Cik

loni

v z

mer

nih

širin

ah

Vse

bina

in sl

ike

prev

zete

s spl

eta,

Sur

vey

of M

eteo

rolo

gy, L

SC

(spl

ošna

, bol

j pol

judn

a pr

edst

avite

v)

•Im

porta

nt fo

r glo

bal h

eat t

rans

port

•The

y al

so re

dist

ribut

e/re

duce

ene

rgy

in th

e at

mos

pher

e•O

ften

are

sign

ifica

nt w

eath

er p

rodu

cers

•Firs

t stu

died

ext

ensi

vely

by

a gr

oup

of sc

ient

ists

from

Ber

gen,

N

orw

ay (

Vilh

elm

and

Jako

b B

jerk

nes,

Hal

vor S

olbe

rg, a

ndTo

rB

erge

ron)

•The

y de

velo

ped

the

Pola

r Fro

nt T

heor

yfo

r the

form

atio

n an

d ev

olut

ion

of m

id-la

titud

e cy

clon

es sh

ortly

afte

r WW

I.

Splo

šno

...

(a) -

The

wav

e cy

clon

e(o

ften

calle

d a

fron

tal w

ave)

de

velo

ps a

long

the

pola

r fro

nt•w

hen

a la

rge

tem

pera

ture

gra

dien

t exi

sts a

cros

s the

po

lar f

ront

-th

e at

mos

pher

e co

ntai

ns a

larg

e am

ount

of

Ava

ilabl

e Po

tent

ial E

nerg

y

(b) -

An

inst

abili

ty(k

ink)

form

s in

the

pola

r fro

nt.

This

inst

abili

ty is

the

inci

pien

t cyc

lone

Teor

ija ra

zvoj

a ci

klon

a iz

val

a na

pol

arni

fron

ti

(c) -

A fu

lly-d

evel

oped

"w

ave

cycl

one"

is se

en 1

2-24

hou

rs fr

om it

s inc

eptio

n.

It co

nsis

ts o

f:•a

war

m fr

ont m

ovin

g to

the

north

east

•a c

old

fron

t mov

ing

to th

e so

uthe

ast

•reg

ion

betw

een

war

m a

nd c

old

fron

ts is

the

"war

m se

ctor

"•t

he c

entra

l low

pre

ssur

e (lo

w, w

hich

is d

eepe

ning

with

tim

e)•o

verr

unni

ng o

f war

m a

ir ov

er th

e w

arm

fron

t•c

old

air s

urgi

ng so

uthw

ard

behi

nd th

e co

ld fr

ont

•wid

e-sp

read

prec

ipah

ead

of th

e w

arm

fron

t•n

arro

w b

and

ofpr

ecip

alon

g th

e co

ld fr

ont

•win

dsp

eeds

con

tinue

to g

et st

rong

er a

s the

low

dee

pens

-th

e A

vaila

ble

Pote

ntia

l En

ergy

(APE

)is b

eing

con

verte

d to

Kin

etic

Ene

rgy

(KE)

•the

pro

duct

ion

of c

loud

s and

prec

ipal

so g

ener

ates

ene

rgy

for t

he st

orm

as l

aten

the

at is

rele

ased

Raz

voja

cik

lona

iz v

ala

na p

olar

ni fr

onti

(d) -

As t

he c

old

fron

t mov

es sw

iftly

eas

twar

d, th

e sy

stem

s sta

rts to

occ

lude

.•S

torm

is m

ost i

nten

se a

t thi

s sta

ge•h

ave

an o

cclu

ded

fron

t tra

iling

out

from

the

surf

ace

low

•trip

le p

oint

/occ

lusi

on-i

s whe

re th

e co

ld, w

arm

and

oc

clud

ed fr

onts

all

inte

rsec

t

Raz

voj c

iklo

na iz

val

a na

pol

arni

fron

ti

(e) -

the

war

m se

ctor

dim

inis

hes i

n si

ze a

s the

syst

ems

furth

er o

cclu

des.

•The

stor

m h

as u

sed

mos

t all

of it

s ene

rgy

and

diss

ipat

es•A

ll of

the

APE

has

bee

n ut

ilize

d an

d th

e K

E ha

s di

ssip

ated

into

turb

ulen

ce-c

loud

/pre

cip

prod

uctio

n ha

s dim

inis

hed

•The

war

m se

ctor

air

has b

een

lifte

d up

war

d•T

he c

old

air i

s at t

he su

rfac

e -s

tabl

e si

tuat

ion.

Raz

voj c

iklo

na iz

val

a na

pol

arni

fron

ti

Mid

-latit

ude

cycl

ones

are

"de

ep"

pres

sure

sy

stem

s ext

endi

ng fr

om th

e su

rfac

e to

tropo

paus

ele

vel

•tha

t the

y ar

e an

exa

mpl

e of

a "

cold

cor

e lo

w"

•for

the

stor

m to

dev

elop

and

gro

w, i

t can

no

t be

verti

cally

"st

acke

d"

Ver

tikal

na st

rukt

ura

cikl

ona

v ra

zvoj

u

•The

upp

er-le

vel l

ow m

ust b

e lo

cate

d no

rth a

nd w

est

of th

e su

rfac

e lo

w -

i.e.,

the

area

of l

ow p

ress

ure

mus

t til

t to

the

north

wes

t with

hei

ght.

