|Charts (* = updated daily)||Data and archive|
|Solar wind (*)||Solar and geomagnetic data - last month (*)|
|Electron fluence (*)||Archived daily reports and monthly data since 2003.01 (February 4, 2023)|
|Solar cycle||Solar cycles 23-25 (February 1, 2023)||Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)|
|Cycle 24-25 progress (February 1, 2023)||Noon SDO sunspot count 1K image / 4K (*)|
|Solar cycles 1-24 (July 1, 2020)||POES auroral activity level [October 2009 - December 2012]|
|Comparison of cycles 21-25 (February 1, 2023)||3rd SSN Workshop, Tucson, 2013|
|Comparison of cycles 12-14, 16, 24-25 (February 1, 2023)||4th SSN Workshop, Locarno, 2014|
|Solar polar fields vs. solar cycles (January 21, 2023)||Cycle 25 spots (final update December 25, 2019)|
|Solar cycles 24-25 transition using 365d smoothing||Research: Solar Cycle 25 Started on November 17, 2019 with 365 Days Smoothing|
The geomagnetic field was at minor to severe storm levels on February 27 due to CME effects. Solar wind speed at SOHO ranged between 568 and 941 km/sec. The high latitude magnetometer at Andenes recorded minor to major storm levels. The February 25 CME was observed reaching DSCOVR at 10:20 UT.
Solar flux density measured at 20h UT on 2.8 GHz was 161.2 - increasing 24.2 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 135.00). The Potsdam WDC planetary A index was 90 (STAR Ap - based on the mean of three hour interval ap indices: 89.5). Three hour interval K indices: 56776766 (planetary), ******** (Boulder), 66655666 (Andenes).
The background x-ray flux was at the class C1 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 15 active regions using 2K resolution (SN: 288) and in 11 active regions using 1K resolution (SN: 188) SDO/HMI images.
Region 13229 [N26W76] decayed quickly and
was mostly quiet. C1 flares: C1.6 @ 20:43 UT
Region 13230 [S22W45] decayed slowly and quietly.
Region 13234 [N23W24] developed slowly and has multiple magnetic delta structures. A major flare is possible. C1 flares: C1.3 @ 00:33, C1.3 @ 02:45, C1.3 @ 06:47, C1.4 @ 13:12 UT UT
Region 13235 [N19W43] decayed slowly and quietly.
Region 13236 [S27W31] decayed further and was quiet.
Region 13237 [S13W14] decayed slowly and quietly.
New region 13238 [N09E64] rotated into view on February 26 and was numbered by SWPC the next day.
Spotted regions not observed (or interpreted
differently) by SWPC:
S8295 [S22W79] decayed slowly and quietly.
S8308 [S22W06] reemerged with tiny spots.
S8310 [S27E22] reemerged with tiny spots.
S8311 [S24E40] was quiet and stable.
S8315 [S08W12] developed slowly and quietly.
New region S8316 [N18E08] emerged as a bipolar group before noon, then decayed slowly.
New region S8317 [N33E85] rotated partly into view and could be capable of major flaring.
New region S8318 [S29E36] was observed with tiny spots in an old plage area.
AR S8319 behind the northeast limb produced a C1.6 flare at 22:01 UT.
|Magnitude||Peak time (UT)||Location||Source||Recorded by||Comment|
February 25: A fast asymmetric full halo CME was observed after the
M6 flare in AR 13229. The CME reached Earth near 11h UT on February 27
February 26-27: No obviously Earth directed CMEs were observed.
[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 trans equatorial
coronal hole (CH1132) was Earth facing on February 24-25. Due to the strong
solar storms overtaking the associated high speed stream, it will not be
possible to observe any disturbance during this solar rotation.
A recurrent northern hemisphere coronal hole (CH1133) will likely rotate across the central meridian on February 28 - March 2.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is very poor. Propagation on long distance northeast-southwest paths is poor.
Unsettled to major storm conditions are likely on February 28 due to CME effects. March 1-2 could see quiet to unsettled conditions. Effects from CH1133 could cause unsettled to minor storm conditions on March 3-4.
|Coronal holes (1)||Coronal mass ejection (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
|Spot count||Location at midnight||Area||Classification||SDO / HMI 4K continuum
image with magnetic polarity overlays
*SWPC reported the spot count as 53 due to a typo
real location: S13W17
SWPC observers were confused by the spots of AR S8315 and changed the location to that group
|Total spot count:||72||138||78|
|Sunspot number:||142||288||188||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||100||172||112||(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):||156||158||150|
|Month||Average solar flux||International sunspot number
|Smoothed sunspot number (4)||Average ap
|166.3||146.1 (SC24 peak)||110.5||10.70|
|2014.04||143.9||144.8||112.5||116.4 (solar max)||7.88|
(Solar minimum using 365d smoothing:
November 17, 2019)
(ISN 13 months smoothed
|2022.08||114.2||117.1||74.6||(92.4 projected, +5.9)||10.92|
|2022.09||135.1||136.5||96.0||(97.4 projected, +5.0)||12.18|
|2022.10||133.5||132.7||95.4||(100.5 projected, +3.1)||11.16|
|2022.11||123.4||120.7||77.6||(103.4 projected, +2.9)||9.33|
|2022.12||147.9||143.4||113.1||(108.2 projected, +4.8)||10.99|
|2023.01||182.4||176.6||143.6||(114.2 projected, +6.0)||8.73|
|2023.02||167.5 (1)||121.8 (2A) / 126.3 (2B) / 150.6 (2C)||(119.2 projected, +5.0)||(14.2)|
|2023.03||(122.3 projected, +3.1)|
|2023.04||(127.7 projected, +5.4)|
|2023.05||(133.5 projected, +5.8)|
|2023.06||(136.8 projected, +3.3)|
|2023.07||(136.3 projected, -0.5)|
|2023.11||(142.5 projected max SC25)|
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: SIDC-SILSO.
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.