Solar Sunspots Hibernation?

Is the cycle of sunspots going dormant for an extended period?

That’s what astronomers suggested at the June 14 annual meeting of the American Astronomical Society’s solar physics division, held at New Mexico State University. Frank Hill, associate director of the National Solar Observatory’s Solar Synoptic Network announced, “The solar cycle may be going into a hiatus.”

First, let’s review what a solar cycle is.

Check out my previous blog on the topic.

Like all fluid bodies in our solar system, the sun has a magnetic field.  Where these field lines intersect the sun’s surface, convection from inside the sun is blocked, resulting in a cooler region on the sun’s surface.  The cooler region is darker because it emits more infrared light, which is invisible to our eyes.  The number of sunspots on the sun is not constant but varies over a period of about eleven years.  Since we began keeping systematic track of sunspots, scientists have observed 23 such cycles.

02 Sun Structure
Creative Commons License photo credit: Image Editor

However, the most recent solar minimum lasted much longer than we expected.

We had hoped to begin seeing sunspots in 2008 or 2009, leading to a 2012 peak.  Instead, solar minimum persisted until 2010.  Scientists now expect the current cycle (#24) to peak in May 2013.

According to Frank Hill, several lines of evidence point to a larger trend, in which solar maxima become delayed as well as less and less pronounced, possibly resulting in an extended period largely without sunspots.  One involves the solar ‘jet stream,’ a stream of plasma inside the sun which is analogous to jet streams in Earth’s atmosphere.  About every 11 years, such streams of plasma form near the poles of the sun and then migrate towards the sun’s equator.  When they reach a latitude of about 22 degrees, more sunspot formation is allowed.

Although cycle 24 is well underway, Hill attempted to detect the solar jet stream that will start cycle 25, which in theory should already be forming in the polar regions.  He was unable to do so, leading him to believe the solar cycle 25 may be delayed and its maximum smaller than for cycle 24.

Also, astronomers Matt Penn and William Livingston, upon analyzing 13 years of sunspot date taken at Kitt Peak in Arizona, determined that magnetic fields associated with sunspots now are weaker than during cycle 23.  If the trend continues, these magnetic fields could become too weak to inhibit convection at the sun’s surface, thus preventing sunspot formation.

This may mean that future solar cycles (25, 26, etc.) will have only very small maxima, resulting in a decades-long period of few if any sunspots.

A sunspot viewed close-up in ultraviolet light, taken by the TRACE spacecraft

The last time this happened was the Maunder Minimum, which occurred roughly from 1645-1715.

Astronomers of the day, such as Giovanni Cassini and Johannes Hevelius, were making systematic observations of the sun, and they noted very few sunspots – only about 50 over one 30-year period.  A less severe drop in sunspot activity, called the Dalton Minimum, occurred in the early ninteenth century.  Each of these extended minima were associated with below average temperatures on Earth.  For example, the Great Frost of 1708-09 was among the worst winters in recorded history.

However, not all solar scientists agree that another Maunder Minimum is on the way.

Douglas Biesecker of the National Oceanic and Atmospheric Administration’s Space Weather Prediction Center points out that cycle 24’s polar jet stream formed about eight months after solar minimum and remained patchy for up to 30 months after that. It may still be too soon after the last solar minimum (December 2008) to draw conclusions about that jet.

Also, Biesecker points out that the raw data on the graph showing the weakening of the magnetic fields in sunspots is scattered and indeterminate enough to allow other analyses.

Of course, only the real sun will determine who’s correct on this issue, and you can observe the real sun right here at the Museum.

Our sundial has three sets of holes aligned with the sun’s midday position at each solstice and at the equinoxes.  As we are  now just past the summer solstice (which occurred at 12:17 p.m. June 21), anyone willing to brave the heat can come to our sundial near local noon (1 p.m. during Daylight Saving Time) and project an image of the sun onto a sheet of paper.  Any sunspots present will be revealed.

Summer Campers Of The Week: Robolab and Battlebots!

School’s out, and you know what that means – summer camp fun at HMNS!

Xplorations Summer Camps!
See more summer camp fun in our set on Flickr!

This week’s photo comes from our Robolab and Battlebots camp, where kids join a “Brain Team” and work together to build and program robots using our LEGO MINDSTORMS NXT(TM) Robotics Engineering system. Then – it’s on! Campers get to race their creations, master obstacle courses, and battle their “Bots” on the robot battlefield!

