Deposited energy is measured in joules. Watts are units of power, not energy.
Yeah, I was trying to find a way to convey the notion of the Romulus' measurement being an undifferentiated aggregation of dissimilar photon values. Flux in watts per unit area wasn't getting the idea across. But in retrospect I shouldn't have tried to introduce another concept without explaining integrating the rate etc. Thanks for keeping me honest.
These X-ray bursts, when severe, can cause HF radio blackouts on the day side of the earth. The easily observable fact that HF radio works is proof the sun is not a continuous strong X-ray source.
During last night's debate with Romulus, the sunnier side of the Earth had just finished up a "measurable x-ray event" in the 1.5-12 keV band which peaked at C2.2. It didn't show on his graph because that data had already fallen off. Total fluence of 0.000551 J m
-2. The initial spike was a thousand-fold increase in flux over the quiescent value.
ETA: 10 keV x-rays are much less energetic than medical diagnostic x-rays. They don't even penetrate beyond the the outer layer of human skin, and don't even propagate substantially in
air. Thus for biological effects from solar x-rays, it doesn't even make sense to talk about whole-body or blood-forming-organ dosage because there simply isn't any. Since the attenuation coefficient for skin at this energy level is practically total, the biological dosage for the 5 kg and 0.8 m
2 of bare-naked human skin facing the sun for the whole duration of the event would be 0.000441 J in 5 kg, or 0.0000882 Gy @ Q = 1, or 0.0882 millisieverts -- about 1/100 the dose you'd get from a chest x-ray.
I asked Romulus several questions about the solar x-ray spectrum. David Groves says he used 8 MeV photon energies, which are so energetic that they used to be considered gamma rays under the old classification! The composite x-ray/gamma fluence spectrum for a solar flare lasting a couple minutes accumulates something like 10
5 photons at 10 keV and may 5 photons total at 8 MeV. So if you consider the average flux, that's a 10
4 difference in solar x-ray flux at those energies. That's the "gradual" decrease Romulus described.