Northern Lights Now – SWPC has issued two geomagnetic storm watches for G2 storming (KP=6+) on August 2nd and G1 storming (KP=5+) on August 3rd. These watches are the result of a pair of solar features that will impact Earth starting midday UTC on August 2nd. The NLN AuroraCast shows the current predicted timing for the timing. As always, these can be within +/- 6 hours:
Please visit NLN’s live blog of this storm and follow out Twitter feed for the most up-to-date information.
The first solar event that will impact Earth is the arrival of a very slow moving CME (Coronal Mass Ejection) that was launched during the July 28th filament eruption. The eruption happened almost dead center (near N01E06) on the solar disk. The associated CME was estimated to be travelling at 125-150 km/s. At that speed, it could take as many as 7 days for the CME to arrive at Earth, but it should be pushed by the ambient solar wind to 350 km/s or so. Then, an even higher wind from a coronal hole high speed wind stream should push it even faster to 600-650 km/s. There are several factors making the timing on this forecast complex – current models show the CME arriving midday to late August 2nd, 5 days after it’s launch.
In the animated GIF below watch the filament eruption in a composite of AIA 211, 193 and 171 wavelengths. These frames are about 14 hours of images taken by the Solar Dynamic Observatory (SDO) cameras. Note that just to the east (left) of the eruption, the coronal hole rotating into center disk is visible as a darker area:
The second feature is a large coronal hole that rotated into geoeffective position on July 31. The high speed stream from this CH measured at STEREO Ahead indicated that winds could reach 650-750 km/s at L1. This very strong wind will likely start impacting Earth either with or just after the CME arrives. If it “pushes” the particles in the CME, they will arrive at the leading edge of the shock. Due to the elongated shape of the CH, the period of elevated winds could be extended in duration. Here is an image of the coronal hole from SDO in AIA 211 from July 31 as it rotated toward Earth:
Together these storms have the potential to arrive with a strong shock and an extended period of high solar wind and active geomagnetic conditions. If they do, it should be a very good couple of nights for aurora hunters worldwide. As an added bonus, the Moon will be waxing just past new, so skies should be dark.
Northern Lights Now – A pair of filament eruptions on April 6th likely produced CMEs that will impact Earth on April 10th and 11th, producing aurora. The first filament was about 15 degrees long along a NE-SW, with the SW terminus just to the NE of Active Region 2528. The eruption produced a wide arching and looping structure. Structures like these are often correlated with coronal mass ejections (CMEs) that have a “slinky” or coiled structure. The second, smaller filament, erupted from the southern hemisphere of the solar disk in Earth strike zone. If it did produce a CME, will likely be directed towards Earth. The two eruptions together mean there is an increased likelihood of aurora on April 10-11 as the solarstorms arrive.
In this animatedGIF (also shared on the NLN Twitter Account), watch the first filament eruption. Note the wide spread between the east and west side, and the apparent arcing between the two sides – particularly on the southern extent. The large bright area on at the southern end is active region 2528 (Beta). Towards the end of the loop, the launching Plasma material can be seen. It’s trajectory actually looks to be mosly to the North and West of the Earth-Sun line. If this storm does arrive at Earth, it will likely be a glancing blow. It is possible that additional material launched from the Eastern (right) side of the filament may not be visible in the imagery and directed towards Earth. LASCO imagary, coming available over the next 12 hours should confirm the extent and direction of the CME. Click either of the two video below for a zoomed in view.
The second eruption was much faster. The video below is taken from the last 3 hours of the same full-disk video as the one above. It is zoomed in to the central southern hemisphere of the visible disk and slowed to about half the speed. This is a fast eruption. Notice the dark area at the beginning of the clip, the eruption happens just to the north of this. It is a faint East to West wisp of plasma that lifts off temporarily hiding the dark area behind it. The eruption is in the Earth strike zone so, even though it is smaller, may have more impact on Earth than the second eruption.
Stay tuned to NLN for more updates on these two solar storms.
Northern Lights Now – The Space Weather Prediction Center (SWCP) has posted a G1 geomagnetic storm watch indicating probable KP>5 for February 14th and 15th 2016. This means aurora borealis may be visible in mid latitudes. The timing indicates that Europe and North America will be best positioned for a show Valentine’s Day Evening. As always with storm watches like this, the actual storming period could arrive up to 6 hours before or after the predicted arrival. Now is the time to start monitoring developments in space weather and cloudcover forecasts to know if the northern lights will be visible to you and planning your night our aurora hunting.
Update: Feb 13: NLN is now posting live updates for this storm.
As of the time the watch was posted, Earth is expected to see KP levels at 5 or above from 21:00GMT on 2/14 through 06:00GMT on 2/15 (4:00m-1:00am EST). There may be up to 12 hours past the arrival of the storm where KP may still be in the KP=4+ range. The forecast may be updated as more data comes in, so keep an eye on the NLN 3-day AuroraCast page for updates over the next couple days. As of this post, here is the current AuroraCast:
This storm is caused by a Coronal Mass Ejection (CME) that erupted from the surface of the Sun during a C8.92 flare on February 11th. You can see that eruption in the northwest (upper left) quadrant of the solar disk in this timelapse captured from the Solar Dynamic Observatory Satellite. SDO is a camera trained on the Sun that takes thousands of high resolution images per day in multiple different wavelengths. As the Flare erupts over the course of almost 90 minutes, you can see a dark area moving up and away from the eruption location. This dark area, several times the size of Earth, is the CME. It appears as dimming because the ejected plasma is cooler than the Sun and located between the Sun and the camera on the SDO sattelite.
Normally, CME’s take 2-3 days to arrive at Earth after an eruption. The eruption is moving much slower and will take 3-4 days to arrive. That could mean that it will arrive with lower solar wind speed, which would dampen chances for a great show. But it also means that as it arrives, it may put on a longer show. Stay tuned for updates!