HELIOS-63

This Helios Newsletter continues a series newsletters under the same name as above and that were issued as the newsletter of the Solar Section of the Norwegian Astronomical Society. Helios no. 1 was issued on 2nd May 1979 and ended almost simultaneously as I resigned as the leader of that section, i.e. in August 1989. Now I bring it to life again, started where I left it.
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Extracts from Preliminary Report and Forecast, SEL, Boulder, CO. USA:

SWO PRF 1320 19 December 2000
1
Space Weather Highlights SWO PRF 1320
11 – 17 December 2000 19 December 2000
Solar activity was low during most of the period, but rose to moderate levels on 12 December. Region
9267 (N08, L = 083, class/area Dai/210 on 15 December) produced the only M-class flare of the
period, an M1/1f at 12/1507 UTC. This region exhibited minor growth prior to the M-flare. Occasional
C-class flares occurred during the rest of the period from a variety of regions that were mostly
unremarkable. One notable exception was Region 9276 (S15, L = 114, class/area Dao/120 on 17
December), which emerged on 16 December, then grew at a moderate pace as it produced numerous
C-class subflares. Region 9276 crossed the west limb on 18 December. Note: Region 9269 (N15, L =
032, class/area Dao/260 on 17 December) produced a C7/Sf flare at 18/1111 UTC associated with
a halo CME (see the geomagnetic forecast below).

***

SWO PRF 1321 26 December 2000
1
Space Weather Highlights SWO PRF 1321
18 – 24 December 2000 19 December 2000
Solar activity was low during most of the period, but rose to moderate levels on 24 December. Activity
was low through 23 December with occasional C-class subflares from a variety of sunspot regions. A
few of these regions were of moderate size and complexity including Regions 9269 (N14, L = 034,
class/area Dao/260 on 17 December), 9280 (N09, L = 299, class/area Eki/560 on 24 December), and
9283 (S14, L = 256, class/area Dai/200 on 24 December). Region 9269 produced one of the more
interesting events of the period: a C7/Sf flare at 18/1111 UTC associated with a Type II radio sweep
and a halo CME. Activity increased to moderate levels on 24 December due to an impulsive M1/Sf
flare at 24/1115 UTC from Region 9283.

***

SWO PRF 1322 02 January 2001
1
Space Weather Highlights SWO PRF 1322
25 – 31 December 2000 02 January 2001
Solar activity was at low to moderate levels. Moderate levels occurred on 26, 27, and 29 December
due to isolated M-class flares from Region 9289 (S07, L = 201, class/area Eki/890 on 30 December).
These flares included an M1/Sf at 26/1613 UTC, an M4/1f at 27/1544 UTC, an M1/1f at 29/0223
UTC, and an M1/1f at 29/1848 UTC. This region, which also produced occasional C-class subflares,
was large with a minor degree of magnetic complexity. Region 9283 (S11, L - L = 259, class/area
Dao/240 on 27 December) also possessed a minor degree of magnetic complexity and produced
occasional C-class flares including a C3/Sf at 27/0400 UTC with an associated Type II radio sweep
and a long-duration C4/1f at 29/0211 UTC. Region 9283 was slowly decaying at the close of the
period. Other events of interest included a spectacular full-halo CME around midday on 28 December,
which was determined to be from a source on the back side of the Sun.

***

SWO PRF 1323 09 January 2001
1
Space Weather Highlights SWO PRF 1323
01 – 07 January 2001 09 January 2001
Solar activity was at low levels during most of the period. However, activity rose to moderate levels on
03 January by virtue of a optically uncorrelated M1 X-ray flare at 03/2355 UTC. This flare likely came
from a source beyond the northeast limb. Isolated to occasional C-class subflares occurred during the
rest of the period. Region 9289 (S07, L = 201, class/area Eki/890 on 30 December) was the most
interesting spot group on the disk. It was large with a minor degree of magnetic complexity and
produced isolated C-class subflares. It was crossing the west limb at the end of the period. Region
9206 (N12, L = 054, class/area Dai/110 on 08 January) produced a few subflares as it began to rotate
into view late on 07 January. Aside from Region 9206, there were about a dozen small, stable sunspot
groups on the disk as the period ended.

