We can see the anomaly in SO2 actual from the NASA data itself: https://so2.gsfc.nasa.gov/pix/special/time_sres/time_series.html

This clearly shows some crazy spikes right then and there for Eastern Asia. Look at the scale, ffs, its off the charts:

https://so2.gsfc.nasa.gov/pix/special/time_sres/china_so2pca_pbl_ts_plot.png

And there's also a weird data hole around Feb 2 (0 everywhere).

Doesn't mean we know what it was from, but it cannot be denied that there are/were crazy spikes in SO2 over that region recently.

@AndiDuen
In Thunderstorms layer, l/km2 means lightning per square kilometer.
The amount of rain is in mm or in inches, but never mm/m2. Sometime one uses l/m2 (liter per square meter).
10mm=10l/m2