This channel (as well as AIA 1600) often shows a web-like pattern of bright areas that highlight places where bundles of magnetic fields lines are concentrated. However, small areas with a lot of field lines will appear black, usually near sunspots and active regions.
Where: Temperature minimum and photosphere
Wavelength: 1700 angstroms (0.00000017 m) = Far Ultraviolet
Primary ions seen: Continuum
Characteristic temperature: 6,000 K (11,000 F)
Sunspot 1875 lit off a small solar flare directly at the Earth. The magnetic explosion it released caused another nearby sunspot 1877 to also explode with a M9.3 magnitude solar flare. Both of these flares are Earth directed, and a geomagnetic storm is expected to impact the earth in the next 24-48 hours.
The size of the incoming geomagnetic storm is undetermined so far, but there is a good chance it will be a Major-severe Geomagnetic Storm. The speed of the storm is also undetermined, but based off of previous Earth directed storms could reach us withing 48 hours.
Stay tuned, or sign up for our space weather alerts for more information as it becomes available.
Update 3: 10/25/2013 10:30AM MST
Sunspot 1882 lights off two large X-Class flares, causing R3 radio blackout. Read More.
Update 2: 10/23/2013 8:50PM MST
The speed of the incoming storm is 1321 km/s, and it should arrive in 31 hours. That puts the impact time at around Friday, October 25th at 3AM MST.
These sunspots may not be done with us. Shortly after the two quick solar flares, the Flare Monitor at the Univerity of Bradford updated it predictions on the current solar disk.
Those predictions are that sunspot 1875 has a 69% chance of another X-Class flare (up from 66% previously), and that sunspot 1877 has a 41% chance of another X-Class flare (held steady).
The overall chance of more solar flares dropped slightly to 44% from a previous probability of 49%. This prediction system which has been in beta for a few years has been very
accurate at times, when tradition spaceweather forecasting was off mark.
Update 1: 10/23/2013 8:30PM MST
The solar flares caused an R2 – Moderate radio blackout on the sunlit side of the earth.
Potential Impacts: Area of impact centered primarily on sub-solar point on the sunlit side of Earth.
Radio – Limited blackout of HF (high frequency) radio communication for tens of minutes.
D Region Absorption Predictions 10/23/2013 8:30PM MST
Area of impact centered on sub-solar point on the sunlit side of Earth.
Conditions in the D region of the ionosphere have a dramatic effect on high frequency (HF) communications and low frequency (LF) navigation systems. The global D Region Absorption Predictions (D-RAP) depicts the D region at high latitudes where it is driven by particles as well as low latitudes, where photons cause the prompt changes. This product merges all latitudes using appropriate displays, and is useful to customers from a broad base that includes emergency management, aviation and maritime users. [more]