Average daily sunspot numbers increased slightly this week from 111.4 to 113.3, but average daily solar flux declined by 22 points from 155.4 to 133.4. Although there seems to be no shortage of sunspots, they are anemic and not magnetically complex, and thus radiation from the spots is feeble, indicated by lower solar flux values.
Predicted solar flux for the near term is 135 on January 24, 130 …
American Radio Relay League | Ham Radio Association and Resources
Average daily sunspot numbers for the past week declined from 114.6 to 107.4, and average solar flux went from 138.8 to 139.2. This is comparing the period from December 26 through January 1 with the previous seven days.
The average daily sunspot number for the entire year of 2013 was 97.1, the highest since 2003. For 2008-2013 the yearly average was 4.7, 5.1, 25.5, 80.1, 82.3 and 97.1.
We’ve als…
American Radio Relay League | Ham Radio Association and Resources
Sunspot numbers made a profound leap over the past week, with the sunspot number on November 15 reaching 272, then 282 on November 17. This is a record for the current solar cycle, and this level of activity has not been observed for over a decade. Unfortunately the sunspot number declined rapidly since then, falling below 100.
You can check in the ARRL Propagation Bulletin archives to see what …
American Radio Relay League | Ham Radio Association and Resources
Solar activity remains robust. Yesterday, Thursday, November 14 the daily sunspot number rose to 234, a number not seen since the last blast of the second peak of the previous solar cycle, exactly a decade ago.
Way back on October 27 through November 1, 2003 the daily sunspot numbers were 238, 230, 330, 293, 266, and 277. That was it. Nothing as high as a sunspot number of 234 since then.
But the…
American Radio Relay League | Ham Radio Association and Resources
Solar activity eased off over the past week, with average daily sunspot numbers declining nearly 30 points from 161.6 to 131.7, and average daily solar flux down over 12 points from 158.3 to 146. Geomagnetic indicators were quiet. Still, activity remains strong. The last three days of the reporting week (November 4-6) had increasingly stronger sunspot numbers, all higher than the week’s average…
American Radio Relay League | Ham Radio Association and Resources
Solar activity is increasing, suggesting that perhaps now in Fall 2013 we are in the midst of a second peak in cycle 24. We hope it sustains.
Sunspot numbers this week ran up all the way to 228, a level not seen in the past decade since October 27 through November 1, 2003 when the daily sunspot numbers were 238, 230, 330, 293, 266 and 277. Prior to that, on January 11, 2003 the daily sunspot num…
American Radio Relay League | Ham Radio Association and Resources
Our sun is still very quiet, but solar flux and sunspot numbers were higher this week than last. Average daily sunspot numbers rose from 42.3 to 75.6, and average daily solar flux rose from 95.3 to 109.6. There were no big geomagnetic events this week.
Predicted solar flux is 110 on September 27 through October 2, then 105, 100, 95, 100, 105 and 100 on October 3-8, 95 on October 9-10, then 100, …
American Radio Relay League | Ham Radio Association and Resources
Solar activity was very, very quiet over the past week. For the reporting period September 5-11, the average daily sunspot number was only 37.7. Average daily sunspot numbers as reported in this bulletin have not been nearly this low since June 6-12 of this year, when it was 39.6. The last time it was lower was June 21-27 of last year, when it was 26.3.
Australia’s IPS Radio and Space Services i…
American Radio Relay League | Ham Radio Association and Resources
Conditions were quieter again this week. Average daily sunspot numbers declined from 77 to 69, and average daily solar flux was off by 9.5 points to 106.9, when compared to the previous seven days, August 22-28.
Predicted solar flux for the near term is 105 on September 6-10, 100 on September 11-12, 110 on September 13, 120 on September 14-15, 115 on September 16-17, 110 on September 18, 105 on …
American Radio Relay League | Ham Radio Association and Resources
Solar activity picked up this week, with average daily sunspot numbers for August 15-21 up nearly 42 points (forty-nine percent) to 126.9, when compared to the previous seven days. Likewise, average daily solar flux increased from 111.7 to 126.3.
