic maps of the solar corona	MPG (1.2Meg) AVI (1.4Meg) MOV (2.3Meg)	X-ray synoptic maps of the solar corona, from 0 to 360 degrees in longitudes and from -83 to +83 degrees in latitude, for 124 solar rotations for 10 years, from 1991 to 2001 (each frame corresponds to one rotation).
A movie of synoptic maps of the solar magnetic field and solar corona in EUV	AVI (1.8Meg)	Synoptic maps of the magnetic field on the solar surface and solar corona in Extreme UV radiation for 71 solar rotation (each frame shows one rotation) for 6 years, from 1996 to 2001. The data are from the SOHO mission.
Solar synoptic map CR 1929	TIF(2.1Meg) GIF(0.2Meg) JPEG(1.2Meg) PDF(0.4Meg)	Synoptic maps of the Sun's magnetic field and solar corona in EUV and X-rays
Solar synoptic map CR 1949	TIF(2.1Meg) GIF(0.2Meg) JPEG(1.2Meg) PDF(0.4Meg)	Synoptic maps of the Sun's magnetic field and solar corona in EUV and X-rays
Combined synoptic maps of magnetic field and X-ray corona (Part 1)	TIF(3.1Meg) GIF(0.4Meg) JPEG(1.6Meg)	Synoptic maps of the Sun's magnetic field and solar corona in X-rays for 10 years.
Part 2	TIF(3.1Meg) GIF(0.4Meg) JPEG(1.6Meg)
Part 3	TIF(3.1Meg) GIF(0.4Meg) JPEG(1.6Meg)
Solar synoptic maps averaged over longitude	TIF(2.0Meg) GIF(0.2Meg) JPEG(0.8Meg) PDF(0.1Meg)	Evolution of the mean synoptic structure of the Sun's magnetic field and solar corona with the solar cycle.
Impulses of solar activity	TIF (3.6 Meg) GIF (0.2Meg) JPEG (0.8Meg) PDF (0.3Meg)	Quasi-periodic variations of solar activity (with period of 1-1.5 years).
Sunspot numbers and coronal intensity	TIF (3.6 Meg) GIF (0.2Meg) JPEG (0.8Meg) PDF (0.3Meg)	The relationship between the sunspot number and coronal intensity in EUV and X-rays (AlMg) filter.

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