***

SWO PRF 1324 16 January 2001
1
Space Weather Highlights SWO PRF 1324
08 – 14 January 2001 16 January 2001
Solar activity was at low to moderate levels during the period. The period began with activity at low
levels due to isolated C-class subflares. Activity increased to moderate levels on 09 January due to an
M1/1n flare from Region 9306 (N12, L = 055, class/area Fac/510 on 14 January). Region 9306, which
showed gradual development through the period, was a large region with a moderate degree of
magnetic complexity. Activity remained at moderate levels during 10 January by virtue of an impulsive
M3/1n flare at 10/1016 UTC from Region 9302 (N19, L = 088, class/area Cso/110 on 5 January),
which was in a short-lived growth phase at the time of the flare. Region 9306 produced a long-duration
C5/1n flare at 10/0103 UTC associated with a partial- halo CME, and Type II and IV radio sweeps.
Another Type IV radio sweep occurred at 10/0119 UTC. Activity decreased to low levels during 11 -
14 January due to isolated to occasional low-level C-class subflares. A large filament erupted from
the northwest limb at approximately 14/0430 UTC. A large coronal mass ejection followed the
eruption, but it did not appear to be Earth-directed.

***

SWO PRF 1325 24 January 2001
1
Space Weather Highlights SWO PRF 1325
15 – 21 January 2001 23 January 2001
Solar activity reached high levels during the period. Activity was low during 15 - 18 January due to
isolated to occasional C-class flares. Activity increased to moderate levels on 19 January with an
isolated M1/Sf flare at 19/1730 UTC from Region 9313 (S07, L = 272, class/area Eao/220 on 20
January). Activity increased to high levels on 20 January as Region 9313 produced a M7/2b flare at
20/2120 UTC with an associated 850 sfu Tenflare, Type II radio sweep, and a halo CME. Region
9313 also produced a M1/2f parallel ribbon flare at 20/1847 UTC associated with a Type II radio
sweep and a halo CME. Both flares occurred during a period of gradual growth in the region. Activity
declined to moderate levels on the last day of the period with an isolated M1/Sf flare at 21/2313 UTC
from Region 9313.

***

SWO PRF 1326 30 January 2001
1
Space Weather Highlights SWO PRF 1326
22 – 28 January 2001 30 January 2001
Solar activity was at low to moderate levels during the period. Moderate levels occurred on 24, 26,
and 28 January due to isolated M-class flares from several different regions. Activity was at low levels
on 22 and 23 January but increased to moderate levels on 24 January due to an M1/2f flare at 24/1447
UTC from Region 9311 (N06, L=335, class/area Dao/140 on 24 January). This flare occurred during
a period of gradual growth in the region. Activity returned to low levels on 25 January due to the
occurrence of only C-class flares. An M1/1b flare on 26 January at 26/0607 UTC from Region 9325
(N10, L=184, class/area Hsx/050 26 January) with an associated Type II radio sweep increased activity
levels back to moderate. Only isolated low-level C-class subflares occurred on 27 January. Activity
increased to moderate levels on 28 January with an isolated M1/1n flare at 28/1603 UTC from Region
9313 (S04, L=272, class/area Cso/030 on 28 January) with an associated full halo CME. Significant
decay was observed in Region 9313 just prior to the flare. Active Region 9306 (N12, L=058) is
scheduled to return on 02 February.

***

SWO PRF 1327 06 February 2001
1
Space Weather Highlights SWO PRF 1327
29 January – 04 February 2001 06February 2001
Solar activity was at low to moderate levels during the period. Activity was low during 29 January -
02 February with isolated B- and C-class subflares including a C7/Sf flare at 01/0712 UTC from
Region 9330 (S25, L = 112, class/area Eso/230 on 31 January). Activity increased to moderate levels
on 03 February with an isolated M2/Sf flare at 03/0006 UTC from Region 9334 (N11, L = 075,
class/area Eai/220 on 04 February), which rotated into view on 01 February. This flare was associated
with Type II and IV radio sweeps and a non-Earth-directed CME. Old Region 9306 (N12, L = 058)
returned on 30 January as a small D-type group, now numbered as Region 9335 (N08, L = 064,
class/area Dao/130 on 04 February). Activity dropped to low levels on 04 February with isolated, low-level
C-class subflares, mostly from Regions 9330 and 9334. Both regions were moderately sized,
simply structured, and mildly active as the period ended.

