The geomagnetic field was at unsettled to minor storm levels on February 15 under the influence of effects associated with CH1270. Solar wind speed at SOHO ranged between 504 and 704 km/sec, averaging 589 km/sec (+92 km/sec compared to the previous day). The high latitude magnetometer at Andenes recorded unsettled to major storm levels. The above 10 MeV proton flux was at background levels all day.
Solar flux density measured at 20h UT on 2.8 GHz was 184.0 - decreasing 51.6 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 192.96. In comparison SC24 peaked on June 28, 2014 at 145.50 while SC23 peaked on February 23, 2002 at 198.15. Current SC25 peak: 193.35 on August 7, 2024 (subtracting a baseline solar flux level of 65, this is +59.44% compared to the SC24 peak and -3.61% compared to the SC23 peak). The Potsdam WDC planetary A index was 24 (STAR Ap - based on the mean of three hour interval ap indices: 24.0). Three hour interval K indices: 45334334 (planetary), 44344333 (Boulder), 45334456 (Andenes).
The background x-ray flux is at the class C1 level (GOES 18).
At the time of counting spots (see image time), spots were observed in 21 active regions using 2K resolution (SN: 443) and in 20 active regions using 1K resolution (SN: 326) SDO/HMI images.
AR 13986 [N06W62] was quiet and stable.
AR 13989 [N18W12] was quiet and stable.
AR 13990 [S09E02] simplified and lost the magnetic delta
configuration. There's still some polarity
intermixing and further M class flaring is possible. C1 flares: C1.5 @
05:43, C1.8 @ 13:20, C1.8 @ 23:30 UT
AR 13991 [S12E21] developed slowly and quietly.
AR 13992 [S06W52] decayed slowly and was mostly quiet.
AR 13993 [N16E49] was mostly quiet and stable.
AR 13994 [S18W18] was mostly quiet and stable. C1 flares: C1.6 @
02:13 UT
AR 13995 [S22W46] decayed slowly and quietly.
New AR 13996 [S16E66] rotated into view on February 14 and was
numbered the next day by SWPC. The spot group produced several C flares. C1
flares: C1.9 @ 01:19, C1.4 @ 01:44, C1.4 @ 03:24, C1.5 @ 03:28, C1.2 @
03:58, C1.3 @ 04:19, C1.6 @ 12:21, C1.9 @ 13:33, C1.4 @ 18:29 UT
New AR 13997 [N02E43] emerged on February 13 and received its NOAA
number 2 days later as development persisted.
Spotted regions not observed (or interpreted
differently) by SWPC/USAF:
S10791 [S19E08] was quiet and stable.
S10795 [N18E13] was quiet and stable.
S10796 [N12E18] was mostly quiet and stable. C1 flares: C1.9 @ 01:04
UT
S10797 [N10W53] was quiet and stable.
S10799 [S03W33] was quiet and stable.
S10801 [S30W22] was quiet and stable.
New region S10802 [N12E27] was observed with
tiny spots in an old plage area.
New region S10803 [S14E80] rotated into view with a few spots. C1
flares: C1.5 @ 09:29 UT
New region S10804 [N06E65] emerged after noon with tiny spots.
New region S10805 [S08E48] was observed with tiny spots in an old
plage area.
C2+ flares
Magnitude | Peak time (UT) | Location | Source | Recorded by | Comment |
C2.3 | 00:31 | 13997 | GOES16 | ||
C3.1 | 00:39 | 13996 | GOES16 | ||
C2.8 | 07:23 | 13996 | GOES16 | ||
C2.4 | 13:58 | 13996 | GOES16 | ||
C2.2 | 14:06 | 13996 | GOES16 | ||
C3.6 | 19:36 | behind northwest limb | 13983 | GOES16 | |
C2.0 | 20:15 | 13997 | GOES16 | ||
C2.0 | 21:03 | 13992 | GOES16 | ||
C2.8 | 22:16 | 13997 | GOES16 | ||
C2.6 | 22:28 | S10803 | GOES16 | ||
C2.0 | 23:00 | 13992 | GOES16 | ||
C3.9 | 00:05 | S10803 | GOES16 | incorrectly assigned to AR 13996 by SWPC |
February 13-15: No obviously Earth directed CMEs.
[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 recurrent negative polarity southern hemisphere coronal hole (CH1270) was in an Earth facing position on February 9-14.
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 fair.
The geomagnetic field is expected to be at quiet to active levels on February 15-17 due to effects from CH1270.
