October 2010

Propagation Summary
Conditions have remained fairly steady during September. October should begin quiet apart from a slight disturbance on the 5th and the 12th . The Boulder A index is peaking at around 10 every 7 days, and the K index is varying between 2 and 3 during these peaks. Sunspot numbers have remained around the 80 mark during August and September. October should remain the same. According to the trend charts at Solar Cycle 24.com, the Solar flux is forecast to reach 100 by the end of 2010, but after a drop in mid 2010, numbers have continued to remain at around 80 and if this trend continues, it will not reach the predicted peak of 140 by 2014.

Solar Storms can Change Directions, Surprising Forecasters
Solar storms don't always travel in a straight line. But once they start heading in our direction, they can accelerate rapidly, gathering steam for a harder hit on Earth's magnetic field.
So say researchers who have been using data from NASA's twin STEREO spacecraft to unravel the 3D structure of solar storms.
Their findings are presented in Nature Communications. Magazine "This really surprised us," says co-author Peter Gallagher of Trinity College in Dublin. "Solar coronal mass ejections (CMEs) can start out going one way—and then turn in a different direction." The result was so strange, at first they thought they'd done something wrong. After double- and triple-checking their work on dozens of eruptions, however, the team knew they were onto something. The sun's global magnetic field, which is shaped like a bar magnet, guides the wayward CMEs back toward the sun's equator. When the clouds reach low latitudes, they get caught up in the solar wind and head out toward the planets—"like a cork bobbing along a
river," says Gallagher. (NASA Science News 21 September 2010)

Solar Probe to Plunge Directly into Sun's Atmosphere
NASA's plan to visit the sun took a leap forward today with the selection of five key science investigations for the Solar Probe spacecraft. Slated to launch no later than 2018, the smart car-sized spacecraft will plunge directly into the atmosphere of the sun, aiming to solve some of the biggest mysteries of solar physics. This means that researchers can begin building sensors for ‘in situ’ measurements of the solar system's innermost frontier. Lika Guhathakurta, NASA Solar Probe Programme scientist said: "For the first time, we'll be able to 'touch, taste and smell' the sun." Last year, NASA invited top researchers around the world to submit proposals detailing possible science investigations for the pioneering spacecraft. More details at: NASA Science News

About Sunspot Cycles
Dark spots appear at places on the Sun where its magnetic field is concentrated. The number of sunspots is controlled by the amount of distortion of the Sun's magnetic field. The magnetic field becomes distorted because the Sun's equator and core rotate more quickly than its other parts. As a result, sunspot activity varies over an average 11-year cycle. During this period, the Sun goes from a solar minimum (fewer spots) to a solar maximum (more spots) and back to a minimum again. The solar magnetic activity cycle is the main source of the ~10.7 year periodic solar variation, which drives variations in space weather and to some degree weather on the ground and possibly climate change. (BBC article via Ken Fletcher)
Thanks to Ken Fletcher and Mike Terry for regular updates.