HELIOS no. 53
01.September 1998
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.
Comments? Post them!
LAST BEARALERT (Big Bear Solar Observatory):
BBSO SOLAR ADVISORY 1998 August 30 18:30 UT
NOAA 8307 (N31W60)
Although it is in decay phase, 8307 is still capable of producing an
M-class event before it rotates from view. Beta-gamma magnetic class
NOAA 8319 (N19W38)
8319 continues in strong growth phase with some of the new flux contributing
to a small increase in magnetic complexity. There is positive,leader, flux
emerging within the negative polarity trailing flux. The region still
displays arch filaments, Ellerman bombs, and bright H-alpha plage.
Expect low- to middle-level M-class flares. Beta-gamma mag. class
NOAA 8322 (N22W23)
8322 has grown overnight, still developing today. There is a
possibility
that, if growth continues, a small
delta configuration will form in
the intermediate portion of the region. Beta-gamma mag. class
NOAA 8323 (S22E57)
8323 has a delta configuration located in the NE portion of
the trailing spots.
Still too close to the SE limb for complete evaluation, but expect M-class
events at this time. Beta-gamma-delta mag. class
WM
Does the Relative number show the actual activity?
The above graph is a comparison towards Radio Flux 10,7 cm, where Smoothed 24 week
R-nos. and CV-nos. are "adjusted" as an averaged constant. Where R-nos.
are too high, they will leave a positive number; too low will give a negative number.
The farther away from the zero-line this adjusted value is, the poorer value.
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Latest solar news referred from NOAA/SWO of Boulder, Colorado, USA:
(from SWO 1184 thru 1190)
SWO PRF 1191 30 June 1998
30 June 1998
Space Weather Highlights
22-28 June 1998
Solar activity was low during most of the period, but increased to moderate levels on 27
June. Region 8253 (N18, L = 082, class/area Dac/270 on 25 June) produced the sole M-class
flare of the period, an M1/1N at 27/0121UT with minor radio emissions. Region 8253 also
produced occasional subflares during most days and exhibited a slight degree of
complexity. Another flare of note was a C2/SF at 22/0433UT from Region 8243 (N17, L = 214,
class/area Dho/270 on 22 June). Types II and IV radio sweeps accompanied the flare. A
20-degree filament disappeared from the southwest quadrant on 22 June.
+++
SWO PRF 1192 07 July 1998
07 July 1998
Space Weather Highlights
29 June 05 July 1998
Solar activity was low during most of the period, but increased to moderate levels on 03 -
04 July. An optically uncorrelated M1-Class Flare occurred on 03/0112UT. Region 8256 (S24,
L = 048, class/area Bxo/020 on 04 July) produced, an M1/SN at 04/0412UT and a C9/1N at
04/1639UT.
Another flare of note was a C7/2F at 05/1144UT from Region 8264 (N16, L = 335, class/area
Cao/200 on 05 July). These regions showed very little activity after 04 July.
+++
SWO PRF 1193 14 July 1998
14 July 1998
Space Weather Highlights
06-12 July 1998
Solar activity ranged from very low to low. Isolated B- and C-class x-ray flares occurred.
Sunspot regions were simple and stable during most of the period. All in all, an
unremarkable week.
+++
SWO PRF 1194 21 July 1998
21 July 1998
Space Weather Highlights
13-19 July 1998
Solar activity ranged from very low to low during most of the period, but rose to moderate
levels on 14 July. Region 8270 (S21, L = 217, class/area Dao/100 on 14 July) produced an
impulsive M4/1B at 14/1259UT with an associated 250 SFU Tenflare and a Type IV radio
sweep. Region 8270 displayed minor growth and some magnetic complexity prior to the M4
flare, but was otherwise a small, stable sunspot group. A weak Type II radio sweep
occurred at 18/1700UT and was associated with an optically uncorrelated C-class x-ray
flare.
+++
SWO PRF 1195 28 July 1998
28 July 1998
Space Weather Highlights
20-26 July 1998
Solar activity ranged from very low to low. The largest flare of the period was a C8/SF on
24 July from Region 8280 (S22, L = 056, class/area Eho/500 on 24 July), which was
otherwise stable for much f the period. Region 8282 (N32, L = 054, class/area Dki/560 on
26 July) grew at a moderate pace during 24 July to become a moderate-sized group
containing a weak magnetic delta configuration. It produced isolated subflares as it grew,
then stabilized on 25 July.
+++
SWO PRF 1196 04 August 1998
04 Aug 1998
Space Weather Highlights
27 July 02 Aug 1998
Solar activity ranged from very low to low. Low levels occurred during 31 July - 02 August
by virtue of isolated C-class flares, three of which were notable. The first was an
optically uncorrelated C1 x-ray flare at 31/0345UT with associated Types II and IV radio
sweeps. The second was a long-duration C2/2F at 31/0538UT accompanied by a Type II radio
sweep from Region 8283 (N27, L = 346, class/area Hsx/050 on 29 July). The final flare of
note was a B7/1F at 01/0631UT with associated Types II and IV radio sweeps from Region
8288 (S27, L = 315, class/area Hax/020 on 01 August).
Sunspot groups were generally characterized by weak magnetic fields, small spot counts,
and no
remarkable growth or decay.
