Solar Terrestrial Activity Report

Activity chart

Last major update issued on July 4, 2014 at 05:00 UTC.

[Solar and geomagnetic data - last month (updated daily)]
[Solar wind and electron fluence charts (updated daily)]
[Solar cycles 23-24 (last update July 1, 2014)] [Cycle 24 progress (last update July 1, 2014) ]
[Solar cycles 1-20]
[Graphical comparison of cycles 21, 22, 23 and 24 (last update July 1, 2014)]
[Graphical comparison of cycles 10, 12, 13, 14, 16 and 24 (last update July 1, 2014)]
[Historical solar and geomagnetic data charts 1954-2006 (last update April 5, 2007)]
[Archived reports since January 2003 (last update May 1, 2014)]

[POES auroral activity level October 2009 - December 2012]
[Solar polar fields vs solar cycles - updated June 4, 2014]
[Presentations: 3rd SSN Workshop, Tucson, 2013 (pdf) / 4th SSN Workshop, Locarno, 2014]

Recent activity

The geomagnetic field was quiet on July 3. Solar wind speed at SOHO ranged between 294 and 349 km/s.

Solar flux at 20h UTC on 2.8 GHz was 178.1 (increasing 45.1 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 134.8. The Potsdam WDC planetary A index was 6 (STAR Ap - based on the mean of three hour interval ap indices: 6.1). Three hour interval K indices: 22221111 (planetary), 33331221 (Boulder).

The background x-ray flux is at the class C1 level.

At the time of counting spots (see image time), spots were observed in 12 active regions using 2K resolution (SN: 352) and 12 active regions using 1K resolution (SN: 233) SDO images on the visible solar disk.

Region 12100 [N11W26] decayed slowly and quietly.
Region 12102 [N12E03] gained small spots and was mostly quiet.
Region 12104 [S11E12] decayed slowly. There is a magnetic delta structure in the western part of the southernmost penumbra. A major flare remains a possibility.
Region 12105 [S09W29] decayed slowly and quietly.
Region 12106 [N16E21] decayed slowly and quietly.
Region 12107 [S19E24] decayed slowly and was mostly quiet.
Region 12108 [S08E42] developed slowly and quietly.
Region 12109 [S08E62] developed in the trailing spot section and has major flare potential.
New region 12110 [S16E48] emerged on July 2 and was numbered the next day by SWPC as the region developed slowly.

Spotted regions not numbered (or interpreted differently) by SWPC:
S3599 [N04E04] was quiet and stable.
S3607 [N10W06] was quiet and stable.
New region S3610 [N06E79] rotated into view with a few spots.

C2+ Flares (GOES):

Magnitude Peak time (UTC) Location AR
C2.6 (LDE) 03:59 SE limb  

Coronal mass ejections (CMEs)

July 1-3: No obviously Earth directed CMEs were observed in LASCO and STEREO imagery.

Coronal holes

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 trans equatorial coronal hole (CH626) could rotate into an Earth facing position on July 5.

Coronal hole map

Propagation

Long distance low and medium frequency (below 2 MHz) propagation along paths north of due west over upper middle latitudes is poor. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on July 4-7. On July 8-9 there is a chance of unsettled intervals due to possible effects from CH626.

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.

Active solar regions

(Click on image for 2K 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 numbered solar regions according to the Solar Region Summary provided by NOAA/SWPC. 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.

Active region Date numbered
detected
Spot count Location at midnight Area Classification SDO / HMI 4K continuum
image with magnetic polarity overlay
Comment
SWPC Magnetic
(SDO)
SWPC STAR Current Previous
2K 1K
12096 2014.06.21
2014.06.22
      N10W80          

plage

12097 2014.06.22       N14W72         plage
12100 2014.06.25
2014.06.27
14 16 10 N11W27 0030 DAO DRI

area: 0050

S3579 2014.06.26       S10W43           plage
12099 2014.06.26
2014.06.27
      S16W89           plage
12103 2014.06.26
2014.06.28
      S10W18         plage
S3583 2014.06.27       N00W07           plage
12102 2014.06.27
2014.06.28
19 53 21 N13E04 0060 DAI CAI

