venerdì 1 marzo 2019

The K7RA Solar Update

At 2256 UTC on February 28 the Australian Space Forecast Centre issued a Geomagnetic Disturbance Warning. “The Earth is currently under the influence of strongly elevated solar wind speed associated with a coronal hole. A period of significant southward Bz component could produce an isolated Minor Storm period.” The Bz component refers to the interplanetary magnetic field. See: https://bit.ly/1S6H68D

No sunspots emerged during the entire month of February. Currently on February 28 the Earth is bathed in solar wind from a wide hole in the Sun’s atmosphere.

The average daily solar flux and geomagnetic indices were practically unchanged over last week (February 21-27) compared to the previous seven days. Average daily solar flux was 70.7 (it was 70.6 in the prior week), average daily planetary A index was unchanged at 4.9, and average daily mid-latitude A index was 4, virtually unchanged from 3.9 the previous week.

Predicted solar flux over the next 45 days is 70 on March 1-8, and 71 on March 9 through April 14. Predicted planetary A index is 20, 14, 10, 8, 8, 5 and 5 on March 1-7, 10, 8 5 and 5 on March 8-11, 12 and 10 on March 12-13, 5 on March 14-19, 10 on March 20, 5 on March 21-25, then 18, 24, 16, 12 and 8 on March 26-30, then 5, 8, 5, 8, 10 and 8 on March 31 through April 5, 5 on April 6-7, then 12 and 10 on April 8-9, and 5 on April 10-14.

Geomagnetic activity forecast for the period March 1-27, 2019 from F.K. Janda, OK1HH.

Geomagnetic field will be:
Quiet on March 15, 23-25
Quiet to unsettled on March 4-7, 9-10, 16, 18, 22
Quiet to active on March 3, 8, 11-14, 17, 19-20
Unsettled to active on March 1-2, 7, 21, 26
Active to disturbed on March 27

Solar wind will intensify on March (1-3, 6-9,) 13-14, (15,) 21-22, 25-26

Parenthesis means lower probability of activity enhancement.

Here is the latest Space Weather forecast from Dr. Tamitha Skov, WX6SWW: https://youtu.be/1EKJ3d3c3bA

I received this from Jon Jones, N0JK: "I’m in Hawaii (Kapolei, O'ahu) this week visiting relatives. No 6-meter propagation this week, although the KH6HI/b 50.064 MHz beacon is 599. I had lunch on February 20 with Bert, KH6HI, and Tom, NH6Y, who are among the most active 50 MHz operators in the 50th state. They are looking forward to the summer sporadic-E season. Tom notes that North America seems to have a better and more frequent path to Japan than from Hawaii on 50 MHz Es."

Here is a February 23 email from Ken Brown, N4SO, of Grand Bay, Alabama: "In addition to the low bands, 10.136 MHz remains very good on the FT8 mode. Recently, I copied JA4FKX working 0-land stations at 16:10 UTC. (The path to Japan and Indonesia opens way before daylight.) During the night, conditions are similar to 7 MHz.”


And a note from KD6JUI, who operates almost exclusively from his freshwater kayak in Northern California: "I had an exceptional day last Tuesday, the 19th. While running 10 W SSB from the kayak, I got into Brazil on SSB. Also heard Spain coming in loud and clear. Noise was higher than usual.

“I am still able to make enough contacts on 17, 20 and 30 meters from the kayak to keep me happy. Being on the water helps, I'm sure.”


This weekend is the ARRL International SSB DX Contest. See http://www.arrl.org/arrl-dx 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 at http://arrl.org/propagation-of-rf-signals. For an explanation of 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 February 21 through 27, 2019 were 0, 0, 0, 0, 0, 0, and 0, with a mean of 0. 10.7 cm flux was 70.8, 71.2, 70.7, 70.5, 70.4, 70.6, and 70.7, with a mean of 70.6. Estimated planetary A indices were 11, 4, 3, 2, 2, 2, and 10, with a mean of 4.9. Estimated mid-latitude A indices were 9, 3, 2, 1, 2, 2, and 9, with a mean of 3.9.