Return Home

• Local Elk Forest
  • Latest News
  • Holiday Party
  • Board Members
  • EF Bylaws (PDF)
  • Phone Directory
  • Meeting Minutes
    • August, 2009
    • June, 2009
    • August, 2008
    • July, 2008
    • April, 2008
    • Nov, 2007
    • August, 2007
    • June, 2007
    • Aug, 2006
    • Meetings 2005
    • Aug, 2004
    • Aug, 2003
    • Aug, 2002
    • Aug, 2001
    • Aug, 2000
    • Aug, 1999
• Weather/Tides
• Astronomy
• March Astronomy
• April Astronomy
• Emerg. Planning
  • Why Bother?
  • What Can You Do?
  • Extinguisher Training
  • Kitchen Oil Fire
  • Shutting off Utilities
  • Emerg. Alert Stations
  • ICE Cell Phone #
  • Impt. Phone #
  • Address Markers
  • CPR / First Aid
  • Bioterrorism
  • Questionnaire
  • Vial-of-Life
    • What is V-o-L?
    • V-o-L Website
    • Our WORD Form
    • Print Labels
• Links
  • Cecil County Links
  • State Links
  • C&D Canal Links
  • Other Links
• Nice People
• Contact Us

By local resident Jerry Truitt of the Delmarva Stargazers amateur astronomy club.

	We are at the start of a new solar cycle. This is an exciting time for those who observe the sun. The special equipment required to see the activity on the sun is not cheap and it has been useless for a long time. Our sun has been in a very quite period for some time now so the new cycle is welcome. The follow is an article from the SOHO. SOHO, the Solar & Heliospheric Observatory, is a project of international collaboration between ESA and NASA to study the Sun from its deep core to the outer corona and the solar wind. SOHO was launched on December 2, 1995. The SOHO spacecraft was built in Europe by an industry team led by prime contractor Matra Marconi Space (now EADS Astrium) under overall management by ESA. The twelve instruments on board SOHO were provided by European and American scientists. Nine of the international instrument consortia are led by European Principal Investigators (PI's), three by PI's from the US. Large engineering teams and more than 200 co-investigators from many institutions supported the PI's in the development of the instruments and in the preparation of their operations and data analysis. NASA was responsible for the launch and is now responsible for mission operations. Large radio dishes around the world which form NASA's Deep Space Network are used for data downlink and commanding. Mission control is based at Goddard Space Flight Center in Maryland.
Artist's concept of the Sun's meridional circulation, a large scale flow that transports solar plasma from the equator to the poles and back like a giant conveyor belt. Credit: Science@NASA.
One of the outstanding questions facing solar physicists is the origin of the solar magnetic cycle: What drives the 11-year sunspot cycle? We have just passed an extended and deep minimum, unlike any in the past 100 years. The late onset of the new solar cycle (#24) and the unusually deep minimum between cycles 23 and 24 took all experts by surprise, which suggests that there is a fundamental lack in our understanding of the origin of the solar activity cycle. The Sun's meridional circulation is a massive flow pattern within the Sun that transports hot plasma near the surface from the solar equator to the poles and back to the equator in the deeper layers of the convection zone, similar to a "conveyor belt". The flow is rather slow, with typical speeds of 10-15 m/s (20 to 30 mph). The structure and strength of this meridional flow is believed to play a key role in determining the strength of the Sun's polar magnetic field, which in turn determines the strength of the sunspot cycles. One class of dynamo models predicts that a stronger meridional flow produces weaker polar fields, whereas another class of models predicts stronger polar fields (and a shorter sunspot cycle) for the same flow. Analyzing more than 60,000 full disk magnetograms registered by the MDI instrument on SOHO between May 1996 and June 2009, scientist now measured the latitudinal profile of this flow and its variations over a solar cycle by tracking the motions of small-scale magnetic flux concentrations, which are carried away by the meridional flow like leaves on a river. They found an average flow that is poleward at all latitudes up to 75 degrees, which suggests that it extends all the way to the poles. Perhaps even more importantly, they also found that the flow was faster at sunspot cycle minimum than at maximum and substantially faster on the approach to the current minimum than it was at the last solar minimum. This finding poses new constraints on solar dynamo models and may help to explain why the last solar minimum was so peculiar.
Meridional Flow variation from 1996 - 2009 as measured by SOHO/MDI. The scaled smoothed sunspot number is shown in red to indicate the phase of the solar activity cycle. Note the significantly higher meridional flow speed during the approach to the current minimum compared to the previous minimum (from Hathaway & Rightmire: 2010, Science 327, 1350).
I've also added a new clear sky clock specifically for Elk Forest to our web site. What is a clear sky clock? It's the astronomer's forecast. At a glance, it shows when it will be cloudy or clear for up to the next two days. It's a prediction of when Elk Forest, MD, will have good weather for astronomical observing. The forecast data comes from those very cool guys at the Canadian Meteorological Center. CMC's numerical weather forecasts are unique because they are specifically designed for astronomers. But they have 763 forecast maps. It can be a chore to find the one you want. So, Attilla Danko wrote a script to generate the images like the one above which summarizes CMC's forecast images just for Elk Forest and the surroundings out to about 10 miles. Click anywhere on the clock to be taken to a web site that will provide a detailed expalnation of what the clock is telling you.