AmateurRadio.com

Here is this week’s space weather and geophysical report, issued 2015 Jun 29 0647 UTC.

Highlights of Solar and Geomagnetic Activity 22 – 28 June 2015

Solar activity was at low to high levels. The period began at high levels when Region 2371 (N13, L=302, class/area Fkc/1180 on 21 June) produced an M6/2b flare at 22/1823 UTC with an associated Castelli-U spectral burst, Type II radio sweep (1480 km/s), 1000 sfu Tenflare, and a full halo coronal mass ejection (CME) with an approximate speed of 1047 km/s. Solar activity returned to high levels again on 25 June as Region 2371 produced a long-duration M7/3b flare at 25/0816 UTC with associated Type II (2056 km/s) and Type IV radio sweeps, 3800 sfu Tenflare, and an asymmetric full halo CME with an approximate speed of 1500 km/s. Region 2371 remained relatively quiet and stable after 25 June, only producing low-level C-class flaring for the rest of the period.

A greater than 10 MeV proton event was in progress at the beginning of the period. The event began at 21/2135 UTC, likely associated with an M2/1n flare at 21/0142 UTC from Region 2371, reached a maximum flux value of 1070 pfu at 22/1900 UTC and ended 24/0705 UTC. A brief enhancement to the S3 (Strong) levels was observed due to a shock enhancement from the arrival of the 21 June CME. Another greater than 10 MeV proton event began at 26/0350 UTC in association with an M7/3b flare at 25/0816 UTC from Region 2371, reached a maximum of 22 pfu (S1-Minor) at 27/0030 UTC and ended at 27/0755 UTC.

The greater than 2 MeV electron flux at geosynchronous orbit was high levels through the period with the exception of 23 June. A maximum flux of 26,376 pfu was observed at 24/1620 UTC.

Geomagnetic field activity ranged from quiet to severe storm conditions. At 22/0451 UTC, a small shock was observed at the NASA/ACE spacecraft. Total field increased from 8 nT to 17 nT with a corresponding solar wind increase from 360 km/s to 431 km/s. The shock was associated with the arrival of the 19 June CME caused by a filament eruption in the SE quadrant observed in SDO/AIA imagery beginning at 19/0500 UTC. A geomagnetic sudden impulse (SI) of 19 nT (Guam) was observed at 22/0545 UTC. The geomagnetic field responded with unsettled to active levels. At 22/1759 UTC, another shock was observed in ACE data from the 21 June CME associated with a double peak M2 flare from Region 2371 at 21/0142 UTC. Total field increased to a maximum of 41 nT at 22/1935 UTC, solar wind speed increased to 737 km/s and the Bz component went negative to -39 nT at 22/1850 UTC. A prolonged period of mostly southward Bz occurred between 23/0013 UTC and 23/1246 UTC reaching as high as -25 nT. An SI of 48 nT (Hartland) was observed at 21/1650 UTC. The geomagnetic field responded with minor to major storm levels with severe storm periods observed between 22/1800-2100 UTC and 23/0000-0600 UTC. At 24/1258 UTC, the 22 June CME associated with the M6/2b flare on 22 June was observed in ACE data. Solar wind speeds increased from approximately 550 km/s to around 760 km/s with a relatively weak increase in total field from 5 nT to 13 nT. The Bz component was mostly positive during this event with negative values reaching a maximum of -11 nT between 25/0547 UTC and 25/1357 UTC. The geomagnetic field responded with only quiet to active periods on 24 June, but increased to minor to major storm levels mid-period on 25 June. Another CME associated with the M7/3b flare on 25 June arrived at 27/0223 UTC at the ACE spacecraft. Solar wind speeds increased from near 475 km/s to 860 km/s before slowly decreasing to 480 km/s by the end of the day. Total field reached a maximum of 13 nT at 27/0304 UTC and the Bz component was variable between +9 nT and -7 nT. As a result, the geomagnetic field never increased beyond unsettled conditions.

Forecast of Solar and Geomagnetic Activity 29 June – 25 July 2015

Solar activity is expected to be at low levels with a chance for M-class flare (R1-R2, Minor-Moderate) activity from 30 June through 24 July with the return of old Regions 2365 (S13, L=079) on 30 June, 2367 (S20, L=002) on 05 July, and 2371 (N13, L=302) on 11 July.

There is a chance for a greater than 10 MeV proton event from 11 July through 24 July with the return of old Region 2371 to the visible disk.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at high levels from 29-30 Jun and again from 08-19 July due to residual CME effects and recurrent coronal hole high speed streams (CH HSS).

Geomagnetic field activity is expected to be at active to minor storm (G1-Minor) levels from 06-08 July and again from 11-12 July due to recurrent CH HSS activity.

Don’t forget to visit our live space weather and radio propagation web site, at: http://SunSpotWatch.com/

Live Aurora mapping is at http://aurora.sunspotwatch.com/

If you are on Twitter, please follow these two users: + https://Twitter.com/NW7US + https://Twitter.com/hfradiospacewx

Get the space weather and radio propagation self-study course, today. Visit http://nw7us.us/swc for the latest sale and for more information!

Check out the stunning view of our Sun in action, as seen during the last five years with the Solar Dynamics Observatory (SDO): https://www.youtube.com/watch?v=zXN-MdoGM9g

We’re on Facebook: http://NW7US.us/swhfr