***

SWO PRF 1328 13 February 2001
1
Space Weather Highlights SWO PRF 1328
05 - 11 February 2001 13 February 2001
Solar activity was low with isolated B- and C-class subflares observed daily. Region 9335 (N09, L =
062, class/area Eao/100 on 06 February) was the principal flare producer during 05 - 08 February as it
grew at a gradual pace. Its largest flare was a C8/1f at 05/1520 UTC associated with a Type II radio
sweep. Region 9335 slowly decayed during the rest of the period. Region 9338 (S19, L = 052,
class/area Dao/210 on 11 February) became active on 09 February, as it produced isolated C-class
subflares during a relatively brief period of growth. Region 9338 stabilized on 11 February. Region
9346 (N18, L = 104, class/area Bxo/030 on 09 February) produced the most interesting event of the
period, A C6/1f flare at 11/0123 UTC associated with a Type II radio sweep, halo CME, and a proton
flux enhancement. Region 9346 was in a state of gradual decay and nearing the west limb at the time of
the flare.

***

SWO PRF 1329 20 February 2001
1
Space Weather Highlights SWO PRF 1329
12 - 18 February 2001 20 February 2001
Solar activity was very low to low with isolated, optically uncorrelated B- and C-class X-ray flares.
Sunspot groups were largely stable and unremarkable. A long-duration B8 X-ray flare occurred at
15/1416 UTC associated with a partial-halo CME. The 10.7 cm solar radio flux dropped to 130 sfu
during 16 - 17 February, the lowest readings since May 2000.

***

SWO PRF 1330 27 February 2001
1
Space Weather Highlights SWO PRF 1330
19 - 25 February 2001 27 February 2001
Solar activity was low during most of the time, briefly dipping to very low levels on the last day of the
period. Most of the sunspot groups were small and simply structured. The exception was Region 9354
(S09, L = 284, class/area Dao/240 on 25 February), which was a moderate-sized group that showed
gradual development through 23 February as it produced isolated B- and C-class subflares. It was
stable during 24 - 25 February as it approached the west limb.

***

SWO PRF 1331 06 March 2001
1
Space Weather Highlights SWO PRF 1331
26 February – 04 March 2001 06 March 2001
Solar activity was very low to low. Isolated B- and C-class subflares occurred. By and large, the visible
sunspot groups were small and simply structured with only minor changes evident. There were two
significant events during the period: a beyond-the-west-limb event on 26 February associated with a
>10 MeV proton flux enhancement, and an 11-degree filament disappearance on 28 February
associated with a full-halo CME.

***

SWO PRF 1332 13 March 2001
1
Space Weather Highlights SWO PRF 1332
05 – 11 March 2001 13 March 2001
Solar activity increased to high levels during the period. The week began with activity at low levels as a
few small, growing sunspot groups produced low-level C-class subflares. One of these groups, Region
9368 (S25, L = 088, class/area Eai/610 on 08 March), continued to increase in size and magnetic
complexity through 10 March. As it grew, it produced two very impulsive major flares: an M5/1b at
08/1118 UTC and an M6/1b at 10/0405 UTC. Both flares had associated Type II radio sweeps and
non-Earth-directed CMEs. Activity returned to low levels on 11 March with isolated C-class subflares
as Region 9368 began to decay.

***

SWO PRF 1333 20 March 2001
1
Space Weather Highlights SWO PRF 1333
12 - 18 March 2001 20 March 2001
Solar activity decreased to mostly low levels following last week's brief period of major flare activity
from Region 9368 (N25, L = 086, class/area Eki/610 on 08 March). This region was decaying as it
quietly crossed the west limb on 12 March. There were two sunspot groups of note during the period:
Region 9373 (S07, L = 329, class/area Eai/320 on 12 March) and Region 9384 (N11, L = 334,
class/area Dao/120 on 16 March). Region 9373 produced C-class flares during the period as it
displayed alternate periods of growth and decay. Region 9373 was of moderate size and magnetic
complexity at the close of the period. Region 9384 produced C-class subflares as well, mostly during
15 - 16 March as it grew. Region 9384 stabilized on 17 March as a moderate-sized group with a
minor degree of magnetic complexity. A full-halo CME occurred on 15 March following a filament
eruption near center disk.

