Highlights of Solar and Geomagnetic Activity
Solar activity reached moderate levels on 17 Mar due to an M1/Sn
flare (R1 - Minor) at 17/1507 UTC from Region 3247 (S24, L=162,
class/area=Cao/100 on 08 Mar). The other 17 numbered active regions
on the visible disk only produced low levels of solar activity
eruptions but only a DSF on ~17/0930 UTC, centered near S40W38, was
modeled and thought to have an Earth-directed component. Model
output suggested anticipated onset of the CME to be late on 20 Mar
to early on 21 Mar. Lastly, a Type IV radio sweep was observed in
conjunction with an impulsive C9/1n 18/0716 UTC flare from Region
The greater than 10 MeV proton flux reached S1 (Minor) levels on 13
Mar. The enhancement was associated with a full-halo CME first
observed in SOHO/LASCO C2 imagery beginning near 13/0336 UTC. The
energetic event was determined to be associated with activity on the
far-side of the Sun but still was able to produce significant
enhancements in relativistic proton flux on the GOES-16 satellite.
S1 conditions were reached again on 14 Mar, with an additional
enhancement associated with a shock ahead of a CME that would arrive
on 15 Mar that would increase 10 MeV protons back above the S1
threshold to an eventual peak flux of 22 pfu at 15/0425 UTC. After
the last observation above the S1 threshold observed at 15/0530 UTC.
The greater than 2 MeV electron flux at geosynchronous orbit was
moderate levels over the summary period.
Geomagnetic field activity range from quiet to G2 (Moderate)
Mar. Total magnetic field strength (Bt) increased from 8 nT 18 nT
ncreased from ~425 km/s to ~525 km/s. Bt reached a peak of 24-25 nT
before both speeds and Bt underwent a gradual decline. Weaker
activity, also associated with transient activity produced active
conditions on 14 Mar and 16 Mar. Mostly quiet to unsettled
conditions were observed on 17-19 Mar and only quiet conditions were
observed on 13 Mar.
Forecast of Solar and Geomagnetic Activity
Solar activity is expected to be at low levels with a chance for
R1-R2 (Minor-Moderate) events. This is due to the flare potential of
expected to return to the visible disk from the far-side of the Sun
over the outlook period.
No proton events are expected at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit is
expected to range from moderate to high levels. High levels are
likely on 26-29 Mar and 31 Mar - 06 Apr due to multiple, recurrent
CH HSSs. The remainder of the outlook period is likely to be at
normal to moderate levels.
Geomagnetic field activity is expected to be at quiet to G2
(Moderate) geomagnetic storm levels. G2 conditions are likely on 25
Mar; G1 (Minor) conditions are likely on 26 Mar and 30-31 Mar;
active conditions are likely on 20-21 Mar, 01-02 Apr and 10-11 Apr;
unsettled conditions are likely on 24 Mar, 27-28 Mar, 03-04 Apr, 12
Apr and 14-15 Apr. With the exception of 20-21 Mar, which is
expected to include possible transient influence as well, all
anticipated enhancements in geomagnetic conditions are in response
to multiple, recurrent CH HSSs. The remainder of the outlook period
s expected to be at mostly quiet levels.