The latest prediction from USAF/NOAA has solar flux at 130, 125, 120, and 115 on August 23-26, 110 on August 27-29, 105 on August 30, 95 on August 31 t…
American Radio Relay League | Ham Radio Association and Resources
Again this week, solar activity was unchanged, with average daily sunspot numbers slipping from 85.4 to 85, and average daily solar flux increasing 4.4 points to 111.7. Geomagnetic conditions were stable.
The latest solar flux prediction from USAF/NOAA has flux values of 125 on August 16, 130 on August 17-18, 120 on August 19-20, 110 on August 21-23, 105 on August 24, 110 on August 25-26, 115 on…
American Radio Relay League | Ham Radio Association and Resources
Solar indicators barely moved this week, with average daily sunspot numbers up 5.8 points to 85.4, and average daily solar flux down 2.4 points to 107.3.
Predicted solar flux for the next week is low, with the predicted average for Thursday August 8 through Wednesday August 14 at 104.9, a little lower than the 107.3 average for this past week.
Solar flux is predicted at 105 on August 9-16, 110 on…
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers sank nearly 50 points this week to 94.3, while the average daily solar flux was down more than 16 points to 117.8. The geomagnetic indices were quite high, due to a solar wind storm. Sunspot numbers for May 23-29 were 117, 99, 107, 92, 87, 75 and 83, with a mean of 94.3. The 10.7 centimeter flux was 134.5, 127.3, 121.3, 120, 110.1, 104.8 and 106.9, with a mean …
American Radio Relay League | Ham Radio Association and Resources
This week, the average daily sunspot numbers remained about the same, with the number nudging up from 120.9 to 121.7, while the average daily solar flux numbers went from 136.5 to 137.5. For the past two weeks, the average planetary A index has been the same as the mid-latitude A index. Last week they were both 9.9; this week, both values were 8.
Sunspot numbers for May 2-8 were 102, 139, 156, 1…
American Radio Relay League | Ham Radio Association and Resources
Solar activity made a healthy jump over the past week, with the average daily sunspot numbers up more than 30 points to 120.9, while the average daily solar flux increased more than 27 points to 136.5. The most active day for geomagnetic indices was May 1, when the planetary A index reached 21 and the high-latitude College A index (measured near Fairbanks, Alaska) was a whopping 57. That number…
American Radio Relay League | Ham Radio Association and Resources
Solar activity was quiet this week: The average daily sunspot number declined nearly 23 points to 90.6, while the average daily solar flux values were down nearly 13 points to 109.1. The most active day was April 24, with a planetary A index of 19 and mid-latitude A index of 15. The average daily mid-latitude A index was the same this week as last, 4.9. Sunspot numbers for April 18-24 were 86, …
American Radio Relay League | Ham Radio Association and Resources
Both the average daily sunspot numbers and the solar flux were up this week, with the sunspot numbers rising nearly 57 points to 138.1, and the average daily solar flux up more than 25 points to 138.8. Paired with the average daily planetary A index dropping from 9.4 to 4.1, this is great news for HF propagation. On April 8, the daily sunspot number reached 162; two days later, it was at 163. T…
American Radio Relay League | Ham Radio Association and Resources
Solar activity increased over this past week, with the average daily sunspot numbers up 32 points to 81.6, while the average daily solar flux increased more than 16 points to 113.4. The geomagnetic field was active on March 29 due to solar wind. Sunspot numbers for March 28-April 3 were 49, 73, 70, 83, 84, 103 and 109, with a mean of 81.6. The 10.7 centimeter flux was 98.7, 105.1, 108.4, 113.3,…
American Radio Relay League | Ham Radio Association and Resources
Solar activity was down this week, with the average daily sunspot number at 49.6, less than half last week’s figure. The average daily solar flux dropped 22 points to 97, and geomagnetic activity was quiet also. Sunspot numbers for March 21-27 were 60, 54, 56, 45, 56, 41 and 35, with a mean of 49.6. The 10.7 centimeter flux was 106.1, 100.9, 98.2, 96, 92.6, 92.4 and 93, with a mean of 97. The e…
American Radio Relay League | Ham Radio Association and Resources
This past week, the average daily sunspot numbers were up 16.2 points to 101.1, while the average daily solar flux remained about the same, rising from 118.5 to 119. An eruption on March 15 caused a coronal mass ejection (CME) that hit Earth on March 17, causing the planetary A index to jump to 46. Sunspot numbers for March 14-20 were 133, 105, 90, 126, 116, 68 and 70, with a mean of 101.1. The…
American Radio Relay League | Ham Radio Association and Resources
Both the averages of daily sunspot numbers and solar flux rose, with the sunspot numbers up nearly 36 points to 93.3, and the solar flux up nearly 12 points to 112.6. The most active geomagnetic day was Friday, March 1, when the planetary A index was 27 and the mid-latitude A index was 23; Alaska’s high latitude College A index was a whopping 64.