Looking for something fun an educational for the kids to do this summer? Lots of summer camp classes have space available – check it out!

See you at Summer Camp!

Dino Gangs? Live Chat Wednesday, June 22!

Fossil 2
Creative Commons License photo credit: BarryKidd Photography

The mighty T. rex: dull-witted, solitary creature, or deadly pack animal? The debate is on!

Join Dr. Phillip J Currie, Research Chair in Dinosaur Paleobiology at the University of Alberta, and noted dinosaur bloggers Brian Switek (@laelaps) and David Orr for a live webchat tomorrow to discuss the new research that might change your mind about these fearsome beasts.

Wednesday, June 22 at 7 am Central
Chat location: facebook.com/discoveryuk

And, if you’re lucky enough to have access to The Discovery Channel UK, check out the new documentary, Dino Gangs which reveals this new evidence from Dr Currie.

 

The Reinforcement Crew [HMNS at AAM]

Last month Houston museums were buzzing more than usual during the American Association of Museums annual meeting.  It was a great time for all of us to show off our institutions to colleagues from across the country and the world.  In addition, Houston museum professionals had the opportunity to soak up a plethora of information about the latest discoveries, standards and issues in our field.  Keynote speaker Neil deGrasse Tyson from the Rose Planetarium in New York also gave us a lot to ponder.

And the HMNS staff was right in the middle of it.

In my last blog I posted about a session open to the public that Lisa Rebori put together.  She was also a panelist in a session which covered the federal indemnity program that enables so many wonderful temporary exhibits to travel around the country.  Lynn Wisda, Director of Volunteers, gave a presentation on the creative use of volunteers in collections.  Daniel Burch from our Adult Education program weighed in on interpreting current events for public audiences and Kathleen Havens from Youth Education shared how HMNS works with local homeschoolers.  Of course the Lois phenomenon of last summer deserved its very own session and Erin Flis, Brad Levy, and Zac Stayton related all the merriment to a thoroughly entertained audience.  (Ok, I’m biased, but this was one of my favorite sessions.  Thanks again Lois!)

So every single day of the meeting there was a HMNS staff member making the museum proud.

The Reinforcement Crew

However, it wasn’t all dashing about inside the convention center.  The meeting is more than just sharing information and networking; often a real impact takes place.  Every year the Registrars Committee has a volunteer day in the host city the day before the meeting begins; it’s called the Reinforcement Crew.  Collections management professionals from all around the country volunteer to come a day early and help out in local museum collections, usually smaller institutions that can use a little extra labor and expertise with a day long project.  This year these gracious folks, twenty volunteers, worked tirelessly to better our hometown museums.

Bryanna at the Holocaust Museum

Starting last summer Carol Manley, Director of Collections and Exhibitions at the Holocaust Museum, and I set about the Houston museum community asking who might want help and what kind of help their collections might need.  It was very rewarding to be allowed to work with five local museum collections.

At the Buffalo Soldiers Museum a crew of four managed to identify, photograph and tag over two hundred objects.  The group working at the Printing History Museum inventoried 918 (wow!) printed music sheets and re-housed them in archival boxes.  HMNS Collections staff Bryanna O’Mara volunteered her expert sewing skills and textile expertise at the Holocaust Museum where they carefully rolled banners and folded WWII uniforms and hats in acid-free tissue and placed them in archival storage.

The volunteers at the Maritime Museum spent the day delicately cleaning ship models of all shapes and sizes.  But it was the good, not to mention hardy, folks who helped sort through collections in an un-air-conditioned section of the Fire Museum who deserve an extra round of applause.  (Yes, there were many comments made about being hot in a fire museum.)  None of this great work would have happened without Mark Ryan and Heather Kajic of the Registrars Committee who oversaw the organization of volunteers, donations of archival supplies, and every other logistic to pull the whole project off.

So while AAM and thousands of museum professionals left Houston weeks ago, there remains a lasting impact from these volunteers who selflessly and with much good fellowship left five Houston museum collections in better shape.

The Reinforcement Crew did all this without publicity or even much recognition of their efforts because they love museum collections that help tell our stories.  All of us at HMNS extend our heartfelt thanks to them for sharing their skills and time in our Houston museum community.

Reinforcement Crew at the Buffalo Soldiers Museum
Reinforcement Crew at the Maritime Museum