The geomagnetic field was at quiet levels on June 2. The high latitude magnetometer at Andenes recorded quiet to minor storm levels. The above 10 MeV proton flux was at background levels at the end of the day.
Solar flux density measured at 20h UT on 2.8 GHz was 179.8 - increasing 8.6 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 161.42. In comparison SC24 peaked on June 28, 2014 at 145.50. Current SC25 peak: 161.42 on December 3, 2023). The Potsdam WDC planetary A index was 4 (STAR Ap - based on the mean of three hour interval ap indices: 3.8). Three hour interval K indices: 01011112 (planetary), 10012122 (Boulder), 01021205 (Andenes).
The background x-ray flux is at the class C2 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 18 active regions using 2K resolution (SN: 417) and in 15 active regions using 1K resolution (SN: 281) SDO/HMI images.
Region 13691 [N26W45]
decayed further losing many spots and most of the penumbral area.
Region 13693 [N06W61] decayed slowly and quietly.
Region 13695 [N27W29] decayed slightly and was
quiet.
Region 13696 [N09W24] decayed slowly and quietly.
Region 13697 [S18E08] gained area early in the
day, then decayed after noon, especially in the southeastern spot section. The leading penumbra which had a strong
magnetic delta configuration decayed and fragmented. There is still a delta,
but it has weakened. Another major
flare is possible.
Region 13698 [N22W04] was mostly quiet and stable.
Region 13699 [N04W33] decayed slowly and quietly.
Region 13700 [S04W50] produced several C flares, a minor M class
flare is possible.
Region 13701 [S05E17] was mostly quiet and stable.
New region 13702 [N17E70] rotated into view on June 1 and was
numbered by SWPC the next day.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S9750 [N22W30] developed slowly and quietly.
S9758 [S07E32] developed slowly and quietly.
S9762 [S14E46] was quiet and stable.
New region S9763 [N03W53] emerged with tiny spots.
New region S9764 [N18W32] emerged with a few spots.
New region S9765 [S17E77] rotated into view with a tiny spot.
New region S9766 [S21W10] was observed with tiny spots in an old
plage area.
New region S9767 [S40E36] emerged with a tiny spot.
C2+ flares
| Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
| C4.3 | 00:06 | 13697 | GOES16 | ||
| C4.5 | 00:25 | 13698 | GOES16 | ||
| C4.9 | 00:39 | 13700 | GOES16 | ||
| C4.6 | 01:50 | 13697 | GOES16 | ||
| C4.4 | 01:56 | 13697 | GOES16 | ||
| C4.9 | 02:22 | 13697 | GOES16 | ||
| C3.3 | 02:36 | 13697 | GOES16 | ||
| C3.2 | 02:46 | 13697 | GOES16 | ||
| C4.7 | 03:28 | 13700 | GOES16 | ||
| C4.9 | 03:32 | 13697 | GOES16 | incorrectly attributed to AR 13700 by SWPC | |
| C3.8 | 04:06 | 13700 | GOES16 | ||
| C4.4 | 04:32 | 13697 | GOES16 | ||
| M1.2 | 04:50 | 13697 | GOES16 | ||
| C7.5 | 05:11 | 13697 | GOES16 | ||
| C7.7 | 05:22 | 13700 | GOES16 | ||
| C2.4 | 06:03 | 13700 | GOES16 | ||
| C3.5 | 06:28 | 13697 | GOES16 | ||
| C4.0 | 06:33 | 13697 | GOES16 | ||
| C3.5 | 06:39 | 13697 | GOES16 | ||
| C3.2 | 07:11 | 13700 | GOES16 | ||
| C2.7 | 08:05 | 13697 | GOES16 | incorrectly attributed to AR 13700 by SWPC | |
| C3.7 | 08:27 | 13697 | GOES16 | ||
| M2.0 | 08:50 | S19E14 | 13697 | GOES16 | |
