Tag Archives: coronal hole

The Sun Online and solar activity. September 10, 2014

There are currently 9 sunspot groups visible. Only 2 low-level C-class flares were observed over the last 24 hours, both having NOAA 2157 as their source. This active region still has a delta in its main trailing spot. NOAA 2158 seems to have lost its delta structure, and has not produced any flares. The other sunspot groups are quiet. Two active regions are approaching the east limb. The greater than 10 MeV proton flux is still slightly enhanced and is currently at 1 pfu. It continues its slow decline.
C-class flares are expected, with a chance on another M-class event. Solar wind speed was mostly between 350 and 400 km/s, with Bz varying between +6 and -5 nT. Geomagnetic conditions were quiet to unsettled. Quiet to unsettled geomagnetic conditions are expected on 10 and most of 11September, possibly modulated by the high speed stream from a coronal hole that passed the central meridian on 5 September, and a glancing blow from the 6 September CME. Locally, an isolated active period is possible. Late on 11 and on 12 September, the impact of the halo CME related to the M4.5 flare from 9 September may result in active conditions and possibly a brief period of minor geomagnetic storming.
SIDC

Equipment: Coronado 90 + Imaging Source DMK + LX75
Processing: Photoshop, Avistack 300 frames
Date: 10/08/14
Time UT: 16:00
Exposure 1/500 sec.

Observatory Sponli

The Sun Online and solar activity. September 9, 2014

There are currently 8 sunspot groups visible. NOAA 2157 seems to be slightly declining and simplifying. NOAA 2158 developed some small spots to the west and south of the main spot. Except for the northern part, this main spot is now completely surrounded by opposite magnetic polarity flux. Both NOAA 2157 and 2158 retained their delta structures. Two C-class flares and 1 M-class flare were recorded. The strongest event was a long duration M4.5 flare peaking at 00:29UT and originating in NOAA 2158. SDO/AIA-imagery indicated post-flare coronal loops, coronal dimming and an EIT-wave. A type II radio-burst with an associated shock speed of 999 km/s was observed. The greater than 10 MeV proton flux, currently still enhanced at 2 pfu, has not increased in response to this flare (so far). The M4.5 flare was associated to a halo CME first observed by SOHO/LASCO on 9 September at 00:06UT, with a plane-of-the-sky speed around 560 km/s . The bulk of the CME is directed away from the Earth (to the northeast), but there’s still a good chance Earth will be impacted by the CME-driven shock. Estimated impact time is 12 September at 03:00UT, with an uncertainty of 12 hours.
There remains a reasonable chance on an M-class flare. The warning condition for a proton event remains in effect.
Solar wind speed was mostly between 350 and 450 km/s, with Bz oscillating between +5 and -5 nT. Geomagnetic conditions were quiet.
Quiet to unsettled geomagnetic conditions are expected for the next three days, possibly modulated by the high speed stream from a coronal hole that passed the central meridian on 5 September. On 10 September, there’s a chance on unsettled conditions with an isolated active period in response to the possible glancing blow from the 6 September CME. On 12 September, the impact of the halo CME related to the M4.5 flare from 9 September may result in active conditions and possibly a brief period of minor
geomagnetic storming.
SIDC

Equipment: Coronado 90 + Imaging Source DMK + LX75
Processing: Photoshop, Avistack 300 frames
Date: 09/08/14
Time UT: 16:00
Exposure 1/500 sec.

Observatory Sponli

The Sun Online and solar activity. September 8, 2014

There are currently 8 sunspot groups visible, with both NOAA 2157 and 2158 dominating the outlook of the solar disk. Five C-class flares were recorded, with the strongest a C7.8 flare peaking at 19:43UT. All C-class flares originated from active region NOAA 2157. No earth-directed CMEs were observed. The greater than 10 MeV proton flux is still enhanced, and currently at a steady 4 pfu. Both NOAA 2157 and 2158 have gained some sunspot area overnight, with magnetic delta structures prominently present.
There’s still a reasonable chance on an M-class flare. The warning condition for a proton event remains in effect.
On 8 September around 04:00UT, ACE observed a transient in the solar wind with wind speeds gradually increasing from a steady 340 km/s up to 430 km/s. The IMF continued pointing towards the Sun, with Bz evolving from an initial -3 nT towards its current +5 nT. Geomagnetic conditions remained quiet.
Quiet to unsettled geomagnetic conditions are expected for the next three days, possibly modulated by the high speed stream from a coronal hole that passed the central meridian on 5 September. On 10 September, there’s a chance on unsettled conditions with an isolated active period in response to the possible glancing blow from the 6 September CME.
SIDC

Equipment: Coronado 90 + Imaging Source DMK + LX75
Processing: Photoshop, Avistack 300 frames
Date: 09/08/14
Time UT: 16:00
Exposure 1/500 sec.

Observatory Sponli

The Sun Online and solar activity. August 31, 2014

A handful of C-class flares were observed, with NOAA AR 2149 and AR 2152 as source regions. NOAA AR 2152 has grown in size and complexity and has developed to a beta-gamma region. More C-class flares are expected, with a slight chance for an M-class flare. No Earth-directed CMEs were visible in
coronographic images.
The solar wind is under influence of a coronal hole (CH) high speed stream (HSS). The solar wind speed, as observed by ACE, reached values between 400 and 450 km/s. The magnetic field is relatively stable around 6 to 7 nT, with a fluctuating Bz. Geomagnetic conditions are unsettled to active and are expected remain so for the next few hours, until quiet conditions
return.
SIDC

Equipment: Coronado 90 + Imaging Source DMK + LX75
Processing: Photoshop, Avistack 300 frames
Date: 08/31/14
Time UT: 16:00
Exposure 1/500 sec.