Sunspot numbers for February 28-March 6 were 63, …
American Radio Relay League | Ham Radio Association and Resources
There was a modest rise in the average daily sunspot numbers over the past seven days, rising 27 points to 78.3, while the average daily solar flux was up marginally, only 1.6 points to 105.6. The geomagnetic indices also went up, with the planetary A index rising from 5.6 to 6.4, and the middle latitude A index rising from 5.1 to 6. There was a more substantial rise in both the solar flux and …
American Radio Relay League | Ham Radio Association and Resources
Solar activity continues at the low levels that we have seen in the past few weeks. The sunspot numbers have been remarkably consistent, with the average daily numbers for the weeks since January 17 at 56.4, 55.7, 50.7 and finally 51.3 for this past week. As you can see, the average daily sunspot number rose less than 1 point from the previous week to the past week, while the average daily sola…
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers hardly changed from last week and the week prior, but the average daily solar flux bounced back to about the level it was from two weeks ago: The average daily sunspot numbers were down 5 points to 50.7, while the average daily solar flux was up 7.7 points to 106.4. Sunspot numbers for January 31-February 6 were 47, 65, 54, 79, 30, 41 and 39, with a mean of 50….
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers this past week dropped nearly 73 points to 56.4, while the average daily solar flux declined nearly 47 points to 110.7. The average geomagnetic indices were up about 50 percent, but it was still very quiet. The difference was mostly due to events on January 17 when the planetary A index was 13 — higher than in recent weeks, but still moderate. The cause of the…
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers fell 13.5 points this week, from 61.1 to 47.6, while the average daily solar flux was about the same this week as last, rising 1.1 points to 102.7. Geomagnetic indices were even quieter this week than last. Sunspot numbers for December 6-12 were 49, 23, 35, 40, 49, 55 and 82, with a mean of 47.6. The 10.7 centimeter flux was 97.4, 97.1, 101.1, 103.7, 104, 103.7…
American Radio Relay League | Ham Radio Association and Resources
Solar activity declined again this week, with the average daily sunspot numbers dropping 17.8 points, from 78.9 to 61.1, while the average daily solar flux declined 19.4 points, from 121 to 101.6. Sunspot numbers for November 29-December 5 were 89, 67, 49, 43, 44, 58 and 78, with a mean of 61.1. The 10.7 centimeter flux was 113.1, 110.6, 101.7, 97.7, 96.6, 96.2 and 95.5, with a mean of 101.6. T…
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot number for the week was down nearly 38 percent to 78.9, compared to last week’s average of 126.9. The average daily solar flux dropped nearly 13 percent, to 121 from 138.9. The seven-day reporting period for these data ran from November 22-28. Sunspot numbers for November 22-28 were 93, 85, 87, 64, 81, 76 and 66, with a mean of 78.9. The 10.7 centimeter flux was 127.7,…
American Radio Relay League | Ham Radio Association and Resources
Solar activity retreated again this week, with the average daily sunspot numbers declining 8.7 points to 49.7, while the average daily solar flux was down nearly 20 points to 97.2. Sunspot numbers for November 1-7 were 48, 34, 35, 46, 47, 61 and 77, with a mean of 49.7. The 10.7 cm flux was 98.4, 96.5, 93.3, 95, 96.6, 98.7 and 101.7, with a mean of 97.2. The estimated planetary A indices were 1…
American Radio Relay League | Ham Radio Association and Resources
