are those "or" necessary?

[weiyuan-jiang]

GOCART/Process_Library/Chem_MieTableMod2G.F90

Lines 731 to 736 in 150f6b8

	if(present(refr) .or. present(tau) .or. present(ssa) ) then
	refrIn = TABLE%refr(irh ,ichannel,TYPE) * (1.-arh) &
	+ TABLE%refr(irhp1,ichannel,TYPE) * arh
	endif
	if(present(refi) .or. present(tau) .or. present(ssa) ) then

I remove those "or"s. It seems unnecessary to me. @tclune

[tclune]

I think the intent is that refrIn is needed for filling in tau and ssa if they are around.

[weiyuan-jiang]

No, not here. That is for bcsa and bext

[amdasilva]

I have not look into this in great detail, but I think I can guess the dependency. For a single species, refer and refi are intensive properties that can be pulled directly from the LUT. However, if you want a "combined index of refraction" of all aerosols you need to involve some "mixing rule" and the final result is an weighted average of all individual index of refraction, weighted by something like ssa * tau.

[amdasilva]

@pcolarco Can you take a look at this fragment:

if(present(refr) .or. present(tau) .or. present(ssa) ) then
        refrIn =   TABLE%refr(irh  ,ichannel,TYPE) * (1.-arh) &
                 + TABLE%refr(irhp1,ichannel,TYPE) * arh
     endif

     if(present(refi) .or. present(tau) .or. present(ssa) ) then
        refiIn =   TABLE%refi(irh  ,ichannel,TYPE) * (1.-arh) &
                 + TABLE%refi(irhp1,ichannel,TYPE) * arh

I do not understand the role of .or. present(tau) .or. present(ssa) above.

[pcolarco]

What piece of code is this in?

[pcolarco]

@amdasilva This isn't in the current codebase. I see the reference now, but this is several years old and has since been refactored.