Cloud spotting blues
--------------------
tfurrows wrote a phlog post yesterday[1] centred mostly around
responding to severe weather advisories and warnings. Right at
the end he mentions participating in "weather spotter / Skywarn
training", something provided by the US National Weather Service.
This seems to basically be a program to "crowdsource" early detection
of heavy weather (what did we call "crowdsourcing" before that
became a term?). I would certainly be interested to read more
about this experience!
I have never lived anywhere where heavy weather was a routine
enough event for there to be an established warning system in place
(maybe that statement will sound very strange to everybody in
the near future). But in recent years I think I have tried twice
to familiarise myself with the standard nomenclature / taxonomy
for clouds, partially as a natural response to spending more time
outdoors but also as part of a conscious effort to try to reverse
where possible the disconnectedness from the natural world that
my civilised upbringing has instilled in me. Cloud spotting is
the most aesthetically pleasing part of becoming in general more
"weather literate", and it doesn't require buying any instruments,
so why not start there?
To be honest I have really struggled to get the hang of it. I *want*
to blame the system for being a silly one, but I know *that*
is silly. It can hardly be said that its not fit for purpose.
Professional meteorologists have used it for centuries. It is the
system by which observations are conveyed to aviators and mariners
who rely on that information for safety of life and limb. And it's
silly for me to expect natural phenomena to fit into a perfectly
regular and systematic analytic framework, but as a geek it's hard
to let go of that mentality.
While there are no shortage of exceptions and special cases, the core
of the system seems to be that clouds are categorised into one of
five basic shapes or "forms", and one of three levels of altitude.
Each form has a name (let's pretend they are A, B, C, D and E)
and each altitude has a name (lets pretend they are 1, 2 and 3),
and those names can be combined so you have, e.g. type 1A clouds and
type 3C clouds and type 2D clouds. So far this is pretty sensible.
For the record there are *not* fifteen recognised cloud types
like you might naively expect. I assume this is simply because
atmospheric physics makes some forms impossible at some altitudes,
but I've never found any kind of introductory cloud classification
text which makes this explicit.
Where it gets a bit weird is that the five forms and three altitudes
don't have single letter of single digit names, but rather Latin
names. Which is fine, that's how everything was done in the days
this system was introduced. But some of the names assigned to forms
are incredibly similar to some of the names assigned to altitudes,
and one of the form names is basically a mashup of the two others,
all of which is a recipe for disaster, as we shall soon see.
The five forms are:
* Stratiform (sheets)
* Cirriform (wisps and patches)
* Stratocumuliform (patches, rolls and ripples)
* Cumuliform (heaps)
* Cumulonimbiform (towers)
The three altitudes are:
* Low (strato or stratus)
* Middle (alto)
* High (cirro or cirrus)
and there's a bonus "multi-level" altitude called nimbo.
You nominally create names by combining the altitude with the
form, and sometimes this works just fine. What do you call sheets
of cloud at middle altitude? Well, middle altitude is "alto",
and sheets are "stratiform", so we call these "Altostratus" clouds
(standard abbreviation As). Fine and dandy. Sheets of cloud higher
up in the atmosphere are "Cirrostratus" (Cs), again no problem.
But not every recognised cloud type has this simple two-part
structure. Sometimes applying the systematic approach results
in a name that just sounds silly. What should we call a low
altitude sheet of cloud, "Stratostratus"? Are high altitude wisps
"Cirrocirrus"? No, that would be dumb (or rather it's a lot like
what linguists call "reduplication", which sounds silly and childish
to English speakers but is actually a productive grammatical tool in
some languages), so in those cases we just disregard systematicity
and call them by their altitude alone (or is it their form alone?),
so we have "Stratus" clouds (St) and "Cirrus" clouds (Ci). I guess
what has happened is that some of the names for the five forms were
chosen based on the altitude at which they most typically form.
That is obviously a terrible idea when the plan is to have a
system which combines altitude and form, but how else can you
explain this mess? Then again, maybe that isn't what happened.
I don't speak Latin, but maybe the "strat" part of "stratiform"
really does mean something like "sheet", after all archaeologists
talk about "strata", which are thin, flat layers of dirt. Is it
just a total coincidence that "low altitude" and "sheet" *and*
"high altitude" and "wisp" are *both* similar sounding in Latin?
That seems extremely unlikely...
Anyway, here's the boss fight of this whole thing. There's a kind
of cloud called Stratocumlus (Sc). What *is* that? Is it a low
altitude heap of cloud, strato + cumuliform = Stratocumlus? Or is it
low altitude patches, rolls and ripples and somebody (quite rightly)
decided that "strato + stratocumuliform = Stratostratocumulus"
was just getting out of hand? It's the second one. The "system"
proposes a name for one combination of altitude and form which
is long, cumbersome, and silly sounding, so the "solution" is
to abbreviate it, which results in a name exactly the same as
the one the "system" would propose for the combination of the
same altitude with a *different* form. How much more broken can
you get? At first I thought "Oh, maybe this is a rookie mistake,
maybe somebody who actually understands the physics of cloud
formation finds it obvious that low altitude heaps of cloud can
never exist and therefore Stratocumulus isn't ambiguous at all".
