|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 (May 1, 2022)|
|Solar cycle||Solar cycles 23-25 (May 1, 2022)||Historical solar and geomagnetic data charts 1954-2006 (April 5, 2007)|
|Cycle 24-25 progress (May 1, 2022)||Noon SDO sunspot count 1K image / 4K (*)|
|Solar cycles 1-24 (June 1, 2020)||POES auroral activity level October 2009 - December 2012]|
|Comparison of cycles 21-25 (May 1, 2022)||3rd SSN Workshop, Tucson, 2013|
|Comparison of cycles 12-14, 16, 24-25 (May 1, 2022)||4th SSN Workshop, Locarno, 2014|
|Solar polar fields vs. solar cycles (April 10, 2022)||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 quiet on May 25. The high latitude magnetometer at Andenes recorded quiet to unsettled levels.
Solar flux density measured at 20h UT on 2.8 GHz was 136.5 - increasing 4.3 over the previous solar rotation. (Centered 1 year average SF at 1 AU - 183 days ago: 99.30). The Potsdam WDC planetary A index was 5 (STAR Ap - based on the mean of three hour interval ap indices: 5.1). Three hour interval K indices: 22220111 (planetary), 22222322 (Boulder), 23211333 (Andenes).
The background x-ray flux is at the class C1 level (GOES 16).
At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 202) and in 11 active regions using 1K resolution (SN: 146) SDO/HMI images.
Region 13014 [N22W74] decayed slowly and was
mostly quiet. Only a small magnetic delta remains as the region is about to
rotate over the northwest limb. A major flare is still possible. C1 flares:
C1.2 02:20, C1.2 @ 04:26, C1.5 @ 05:20, C1.3 @ 07:41 UT
Region 13016 [S18W42] produced an M1.3 flare which also coincided with a filament eruption between this region and AR 13018. The region was mostly unchanged and has only tiny spots.
Region 13017 [N12W59] was mostly quiet and stable, however, activity increased early on May 26 and the region produced a C7.2 flare at 04:49 UT. The region has a small magnetic delta.
Region 13018 [S08W54] reemerged with a tiny spot.
Region 13019 [N12W08] decayed slowly and was mostly quiet. C1 flares: C1.5 @ 05:02 UT
Region 13020 [S21E19] decayed slowly and quietly.
Region 13021 [N13E29] decayed slowly and quietly.
Region 13022 [S08E43] decayed slowly and quietly.
New region 13023 [S14E65] rotated into view on May 24 and was numbered by SWPC the next day.
New region 13024 [S33E68] rotated into view on May 24 and received its NOAA number the following day.
Spotted regions not observed (or interpreted
differently) by SWPC:
S7587 [N32W10] reemerged with a tiny spot.
New region S7594 [S20E08] emerged before noon with tiny spots, then decayed slowly.
|Magnitude||Peak time (UT)||Location||Source||Recorded by||Comment|
|M1.3/1N||18:24||S19W41||13016||GOES16||CME, weak type IV and strong type II radio sweeps|
|C2.4||23:21||behind NW limb||GOES16|
May 23-25: No obviously Earth directed CMEs were observed in available LASCO imagery. Several CMEs were observed on May 25, mostly from backsided sources, the most impressive had its origin a few days behind the southeast limb. The CME associated with the eruption in AR 13016 appears not to have any significant Earth bound components.
[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 southern hemisphere coronal hole (CH1080) rotated across the central meridian on May 24-26.
Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle and high latitudes is fair. Propagation on long distance northeast-southwest paths is poor.
Quiet geomagnetic conditions are likely on most of May 26. A high speed stream from CH1080 could cause quiet to active conditions from late on May 26 until May 29.
|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
|Total spot count:||23||82||36|
|Sunspot number:||93||202||146||(total spot count + 10 * number of spotted regions)|
|Weighted SN:||53||112||66||(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):||102||111||117|
|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
|2021.11||86.2||84.4||34.8||(50.0 projected, +5.0)||9.83|
|2021.12||103.0||99.8||67.5||(55.8 projected, +5.8)||6.40|
|2022.01||103.8||100.5||54.0||(60.3 projected, +4.5)||8.92|
|2022.02||109.1||106.5||59.7||(65.2 projected, +4.9)||10.46|
|2022.03||117.0||115.8||78.5||(70.7 projected, +5.5)||10.20|
|2022.04||130.8||131.7||84.1||(75.9 projected, +5.2)||11.79|
|2022.05||140.6 (1)||82.4 (2A) / 102.2 (2B) / 115.3 (2C)||(82.3 projected, +6.4)||(6.3)|
|2022.06||(88.2 projected, +5.9)|
|2022.07||(95.4 projected, +7.2)|
|2022.08||(102.1 projected, +6.7)|
|2022.09||(107.1 projected, +5.0)|
|2022.10||(110.3 projected, +3.2)|
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.