As the Sun Turns: Solar Minimums and Maximums

[Maria]

Belgium's Daily Comment from the Royal Observatory is printed below:

COMMENT: There are presently two small and simple sunspot groups on the
visible side of the Sun, Catania sunspot group 68 and Catania sunspot group
69 (NOAA AR 2694). Solar activity is extremely low, and there were no
C-class flares reported for more than ten days. We do not expect
significant change in the level of flaring activity.
During last 24 hours there were no Earth directed CMEs reported, and the
solar protons remained at background level.

Solar wind speed is 410 km/s, and the interplanetary magnetic field
magnitude is about 4 nT.
The geomagnetic conditions are presently quiet and we expect them to stay
so in the coming hours.

TODAY'S ESTIMATED ISN : 011, BASED ON 07 STATIONS.

The EISN plot currently reports 11 sunspots based on 9 of 15 reporting
stations with a 1.1 standard deviation. This means that six station reports
have been rejected as outliers.
cf. http://www.sidc.be/silso/eisnplot

For December 2017, the ISN monthly mean was 8.2
cf. http://www.sidc.be/sunspots/bulletins/m ... 201712.pdf

[Maria]

Finally, we are getting the truth. Beligum has been correct all along.

NOAA finally has acknowledged the presence of a second Active Region,
AR2695, and has listed the decaying and older AR2694 as an alpha plage.

Both regions are approaching the Western limb of the solar disc and will be
disappearing from view as they cross over to the far side of the sun.

I. Regions with Sunspots. Locations Valid at 11/2400Z
Nmbr Location Lo Area Z LL NN Mag Type
2695 S08W59 260 0010 Bxo 02 02 Beta
IA. H-alpha Plages without Spots. Locations Valid at 11/2400Z Jan
Nmbr Location Lo
2694 S32W44 245

[Maria]

EISN for the second week in January from Belgium's Home Page at http://www.sidc.be/silso/home
shows a decline in Estimated International Sunspot Numbers (EISN).

08 January : 13
09 January : 12
10 January : 21
11 January : 11
12 January : 0 -- Only two early reporting stations have responded , so this may change as the day progresses.

The average EISN for January is now approximately 8.
December had a mean ISN of 8.2

[Maria]

NOAA has confirmed that the two new active regions have both decayed into alpha plages.

Joint USAF/NOAA Solar Region Summary
SRS Number 13 Issued at 0030Z on 13 Jan 2018
Report compiled from data received at SWO on 12 Jan
I. Regions with Sunspots. Locations Valid at 12/2400Z
Nmbr Location Lo Area Z LL NN Mag Type
None
IA. H-alpha Plages without Spots. Locations Valid at 12/2400Z Jan
Nmbr Location Lo
2694 S32W58 246
2695 S09W73 261

Belgium agrees.

The EISN/SILSO plot shows two spotless days: January 12 and January 13 (from early reports).
cf. http://www.sidc.be/silso/eisnplot

[Maria]

Per Belgium's EISN plot, there are five reporting stations which confirm that January 13 is yet another spotless day.
cf. http://www.sidc.be/silso/eisnplot

In this solar minimum, the sun may have spotless days with quite a string of them, but what is more fascinating are the magnetic filaments and coronal holes. See the image below from NASA. The creepy crawlers are the magnetic filaments which could snap and send a CME our way. The huge dark black holes are the coronal holes.
cf. https://www.thesuntoday.org/the-sun-now/

[Maria]

Today results may have broken the three day spotless cycle of the sun with the development of a bipolar active region at S14E45. Although NOAA has not acknowledged this active region yet, during this solar minimum, such regions will develop and disappear quite rapidly all within 24 hours or less.

This in from Belgium's Royal Observatory: http://www.sidc.be/products/meu/

COMMENT: Over the past 24 hours solar activity has been quiet. No
significant flares have been recorded. A small bipolar region has emerged
at S14E45 and is showing some evidence of growth that may increase flaring
activity over the next 24 hours. There are no other significant Active
Regions (AR) on the solar disk. There's a small filament channel located in
the South-West, but appears stable. No Earth directed Coronal Mass
Ejections (CMEs) have been detected. Solar activity is expected to remain
low over the next 24 hours with a small probability of C-class flares.
The solar wind speed has decreased from around 575 to 500 km/s over the
past 24 hours. The total magnetic field strength has remained around 6 nT.
The Bz component fluctuated around 0 nT, ranging between -5 and +5 nT.
Geomagnetic conditions ranged between Kp index 1-4 (NOAA) and local K index
1-3 (Dourbes) over the past 24 hours. Geomagnetic conditions are expected
to be quiet.
TODAY'S ESTIMATED ISN : 007, BASED ON 06 STATIONS.

Meanwhile, the EISN/SILSO plot shows that ten stations have reported, but
five of those have been rejected as outliers. That is a 50 percent rejection,
which is too high to ignore. The current EISN plot shows 000 sunspots
instead of 007 as reported by Belgium earlier. Has this new bipolar region
already decayed? Note the image below was taken about 6.5 hours ago.

solar image_01-15-2018 at 1306UT_new SE region .jpg (96.79 KiB) Viewed 1355 times

cf: http://sidc.oma.be/silso/home

11 January : 11
12 January : 0
13 January : 0
14 January : 0
15 January : 7

[Maria]

Here is a lovely aurora from Norway taken by Marianne Bergli on January 14, 2018.
Aurora sightings are rare during a solar minimum, but other factors, such as CIRs
and exploding magnetic filaments can also produce an aurora as www.spaceweather.com
states below:

"The CIR predicted by Spaceweather.com arrived bang on time," says Bergli. "The auroras were wonderful."

Co-rotating interaction regions are transition zones between slow- and fast-moving streams of solar wind. Shock-like density gradients and enhanced magnetic fields inside CIRs can mimic the effect of CMEs (coronal mass ejections), sparking geomagnetic storms and bright auroras when they interact with Earth's magnetic field. In this case, the geomagnetic storm ranked G1 on NOAA scales.

If you look closely at the black region in the center of this aurora, you can see the image of a bird with a long beak.

The aurora below, also taken by Marianne, looks like an angel in flight.