Solar activity quieted this week, with the average daily sunspot numbers down nearly 37 points to 58.4 and the average daily solar flux declining 27 points to 116.9. Sunspot numbers for October 25-31 were 58, 71, 59, 55, 75, 56 and 35, with a mean of 58.4. The 10.7 cm flux was 130, 130.7, 121.7, 117, 108.4, 106.3 and 104.2, with a mean of 116.9. The estimated planetary A indices were 4, 4, 4, 3…
American Radio Relay League | Ham Radio Association and Resources
Sunspot activity rose this week, with the average daily sunspot numbers up more than 45 points to 97, while the average daily solar flux rose more than 24 points to 129.2. Sunspot numbers for October 11-17 were 82, 89, 85, 97, 119, 107 and 100, with a mean of 97. The 10.7 cm flux was 116.6, 121.9, 124.9, 132.1, 136.8, 137 and 135, with a mean of 129.2. The estimated planetary A indices were 6, …
American Radio Relay League | Ham Radio Association and Resources
There was another decline in sunspot activity this week, but based on activity over the past few days, combined with the projected solar flux values, it is making a steady recovery. The sunspot numbers for October 4-10 were 56, 55, 39, 37, 41, 63 and 71, with a mean of 51.7. The 10.7 cm flux was 109.5, 106.2, 98.8, 98.1, 103.4, 106.2 and 112, with a mean of 104.9. The estimated planetary A indi…
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers rose this week from 56 to 81.3, while the average daily solar flux increased from 101.4 to 129.7. Sunspot numbers for September 20-26 were 68, 74, 46, 57, 90, 121 and 113, with a mean of 81.3. The 10.7 cm flux was 117.4, 116.9, 124.5, 133.6, 136.6, 139.8 and 139.2, with a mean of 129.7. The estimated planetary A indices were 9, 5, 4, 2, 2, 2 and 6, with a mean …
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers dropped this week, from 83.1 to 56, while the average daily solar flux declined from 118.9 to 101.4. Sunspot numbers for September 13-19 were 44, 44, 53, 77, 51, 61 and 62, with a mean of 56. The 10.7 cm flux was 99.1, 100.5, 97.5, 97.3, 101.5, 104.3 and 109.8, with a mean of 101.4. The estimated planetary A indices were 6, 5, 6, 7, 6, 8 and 14, with a mean of …
American Radio Relay League | Ham Radio Association and Resources
Solar activity retreated this week, with the average daily sunspot numbers off nearly 46 points — about 35 percent — to 83.1, while the average daily solar flux declined 18 points to 118.9. Sunspot numbers for September 6-12 were 112, 110, 70, 87, 62, 73 and 68, with a mean of 83.1. The 10.7 cm flux was 128, 133.4, 128.6, 123, 111.3, 105.1 and 102.6, with a mean of 118.9. The estimated planet…
American Radio Relay League | Ham Radio Association and Resources
There was a surprising jump in solar activity occurred this week: The average daily sunspot numbers rose nearly 55 points (that’s almost 74 percent) to 128.7, while the average daily solar flux values were up more than 28 points to 136.9. Sunspot numbers for August 30-September 5 were 118, 144, 120, 108, 156, 150 and 105, with a mean of 128.7. The 10.7 cm flux was 127.8, 130.5, 145.6, 142.3, 14…
American Radio Relay League | Ham Radio Association and Resources
Although solar activity is quite low, there was an increase in sunspot numbers and in the solar flux over the past week. The average daily sunspot numbers were up nearly 20 points — about 36 percent — to 74.1, while the average daily solar flux increased nearly 13 points to 108.7. Sunspot numbers for August 23-29 were 49, 69, 70, 78, 85, 73 and 95, with a mean of 74.1. The 10.7 cm flux was 96…
American Radio Relay League | Ham Radio Association and Resources
The weak solar activity continues: The average daily sunspot numbers for the seven days of August 16-22 were down 23 points — 30 percent — to 54.6, while the average daily solar flux dropped a little over 16 percent — 18.7 points — to 96. These figures offer a comparison between August 9-15 and the latest reporting period of August 16-22. Sunspot numbers for August 16-22 were 34, 42, 56, 69…
