Tom Bruhns wrote:
"If you want dissipated power in a TEM line, then P = Irms^2*R +
Erms^2*G (at a particular frequency where R and G have fixed values)."

Sure. Total loss is the sum of the series and shunt losses.

Tom also wrote:
"Since Irms and Erms are functions of position along the line, P is a
per-unit-length quantity like R and G and total power is found by
integrating the incremental P over the length of the length of the line
you are interested in."

Yes. Loss is a dB per 100 ft. quantity and loss is cumulative over its
length. But, I wouldn`t worry about the volts and amps produced by SWR.
The forward and reflected waves don`t oscillate in value. Only their
interference pattern does that and it is of no consequence. The forward
and reflected waves are smoothly attenuated by "alpha", the attenuation
constant, which is a function of frequency.

Alpha has the same value for the incident and reflected waves, but
though the dB per 100 ft is the same for a wave traveling in either
direction on the line, the reflected wave is likely much smaller than
the incident wave, and the loss produced by the reflected wave will be
much smaller too. The total loss is the sum of the losses produced by
the incident and reflected waves. As was shown yesterday, the ARRL
Antenna Book has charts to determine the added loss caused by standing
waves (actually caused by the reflected power that produces SWR). These
convenient charts almost eliminate arithmetic in determining additional
loss to be expected given the SWR.

Best regards, Richard Harrison, KB5WZI