| C9.2 | 09:02 | 13700 | GOES16 | ||
| C5.8 | 09:23 | 13697 | GOES16 | ||
| C6.0 | 09:33 | 13697 | GOES16 | ||
| C4.6 | 09:47 | 13697 | GOES16 | ||
| C3.5 | 10:13 | 13697 | GOES16 | ||
| C4.6 | 10:28 | 13697 | GOES16 | ||
| C4.5 | 10:39 | 13697 | GOES16 | ||
| C5.8 | 10:59 | 13697 | GOES16 | ||
| C3.6 | 12:19 | 13700 | GOES16 | simultaneous flare in AR 13697 | |
| C3.7 | 12:38 | 13697 | GOES16 | ||
| C2.6 | 13:00 | 13697 | GOES16 | ||
| C2.6 | 14:02 | 13700 | GOES16 | ||
| C2.3 | 14:35 | 13697 | GOES16 | ||
| C2.8 | 15:30 | 13700 | GOES16 | ||
| C2.4 | 15:39 | 13697 | GOES16 | ||
| C3.0 | 16:36 | 13697 | GOES16 | ||
| C4.8 | 17:04 | S16E06 | 13697 | GOES16 | |
| C5.6 | 17:55 | S18E10 | 13697 | GOES16 | |
| C2.4 | 19:55 | S18E09 | 13697 | GOES16 | |
| C2.4 | 22:01 | 13697 | GOES16 | ||
| C2.2 | 22:22 | 13697 | GOES16 | ||
| C3.2 | 22:32 | S04W46 | 13700 | GOES16 | simultaneous flare in AR 13697 |
| C2.4 | 22:45 | 13697 | GOES16 | ||
| C2.2 | 23:13 | 13697 | GOES16 | ||
| C2.2 | 23:53 | 13697 | GOES16 |
May 31 + June 2: No obviously Earth directed CME observed.
June 1: An asymmetrical full halo CME was observed during the M7 long
duration event in AR 13697 peaking at 19:39 UT, that event began shortly
after 18:45 UT according to SDO/AIA imagery. There is some uncertainty as to
whether the M7 flare is the source of the CME. If it is the CME could reach Earth on June 4.
[Coronal hole history (since October 2002)]
[Compare today's report to the situation one solar rotation ago:
28 days ago
27 days ago
26 days ago]
A positive polarity northern hemisphere coronal hole (CH1224) could rotate across the central meridian on June 4-5.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is poor. Propagation on long distance northeast-southwest paths is poor to fair.
The geomagnetic field is expected to be at quiet to unsettled levels on June 3 and initially on June 4. The June 1 CME could reach Earth on June 4 and cause unsettled to major storm conditions.
| Coronal holes (1) | Coronal mass ejections (2) | M and X class flares (3) |
1) Effects from a coronal hole
could reach Earth within the next 5 days. When the high speed
stream has arrived the color changes to green.
2) Effects from a CME are likely to be observed at Earth within 96 hours.
3) There is a possibility of either M or X class flares within the next 48 hours.
Green: 0-30% probability, Yellow: 30-70% probability, Red: 70-100% probability.
(Click on image for 2K resolution).
4K resolution.
Compare to the previous
day's image. 0.5K image
When available the active region map has a coronal hole polarity overlay where red (pink) is negative and blue is positive.
Data for all officially numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC, all other regions are numbered sequentially as they emerge using the STAR spot number. Comments are my own, as is the STAR spot count (spots observed at or inside a few hours before midnight) and data for regions not numbered by SWPC or where SWPC has observed no spots. SWPC active region numbers in the table below and in the active region map above are the historic SWPC/USAF numbers. SWPC data considered to be not sufficiently precise (location, area, classification) are colored red.
