[SFDXA] The K7RA Solar Update

[Bill]

The K7RA Solar Update

Tad Cook, K7RA, of Seattle, Washington, reports for this week's ARRL 
Propagation Bulletin, ARLP009:

Solar disk image taken March 2, 2023, courtesy of NASA SDO/HM.

This was a busy week for geomagnetic storms. A solar wind stream from an 
equatorial hole and a Coronal Mass Ejection (CME) seemingly blew 
geomagnetic numbers off the scale, with the planetary A index on Monday 
hitting 94. An aurora was visible as far south as Colorado.

This week, the source of the 10.7-centimeter solar flux from the 
Dominion Radio Astrophysical Observatory in Kaleden, British Columbia, 
was again saturated by solar wind on February 25, and the measurement 
was 279.3. The National Oceanic and Atmospheric Administration (NOAA) 
corrected this to 152, which I thought was a bit too low. The other 
recent saturation was on February 17, at 343.1, but for some reason, the 
NOAA let this stand.

https://services.swpc.noaa.gov/text/daily-solar-indices.txt

Average daily sunspot numbers rose from 107 to 126.3, but average daily 
solar flux declined from 162.4 to 158.2.

Average daily planetary A index rose from 10.6 to 27.7.

Over the next few weeks, it appears that solar flux values should hit a 
peak around March 17 - 18.

Predicted solar flux is 164, 162, and 158 on March 2 - 4; 154 on March 5 
- 8; 165 on March 9 - 12; 170 on March 13 - 15; 175 on March 16; 180 on 
March 17 - 18; 175, 170, and 165 on March 19 - 21; 160 on March 22 - 23; 
155 on March 24 - 26; 150 on March 27 - 28; 145 on March 29 - 30, and 
140, 145, 150, 155, and 160 on March 31 through April 4.

Predicted planetary A index is 8, 5, 12, 18, 24, 14, and 8 on March 2 - 
8; 5 on March 9 - 14; 15, 8, 8, 5, 8, and 15 on March 15 - 20; 5 on 
March 21 - 23; 12, 16, 56, 32, 16, and 10 on March 24 - 29; 8 on March 
30 - 31, and 16, 18, and 15 on April 1 - 3.

The predicted A index of 56 and 32 on March 26 - 27 suggests a return of 
this week's disturbance in the next solar rotation.

/Newsweek/ reported a radio blackout at the following link:

https://bit.ly/3YsJREJ

/Sky & Telescope/ also reported on aurora season:

https://bit.ly/3ZbC1As

/The News Tribune/ wrote a story about the northern lights:

https://bit.ly/3ymZrqR

The above story features western Washington, where I live. 
Unfortunately, the sky was overcast, but folks in eastern Washington 
were able to see the aurora. Remember that many of the images you see 
were from cameras with a long exposure time, which makes them much 
brighter than what can be seen with the naked eye.

Thanks to spaceweather.com for this NASA video clip of sunspot group 
AR3234 growing as it comes over our sun's eastern limb:

https://bit.ly/3J1IIiJ

Sunspot numbers for February 23 through March 1, 2023, were 108, 130, 
129, 120, 192, 100, and 105, with a mean of 107. The 10.7-centimeter 
flux was 148.2, 164.1, 152, 159, 161.2, 160.9, and 162, with a mean of 
162.4. Estimated planetary A indices were 22, 6, 10, 26, 94, 28, and 8, 
with a mean of 10.6. Middle latitude A index was 16, 4, 9, 18, 60, 19, 
and 6, with a mean of 8.4.

73,

K7RA
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/sfdxa/attachments/20230302/51a158b2/attachment-0001.html>