Finally – Strong solar winds and G1 storming arrived as the impact from the coronal hole was felt. Solar wind speeds increased in a stepped pattern with several shocks – first to 500km/s, then to 650km/s then peaking around 759 km/s. Winds have been in the 700-760 km/s range since. The Bz has been shifting back and forth between negative and positive which has lead to several short bouts of aurora. Some aurora hunters have been lucky, while others, just a couple hundred miles away or looking at a slightly different time have seen nothing. While there have been periods of G2 storming, the official record of 3-hour averages will only show G1 activity from this storm (so far). Here’s an image of the Geomagnetic activity over the last couple days.
There is still a chance for more activity over the next 6-12 hours, and solar winds are expected to remain elevated for the next 72 hours. Any disturbances on the wind stream could lead to a spike in activity – so keep an eye on the KP!
Speaking of disturbances, those could come from flares originating in the two beta-delta active regions. Both AR2443 and AR2445 are in the Earth stike zone and are displaying magnetic activity that could lead to M-class flaring. If they do generate a fast moving CME, it could catch up to the wind speed and create a show.
Here’s a great Aurora image from Kiruna, Sweden by Mia Stålnacke
The anticipated high wind stream associated with the coronal hole are later that expected. NOAA forecaster had been anticipated to arrive mid-day on November second but as of this writing, only the leading edges of the wind stream have arrived at the ACE satellites. They are still predicting that when the winds arrive they will be in excess of 800 km/s and when they do they could last as long as 12-18 hours. This should be strong enough and long enough for an extended period of northern lights activity.
Earlier on November 2nd, there was a shock passage measured at ace satellites with a very typical pattern. First the Bt increased from around 3-4 to 10 nT, next the proton density increased by almost 8 fold in three waves. On the third wave, the solar wind speed increased from 325 km/s to 410 km/s. Shortly after this (though not captured in the image below), the Bz shifted south. This was a short lived wave, but when the main high speed stream arrives, it may have a similar pattern. Graphs in this image are form SpaceWeatherLive
On the Sun:
Active Region 2443 has regained it’s delta spot and is not classified Beta-Delta. It produced several flares over the period. One flare late in the Nov 1 period laucnhed a CME that was determined to be south and East (in front) of the Earth-Sun line. This region is now in the Earth strike zone and has potential to produce more flares and CME eruptions.
Aurora Brief Number 14 of 14 (though, there may be bonus since we’re in the middle of a storm!)
Other Briefs: Previous Brief — Next Brief
Today on the Sun:
A G3 (KP=7) geomagnetic storm watch is in effect! All eyes are on the solar wind data. The increased solar wind and solar wind density that will result from the coronal hole that was pointed towards Earth on Friday should arrive any moment. When it does, the wind speed may increase to above 800 km/s from the current 330 km/s. Density and Bt should also increase. If those play out as expected, the next metric to watch is Bz – the north/south component of the magnetic field. It needs to be pointed south, negative Bz values, for aurora to take place. About 30-40 minutes after the Bz turns south, the KP will start to rise.
You can monitor the KP live on the NLN live KP dashboard or on the chart to the right. As the KP is higher, the latitude it is possible to see the Aurora is lower. In Australia and New Zealand, this means Higher KP indicates northern lights should be visible further North. In the southern hemisphere, KP=7 means aurora can potentially be seen in Melbourne, AU or Wellington, NZ. For northern hemisphere hunters, KP=7 means aurora can potentially be seen as far south as Salt Lake City, UT, Richmond, VA, Brussels (Belgium) and Warsaw (Poland). On the live KP page, there is the ovation model, a convenient map showing the estimates of the chances that Aurora are visible at the moment in different locations around the northern hemisphere.
On the Sun AR 2443 continued to produce C-class flaring. It grew in area, but lost it’s delta spot while growing. Chances of M-class flares are slightly lower today than yesterday.