Observatory Sponli

The Sun Online and solar activity. August 30, 2014

The Sun produced several small C-class flares, originating from NOAA AR 2146, AR 2149 and AR 2152. AR 2146 has now rotated around the West limb. No Earth-directed CMEs were detected. More C-class flares are expected, with a slight chance for M-class flares. Solar wind speed values ranges between 400 and 450 km/s. The magnitude of the interplanetary magnetic field remained relatively stable around 6 to 7 nT, while Bz is fluctuating between -6 and +6 nT. Geomagnetic conditions are unsettled to active and are expected remain so for the next 48 hours, due to the influence of the increased solar wind related to the equatorial coronal hole.
SIDC

The Sun Online and solar activity. August 28, 2014

Only two small C-class flares were observed in the past period. All active regions at the frontside are relatively stable. No Earth directed CMEs were observed. Flaring activity is expected to remain at the level of C-flares. A equatorial coronal hole has crossed the central meridian, which is likely to influence the solar wind conditions near Earth starting on August 30.The magnitude of the interplanetary magnetic field declined from 15 to 9 nT, with Bz mainly being southward. The solar wind speed is fluctuating between 300 and 380 km/s.
Geomagnetic activity reached active levels (local K=4 at Dourbes), with even an single time slot of minor storm level (NOAA Kp=5). A return to quiet to unsettled conditions is expected, till the potential arrival of a shock related to the August 25 CMEs later today.
SIDC

The Sun Online and solar activity. August 12, 2014

There were no C flares during the past 24 hours. In the next 48 hours, eruptive conditions (C flaring) are possible, especially from AR 2139, 2137, and 2134.Over the past 24 hours, solar wind speed as observed by ACE increased from about 420 to a maximum of 560 km/s and then decreased again till the current values around 440 km/s. This is probably the effect of a coronal hole high speed stream. The magnitude of the Interplanetary Magnetic Field (IMF) varied between 4 and 9 nT. Over the past 24 hours, geomagnetic conditions were quiet (K Dourbes between 1 and 3; NOAA Kp between 1 and 3). Quiet geomagnetic levels (K Dourbes < 4) are expected on August 12, 13 and 14, with possible excursions to active levels on August 13 due to the expected arrival of a coronal hole high speed stream.
SIDC

Equipment: Coronado 90 + Imaging Source DMK + LX75
Processing: Photoshop, Avistack 300 frames
Date: 08/12/14
Time UT: 16:00
Exposure 1/500 sec.

Observatory Sponli

The Sun Online and solar activity. August 10, 2014

Flaring activity remains at a low level. NOAA AR 2137 was numbered yesterday and shows flux emergence. This region, and NOAA AR 2135, produced flares at the high B-level in the past 24 hours. A C-class flare is possible from both regions. No earth-directed CMEs were observed since our last bulletin. We expect the current quiet geomagnetic conditions to persist in the coming days, with the chance for an isolated unsettled period (K=3). Unsettled to at most active geomagnetic conditions are
possible starting August 13, under the influence of a small coronal hole that is currently passing the central meridian.
SIDC

Equipment: Coronado 90 + Imaging Source DMK + LX75
Processing: Photoshop, Avistack 300 frames
Date: 08/10/14
Time UT: 16:00
Exposure 1/500 sec.

Observatory Sponli

The Sun Online and solar activity. August 9, 2014

Four C-class flares were observed since our last bulletin. The largest one was a C4.5 flare at 16:57 UT on August 8 in NOAA AR 2135, that has developed into a beta-gamma region. This region, as well as NOAA AR 2132, is expected to produce more C-class flares in the coming days. There is also a small chance for an M-flare. CACTus reported on a halo CME observed in LASCO images on August 8 around 16:36 UT. This full halo CME was associated to a strong eruption observed in the center of the solar disk in STEREO-a/EUVI 195 images starting at 15:55 UT. This is thus a back-sided event and therefore the CME will not be geo-effective.We expect quiet geomagnetic conditions to persist, with a chance for unsettled conditions (K maximum 3) under the possible influence of a coronal hole wind stream.
SIDC

Equipment: Coronado 90 + Imaging Source DMK + LX75
Processing: Photoshop, Avistack 300 frames
Date: 08/09/14
Time UT: 16:00
Exposure 1/500 sec.

Observatory Sponli

The Sun Online and solar activity. August 8, 2014

NOAA AR 2132 produced a C2.2 flare on August 7 with peak time 22:56 UT, the strongest flare in the past 24h. On the same day, NOAA AR 2135 produced a C1.4 flare around 17:28 UT. We expect more flaring at C-class level from these region and possibly also from region 2134. We maintain the warning
condition for proton activity. No earth-directed CMEs were observed. Geomagnetic conditions are quiet to unsettled. We expect a maximum K value of 3 later today and tomorrow under the possible influence of a coronal hole wind stream.
SIDC

Equipment: Coronado 90 + Imaging Source DMK + LX75
Processing: Photoshop, Avistack 300 frames
Date: 08/08/14
Time UT: 16:00
Exposure 1/500 sec.

Observatory Sponli

Related posts:

Related posts:

Related posts:

Related posts:

Related posts:

Related posts:

Related posts:

Related posts:

Related posts:

Related posts: