IF you are already cold
THEN think twice before spending your days in hypothetical clouds
IF you are already fragile
THEN be careful who you touch
ELSEIF you are ready to multiply
THEN make sure you’ve a raincoat and a pair of gloves, and get out there
ENDIF
This was inspired by me looking bemusedly at pages of computer code from an atmospheric model (The Weather Research and Forecasting Model), kindly sent to me by Chris at the University of Manchester. I chose the extract below to respond to. Along the way I learnt that ‘rime’ means ‘Frost formed on cold objects by the rapid freezing of supercooled water vapour in cloud or fog’. The title – Remaining values should probably be left alone – comes from the notes at the beginning of the code telling programmers which values they can and cannot change.
Ice multiplication from rime-splinters (Hallet & Mossop 1974).
if (prg_gcw(k).gt. eps .and. tempc.gt.-8.0) then
tf = 0.
if (tempc.ge.-5.0 .and. tempc.lt.-3.0) then
tf = 0.5*(-3.0 – tempc)
elseif (tempc.gt.-8.0 .and. tempc.lt.-5.0) then
tf = 0.33333333*(8.0 + tempc)
endif