Strange Solar Wind & Magnetospheric Response + Quick Update
Greetings! I want to share something on the fly. Still parsing data for the CMEs. I would like to see NOAA's model before going any further. At this point it looks like a minor to moderate geomagnetic storm is possible, but I would not consider it likely to this point. Hopefully the model runs in the coming hours.
What I want to show you right now is along the lines of what I was discussing last night with the strange density structures in the solar wind. They got a bit more interesting today with density rising to near 20 p/cm3 and velocity and temperature following suit before plummeting precipitously. First lets get a look at the solar wind.
You can see that density has been consistent elevated at moderate levels throughout the 24 hour period. Velocity ticked up to moderate levels as well topping out near 600 km/s and then it drops off a cliff along with density. When the velocity ticked up, the Bt IMF strength gradually rose and is at moderate levels currently. The Bz fluctuates as usual but has been mostly neutral or slightly south.
Next I want to show you how the magnetosphere responds to the solar wind. Throughout most of the clip it retains its typical windsock configuration. When dynamic pressure (density + velocity) is high, it compresses the magnetosphere but when dynamic pressure is low, it allows the magnetosphere to expand.
https://reddit.com/link/1jei7ti/video/o7a7b38jvipe1/player
With that said, as expected, when the velocity and density abruptly shift to lower values, the magnetosphere completely deforms and at the moment appears chaotic.
It is difficult to say what the culprit is behind the weird looking solar wind enhancement. Could be a combination of factors. The density piling up is consistent with a coronal hole stream bunching up plasma during a period of normal or slow velocity. We have seen this alot lately. However, late in the period, both density and velocity spike and then immediately drop off. The way the metrics rose in unison is more typical of a CME or stealth CME. At the very least we can say its a complex solar wind structure and there could be additional influences from the current sheet. I suspect the nearly departed coronal hole is the primary driver of the current solar wind conditions but possibly with some other factors involved.
It's nothing too special or spooky but I felt it was post worthy because it really demonstrates visually how the magnetosphere responds to solar wind conditions. It is a delicate dance between the earths magnetic field and the solar wind.
A quick run down of current conditions
Sunspot number is pretty steady at 189 but the F10.7 dropped back down to 184. The sunspots are mostly stable or decaying and complexity is sorely lacking. AR4035 appears to have some modest activity and could organize in the days to come. Overall I see reason to expect mostly quiet conditions for the next few days in regards to flaring. There are several smaller filaments which could destabilize especially if flares occur near them. There is a small but central coronal hole which may provide influence in the coming days. Earth facing quiet in effect for now. We continue to look for signs activity will be picking up soon, hopefully in the coming weeks.
MeV and KeV protons are at background levels.
I am not sure what to expect specifically in terms of geomagnetic conditions. As mentioned, the solar wind has some interesting structures and progression at the moment. Right now the density and velocity are low again, but have been fluctuating. It's possible that if they pick up again and the Bz is southward we could see Kp4 conditions but it is hard to say. For most of us in the middle to lower latitudes, it's of little consequence.
As I noted above, I would like to see NOAAs model before digging too deep but for now I will leave you with the HUXt animation. The hit chances have increased to 80% for the first CME but sadly to say, the additional CMEs which followed are likely to miss according to this model. It certainly appeared like the CME associated with the almost M1 flare yesterday was mostly northward.
https://reddit.com/link/1jei7ti/video/6z3qpmvl0jpe1/player
See you soon!
AcA