May 30 2012 Coronal Hole Emitting Solar Wind Directed towards Earth 2 HD

 

A large coronal hole is emerging over the sun's eastern limb. Solar wind flowing from the opening should reach Earth on June 6-7.

The energy that heats the corona and accelerates the solar wind originates in subphotospheric convective motions.

However, even after a half-century of investigation, the physical processes that transport this energy to the corona and convert it into thermal, magnetic, and kinetic energy are still not known.

Coronal holes are the darkest regions of the ultraviolet and X-ray Sun, both on the disk and above the limb. Coronal

holes are associated with rapidly expanding open magnetic fields and the acceleration of the high-speed solar

wind.

From paper reviews measurements of the plasma properties of coronal holes and how these measurements have

been used to put constraints on theoretical models of coronal heating and solar wind acceleration. Heat deposition at

the dense and collisional coronal base is of comparable importance (in determining, e.g., temperature gradients and

asymptotic outflow speeds) as extended heating in the collisionless regions above 2 solar radii.

Thus, a complete understanding of the physics requires both observations of the solar disk and inner corona (Yohkoh, EIT, CDS, SUMER) and coronagraphic observations of the wind’s acceleration region (UVCS, LASCO). Although strong evidence has been found to suggest that the high-speed wind is driven mainly by proton pressure, the differences between proton, electron, and heavy ion velocity distributions are extremely valuable as probes of the dominant physical processes.

CME C3 TARGETS MARS: The magnetic canopy of sunspot AR1492 having erupted on May 27th at 0551UT, producing a long-duration C3-class solar flare and having hurled a coronal mass ejection (CME) toward Mars, will hit the MSL spacecraft (containing Mars rover Curiosity) on May 31st at 0100 UT followed by Mars itself about 10 hours later. According to analysts at the Goddard Space Weather Lab.

AR 1492 Sunspot Facing Directly Towards Earth

Still Poses a Threat