PROP @ ARL $ARLP024

ARLP024 Propagation de K7RA

ZCZC AP24

QST de W1AW 

Propagation Forecast Bulletin 24  ARLP024

From Tad Cook, K7RA

Seattle, WA  June 13, 2014

To all radio amateurs

SB PROP ARL ARLP024

ARLP024 Propagation de K7RA

Last week's bulletin opened with your author (me) moaning about a

decline in solar activity, but this was short lived. The current

week saw average daily sunspot numbers more than double, rising from

60.1 to 144.3, and average daily solar flux rise from 104.1 to

146.4. In addition, on June 12 the daily sunspot number was 196, and

solar flux was 174.5. It actually was not long ago when sunspot

numbers were last at that level. April 16-19, 2014 had numbers

ranging from 245-296.

Predicted values are also up. The latest has solar flux at 170, 165

and 155 on June 13-15, 145 on June 16-18, 140 on June 19, 130 on

June 20-21, then reaching down for a low of 110 on June 24-25, then

peaking at 165 on July 8. The outlook for Field Day Weekend has

brightened, with solar flux at 115 on June 27-28 and 120 on Sunday,

June 29.

Predicted planetary A index is 18, 20, 10 and 8 on June 13-16, 5 on

June 17, 8 on June 18, 5 on June 19-24, 8 on June 25-26, 5 on June

27 through July 5, 15 on July 6, 5 on July 7-9, 8 on July 10, 5 on

July 11-14, and 8 on July 15-16.

OK1HH predicts mostly quiet geomagnetic conditions on June 13, quiet

to active June 14, quiet to unsettled June 15, quiet June 16-18,

quiet to active June 19, quiet to unsettled June 20, mostly quiet

June 21, quiet June 22-24, mostly quiet June 25, quiet to active

June 26, active to disturbed June 27, quiet to unsettled June 28,

quiet on June 29, quiet to active June 30, mostly quiet July 1-2,

quiet to unsettled July 3-4, quiet July 5, quiet to unsettled July

6, active to disturbed July 7, quiet to active July 8, and mostly

quiet July 9.

Again this week there was an interruption in data from the middle

latitude geomagnetic observatory in Fredericksburg, Virginia, so the

middle latitude A index numbers at the end of this bulletin for June

8-9 are my own guesses.

We saw a lot of geomagnetic activity over last weekend, June 8-9,

when the planetary K index reached 6 in two 3-hour periods, and the

planetary A index was 13 on Saturday, then 39 on Sunday. This

geomagnetic storm was from a CME which hit Earth at 1630 UTC on June

7, but left the Sun on June 4.

A significant solar flare on June 10 could cause polar geomagnetic

storms today, Friday June 13. It will probably deliver a glancing

blow to Earth's magnetic field. See

http://earthsky.org/space/x2-solar-flare-today for an article about

the June 10 flare, and for a UPI story on possible effects today,

see

http://www.upi.com/Science_News/2014/06/12/Solar-storm-to-hit-Earth-on-Friday-the-13th/7891402590302/

.

Ted Leaf, K8HI sent a fascinating video and article about renewed

activity at the peak of the current solar cycle. See

http://earthsky.org/space/solar-maximum-is-back .

Max White, M0VNG sent two relevant articles. See

http://www.upi.com/Science_News/2014/06/11/Another-giant-solar-flare-erupts/4281402500673/

and

http://www.sciencecodex.com/the_solar_wind_breaks_through_the_earths_magnetic_field-135443

.

David Moore sent a review of "Nearest Star; the surprising science

of our Sun" which you can read at

http://www.thespacereview.com/article/2513/1#.U5NRe3TXbgY.email .

An excellent book I've been reading is "Tesla: Inventor of the

Electrical Age" by W. Bernard Carlson. This may be the best

biography yet on Tesla, as other articles and books I've seen

accepted uncritically some of his later work, which included

transmitting electrical power via wireless. I think copper wire

works better for this.

NASA has a new and slightly revised prediction for Cycle 24.  View

it at http://solarscience.msfc.nasa.gov/predict.shtml . The changes

from a month ago are:

May 2, 2014 forecast: "The current prediction for Sunspot Cycle 24

gives a smoothed sunspot number maximum of about 70 in the Fall of

2013. The smoothed sunspot number reached 75.0 in October 2013."

to:

June 12, 2014 forecast: "The current prediction for Sunspot Cycle 24

gives a smoothed sunspot number maximum of about 70 in late 2013.

The smoothed sunspot number reached 75.4 in November 2013."

These are smoothed numbers, averaged with real and predicted values

over a year, so when we have higher and extended activity this year,

that changed the maximum from fall of 2013 to late 2013, and 75.0 in

October 2013 to 75.4 in November 2013.

Astrophysicists at Trinity College in Dublin are using crowdsourcing

for classifying sunspots. They want people to visit

http://www.sunspotter.org/ to rank pairs of sunspot images based on

complexity. As you are presented with each pair, use your gut

feelings and vote for the image that seems the most complex. Or if

you want examples, go to http://www.sunspotter.org/#/classify .

We learned of this from the Irish internet news site TheJournal.ie,

and you can read their article "Trinity College astrophysicists want

you to play 'Hot or Not' with sunspots" at

http://www.thejournal.ie/article.php?id=1513613 .

Another interesting project to use crowdsourcing is "Seafloor

Explorer," where they want help classifying real images of the ocean

floor. Check it out at http://www.seafloorexplorer.org/ . People who

believe they see a face on Mars or pyramids on the moon should find

a lot to like here.

Find other projects and educational info at

https://www.zooniverse.org/projects. Click on "Study explosions on

the Sun" to enter their Solar Stormwatch project.

This weekend is the ARRL June VHF Contest. The multiplier is number

of grid squares worked. The contest begins at 1800 UTC Saturday. See

http://www.arrl.org/june-vhf for details.

If you would like to make a comment or have a tip for our readers,

email the author at, k7ra@arrl.net.

For more information concerning radio propagation, see the ARRL

Technical Information Service web page at

http://arrl.org/propagation-of-rf-signals. For an explanation of the

numbers used in this bulletin, see

http://arrl.org/the-sun-the-earth-the-ionosphere. An archive of past

propagation bulletins is at

http://arrl.org/w1aw-bulletins-archive-propagation. More good

information and tutorials on propagation are at http://k9la.us/.

Monthly propagation charts between four USA regions and twelve

overseas locations are at http://arrl.org/propagation.

Instructions for starting or ending email distribution of ARRL

bulletins are at http://arrl.org/bulletins.

Sunspot numbers for June 5 through 11 were 102, 132, 155, 144, 152,

149, and 176, with a mean of 144.3. 10.7 cm flux was 110.5, 133,

136.7, 148.6, 161.2, 166.2, and 168.4, with a mean of 146.4.

Estimated planetary A indices were 7, 6, 13, 39, 5, 7, and 7, with a

mean of 12. Estimated mid-latitude A indices were 7, 5, 14, 40, 6,

7, and 8, with a mean of 12.4.

NNNN

/EX