American Radio Relay League | Ham Radio Association and Resources
There was a big drop in solar activity over the past week, with the average daily sunspot numbers declining nearly 42 points to 77.6, and the average daily solar flux down 20 points to 114.7. Sunspot numbers for August 9-15 were 124, 105, 98, 76, 62, 46 and 32, with a mean of 77.6. The 10.7 cm flux was 131.2, 125.4, 119.7, 112.3, 108.1, 105.8 and 100.7, with a mean of 114.7. The estimated plane…
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers rose more than 20 points this week — about 20 percent — to 119.4, while the average daily solar flux was up 3 points to 134.7. Sunspot numbers for August 2-8 were 126, 160, 140, 107, 108, 96 and 99, with a mean of 119.4. The 10.7 cm flux was 134.6, 139.7, 138.7, 134, 134.1, 128.5 and 133.3, with a mean of 134.7. The estimated planetary A indices were 16, 7, 7…
American Radio Relay League | Ham Radio Association and Resources
Solar activity rose moderately this week, with the average daily sunspot numbers up nearly 3 points to 120.9, and the average daily solar flux rising more than 28 points to 166.8. There was quite a bit of geomagnetic activity — the most happening on July 9 — when the mid-latitude A index reached 29, the planetary A index was 30 and Alaska’s college A index was 60. Sunspot numbers for July 5-1…
American Radio Relay League | Ham Radio Association and Resources
Solar activity jumped way up this week, with the average daily sunspot numbers increasing by nearly 92 points to 118.1, while the average daily solar flux rose to 138.5 from 92.8 the week before. One new sunspot group appeared on June 29, another on July 1 and two more on July 4. Sunspot numbers for June 28-July 4 were 73, 97, 90, 137, 165, 136 and 129, with a mean of 118.1. The 10.7 cm flux wa…
American Radio Relay League | Ham Radio Association and Resources
Sunspot activity continued to drop until early this week: The average daily sunspot numbers were 26.3, down more than 58 points from last week’s numbers, while the average daily solar flux declined to 92.8, down over 33 points from last week’s average. The weekly sunspot number average has declined since the May 31-June 6 period, when it was 130.4, followed by 116.1 the next week, 84.6 the next…
American Radio Relay League | Ham Radio Association and Resources
Sunspot numbers seemed to be in a free-fall this week: The average daily sunspot numbers declined more than 29 points to 87, while the average daily solar flux fell 6.2 points to 126.2. Sunspot numbers for June 14-20 were 114, 113, 110, 96, 66, 64 and 46, with a mean of 87. The 10.7 cm flux was 148.6, 144.9, 134.5, 124, 118, 109.9 and 103.7, with a mean of 126.2. The estimated planetary A indic…
American Radio Relay League | Ham Radio Association and Resources
Solar activity was lower this week, although for the past few days, both the sunspot numbers and solar flux were rising. The average daily sunspot numbers declined more than 14.3 points to 116.1, while the average daily solar flux was off by 14.5 points to 115.9. There were five new sunspot groups this week: two each on June 9-10, and one more on June 13. Sunspot numbers for June 7-13 were 98, …
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers increased about 60 percent during the past week (May 31-June 6), when compared to the previous seven days (May 24-30). The increase was 48.5 points, from 81.9 to 130.4. The average daily solar flux was also up: 18.6 points from 111.6 to 130.2. Sunspot numbers for May 31-June 6 were 76, 151, 113, 133, 155, 154 and 131, with a mean of 130.4. The 10.7 cm flux was …
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers sank more than 28 points this week (nearly 26 percent) to 81.9, while the average daily solar flux declined more than 16 points to 111.6. This is for the seven days of May 24-30, and is compared to the previous seven days, May 17-23. Sunspot numbers for May 24-30 were 96, 86, 70, 83, 87, 73 and 78, with a mean of 81.9. The 10.7 cm flux was 115.5, 117.2, 110, 11…