•An

area

of d

iver

genc

eM

UST

be

dire

ctly

abo

ve th

e su

rfac

e lo

w•I

f div

erge

nce

alof

t > c

onve

rgen

ceat

surf

ace,

the

low

w

ill d

eepe

n, in

tens

ifyin

g th

e st

orm

•If d

iver

genc

e al

oft <

con

verg

ence

at s

urfa

ce, t

he lo

w

will

dec

ay

Que

stio

n:

Wou

ld a

wav

e cy

clon

e in

tens

ify o

r dis

sipa

te if

the

uppe

r tro

ugh

wer

e lo

cate

d to

the

east

of t

he su

rfac

e di

stur

banc

e?N

ariš

i reš

itev

Ver

tikal

na st

rukt

ura

cikl

ona

v ra

zvoj

u

Ant

icyc

lone

:•T

he u

pper

-leve

l hig

h M

UST

be

loca

ted

sout

h an

d w

est o

f th

e su

rfac

e hi

gh -

i.e.,

the

area

of h

igh

pres

sure

mus

t tilt

to

the

sout

hwes

t with

hei

ght

•An

area

of c

onve

rgen

ce M

UST

be

dire

ctly

abo

ve th

e su

rfac

e hi

gh•if

con

verg

ence

alo

ft >

dive

rgen

ce a

t sur

face

, pre

ssur

e at

su

rfac

e w

ill in

crea

se a

nd th

e hi

gh w

ill b

uild

(int

ensi

fy)

•if c

onve

rgen

ce a

loft

< di

verg

ence

at s

urfa

ce, p

ress

ure

at

surf

ace

will

dec

reas

e an

d th

e hi

gh w

ill d

ecre

ase

in

inte

nsity

Ver

tikal

na st

rukt

ura

cikl

ona

v ra

zvoj

u

Stor

m m

otio

n an

d sp

eed:

•The

dire

ctio

n an

d sp

eed

of th

e (id

ealiz

ed) c

yclo

ne is

clo

sely

app

roxi

mat

ed

by th

e sp

eed

and

dire

ctio

n of

the

flow

at 5

00m

b -s

teer

ing

leve

l•c

yclo

ne m

oves

in d

irect

ion

of 5

00m

bw

inds

•cyc

lone

mov

es w

ith sp

eed

= 1/

2 50

0mb

win

d sp

eed

•Lon

g w

aves

-ar

e a

fund

amen

tal f

eatu

re o

n an

un

even

ly h

eate

d ro

tatin

g sp

heric

al p

lane

t.•a

lso

refe

rred

to a

sRos

sby

wav

es•u

sual

ly a

re 4

-6 o

f the

m a

roun

d th

e gl

obe

at a

gi

ven

time

•wav

elen

gth

varie

s bet

wee

n 40

00-8

000

km

Dol

gi v

alov

i v z

ahod

nem

toku

•Sho

rt w

aves

(sho

rt w

ave

troug

hs)-

are

embe

dded

in th

e lo

ng w

aves

•mov

e qu

ickl

y to

the

east

•wea

ken

whe

n m

ove

to a

long

-wav

e rid

ge•s

treng

then

whe

n th

ey m

ove

to a

long

-wav

e tro

ugh

•Sho

rt w

aves

are

read

ily o

bser

vabl

e at

mid

leve

ls (e

.g.,

500

mb

char

t)•S

hort

wav

es a

re a

n im

porta

nt in

gred

ient

for t

he d

evel

opm

ent a

nd in

tens

ifica

tion

of a

m

id-la

titud

e cy

clon

e -t

hrou

ghba

rocl

inic

inst

abili

ty

Kra

tki v

alov

i v z

ahod

nem

toku

•con

side

r a lo

ng w

ave

troug

h ov

er a

stat

iona

ry fr

ont (

a). T

hen,

ash

ort w

ave

mov

es in

to th

e tro

ugh,

inte

nsify

ing

the

troug

h (b

)•N

otic

e th

at in

itial

ly (a

), th

e st

ream

lines

and

isot

herm

s are

par

alle

l to

each

oth

er -

the

atm

osph

ere

isba

rotr

opic

•In

(b),

the

shor

t wav

e ha

s act

ed to

cau

se th

e st

ream

lines

to c

ross

the

isot

herm

s bot

h w

est

and

east

of t

he tr

ough

. The

atm

osph

ere

ther

e is

now

"bar

oclin

ic".

•In

the

baro

clin

icre

gion

wes

t of t

he tr

ough

, col

d-ai

r ad

vect

ion

is o

ccur

ring

•In

the

baro

clin

icre

gion

eas

t of t

he tr

ough

, war

m-a

ir a

dvec

tion

is o

ccur

ring

Bar

oklin

i raz

voj:

adve

kcija

, CA

in W

A v

sred

nji t

ropo

sfer

i

•Col

d-ai

r adv

ectio

n w

est o

f the

trou

gh w

ill p

rodu

ce si

nkin

g m

otio

n as

the

cold

air

desc

ends

to th

e su

rfac

e be

hind

the

cold

fron

t•W

arm

-air

adve

ctio

n ea

st o

f the

trou

gh w

ill p

rodu

ce ri

sing

mot

ion

near

the

cent

er o

f th

e lo

w a

s the

war

m a

ir as

cend

s.•T

his s

inki

ng a

nd ri

sing

of c

old

and

war

m a

ir du

e to

col

d an

d w

arm

air

adve

ctio

n is

ca

lled

baro

clin

icin

stab

ility

-a n

eces

sary

ingr

edie

nt fo

r the

dev

elop

men

t and

in

tens

ifica

tion

of a

mid

-latit

ude

cycl

one.

Bar

oklin

i raz

voj:

adve

kcija

, CA

in W

A v

sred

nji t

ropo

sfer

i

•War

m c

onve

yor

belt

-•O

rigin

ates

at l

ow le

vels

in th

e w

arm

sect

or•D

ry c

onve

yor

Bel

t -•O

rigin

ates

at u

pper

leve

ls a

nd d

esce

nds t

o th

e su

rfac

e•O

ften

prod

uces

a re

gion

of c

lear

ing

skie

s beh

ind

the

cold

fron

t.•C

old

Con

veyo

r B

elt -

•orig

inat

es N

E of

low

, sw

irls i

nto

the

low

at t

hen

asce

nds t

o up

per l

evel

s

Bar

oklin

i raz

voj:

adve

kcija

, CA

in W

A v

sred

nji t

ropo

sfer

i

•Jet

stre

aks(

win

d m

axim

um in

jet s

tream

) ten

d to

be

foun

d in

bas

e of

trou

gh•C

onve

rgen

ceof

air

occu

rs in

the

entra

nce

regi

on a

nd is

max

imiz

ed o

n th

e le

ft si

de (p

oint

C)

•Div

erge

nce

of a

ir oc

curs

in th

e ex

it re

gion

and

is m

axim

ized

on

the

left

side

(poi

nt D

)

Pom

en v

etro

vneg

a st

ržen

a

•C

yclo

nic

deve

lopm

ent u

sual

lyne

ed to

hav

e a

dist

urba

nce

at th

e su

rfac

e (a

rea

of lo

wer

pr

essu

re) n

orm

ally

alo

ng th

e po

lar f

ront

•Als

o ne

ed u

pper

-leve

l sup

port

-a sh

ort w

ave

with

ass

ocia

ted

uppe

r-le

vel l

ow/tr

ough

mus

t be

situ

ated

such

that

the

uppe

r-le

vel l

ow is

to th

e no

rthw

est o

f the

surf

ace

low

.

Povz

etek

•The

shor

twav

ege

nera

tes w

arm

and

col

d-ai

r ad

vect

ion

at m

id-u

pper

leve

ls (r

efer

red

to

diff

eren

tial t

empe

ratu

re a

dvec

tion)

•The

diff

eren

tial t

empe

ratu

re a

dvec

tion

gene

rate

s sin

king

and

risi

ng m

otio

n•A

t jet

-stre

am le

vel,

jet s

treak

s in

the

base

of a

tro

ugh

gene

rate

are

as o

f con

verg

ence

wes

t of

the

troug

h, a

nd d

iver

genc

e ea

st o

f the

trou

gh.

•With

out u

pper

leve

lsup

port,

surf

ace

dist

urba

nces

can

not

read

ily in

tens

ify

•Ea

stof

vort

max

will

be

dive

rgen

ce, u

pwar

d m

otio

n•W

esto

fvor

tmax

will

be

conv

erge

nce,

dow

nwar

d m

otio

n•W

hen

avo

rtm

ax m

ove

tow

ard

the

pola

r fro

nt, i

t is

poss

ible

that

it w

ill h

elp

gene

rate

a w

ave

cycl

one

•Eve

nin

the

abse

nce

of su

rfac

e fr

onts

, a sh

ort w

ave

can

prod

uce

an a

rea

of c

loud

ines

s and

som

etim

espr

ecip

.•S

hort

wav

es a

re re

adily

seen

at u

pper

leve

ls in

mod

el

pred

ictio

ns•m

ost e

asily

obs

erve

d in

wat

er v

apor

sate

llite

imag

ery

Dia

gnoz

a s p

omoč

jo v

rtinč

nost

i

Sate

lit: h

ttp://

ww

w.ss

d.no

aa.g

ov/e

umet

/nea

tl/fla

sh-w

v.ht

ml