Clouds Deproj

Cl ou ds ar e vis ib le accu mulati on s of wat er dro plet s or sol id i ce cr ystal s that flo at i n the Earth 's tr op os phe re (the l ow est pa rt of the Earth ’s Atm os phe re ), m ov in g wi th the win d. Fro m s pace, cl oud s are vis ibl e as a wh ite ve il su rr ou nd in g the pla net.

Cl ou ds f or m w he n wat er vap or (w ater that ha s eva po rate d fr om the su rf ace o f the Ea rth) c on de ns es (tu rn s i nto li qui d wat er o r s oli d ic e) o nto mic ro sco pic dust part icl es ( or oth er tin y part icle s) flo atin g i n the a ir. T hi s con de ns ati on (clou d fo rm ati on ) hap pe ns w he n war m an d col d air me et, wh en war m ai r ri se s up the s id e of a mou ntai n and cool s as it r is es, and w he n wa rm ai r f lo ws ov er a c old er a rea, l ike a coo l bo dy o f water . Thi s occu rs becau se co ol ai r can h old

le ss w ate r vapo r than w ar m ai r, an d exc es s water con de ns es int o eith er liqu id o r ic e.

Cl ou ds ar e de fi ne d by bot h the wa y they lo ok an d ho w high th ey ar e in the atmo sph er e. For exam ple, ci rr o (me an in g "wi sp of hai r" ) is a pre fi x give n to hi gh -altitu de cloud s (ab ove 20, 00 0 feet ). Alto (me an in g "h ig h") is a pr ef ix give n to mid -altitu de cloud s (bet we en 6,0 00 an d 20,0 00 feet ). Th er e is no pre fi x fo r low altitu de cl oud s. Wh en clou ds are by the grou nd we call the m fo g. Nim bo (m ea ni ng "rai n" ) as a pr ef ix, or nim bus ad de d as a suf fi x, in a cloud nam e in di cate s that the clou d can pro duce prec ip itati on (ra in , sno w, or oth er fo rm s of falli ng wate r) . Cum ulo (me an in g "heap" ) re fe rs to pil ed -up cl oud s. St rato (m ea ni ng "lay er" ) re fe rs to flat, wi de , lay er ed cloud s.

Type of Cloud Abbreviation Appearance Composition Altitude (Genus) (height) Sb Can cause Near Cumulo-nimbus lightning, thunder, ground up =Thunderheads hail, strong rains, strong winds, and tornadoes

Cirro-stratus

Cs

Thin, wispy, appears in sheets. Located above

to 75,000 feet (Vertical clouds) Above 18,000 feet (High-

thunderheads

Cirrus

Ci

Thin, wispy, filamentous, or curly

Cirro-cumulus

Cc

Small, puffy, patchy and/or with a wavelike appearance

Alto-cumulus

Ac

Alto-stratus

As

Medium-sized puffy, patchy, scattered clouds often in linear bands Thin, uniform

Strato-cumulus

Sc

Broad and flat on the bottom, puffy on top,

Cumulus

Cu

Puffy and piled up.

Stratus

St

Uniform, flat, thick to thin layered clouds will illdefined edges

Nimbo-stratus

Ns

Uniform, dark, flat, low, featureless clouds that produce precipitation

Fog

Very low stratus clouds

altitude clouds) Mostly Above composed of ice 18,000 feet crystals (Highaltitude clouds) Above 18,000 feet (Highaltitude clouds) 6,500 20,000 feet (Middlealtitude clouds) 6,500 20,000 feet (MiddleAlttude clouds) Below 6,500 feet (Lowaltitude clouds) Below 6,500 feet (Vertical clouds) Mostly Below 6,500 composed of feet liquid droplets (Lowaltitude clouds) Mostly Below 6,500 composed of feet liquid droplets (Lowaltitude clouds) Mostly In contact composed of with the

liquid droplets

gound (Groundhugging clouds)

Mammatu s c loud s ar e dark cl oud s shap ed l ike sa gg in g p ouch es. Th es e clou ds o fte n app ear after a to rn ad o.

Orogr ap hic c lou ds are clou ds that ar e fo rme d as m oi st ai r r is es ov er mou ntai ns or othe r majo r ge og ra phi c fe atur es. Th e ai r fl oats up the s id e o f the m ounta in and c ool s quickl y, co nd en si ng an d turn in g i nto a clou d.

A pil eus c lou d is a s mo oth clou d that is f ou nd ov er or o n the top of a maj or ge og ra phic featu re, lik e a mou ntai n.

A c ontr ail (s ho rt fo r C ON de nsat io n TRAI L) is a clou d- like vap or tra il that fo rm s ai rc raf t wh en f ly in g in cold, clear , Th e co ntra il for ms fr om the w ater co ntai ne d i n the jet' s en gi ne exhau

b eh in d so me hum id ai r. vapor st.