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers declined seven points over the past week to 110.3, while the average daily solar flux dropped 3.3 points to 131. Sunspot numbers for May 17-23 were 114, 118, 110, 124, 120, 95 and 91, with a mean of 110.3. The 10.7 cm flux was 136.3, 132.2, 130.9, 130.8, 125.1, 121.3 and 117.2, with a mean of 127.7. The estimated planetary A indices were 6, 8, 5, 13, 7, 16 and …
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers for the past week rose nearly 25 points, or about 27 percent, to 117.3. The big day was Monday, May 14 when the daily sunspot number jumped to 156. This was the day after four new sunspot groups, numbered 1481 through 1484 arrived. Sunspot numbers for May 10-16 were 93, 102, 85, 138, 156, 125 and 122, with a mean of 117.3. The 10.7 cm flux was 130.7, 136.4, 129…
American Radio Relay League | Ham Radio Association and Resources
The average daily solar flux for the past week rose slightly, 116.2 to 119, but the average daily sunspot numbers declined more than 14 points (about 13 percent), to 92.6. Sunspot numbers for May 3-9 were 107, 101, 88, 104, 79, 90 and 79, with a mean of 92.6. The 10.7 cm flux was 114, 114, 116, 117.3, 121.7, 122.8 and 127.3, with a mean of 119. The estimated planetary A indices were 8, 4, 4, 5,…
American Radio Relay League | Ham Radio Association and Resources
The average daily sunspot numbers declined 38 points to 106.7 this week, while the average daily solar flux declined nearly 18 points to 116.2. Sunspot numbers for April 26-May 2 were 117, 99, 118, 114, 104, 99 and 96, with a mean of 106.7. The 10.7 cm flux was 119.2, 117.9, 121.1, 116, 114.1, 109.9 and 115.5, with a mean of 116.2. The estimated planetary A indices were 17, 8, 5, 5, 3, 4 and 5,…
American Radio Relay League | Ham Radio Association and Resources
Solar activity revived over the past week, with a big increase in sunspot numbers. On Friday, April 20, the daily sunspot number reached 162; four days later on April 24, the number reached 169. This level of activity has not been seen since last fall, when the daily sunspot number reached 173 on September 16, 184 on October 21 and 208 on November 9.
The average daily sunspot numbers more than d…
American Radio Relay League | Ham Radio Association and Resources
As promised in the April 19th edition of The ARRL Letter, this week’s bulletin features a report on recent solar activity and solar cycle progression from Carl Luetzelschwab, K9LA.
Both the solar flux and sunspot numbers reached a short term low on April 8-11, but they are now rising again. For the past week — April 12-18 — the average daily sunspot numbers more than doubled, compared to the p…
American Radio Relay League | Ham Radio Association and Resources
Eight new sunspot groups appeared this week, but the average daily sunspot number declined four points to 71.1; the average daily solar flux rose by less than two points to 103.7. Sunspot numbers for March 22-28 were 86, 74, 65, 84, 56, 63 and 70, with a mean of 71.1. The 10.7 cm flux was 102.4, 104.8, 102.7, 101.3, 102.4, 105.6 and 107, with a mean of 103.7. The estimated planetary A indices w…
American Radio Relay League | Ham Radio Association and Resources
Solar activity declined this week: The average daily sunspot numbers were off by more than 13 points to 75.1, while the average daily solar flux dropped over 32 points to 102.1. The solar flux dropped barely below 100, but rounded up to 100 as shown on the NOAA SEC site. The next short-term peak in solar flux is expected at the 135 level for April 3-6. The predicted solar flux for March 23-25 i…
American Radio Relay League | Ham Radio Association and Resources