***

SWO PRF 1334 27 March 2001
1
Space Weather Highlights SWO PRF 1334
19 - 25 March 2001 27 March 2001
Solar activity ranged from low to high. The period began with activity at low levels due to isolated C-class
subflares, mostly from Region 9373 (S07, L = 329, class/area Fai/270 on 19 March), which was
in a growth phase at the time. A faint full-halo CME was observed early on 19 March, associated with
a filament disappearance near center disk. Activity increased to high levels on 20 March due to five
low-level M-class flares from a few developing regions including 9373, 9384 (N11, L = 334, class/area
Dao/120 on 16 March), and 9390 (N15, L = 185, class/area Fao/300 on 22 March)(please refer to the
Energetic Events list for flare times). Activity decreased to moderate levels on 21 March with an
isolated M1/Sn from Region 9373 as it approached the west limb. An increasing trend commenced on
22 March as Region 9393 (N20, L = 152, class/area Ekc/1100 on 26 March) began rotating into view.
This very large (its dominant spot mass spans about five degrees), magnetically complex region may
have been the source for an M1 X-ray flare at 22/0821 UTC associated with Types II and IV radio
sweeps. This region showed significant growth during the last few days of the period and displayed
increased potential for major flare activity. Region 9390 also produced an isolated M-class flare on 22
March while in a slow growth phase. Activity decreased to low levels on 23 March with occasional C-class
subflares. Activity returned to moderate levels during 24 - 25 March with isolated, low-level M-class
flares from developing Regions 9393, 9390, 9376 (S13, L = 301, class/area Cro/020 on 16
March), and 9401 (N22, L = 136, class/area Dao/150 on25 March). A faint full-halo CME occurred
late on 25 March, associated with a long-duration C9/1f parallel-ribbon flare from Region 9402 (N17,
L = 175, class/area Bxo/010 on 25 March).
Data were available from the Advanced Composition Explorer (ACE) spacecraft for most of the
period. A CME signature was observed during 19 – 20 March beginning with a shock front passage at
ACE at 19/1020 UTC. This CME's most notable characteristic was a strong, sustained southward
turning of IMF Bz late on 19 March continuing through 20 March with maximum southerly deflections
to minus 20 nT (GSM) detected at approximately 20/1400 UTC. A second CME shock front passed
ACE at 22/1240 UTC. No significant disturbances were observed in the solar wind flow during the
rest of the period.
No proton events were observed. However, a greater than 10 MeV proton flux enhancement at
geosynchronous orbit began late on 25 March.
The greater than 2 MeV electron flux at geosynchronous orbit briefly reached high levels on 22 March,
but was otherwise at normal to moderate levels.
A major geomagnetic storm occurred during 19 - 20 March due to a CME passage at Earth. Active to
major storm levels occurred during this storm with isolated severe storm levels detected at high
latitudes. Activity decreased to mostly quiet to unsettled levels on 21 March as storm effects subsided.
Field activity was at mostly quiet levels on 22 March until a sudden commencement occurred at
22/1340 UTC (12 nT, Boulder USGS magnetometer) due to another CME passage. Unsettled to
minor storm levels occurred during 22 - 23 March as a result of this passage. Quiet to unsettled
conditions prevailed during 24 – 25 March.

******

CV-106	GUNTHER GROENEZ	BELGIUM	23.dec-2000
CV-107	MONTY LEVENTHAL	AUSTRALIA	13.jan.2001
CV-108	HUBERTUS SCHULZE-NEUHOFF	GERMANY	24.jan.2001
CV-109	SABINE KUMMERER	NORWAY	20.feb.2001
CV-110	FRIEDRICH SMIT	GERMANY	14.mar.2001