Cl ou ds are usuall y div id ed int o fo ur m ai n fam ili es on the bas is o f the ir hei ght ab ove the gro un d: • • • •

high cloud s, mid dl e cloud s, lo w cl oud s, and cl oud s wit h vert ical dev elo pm ent

that m ay ext en d thr oug h all level s. The f ou r mai n div is io ns are furt he r sub div id ed i nto gen er a, sp eci es, a nd var iet ie s, which de scr ib e in detail the app ea ranc e of clou ds an d the man ne r in wh ich the y ar e fo rm ed . Mo re than 100 di ff ere nt ki nd s of cloud s ar e dist in gui sha ble . Only th e pr ima ry fam il ie s an d most imp orta nt ge ne ra a re d esc ri be d b elo w.

Th es e ar e clou ds co mp os ed o f ic e pa rticl es, fou nd at aver ag e level s of 8 km ( 5 m i) or m or e ab ove th e earth . The f am ily c onta in s thr ee pri nci pal gen era . Ci rr us cl oud s ar e is olate d, feathe ry , and th rea dlik e, of te n wit h ho oks o r tufts, and a re arra ng ed in ba nd s. Cir ro st ratus cl oud s appe ar as a f in e, w hit ish ve il; they occa si on ally e xhi bit a f ib ro us st ructur e an d, wh en s ituate d bet we en the obs erv er and th e mo on , pr oduc e halo ph en om en a. Cir ro cum ulus cl oud s fo rm s mall, w hit e, fl eec y bal ls an d wi sp s, ar ra ng ed i n g rou ps o r r ow s. Cir ro cum ulus an d ci rr us clou ds a re p opula rly desc ri be d b y the phr as e “mack er el scal es a nd mar es ' tails. ”

Th es e ar e clou ds co mp os ed o f w ater dr opl ets an d ra ng in g i n altitud e fro m ab out 3 to 6 km (ab out 2 to 4 mi) abov e the eart h. Tw o pri nci pal gen era are i nclu de d in the fa mil y. Alto str atus clou ds app ea r as a thick, gr ay o r blu is h veil, throu gh w hic h the sun or m oo n m ay be se en onl y di ff us ely, as thro ugh a f ro ste d gl as s. Altocu mulus cl oud s have the app ea ranc e of den se, fle ecy b alls o r pu ff s so me wh at lar ge r tha n cir ro cumu lus. Th e sun or m oo n s hi ni ng th rou gh altocu mulus cloud s ma y pr oduc e a co ro na, or c olo re d ri ng , ma rke dly s mall er in diam ete r than a hal o

Th es e clou ds, al so co mp os ed o f w ate r dr opl ets, are g en er ally le ss tha n 1.6 km (1 mi ) h igh . Th re e p ri nci pal fo rms com pr is e thi s gr oup. St ratocu mulus cloud s co ns ist o f lar ge roll s of cl oud s, so ft an d gr ay lo oki ng , wh ich f re que ntly cov er the ent ir e sky. Becau se the cloud m as s is usual ly not ver y thick, blu e sky o fte n app ear s betw ee n break s in the cloud deck. Nim bo str atus clou ds a re thick, dark, a nd shapel es s. Th ey ar e pr ec ipitat io n clou ds f ro m whic h, as a rule , rai n o r sn ow fall s. St ratus clou ds a re sh eet s of hi gh fog . The y app ear as flat, w hit e blank ets, usu ally le ss tha n

610 m ( 20 00 ft ) abov e the g ro un d. Wh en the y are b rok en up b y wa rm , ri si ng air , the sky bey on d usuall y appea rs clear and blu e.

Cl ou ds o f thi s type r an ge i n he ig ht fr om le ss tha n 1.6 km (1 mi ) to m or e than 13 k m (8 mi ) ab ove th e earth . Tw o ma in f or ms ar e in clud ed in thi s gr oup. Cum ulus clou ds are d om e- shap ed, w oo lpack cl oud s mo st oft en se en du ri ng the mi dd le a nd latte r part o f the da y, whe n sola r he atin g pro duce s the ve rtical a ir cu rr ent s nec es sa ry for thei r f or mat io n. Th es e clou ds usual ly have flat bas es an d roun de d, cauli fl ow er like to ps. Cu mul on im bu s cloud s ar e dark, h eavy- lo oki ng cl oud s ri si ng like m ou ntai ns h ig h int o the atm os phe re , oft en sho wi ng an anv il- shap ed veil

of ic e clou ds, f als e ci rru s, at the top. Popul arl y kn ow n as thu nd er hea ds, cu mulo ni mb us clou ds are usuall y acco mpa ni ed b y heav y, abr upt sho we rs .

Mrs . Kusum Sharma S.S . Mi stre ss G.G .S. S. Ko t Baba De ep S ingh Amrit sar.