A question about Lasco calibration times

[michaelmozina]

I am wondering if there is a way to find out when LASCO images were last calibrated? I am specifically curious if there were any changes on June 16th, between 12:42 and about 12:50? The reason I ask is that both the Lasco-C2 and C3 images show a significant change in overall intensity between two images. In the case of C2 images, the change is between the shots taken on 12:26 and 12:50. In the case of C3 images, the change takes place between 12:42 and 13:42. That would seem to put the change somewhere between the 12:42 and 12:50 time frame. A change in calibration in this timezone would certainly have that effect, but is there a way I can can check that?

 

[michaelmozina]

I went back to the ACE data for the 16th (careful, it's a 20 meg AVI file) to see what events occurred yesterday. Interestingly enough, at shortly before before 13:00, there is a notable increase in solar wind density, a spike in temperature and a 180 shift in the "By(nT)" axis. The timing of this density surge seems to coincide nicely with LASCO changes in terms of timing.

Edit: Here is a link to the raw data as a single image rather than a movie format.

http://www2.nict.go.jp/y/y223/simulatio ... 90616.html