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!
Northern Lights Now – The trend of busy space weather over the last two months continues tomorrow with a new geomagnetic storm watch issued for January 6, 2016. The watch, which means it’s possible space weather conditions may produce aurora, is due to an expected increase in ambient solar wind speeds. The source of the higher wind speed is a large transequitorial coronal hole that was pointed directly at Earth on January 3.
The current official forecast is only calling for a single 3-hour period of KP=5 for this storm, but there’s a prolonged period of KP=4 before and after the predicted peak period. That’s an unusually short period of activity for a coronal hole, and it may turn out to be an underestimate. It’s possible that at any point in the 15 hours before and after the predicted peak KP values could cross above minor storm thresholds. If any small CMEs are carried along the wind stream their impact can be magnified. Here is the SWPC forecast as of midnight GMT on Jan 5 as visualized by the NLN auroracast infographic:
This is the second rotation for this coronal hole. On the last rotation it produced solar wind speeds around 650 km/s and two short periods of KP= 5.0 – 5.33. The coronal hole actually looks to have a slightly more defined signature in this rotation. Read NLN’s post about the last rotation here
An amazing night of Aurora! It’s possible the two storms mentioned detailed in this post have merged together, producing a prolonged geomagnetic event. Storm levels have been at or above G1 (KP=5) for 15 hours. Bz has maintained a strong southward component. All signs point to another good night of aurora in northern Europe as far south as the Netherland and Germany. If you are planning to go out tonight, don’t forget the Last Minute Aurora Viewing Preparation Guide
UPDATE: 12/20/2015 1:30 AM EST
The Bz has shifted strongly south. Aurora reports are starting to come in. If the storms maintains it’s southward orientation, this is going to be a good storm.
UPDATE: 12/19/2015 10:40 PM EST
The CME has arrived at Earth. It arrived about 16 hours later than the earliest estimates. Now watch for the Bz orientation of the magnetic fields. If it stays negative, we could be in for an amazing show!
UPDATE: 12/18/2015 4:00 PM EST
EPAM is showing a clear rise in particles, the CME arrival is expected any moment now.
Two eruptions on the Sun have unleashed a coronal mass ejection (CME) towards Earth. When it arrives it is expected to induce a G2 geomagnetic storm with the potential for aurora displays at mid-latitudes. The predicted timing of the arrival is good for Europe and excellent for North America. If it arrives on schedule, space weather predictions often are accurate within 3-6 hours, the northern lights show should start in Europe just before midnight, and it will be active as the Sun sets in the United States and Canada. It should last 6+ hours once it begins.
Imaging satellites in space, both ACE and SOHO, captured wonderful clear images of the eruptions. The explosions are so clear that anyone viewing them can easily identify the location and duration. In the video montage below, each view of the sun is campured through cameras with different lenses. Each sequence is roughly 80 images from SDO stitched together as a timelapse. The first, red, shows the eruptions at the 304 angstrom wavelength, followed by 335 angstroms (blue) and then 211 angstroms (purple). In each sequence the first eruptions is dead center and is from a C6.69 flare. The second is an elongated eruption to the South and East.
When flares like this occur, sometimes they eject hot plasma into space in the form of a CME. The LASCO camera aboard SOHO (Solar and Heliospheric Observatory) satellite is a specialized tool with an arm and disk in front of the lens designed to block the light coming directly from the Sun. This enables the camera to view the CME as light reflects off of it as it travels into space.
Both eruptions in the video above generated CMEs. The video below shows the raw image of the sun through lasco on the left, and then a black and white image of the difference between each set of frames coming from the those frames. The differential image makes the size and shape of the CME apparent. When the CME is mostly in one direction it means the CME is off the Earth sun line, but when the CME appears on all sides of the Sun, as is the case in this video, it indicates the CME is headed straight towards Earth. Space weather scientists can measure the speed of the CME from these images and use that estimate to predict when the CME will arrive at Earth.
What to Expect:
As of writing, the forecast is for aurora activity to begin at 21:00GMT on December 18th (4:00pm EST), and to increase over the following 6-9 hours. The NLN 3-day auroracast clock is updated two times per day, visit it for the most up-to-date forecast.
As the CME approached Earth, the first signs it is approaching will be that the EPAM rises – this happens because the approaching plasma in the CME is radiating electrons and protons. Once it arrives, the solar wind speed, the Bt and proton density, this data is available at spaceweatherlive.com, will show a sudden increase. When that happens, watch the Bz – if it is negative aurora hunters are in for a good show. Also watch the live KP. This is the best metric there is for knowing when aurora may be visible, it offers a 40-70 minute forecast. The higher the KP is the lower latitude the aurora will be visible. Here is the NLN auroracast at the time of this post: