MINUTE OF 133st BRIEFING: 23/03/2015, 14H30

Space Weather Exhibition Room /INPE-SJC


Forecaster 1: During the week between 17 to 23 March, were recorded 3 M-class Flares emitted from sunspot 12297. We observed a coronal hole (CH 660) on the solar disc southern hemisphere. This coronal hole were geo-effective from March 19st/20st. We also observed a halo CME directed to Earth. This CME was emitted in the March 15st, associated with a C-class flare. The active region 12305 is coming to the solar disc with complexity Beta/Gama.


Forecaster 2: The forecast models predicted that the CME would arrive on March 18 through of the significant density increase. But the ACE satellite recorded that the velocity increased concomitantly with shock occurred in March 17, followed for a solar wind increasing slowly during March 17st and 18st.  The interplanetary magnetic field was disturbed during March 17st and 18st. The magnetic field magnitude recorded was +40nT. The Bz component remained around -20nT for approximately 12 hours. The neutrons detectors recorded a Forbush decrease in several monitoring stations around the Earth. The solar wind presented a small increase in March 22st and 23st due the presence of the coronal hole. We observed a second sector boundary crossing on March 22st. GOES magnetometer data reached -150 nT on 1200 LT. This indicates that the magnetopause was compressed and this satellite was exposed to magnetosheeth’s magnetic field. The outer radiation belt data observed by Van Allen Probes satellite presented a significant decreasing on the high-energy electron flux population in the abrupt temporal scale from L*> 4.


Forecaster 3: The geomagnetic storm observed from March 17st started with an abrupt impulse on the H component. The Embrace Magnetometer presented values of approximately 40 nT in the SI. This storm period was very fast, lasting for only some hours. After then, it was started the main phase clear initiated by a sharp decreasing on the H component. We observed that the H component reach -320 nT during the peak of the storm (March, 18st). From March 18 started the recuperation phase with duration of 6 days. The Ksa index maximum was 7, however, remained several days oscillating between G1 and G2, including on the recovery phase. The auroral activity was intense, with oscillations in the AE index between 500 nT and 2000 nT. We also observed sub-storms in several days, including the recovery phase. It was recorded on the Northern Hemisphere auroral activities in several places. The Kp index maximum was 8-. The DST index in the peak of the storm was -228 nT.


Forecaster 4: The increasing of TEC observed in March 17 is consistent with positive ionospheric storm. This is caused by electric field penetration and consequently intensifies the equatorial anomaly peak.  Considering the recovery phase (March 18st), we observed that the equatorial anomaly was inhibited through of the appearance of the disturbed dynamo on the electric field systems. Consequently, generate an electric field with opposite signal compared to calm days. We observed scintillations in March 16st and 17st, but the storms inhibited the scintillations that normally are observed in this period. The ionograma presented increase in the F layer over Cachoeira Paulista and Fortaleza. It was also observed for this same period the presence of the F3 layer (17h00 LT). The density of the F layer observed in March 18 was significantly higher than during calm days. We observed over São João do Cariri plasma bubble on March 16, 18 and 22.

Minute translated by Ligia Alves da Silva

Comments are closed