X-ray flux vs solar wind data question

[Crusauvage]

I was hoping that someone can help me understand if there is a correlation between the GOES X-ray flux data and the ACE magnetometer data and if there is a time lag between the two. One time when solar activity was quiet sometime in September(?), the X-ray flux was quiet and so was the ACE.  Then one day, the x-ray flux jumped significantly associated with increased solar flares but ACE stayed quiet.  I noticed an increase in ACE activity a day later.  

I understand the concept of the delay in the solar wind arriving to Earth.  Are the effects of x-ray flux any different?  Thank you for your help.

 

-Crusauvage

[Vancanneyt Sander]

The ACE magnetometer measures the IMF at the satellite. The X-rays are measured by GOES satellite and those measurements are based on the x-Rays coming from the solar surface. Between the Sun and Earth is a relative long distance, so when a solar flare occurs it won’t be seen in the magnetometer. Only when a CME from a solar flare passes the satellite, the magnetometer will respond to it. The ACE electron and proton flux does respond to solar flares, especially of there’s al Earthward component. So when an eruptieve solar flare occurs, it will be seen very shortly by the ACE electron flux and the proton flux will start to rise up until the CME hits Earth. More info, see our help section “How do we know when a CME is Earth directed and when does it arrive”

[Crusauvage]

Thank you for your reply.  While monitoring this week's projected arrival of the CH HSS, I noticed increased GOES X-ray flux activity yesterday 1/19/21.  However, the SSN # was at 13 and radio flux at 75.  Solar wind speed and density remained low to moderate.  The ACE EPAM had a blank section. Do you think this increased X-ray flux came from the CH HSS and arrived ahead of it?  

[Vancanneyt Sander]

Increased x-ray flux is due to the presence of two sunspot regions on the visible solar disk, one region was responsible for a low C-flare. Coronal holes don’t have much x-rays (normal background flux).

EPAM blank section is due to the fact that there was no data during that period. ACE instrument doesn’t have a 24/24 coverage. Gaps in data can also happen due to eclipses from the viewpoint of the satellite.