Archives for Tony

20 March


Solar wind parameters, as measured by the ACE spacecraft, reflected
nominal conditions for the period. Wind speed values averaged
approximately 350 km/s. Total field values increased from an average of
+5nT briefly to near +10 nT, however the he Bz component was mostly
northward over the period. The phi angle was oriented in a predominately
negative (toward) solar sector.

20 March


Solar activity was moderate. The largest event of the period was a
M1/1f(NOAA Scale R1 – Minor) solar flare/radio blackout from Region 2010
(S15E27, Dac/beta) at 20/0356 UTC. Region 2010 showed continued signs of
modest growth over the forecast period. In conjunction with the flare, a
Type II radio sweep was observed at 20/0352 UTC (~372 km/s) and and a
Type IV sweep at 20/0407 UTC – suggesting an associated CME from the
event. NASA SOHO LASCO C2/C3 and NASA STEREO A/B coronagraphs depicted a
slow moving CME of the East limb from Earth’s perspective. Initial
analysis of the event suggests that it is unlikely to have a component
on the Sun-Earth line. The remaining four sunspot regions were stable
and overall unremarkable. A ~10 degree filament that was located along a
magnetic boundary near N15W15 erupted at around 20/0700 UTC. Coronagraph
data from the time period shortly after does not indicate a CME from the
event, nor any other clearly Earthward transients over the period.

19 March


Solar wind parameters, as measured by the ACE spacecraft, reflect
nominal conditions over the period. Speed values on average remained
less than 350 km/s and Bt values were at or less than 5nT. Bz remained
predominately positive over the period.

19 March


Solar activity was low. The largest event of the period was a C9/Sn
flare at 19/0734 UTC from Region 2010 (S15E41, Cao/beta). Region 2010
displayed growth and increased magnetic complexity while also being the
only region of activity worthy of mentioning. Two type II radio sweeps
were observed at 18/2253 UTC and 19/0358 UTC. Both were associated with
low level C-class flares from 2010. Associated with the second event, a
Type IV was observed at 19/0405 UTC. No CMEs have been observed in
conjunction with either event yet, though some data gaps in coronagraph
images (LASCO and STEREO) exist over the periods. The remaining solar
regions were stable and unremarkable. Overall, there were no
Earth-directed coronal mass ejections observed during the period.

18 March


Solar winds at NASA ACE indicated a slight disturbance with solar wind
speeds increasing from around 300 km/s to 330 km/s at around 18/0600 UTC
with associated fluctuations in temperature and density along with a
solar sector boundary crossing from a positive phi angle measurement to
negative just prior.

18 March


Solar activity was low. A few nominal C-class flares occurred during the
period. X-ray background levels were at B5. The largest event of the
period was a C3 at 18/0506 from Region 2010 (S15E51, Bxo/beta). All
regions on the visible disk were either stable or in decay. No
Earth-directed CMEs were observed.

17 March


Solar wind speed at the ACE spacecraft generally declined over the past
24 hours, beginning the period near 360 km/s with speeds approaching 300
km/s by period’s end. Phi was predominantly positive (away) with brief
intervals of negative (towards) orientation between 17/0530 – 1000 UTC.
The Bz component was mostly positive to +2 nT with a brief negative
period between 17/0809-1007 UTC, but never dipped below -2 nT. Bt ranged
between 1 to 3 nT.

17 March


Solar activity remained low (below R1-minor) with a few low-level
C-class events observed. Old Region 2006 (N11, L=011) produced a pair of
C1 events, the largest a C1 at 17/0829 UTC. Region 2002 (S18W50,
Eac/beta-gamma) remained the largest and most active region on the disk
producing four C-class events. The largest event was a C2 at 17/0045
UTC. Over the past 24 hours, the region exhibited some minor
intermediate spot growth with slight decay observed in the leader spot.
All other regions were quiet and stable. No Earth-directed CMEs were
detected.

16 March


Solar wind speed at the ACE spacecraft, reached a peak of 423 km/s at
15/1232 UTC and slowly declined to end-of-period speeds approaching 350
km/s. Total IMF remained below 5 nT. The maximum southward component of
Bz reached -2 nT at 15/1832 UTC. Phi angle was in a predominately
positive (away) sector throughout the period.

16 March


Solar activity remained low (below R1-minor). C-class activity was
observed in three of the nine spotted regions. Region 1998 (S07W72,
Axx/alpha) produced a pair of C1 events at 15/1437 UTC and 16/0604 UTC.
Region 2003 (N05W84, Dao/beta) produced a C6/Sf at 15/1715 UTC followed
by a C7/Sf at 16/0645 UTC. Some decay was observed in the southern
portion of the region. Region 2005 (N13E24, Cho/beta) produced a C2/Sf
at 16/0813 UTC. Overall growth in area was observed with new spots
forming in the northern portion of the region. New Region 2009 (N14E05,
Bxo/beta) emerged on the disk. The largest region on the disk, Region
2002 (S18W37, Ekc/beta-gamma) was quiet with some spot decay noted. All
other regions were quiet and stable. A 30 degree long filament eruption
was observed in the SE quadrant of the disk between 16/0235 – 0323 UTC
centered near S22E50. An associated CME was observed in SOHO LASCO C2
imagery lifting off the E-SE limb beginning at 16/0348 UTC. Plane-of-sky
speed was estimated at 554 km/s. Analysis is ongoing on the potential
geoeffectiveness of this CME.