area: 0150

12104 2014.06.28 23 40 25 S11E12 0400 DKC DKC beta-gamma-delta

area: 0700

S3587 2014.06.28       S23W45           plage
12107 2014.06.28
2014.06.29
7 18 10 S20E22 0310 DKO DHO area: 0410

location: S19E24

S3590 2014.06.28       S23E10           plage
S3591 2014.06.28       S12W08           plage
S3592 2014.06.28       S11W44           plage
12105 2014.06.28
2014.06.29
  1 1 S05W27 0004   AXX location: S08W29
12106 2014.06.29 12 30 12 N15E22 0120 DSO DSI area: 0220
S3597 2014.06.30       S26W44           plage
12108 2014.06.30
2014.07.01
7 28 13 S09E40 0090 DAO DAI area: 0180

location: S08E42

S3599 2014.06.30   2 1 N04E04 0005   AXX  
S3600 2014.06.30       S31W45           plage
S3602 2014.07.01       S19W43           plage
S3603 2014.07.01       N06W22           plage
S3604 2014.07.01       S10W49           plage
S3605 2014.07.01       N05W44           plage
12109 2014.07.01
2014.07.02
15 29 13 S08E61 0410 DKC EKC beta-gamma

area: 0750

S3607 2014.07.01   2 2 N10W06 0007   AXX  
12110 2014.07.02
2014.07.03
2 8 4 S16E48 0010 BXO DRO area: 0030
S3609 2014.07.02       S13E27         plage
S3610 2014.07.03   5 1 N06E79 0060   CAO    
Total spot count: 99 232 113  
Sunspot number: 179 352 233  (total spot count + 10 * number of spotted regions)
Weighted SN: 149 288 169  (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): 107 123 128 k * (sunspot number). k = 0.6 for SWPC, k = 0.35 for MSN 2K, k = 0.55 for MSN 1K (MSN=Magnetic Sunspot Number)

Monthly solar cycle data

Month Average solar flux International sunspot number
(WDC-SILSO)
Smoothed sunspot number Average ap
(3)
Measured 1 AU
2013.02 104.3 101.8 38.0 58.4 (-0.3) 6.11
2013.03 111.3 110.2 57.9 57.5 (-0.9) 10.56
2013.04 124.8 125.9 72.4 57.9 (+0.4) 5.40
2013.05 131.4 134.3 78.7 59.9 (+2.0) 9.73
2013.06 110.1 113.7 52.5 62.6 (+2.7) 12.60
2013.07 115.5 119.3 57.0 65.5 (+2.9) 9.47
2013.08 114.6 118.3 66.0 69.0 (+3.5) 8.27
2013.09 102.6 103.7 36.9 73.1 (+4.1) 5.23
2013.10  132.1 131.2 85.6 75.0 (+1.9) 7.71
2013.11  148.3 145.1 77.6 75.4 (+0.4) 5.68
2013.12 147.7 143.1 90.3 76.0 (+0.6) 4.68
2014.01 157.4 152.4 81.8 (76.9 projected, +0.9) 5.44
2014.02 170.3
(cycle peak)
166.3 102.3 (cycle peak) (76.7 projected, -0.2) 10.70
2014.03 149.9 148.5 91.9 (77.1 projected, +0.4) 4.88
2014.04 143.9 144.8 84.7 (76.2 projected, -0.9) 7.88
2014.05 129.7 132.9 75.2 (73.7 projected, -2.5) 5.75
2014.06 122.0 125.8 71.0 (71.0 projected, -2.7) 6.7
2014.07 166.4 (1)   16.5 (2A) / 170.3 (2B) / 87.6 (2C) (68.3 projected, -2.7) (4.0)

1) Running average based on the daily 20:00 UTC observed solar flux value at 2800 MHz.
2A) Current impact on the monthly sunspot number based on the Boulder (NOAA/SWPC) sunspot number (accumulated daily sunspots / month days). The official WDC-SILSO international sunspot number is typically 30-50% lower. 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.

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 the UTC day. Comments and suggestions are always welcome.

SDO images are courtesy of NASA/SDO and the AIA, EVE, and HMI science teams.