+++
SWO PRF 1197 11 August 1998
11 Aug 1998
Space Weather Highlights
03-09 Aug 1998
Solar activity increased from very low to moderate during the period. Region 8293 (S22, L
= 263, class/area Fac/580 on 09 August) grew steadily to become a moderate-sized,
magnetically complex region with around 70 spots and a beta-gamma-delta magnetic
structure. This region helped push the 10.7 cm radio flux to 154 on 09 August, the highest
reading so far this cycle (the previous high was 141 on 08 April 1998). It produced
several C-class flares during the period. Activity rose to moderate levels on 08 August
due to an optically unassociated M3 at 08/0317UT with moderate discrete radio emissions
and a Type II sweep. Region 8299 (N16, L = 191, class/area Eko/480 on 10 August) produced
two M-class flares on 09 August: an M1/1B at 09/0847UT and an M3/2B at 09/1718UT. Minor
discrete radio bursts accompanied both flares. There were two other events of interest.
The first was a spray from the northeast limb at 06/1605UT accompanied by Types II and IV
radio sweeps. The spray likely originated from Region 8299 as it rotated into view. The
second event of note was a large filament disappearance early on 08 August. The filament,
last seen near N18E03, was 32 degrees long,
north-south aligned, and likely the source of a CME. Were we unable to determine the
degree to which the CME was Earth-directed, given the absence of coronagraph images due to
the recent loss of the SOHO spacecraft.
The geomagnetic field was quiet to unsettled during 03 - 05 August. A major geomagnetic
storm began early on 06 August and continued through midday 07 August. Active to major
storm levels were detected during the disturbance with brief severe storm periods at high
latitudes.
+++
SWO PRF 1198 18 August 1998
18 Aug 1998
Space Weather Highlights
10-16 Aug 1998
Solar activity ranged from low to moderate during the period. Region 8293 (S22, L = 263,
class/area Fac/580 on 09 August) slowly decayed during the period, but produced an M3/1N
flare at 14/0828UT with an associated Type II radio sweep. This region also produced a
C7/SF flare as it crossed the west limb on 15 August. Region 8299 (N16, L = 192,
class/area Cko/520 on 12 August) increased in magnetic complexity during 13 August and
produced a C9/SF flare at 13/1756UT, but was otherwise stable. An optically uncorrelated
M3 x-ray burst with associated Types II and IV radio sweeps occurred at 16/1821UT. Note:
new Region 8307 (N30E90 on 17 August) produced two X-class flares on 17 August.
+++
SWO PRF 1199 25 August 1998
25 Aug 1998
Space Weather Highlights
17-23 Aug 1998
Solar activity rose to high levels during the period. Region 8307 (N31, L = 038,
class/area Dko/570 on 22 August) produced five major flares: an X1 at 17/2120UT with an
associated 290 SFU Tenflare and a loop prominence system, an X2/SN at 18/0824UT
accompanied by a Type IV sweep and a 680 SFU Tenflare, an X4/1B at 18/2219UT with Types II
and IV radio sweeps, a loop prominence system, and a 2400 SFU Tenflare; an X3/1F at
19/2145UT with Types II and IV sweeps and a 1300 SFU Tenflare; and an impulsive M9/2B at
22/0009UT. Region 8307 also produced a few M-class flares.
Real-time solar wind data were available from the Advanced Composition Explorer (ACE)
spacecraft during most of the period. There were two events of interest. The first was a
small, relatively slow shock passage during 19 - 20 August as evidenced by enhanced
densities, slow bulk velocities and a semi-smooth transition of Bz from minus to positive.
The second occurred during 22 - 23 August with increased windspeeds and decreased
densities which indicated the presence of a high-speed windstream associated with an
equatorward extension of the northern polar crown coronal hole.
The greater than 10 MeV proton flux at geosynchronous altitude became slightly enhanced
early on 20 August in the wake of the X3/1F at 19/2145UT and again early on 22 August
following the M9/2B at 22/0009UT.
- - -
Space Weather Forecast
26 August 1998 - 21 September 1998
Solar activity is expected to be moderate to high. New Region 8307 is expected to produce
M- and X-class flares before it departs the visible disk around 01 September.
Region 8307 has crossed into the western hemisphere and is expected to produce event-level
proton fluxes before it departs the disk.
The greater than 2 MeV electron flux at geosynchronous altitude is expected to be at
moderate to high levels during 27 August - 01 September. Otherwise, normal to moderate
fluxes are expected.
The geomagnetic field is expected to be at quiet to unsettled levels during most of the
period.
However, minor to severe storm levels are expected during 26 - 28 August in response to
recent major flare activity. Active levels are also possible during 18 - 19 September due
to recurrent coronal hole effects.
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New members since 01.jul.98:
CV-Helios
Network New Members |
|||
No. |
Name |
Country | Enter Date |
CV-052 |
ALLAN BLAND |
United Kingdom | 04.jul.98 |
CV-053 |
WOLFGANG NENNO |
Germany | 03.jul.98 |
CV-054 |
VIC WINTER |
United States | 06.jul.98 |
CV-055 |
ANTONIO SANCHEZ-IBARRA |
Mexico | 07.jul.98 |
CV-056 |
HANS-GORAN LINDBERG |
Sweden | 10.jul.98 |
CV-057 |
BOB EVANS |
New Zealand | 16.jul.98 |
CV-058 |
PAWEL LACHOWICZ |
Poland | 25.jul.98 |
CV-059 |
BEN PAWLUTSCHENKO |
Australia | 07.aug.98 |
CV-060 |
MARION CAPRIOTTI |
United States | 07.aug.98 |
CV-061 |
ROBERT L. GENT |
United States | 12.aug.98 |
CV-062 |
JAMES ROSS |
United States | 13.aug.98 |
CV-063 |
GORDON GARCIA |
United States | 15.aug.98 |
We wish you all welcome!
Helios no. 54 will be issued 01. November 1998
CV-Helios Network 01.Sep.98