| Active region | SWPC date numbered STAR detected |
Spot count | Location at midnight | Area | Classification | SDO / HMI 4K continuum image with magnetic polarity overlays |
Comment | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| SWPC/ USAF |
Magnetic (SDO) |
SWPC | STAR | Current | Previous | ||||||
| 2K | 1K | ||||||||||
| 13690 | 2024.05.23 2024.05.23 |
1 | N17W60 | 0010 | AXX |
 |
location: N16W58 spotless |
||||
| 13691 | 2024.05.24 2024.05.25 |
18 | 23 | 12 | N25W46 | 0180 | DSO | DAO |
 |
 |
location: N26W45 area: 0080 |
| 13693 | 2024.05.25 2024.05.26 |
1 | N04W62 | 0001 | AXX |
 |
 |
location: N06W61 | |||
| 13696 | 2024.05.25 2024.05.26 |
3 | N08W28 | 0006 | AXX |
 |
 |
location: N09W24 |
|||
| 13694 | 2024.05.26 | S12W54 | location: S15W43 | ||||||||
| 13695 | 2024.05.26 2024.05.26 |
11 | 19 | 8 | N27W33 | 0030 | CAO | DRI |
 |
 |
beta-gamma location: N27W29 area: 0050 |
| 13697 | 2024.05.27 2024.05.28 |
33 | 82 | 45 | S18E07 | 0410 | EKC | EKC |
 |
 |
beta-gamma-delta location: S18E08 area: 0670 |
| S9748 | 2024.05.27 | S22W43 | |||||||||
| S9750 | 2024.05.28 | 9 | 4 | N22W30 | 0020 | DRO |
 |
 |
|||
| 13698 | 2024.05.28 2024.05.30 |
11 | 30 | 14 | N22W04 | 0160 | DSI | EAI |
 |
 |
beta-gamma area: 0300 |
| S9753 | 2024.05.28 | S30W53 | |||||||||
| S9755 | 2024.05.30 | N21W41 |
 |
||||||||
| 13699 | 2024.05.31 2024.05.31 |
8 | 11 | 9 | N04W36 | 0070 | CSO | DAO |
 |
 |
area: 0120 location: N04W33 |
| 13701 | 2024.05.31 2024.06.01 |
5 | 21 | 15 | S04E15 | 0040 | CAO | DRI |
 |
 |
beta-gamma location: S05E17 |
| S9758 | 2024.05.31 | 6 | 5 | S07E32 | 0060 | DRO |
 |
 |
|||
| 13700 | 2024.06.01 2024.06.01 |
8 | 16 | 9 | S04W52 | 0180 | DAI | DAO |
 |
 |
area: 0420 location: S04W50 |
| S9760 | 2024.06.01 | N11E38 |
 |
||||||||
| 13702 | 2024.06.01 2024.06.02 |
1 | 1 | 1 | N17E71 | 0050 | HSX | HSX |
 |
 |
location: N17E70 area: 0130 |
| S9762 | 2024.06.01 | 2 | 2 | S14E46 | 0007 | BXO |
 |
 |
|||
| S9763 | 2024.06.02 | 3 | 1 | N03W52 | 0005 | BXO |
 |
||||
| S9764 | 2024.06.02 | 4 | 4 | N18W32 | 0015 | CRO |
 |
||||
| S9765 | 2024.06.02 | 1 | 1 | S17E77 | 0007 | AXX |
 |
||||
| S9766 | 2024.06.02 | 4 | 1 | S21W10 | 0010 | AXX |
 |
||||
| S9767 | 2024.06.02 | 1 | S40E36 | 0001 | AXX |
 |
|||||
| Total spot count: | 96 | 237 | 131 | ||||||||
| Sunspot number: | 186 | 417 | 281 | (total spot count + 10 * number of spotted regions) | |||||||
| Weighted SN: | 141 | 287 | 181 | (Sum of total spot count + classification weighting for each AR. Classification weighting: X=0, R=3, A/S=5, H/K=10) | |||||||
| Relative sunspot number (Wolf number): | 205 | 229 | 225 | ||||||||
| Month | Average solar flux | International sunspot number (WDC-SILSO) |
Smoothed sunspot number (4) | Average ap (3) |
|
|---|---|---|---|---|---|
| Measured | 1 AU | ||||
| 2014.02 | 170.3 (cycle peak) |
166.3 | 146.1 (SC24 peak) | 110.5 | 10.70 |
| 2014.04 | 143.9 | 144.8 | 112.5 | 116.4 (SC24 solar max) | 7.88 |
| 2017.09 | 91.3 | 92.3 | 43.6 | 18.2 (-1.3) | 18.22 (SC24 peak) |
| 2019.11 | 70.2 | 68.7 | 0.5 | 2.0 (-0.6) (Solar minimum using 365d smoothing: November 17, 2019) |
