Solar Terrestrial Activity Report

Activity chart

Last major update issued on March 11, 2014 at 04:45 UTC.

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

[POES auroral activity level since October 2009 - updated January 26, 2013]
[Solar polar fields vs solar cycles - updated February 23, 2014]
[Presentation 3rd SSN Workshop, Tucson, 2013 (pdf)]

Recent activity

The geomagnetic field was quiet on March 10. Solar wind speed at SOHO ranged between 277 and 329 km/s.

Solar flux at 20h UTC on 2.8 GHz was 151.5 (decreasing 20.7 over the last solar rotation). The 90 day 10.7 flux at 1 AU was 154.1. The Potsdam WDC planetary A index was 3 (STAR Ap - based on the mean of three hour interval ap indices: 3.4). Three hour interval K indices: 10121001 (planetary), 11132312 (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 8 active regions in 2K resolution (SN: 229) and 8 active regions in 1K resolution (SN: 170) SDO images on the visible solar disk.

Region 11991 [S25W82] was quiet and stable.
Region 11996 [N14W51] developed quickly in the leading and central sections. There is at least 1 magnetic delta structure centrally. Further M class flares are possible.
C5+ flare: M1.4 at 23:00 UTC. The region was the source of an M3.5 flare at 03:50 UTC on March 11.
Region 11998 [S09E03] was quiet and stable.
Region 12000 [S10W14] decayed slowly and quietly.
Region 12002 [S19E37] developed quickly and has 2 magnetic delta structures. Further M class flaring is likely.
C5+ flares: M1.1 at 00:26, M1.0 at 04:08, C6.1 at 10:43, C6.0 at 11:42 (attributed to AR 11996 by SWPC),  M1.7 at 15:28 UTC. Filament eruptions were noted starting at 17:29 UTC to the east of the region (and was associated with a CME) and at 22:42 UTC to the west of the region.
New region 12003 [N07W11] emerged on March 9 and was numbered by SWPC the next day.
New region 12004 [S08E64] rotated into view on March 9 and got its NOAA number the following day.

Spotted regions not numbered (or interpreted differently) by SWPC:
New region S3208 [N05E62] emerged with a penumbra spot.

Coronal mass ejections (CMEs)

March 8-10: 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 small southern hemisphere coronal hole (CH607) was in an Earth facing position on March 9.

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 fair. Propagation on long distance northeast-southwest paths is poor.

Forecast

The geomagnetic field is expected to be quiet on March 11. On March 12-13 there is a chance of a few unsettled intervals due to effects from CH607.

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: 0-20% probability, Yellow: 20-60% probability, Red: 60-100% 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
11991 2014.02.25
2014.02.26
  2 1 S26W89 0010   AXX

location: S25W82

11996 2014.03.01
2014.03.02
19 36 18 N14W51 0150 EAI EAC

beta-gamma-delta

area: 0400

S3176 2014.03.02       N09W34           plage
11999 2014.03.04
2014.03.05
      S16W43         plage
11998 2014.03.04
2014.03.05
5 35 19 S09W00 0060 CAO CAO location: S09E03

area: 0140

S3190 2014.03.04       S06W27           plage
S3191 2014.03.04       S24W43           plage
12000 2014.03.05
2014.03.06
  5 3 S11W14 0015   BXO  
S3194 2014.03.05       N16W25           plage
12001 2014.03.05
2014.03.06
8     N19W92 0040 DSO     rotated out of view
S3196 2014.03.07       N10W21         plage
S3197 2014.03.07       N09W34         plage
S3198 2014.03.07       S20W54           plage
S3199 2014.03.07       S27W21           plage
12002 2014.03.07
2014.03.08
19 45 32 S19E37 0150 DAC EKC beta-gamma-delta

area: 0610

S3202 2014.03.08       N25W33         plage
S3203 2014.03.08       N01W48           plage
S3204 2014.03.08       S01E17           plage
12004 2014.03.09
2014.03.10
4 7 2 S08E64 0030 CRO CRO  
12003 2014.03.09
2014.03.10
7 18 14 N06W12 0060 DSO DRI  
S3207 2014.03.09       N08W16         plage
S3208 2014.03.10   1 1 N05E62 0005   AXX    
Total spot count: 62 149 90  
Sunspot number: 122 229 170  (total spot count + 10 * number of spotted regions)
Weighted SN: 92 175 116  (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): 73 80 94 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
2012.11 121.3 118.3 61.8 59.7 (+1.1) 7.08
2012.12 108.6 105.0 40.8 59.6 (-0.1) 3.44
2013.01 127.1 123.1 62.9 58.7 (-0.9) 4.69
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 (72.8 projected, +3.8) 5.23
2013.10  132.1 131.2 85.6 (73.8 projected, +1.0) 7.71
2013.11  148.3 145.1 77.6 (72.7 projected, -1.1) 5.68
2013.12 147.7 143.1 90.3 (71.6 projected, -1.1) 4.68
2014.01 157.4 152.4 82.0 (71.6 projected, 0.0) 5.44
2014.02 170.3
(cycle peak)
166.3 102.8 (cycle peak) (70.9 projected, -0.7) 10.70
2014.03 153.0 (1)   51.4 (2A) / 159.2 (2B) / 120.5 (2C) (71.0 projected, +0.1) (3.9)

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.