The sun had just a few, small active regions for several days this week and its magnetic field reflected that state of affairs (Dec. 13-16, 2016). Solar scientists using computer-generated models are able to portray the magnetic field lines of the sun over just about any length of time. Here we can see that the overall magnetic field structure is rather symmetrical, stable and untangled. If there were many active regions, we’d see a much more chaotic field. The sun here is shown in a wavelength of extreme ultraviolet light. — Solar Dynamics Observatory, NASA.
From the looks of the current visible image of the solar disk shows an almost spotless face, there is a nice little sunspot group on the right side of the image just above the solar equator:
An almost spotless Sun and you just know 15 and 20 meter HF propagation is going down the tubes again. Here’s hoping the bottom of the solar cycle does not last as long as the last time.
The peak of the solar cycle wasn’t much to write home about either, just my opinion. Oh sure we had our good periods but all in all not so good. Funny too because the “forecasts” were for the peak to be HUGE with off the chart solar storm etc. Didn’t happen. I know I watch closely being an Amateur Radio operator (one who LOVES 15 meter QRP CW).
The original caption released with this SDO image:
This week the sun was hitting its lowest level of solar activity since 2011 (Nov. 14-18, 2016) as it gradually marches toward solar minimum. This activity is usually measured by sunspot count and over the past several days the sun has been almost spotless. The sun has a pendulum-like pattern of solar cycle of activity that extends over about an 11-year period. The last peak of activity was in early 2014. At this point in time, the sunspot numbers seem to be sliding downwards faster than expected, though the solar minimum level should not occur until 2021. No doubt more and larger sunspots will inevitably appear, but we’ll just have to wait and see.
sSO gives us a look at pair of unusually long filaments on the Sun.
The two most noteworthy features on the sun this week were a pair of elongated filaments (Sept. 8, 2016). The central one was twisted into the shape of an elaborate arch at the center of the sun (yellow arrows). If this were straightened out, it would extend just about across the entire sun, almost a million miles (1.6 million Km). The other, smaller filament, (white arrows) if made straight, might reach about half that distance. Still, pretty impressive. Filaments are elongated strands of plasma suspended above the sun by magnetic forces. They are notoriously unstable and often break apart within a few days. The image was made by combining three images in different wavelengths of extreme ultraviolet light.
On 02 August 2016 the SDO was witness to a lunar transit. The moon passed between the SDO and the Sun in a transit lasting nearly an hour from 11:13 UTC until 12:08 UTC (07:13 EDT to 8:08 EDT). When the transit over the SDO did not return to science mode.
Returning to science mode wasn’t quite as simple as I thought it would be. Two of the three instruments (the Helioseismic and Magnetic Imager, or HMI, and the Extreme Ultraviolet Variability Experiment, or EVE) were returning data two days later. The A1A instrument came back online and was returning data on 06 August.
There are a few good websites for up to date solar data. Being a ham radio operator I am among a community whose hobby is very dependent on what the Sun is doing. One of the best sites around is from a Canadian Amateur Radio Station VE3EN called SolarHam.
One active region at the edge of the Sun pushed out about ten thrusts of plasma in just over a day long period (July 9-10, 2016). All of them, propelled by magnetic forces, quickly withdrew back into the active region. The images were taken in a wavelength of extreme ultraviolet light.
Here is an image from the Solar Dynamics Observatory or SDO and we can see a large sunspot on the left side. Actually this sunspot is many-many times the size of Earth and is rotating left to right so in about a week will be directly facing us and that gives us a possibility of increased solar activity including a CME.
I’m not saying anything much will happen, just that the possibility exists – you never know there could be a great aurora coming.
This illustration lays a depiction of the sun’s magnetic fields over an image captured by NASA’s Solar Dynamics Observatory on March 12, 2016. The complex overlay of lines can teach scientists about the ways the sun’s magnetism changes in response to the constant movement on and inside the sun. Note how the magnetic fields are densest near the bright spots visible on the sun – which are magnetically strong active regions – and many of the field lines link one active region to another.
This magnetic map was created using the PFSS – Potential Field Source Surface – model, a model of the magnetic field in the sun’s atmosphere based on magnetic measurements of the solar surface. The underlying image was taken in extreme ultraviolet wavelengths of 171 angstroms. This type of light is invisible to our eyes, but is colorized here in gold.
Credits: NASA/SDO/AIA/LMSAL/Steele Hill and Sarah Frazier NASA’s Goddard Space Flight Center, Greenbelt, Md.
The SDO description: Due to the geometry of Solar Dynamic Observatory’s orbit, there are periods when the spacecraft’s view of the Sun is blocked by the Earth and sometimes the Moon. Starting this earlier this week (video taken on Feb. 22, 2016) and for the next few weeks, the Earth will continue to get in the way once a day around 7:00 UT. This eclipse season occurs twice a year, near the equinoxes. The video covers about 15 minutes as the Sun is becoming unblocked again. The Sun was blocked for close to an hour. Such is life in space 22000 miles above Earth.