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 |
STAR | SWPC | STAR | Current | Previous | ||||||
2K | 1K | ||||||||||
13986 | 2025.02.04 2025.02.05 |
1 | 1 | 1 | N06W62 | 0080 | HSX | HAX |
was AR S10772 area: 0180 |
||
13987 | 2025.02.05 2025.02.06 |
S07W61 |
was AR S10774 location: S09W51 |
||||||||
13989 | 2025.02.08 2025.02.09 |
1 | 8 | 2 | N18W14 | 0270 | HHX | CHO |
was AR S10780 location: N18W12 |
||
13990 | 2025.02.09 2025.02.10 |
18 | 69 | 38 | S09W00 | 0310 | CKI | DKI |
beta-gamma was AR S10783 area: 0390 location: S09E02 |
||
13992 | 2025.02.10 2025.02.12 |
7 | 21 | 9 | S05W54 | 0060 | EAO | EAO |
was AR S10785 location: S06W52 area: 0180 |
||
13991 | 2025.02.10 2025.02.11 |
2 | 25 | 9 | S13E17 | 0010 | AXX | CRI |
was AR S10787 area: 0050 location: S12E21 |
||
S10789 | 2025.02.10 | 3 | 1 | S05W04 | 0005 | AXX | |||||
13994 | 2025.02.11 2025.02.13 |
6 | 21 | 16 | S19W18 | 0030 | CRO | CAI |
was AR S10790 area: 0100 location: S18W18 |
||
S10791 | 2025.02.12 | 11 | 3 | S19E08 | 0020 | BXO | |||||
13993 | 2025.02.13 2025.02.13 |
2 | 7 | 4 | N16E47 | 0220 | HSX | CKO |
location: N16E63 area: 0340 location: N16E49 |
||
13995 | 2025.02.13 2025.02.14 |
2 | 5 | 4 | S22W44 | 0020 | CSO | CRO |
was AR S10792 location: S22W46 area: 0060 |
||
S10793 | 2025.02.13 | N10W04 | |||||||||
13997 | 2025.02.13 2025.02.15 |
5 | 23 | 13 | N03E42 | 0030 | CAO | DAI |
beta-gamma was AR S10794 location: N02E43 area: 0140 |
||
S10795 | 2025.02.13 | 8 | 4 | N18E13 | 0020 | BXO | |||||
S10796 | 2025.02.13 | 3 | 1 | N12E18 | 0005 | BXO | |||||
S10797 | 2025.02.14 | 2 | 1 | N10W53 | 0005 | BXO | |||||
13996 | 2025.02.14 2025.02.15 |
9 | 24 | 13 | S11E65 | 0090 | ESO | EAI |
beta-gamma was AR S10798 location: S16E66 area: 0360 |
||
S10799 | 2025.02.14 | 3 | 1 | S03W33 | 0006 | BXO | |||||
S10800 | 2025.02.14 | S14E40 | |||||||||
S10801 | 2025.02.14 | 2 | S30W22 | 0002 | AXX | ||||||
S10802 | 2025.02.15 | 7 | 1 | N12E27 | 0010 | BXO | |||||
S10803 | 2025.02.15 | 4 | 3 | S14E80 | 0020 | CRO | |||||
S10804 | 2025.02.15 | 3 | 1 | N06E65 | 0005 | BXO | |||||
S10805 | 2025.02.15 | 2 | 1 | S08E48 | 0004 | AXX | |||||
Total spot count: | 53 | 252 | 126 | ||||||||
Sunspot number: | 153 | 462 | 326 | (total spot count + 10 * number of spotted regions) | |||||||
Weighted SN: | 106 | 316 | 190 | (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): | 168 | 254 | 261 |
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 |
2023.06 | 161.7 | 166.8 | 160.5 | 125.3 (+1.1) | 8.95 |
2023.07 | 176.4 | 182.2 | 160.0 | 124.6 (-0.7) | 8.15 |
2023.08 | 153.7 | 157.6 | 114.8 | 124.3 (-0.3) | 7.19 |
2023.09 | 154.4 | 156.0 | 134.2 | 124.0 (-0.3) | 14.26 |
2023.10 | 142.8 | 141.9 | 99.4 | 124.8 (+0.8) | 8.16 |
2023.11 | 153.5 | 150.2 | 105.4 | 127.9 (+3.1) | 12.20 |
2023.12 | 151.1 | 146.4 | 114.2 | 129.5 (+1.6) | 9.60 |
2024.01 | 164.6 | 159.3 | 126.0 | 131.2 (+1.7) | 5.46 |
2024.02 | 172.5 | 168.3 | 123.0 | 136.9 (+5.7) | 5.31 |
2024.03 | 154.4 | 152.9 | 103.7 | 141.4 (+4.5) | 11.03 |
2024.04 | 161.3 | 162.6 | 137.0 | 144.5 (+3.1) | 9.69 |
2024.05 | 187.7 | 191.9 | 172.1 | 149.1 (+4.6) | 23.56 (SC25 peak) |
2024.06 | 184.3 | 190.2 | 164.1 | 152.7 (+3.6) | 10.24 |
2024.07 | 196.6 | 203.0 | 196.8 | 154.9 (+2.3) | 7.13 |
2024.08 | 246.1 (cycle peak) |
252.2 | 216.0 (SC25 peak) | (156.2 projected, +1.3) | 15.96 |
2024.09 | 195.7 | 197.8 | 141.1 | (158.3 projected, +2.1) | 15.36 |
2024.10 | 221.0 | 219.6 | 166.3 | (159.1 projected, +0.8) | 18.99 |
2024.11 | 199.6 | 195.3 | 152.5 | (156.5 projected, -2.6) | 9.33 |
2024.12 | 197.3 | 191.2 | 154.5 | (152.1 projected, -4.4) | 8.42 |
2025.01 | 190.3 | 184.2 | 137.0 | (145.8 projected, -6.3) | 13.17 |
2025.02 | 182.7 (1) | 75.9 (2A) / 141.6 (2B) / 171.6 (2C) | (137.2 projected, -8.6) | (14.6) | |
2025.03 | (130.8 projected, -6.4) | ||||
2025.04 | (126.2 projected, -4.6) | ||||
2025.05 | (120.9 projected, -5.3) | ||||
2025.06 | (115.6 projected, -5.3) | ||||
2025.07 | (110.9 projected, -4.7) |
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 27 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
Sunspot activity has been on a slowly decreasing trend since September 2024 (using the mean solar flux over 3 solar rotations as a proxy). The 365 days average ISN has a peak on July 8, 2024, but is still expected to peak in October 2024 due to low sunspot numbers in March and the first half of April 2024. Unless there is an uptick in sunspot activity over the next couple of months, the 365 days average solar flux is likely to peak 1-2% below the peak of solar cycle 23. While the 365d average solar flux peaks of SC23 and SC25 are similar, sunspot numbers will peak significantly lower for SC25 compared to SC23.
--------------------------------------------------------------------------------------
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.