4.19 |
| 2019.12 | 70.8 | 68.6 | 1.6 | 1.8 (-0.2) (ISN 13 months smoothed solar minimum) |
3.22 |
| 2022.10 | 133.5 | 132.7 | 95.5 | 98.9 (+2.4) | 11.16 |
| 2022.11 | 123.4 | 120.7 | 80.5 | 101.2 (+2.3) | 9.33 |
| 2022.12 | 147.9 | 143.4 | 112.8 | 106.7 (+5.5) | 10.99 |
| 2023.01 | 182.4 | 176.6 | 144.4 | 113.3 (+6.6) | 8.73 |
| 2023.02 | 167.2 | 163.2 | 111.3 | 117.8 (+3.5) | 14.48 |
| 2023.03 | 157.2 | 155.6 | 123.3 | 121.1 (+3.3) | 14.42 |
| 2023.04 | 145.4 | 146.4 | 97.6 | 122.9 (+1.8) | 13.40 |
| 2023.05 | 155.6 | 159.2 | 137.4 | 124.2 (+1.3) | 10.67 |
| 2023.06 | 161.7 | 166.8 | 160.5 | 125.3 (+1.1) | 8.95 |
| 2023.07 | 176.4 | 182.2 | 160.0 | 124.4 (-0.9) | 8.15 |
| 2023.08 | 153.7 | 157.6 | 114.8 | 124.1 (-0.3) | 7.19 |
| 2023.09 | 154.4 | 156.0 | 134.2 | 123.9 (-0.2) | 14.26 |
| 2023.10 | 142.8 | 141.9 | 99.4 | 124.8 (+0.9) | 8.16 |
| 2023.11 | 153.5 | 150.2 | 105.4 | 127.8 (+3.0) | 12.20 |
| 2023.12 | 151.1 | 146.4 | 114.2 | (128.7 projected, +0.9) | 9.60 |
| 2024.01 | 164.6 | 159.3 | 123.0 | (127.0 projected, -1.7) | 5.46 |
| 2024.02 | 172.5 | 168.3 | 124.7 | (126.2 projected, -0.8) | 5.31 |
| 2024.03 | 154.4 | 152.9 | 104.9 | (125.6 projected, -0.6) | 11.03 |
| 2024.04 | 161.3 | 162.6 | 136.5 | (125.6 projected, -0.0) | 9.69 |
| 2024.05 | 187.8 | 191.9 | 171.7 (SC25 peak) | (126.7 projected, +1.1) | 23.6 (current SC25 peak) |
| 2024.06 | 183.9 (1) | 12.7 (2A) / 190.0 (2B) / 184.1 (2C) | (125.9 projected, -0.8) | (3.9) | |
| 2024.07 | (124.2 projected, -1.7) | ||||
| 2024.08 | (122.2 projected, -2.0) | ||||
| 2024.09 | (121.0 projected, -1.2) | ||||
| 2024.10 | (119.6 projected, -1.4) | ||||
| 2024.11 | (114.5 projected, -5.1) | ||||
| 2024.12 | (109.1 projected, -5.4) | ||||
1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz
and any corrections applied to that measurement.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days).
2B) Boulder SN current month average to date.
2C) STAR SDO 1K Wolf number 30 day average.
3) Running average based on the quicklook and definitive Potsdam WDC ap indices. Values in red
are based on the definitive international
GFZ Potsdam WDC ap indices.
4) Source: WDC-SILSO, Royal Observatory
Of Belgium, Brussels
The big increase in sunspot counts during the April 14-27 interval caused a major uptick in the smoothed SNs and solar flux. It's not yet clear when the next peak will be, anytime between October 28 and December 20, 2023 looks possible. The 365d smoothed solar flux exceeded the June 27 peak on October 28, while the 365d smoothed ISN and NOAA SN both exceeded the June 2023 peak in late October 2023. It should be noted that the current peak using 13-month smoothing is still in June 2023.
--------------------------------------------------------------------------------------
This report has been prepared by Jan Alvestad. It is based on the analysis of data from whatever sources are available at the time the report is prepared. All time references are to Universal Time. Comments and suggestions are always welcome.
SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.