But no, Cumuliform clouds can exist at low altitude, this is in
fact common in the Summer time. What are those clouds called?
Cumulus humilis. Standard abbreviation? No, it's not Ch, what, you
thought *all* the standard abbreviations would be two letters long?
You still expect consistency? They are "Cu hum". Are there any
other kind of "humilis" clouds in existence? There are not. Okay,
I have done some more reading, Cumulus humilis is a "species" of
the "genus" Cumulus, which is why its abbreviation must begin with
"Cu"; the cloud system is trying to imitate the Linnaean binomial
naming system for living things, in the desperate hope of acquiring
a scrap of scientific credibility by association. I'm not really
sure what a Cumulus (Cu) cloud is. Obviously it is Cumuliform.
It can't be the category "All Cumuliform clouds regardless of
altitude", because high altitude Cumuliform clouds have the
decency to conform to the system and are called Cirrocumulus
(Cc). Oh, wait, no, sorry, that's wrong, Cirrocumulus clouds
are not Cumuliform, they are Stratocumuliform. They *should*
have been named "Cirrostratocumuliform", but apparently that form
gets ambiguously abbreviated just like "Stratostratocumulus" does,
even though it *doesn't* have silly sounding reduplication in it.
You know what, for the third and perhaps final time I wash my
hands of this dog's breakfast of a classification and resolve to
simply observe and appreciate and try to learn to read clouds in
the absence of names, which presumably is how it's been done for
most of human history anyway.
I take back my earlier assertion that as a geek I struggle to
let go of an instinct to impose a rigid and consistent systematic
structure onto natural phenomenon which do not actually fit into one.
I mean, I probably do struggle with that, but that is definitely
not what is happening here, that is not the reason that every time
I try to learn this system I end up refusing for the sake of my own
intellectual dignity. What has happened is that in fact somebody
*else* has tried to impose such a system, has done an awful job
of it, and I can very quickly see how awful it is (yep, I guess I
am also taking back my assertion that I know it's silly to blame
my difficulties on the system itself). It's not that it doesn't
correctly "carve nature at the joints" and identify cloud types of
meteorological significance. It's just that it adds very little
value over giving each of the types its own idiosyncratic name and
in fact I would argue it makes learning your way around clouds
more difficult than a totally unstructured naming scheme would.
The whole 5x3 two-part naming scheme misleads the student into
expecting consistency which does not exist. There are only ten
commonly occurring cloud types in the first place, so only 66% of
the 5x3 names the system generates could possibly ever find use, and
learning 5+3=8 names is only very slightly easier than learning 10
names, so the whole thing is a dubious proposition right off the bat.
And two of those ten forms are not confined to a single altitude but
have substantial vertical extent (those would be Cumulonimbus (Cb)
and Nimbostratus (Ns) - note with wonder and admiration that even
the two "odd clouds out" are not named consistently, with "nimb"
acting as a suffix in Cumulonimbus but as a prefix in Nimbostratus,
why on Earth not?), which means that only 8 of the 15 names are
actually needed. Even if it weren't for confusing similarities
between "stratiform" and "strato/stratus" and "cirriform" and
"cirro/cirrus", even if we really did have "type 1A" and "type 3C",
the system would actually still be over-engineered and hard to
justify over "type A" through "type J".
And yet, it has not been reformed for over 200 years. Does everybody
who needs to use this system professionally hate their life?
That seems unlikely. Maybe the real problem is with my approach.
I am attempting to attain a thorough theoretical understanding
of cloud classification indoors in front of a screen before going
outside to apply my mastery. Maybe going outside with ten labelled
photographs on a "good cloud day" and trying to match things up
would yield much better results. "Stratocumlus" induces rage if you
know that it is supposed to be part of a system where "strato-" is
a prefix for altitude and both "stratocumuliform" and "cumuliform"
are kinds of shape, but if you *don't* know that, if you just know
"there's a kind of cloud called Stratocumulus, here are some photos
of typical examples", there's nothing to be mad about. The existence
of the system is still heavily implied by the names, of course,
I'd eventually try to figure it out...but maybe then the urge to
rage quit wouldn't come until *after* I'd actually learned something.
In case you are masochistic enough to try to master this yourself,
you can consult Wikipedia's "List of cloud types"[2].
[1]
gopher://zaibatsu.circumlunar.space:70/0/~tfurrows/phlog/2023-03-31_storms.txt
[2]
https://en.wikipedia.org/wiki/List_of_cloud_types
UPDATE: Some replies have been posted, by jns[3] and tfurrows[4]:
[3]
gopher://gopher.linkerror.com:70/0/phlog/2023/20230403
[4]
gopher://zaibatsu.circumlunar.space:70/0/~tfurrows/phlog/2023-04-04_reClouds.txt
