cenni di termodinamica dell'atmosfera PAF AA 2011-12 T López-Arias

81 Pages·2012·6.04 MB·Romanian

Con la fisica tra le nuvole:
cenni di termodinamica dell’atmosfera
PPAAFF
A.A. 2011-12
T López-Arias
Parte II
23 maggio 2012
La classificazione delle nuvole
Misura dell’umidità relativa: punto di rugiada e temperatura del bulbo bagnato
Adiabatica secca e umida: stabilità e instabilità atmosferica
Ruolo delle nuvole nella previsione
Quakero di origini
Lavora con suo padre nella
produzione di prodotti chimici
farmaceutici
Con il farmacista William
Allen fonda la “Askesian
Society” dove per la prima
volta legge il suo saggio sulle
nuvole
Nel 1803 scrive “Essay on the
modification of clouds” dove
Luke Howard (1772-1864)
da la nomenclatura dei
ddiivveerrssii ttiippii ddii nnuuvvoollee cchhee
perdura fino ad oggi
Corrisponde a lungo con
Goethe che gli dedica diversi
poemi
Nel 1819 scrive “The weather
of London” Caspar D. Friedrich (1774-1840)
“Since the increased attention which has been given to Meteorology, the study of the
various appearances of water suspended in the Atmosphere is become an interesting
and even necessary branch of that pursuit. [...]
They (the clouds) are subject to certain distinct modifications, produced by the
general causes which effect all the variations of the Atmosphere: they are commonly
as good visible indications of the operation of these causes as is the countenance of
the state of a person’s mind or body”
Neither it is pretended that
“
Electricity is any further
concerned in the production
of rain than as a secondary
agent, which modifies the
effect of two grand
predisposing causes- a
falling temperature and the
influx of vapor”
LLuukkee HHoowwaarrdd,, 11880033
Cirrus, cumulus, stratus, nimbus
From “On the modification of clouds”, Luke Howard, 1803
CIRRUS: Nubes cirrata, tenuissima, quae undique crescat
Parallel, flexuous, or diverging fibres, extensible by increase in any or in all directions
CUMULUS: Nubes cumulata, densa, sursum crescens
Convex or conical heaps, increasing upward from a horizontal base
STRATUS: Nubes strata, aquae modo expansa, deorsum crescens
A widely extended, continuous, horizontal sheet, increasing from below upward
Cirrus (Ci)
Cumulus (Cu)
Stratus (St)
From “On the modification of clouds”, Luke Howard, 1803
Intermediate modifications:
CIRRO-CUMULUS: Nubecualae densiores subrotundae et quasi in agmine appositae
Small, well defined roundish masses, in close horizontal arrangement or contact
CIRRO-STRATUS: Nubes extenuata subconcava vel undulata. Nubeculae hujusmodi appositae
Horizontal or slightly inclined masses attenuated towards a part or the whole of their
circumference, bent downward, or undulated; separate, or in groups consisting of small
clouds having these characters
Compound modifications:
CCUUMMUULLOO--SSTTRRAATTUUSS NNuubbeess ddeennssaa,, bbaassiimm ppllaannaamm uunnddiiqquuee ssuuppeerrccrreesscceennss,, vveell ccuujjuuss mmoolleess lloonnggiinnqquuaa
videtur partim plana partim cumulata
The Cirro-stratus blended with the Cumulus, and either appearing intermixed with the heaps
of the latter or superadding a wide-spread structure to its base
CUMULO-STRATUS Nubes densa, basim planam undique supercrescens, vel cujus moles longinqua
videtur partim plana partim cumulata
The Cirro-stratus blended with the Cumulus, and either appearing intermixed with the heaps
of the latter or superadding a wide-spread structure to its base
CUMULO-CIRRO-STRATUS vel NIMBUS Nubes vel nubium congeries [superné cirrata] pluvium
effundes
The Rain cloud. A cloud or system of clouds from which rain is falling. It is a horizontal
sheet, above which the Cirrus spreads, while the Cumulus enters it laterally and from
beneath
Stratocumulus (Sc)
LOW CLOUDS
Cumulus (Cu)
Cumulonimbus (Cb)
Stratocumulus (Sc)
Stratus (St)
Stratus (St)
Cumulus (Cu)
Cumulonimbus (Cb)
MEDIUM CLOUDS
Altostratus (As)
Nimbostratus (Ns)
Altocumulus (Ac)
Altrostratus opacus o nimbostratus (Ns)
Altocumulus (Ac) stratiformis (str)
Altrostratus (As) translucidus
HIGH CLOUDS
Cirrus (Ci)
Cirrus (Ci)
Cirrostratus (Cs)
Cirrocumulus (Cc)
CCiirrrruuss ffiibbrraattuuss oo uunncciinnuuss
Cirrostratus (Cs)
Cirrocumulus (Cc) stratiformis (Cc str)
Cirrocumulus (Cc) floccus (Cc flo)
Cirrocumulus (Cc) lenticolaris (Cc len)