The problem

If I create a single-column RRTMG process like this:

import climlab
state = climlab.column_state()
rad1 = climlab.radiation.RRTMG(state=state)
rad1.compute_diagnostics()

and then make a clone and modify the insolation:

rad2 = climlab.process_like(rad1)
rad2.insolation *= 1.1
rad2.compute_diagnostics()

we should find that the insolation actually changes! But that's not the case, e.g. taking

rad2.ASR - rad1.ASR

gives

Field([0.])

The reason is that the modified insolation is not passed down to the shortwave radiation subprocess:

print(rad2.insolation)
print(rad2.subprocess['SW'].insolation)

gives

375.43000000000006
341.3

A not-so-good workaround

A workaround is to define the insolation at model creation, like this:

rad3 = climlab.radiation.RRTMG(state=state, insolation=rad1.insolation * 1.1)
rad3.compute_diagnostics()
rad3.ASR - rad1.ASR

gives

Field([25.15180942])

But this is a bug! Modifying the insolation attribute in place should always result in the correct value being passed to the shortwave subprocess.