transient and eddy transient/eddy fluxyu/class/ess200a.2004/lecture.8.eddies.pdftransient eddy...
TRANSCRIPT
1
ESS
200A
Pro
f. J
in-Y
i Yu
Lec
ture
7: D
istu
rban
ce (
Out
line)
Tra
nsie
nts
and
Edd
ies
Cli
mat
e R
oles
Mid
-Lat
itude
Cyc
lone
s
Tro
pica
l Hur
rica
nes
Mid
-Oce
an E
ddie
s
(Fro
m W
eath
er &
Cli
mat
e)
ESS
200A
Pro
f. J
in-Y
i Yu
Tra
nsie
nt a
nd E
ddy
Tra
nsie
nt: d
evia
tions
fro
m ti
me
mea
n
Edd
y: d
evia
tions
fro
m z
onal
mea
n
Why
tran
sien
ts/e
ddie
s m
atte
r to
zon
al a
nd ti
me
mea
ns?
Tim
e M
ean
Zon
al M
ean
ESS
200A
Pro
f. J
in-Y
i Yu
Flu
x C
ompo
nent
s
Thr
ee c
ompo
nent
s co
ntri
bute
to
the
zona
l-an
d ti
me-
mea
n tr
ansp
ort:
(1)M
ean
Mer
idio
nalC
ircu
latio
n (s
uch
as th
e th
ree-
cell
circ
ulat
ion)
(2)S
tatio
nary
pla
neta
ry W
aves
(su
ch a
s th
e w
aven
umbe
r 1-
3 ed
dies
in th
e N
orth
ern
Hem
isph
ere)
.
(3)T
rans
ient
Edd
ies
(suc
h as
the
wea
ther
sys
tem
s =
mid
latit
ude
cycl
ones
an
d an
ticyc
lone
s).
(2)
(1)
(3)
ESS
200A
Pro
f. J
in-Y
i Yu
Tra
nsie
nt/E
ddy
Flux te
mpe
ratu
rem
otio
n
[V*T
*] >
0
On
zona
l ave
rage
, edd
ies
tran
spor
t he
at n
orth
war
d.E
ddie
s co
ntri
bute
to
zona
l-m
ean
heat
tra
nspo
rt
2
ESS
200A
Pro
f. J
in-Y
i Yu
Cli
mat
e R
oles
of
Edd
ies
Stat
iona
ry a
nd tr
ansi
ent e
ddie
s ar
e im
port
ant t
o th
e po
lew
ard
flux
es o
f te
mpe
ratu
re, m
oist
ure,
en
ergy
, and
ang
ular
mom
entu
m.
ESS
200A
Pro
f. J
in-Y
i Yu
Pole
war
d Fl
ux o
f T
empe
ratu
re
Tra
nsie
nt e
ddy
flux
es
dom
inan
t the
mer
idio
nal f
lux
of te
mpe
ratu
re e
xcep
t in
the
Nor
ther
n H
emis
pher
e du
ring
w
inte
r, w
hen
stat
iona
ry e
ddie
s co
ntri
bute
up
to h
alf
of th
e fl
ux.
The
low
-lev
el m
axim
um in
th
e tr
opos
pher
e is
ass
ocia
ted
with
the
stru
ctur
e of
gro
win
g m
id-l
atitu
de c
yclo
nes
(I.e
., w
eath
er s
yste
ms)
.
(Fro
m G
loba
l Phy
sica
l Cli
mat
olog
y)
ESS
200A
Pro
f. J
in-Y
i Yu
Pole
war
d Fl
ux o
f M
oist
ure
Bot
h th
e m
ean
mer
idio
nal
circ
ulat
ion
and
eddi
es tr
ansp
ort
wat
er a
nd p
lay
an im
port
ant
role
in d
eter
min
ing
the
natu
re
of th
e hy
drol
ogic
al c
ycle
.
Moi
stur
e co
nver
genc
e in
the
trop
ics
is d
omin
ated
by
the
tran
spor
t pro
vide
d by
the
mea
n m
erid
iona
l cir
cula
tion.
The
subt
ropc
sse
rves
as
sour
ce
regi
ons
for
wat
er v
apor
.
Edd
ies
rem
ove
wat
er f
rom
the
trop
ics
and
supp
ly it
to m
iddl
e an
d hi
gh la
titud
es.
(Fro
m G
loba
l Phy
sica
l Cli
mat
olog
y)
ESS
200A
Pro
f. J
in-Y
i Yu
Pole
war
d Fl
ux o
f M
omen
tum
In th
e tr
opic
al e
aste
rlie
s, e
astw
ard
angu
lar
mom
entu
m is
tran
sfer
red
from
Ear
th to
the
atm
osph
ere
via
fric
tiona
l for
ces
and
mou
ntai
n to
rque
.
Thi
s w
este
rly
angu
lar
mom
entu
m
is tr
ansp
orte
d up
war
d an
d th
en
pola
rwar
d in
to th
e H
adle
y C
ell.
Edd
ies
then
tran
spor
t ang
ular
m
omen
tum
pol
arw
ard
and
dow
nwar
d in
to m
id-l
atitu
de
wes
terl
ies.
In th
e m
id-l
atitu
de, t
he w
este
rly
mom
entu
m is
ret
urne
d to
the
Ear
th.
3
ESS
200A
Pro
f. J
in-Y
i Yu
Stat
iona
ry P
lane
tary
Wav
es
Stat
iona
ry: T
hese
wav
es d
o no
t mov
e ar
ound
muc
h an
d ar
e fi
xed
in c
erta
in
geog
raph
ic lo
catio
ns.
Pla
neta
ry: T
hese
wav
es h
ave
larg
e w
avel
engt
hs, o
ne th
e or
der
of s
ever
al
thou
sand
s of
kilo
met
ers.
Wav
e: T
heir
str
uctu
res
vary
in th
e zo
nal
dire
ctio
n.
Stat
iona
ry p
lane
tary
wav
es a
re f
orce
d by
la
rge-
scal
e m
ount
ains
(su
ch a
s H
imal
aya
and
Roc
ky m
ount
ain
rang
es)
and
heat
co
ntra
sts
betw
een
cont
inen
ts a
nd o
cean
s.
Stat
iona
ry p
lane
tary
wav
es a
re s
tron
ger
in w
inte
r th
an in
sum
mer
.
Janu
ary
Hei
ght
of 5
00-m
b P
ress
ure
Surf
ace
(Fro
m G
loba
l Phy
sica
l Cli
mat
olog
y)E
SS20
0AP
rof.
Jin
-Yi Y
u
Tra
nsie
nt E
ddie
sM
id-l
atitu
de c
yclo
ne a
nd a
ntic
yclo
ne a
re th
e m
ajor
tran
sien
t edd
ies
that
pla
y an
impo
rtan
t ro
le in
mer
idio
nal t
rans
port
s of
hea
t, m
omen
tum
, and
moi
stur
e.
The
se m
id-l
atitu
de w
eath
er s
yste
ms
grow
fr
om th
e ba
rocl
inic
inst
abili
ty a
ssoc
iate
d w
ith th
e st
rong
nor
th-s
outh
tem
pera
ture
gr
adie
nts
in m
id-l
atitu
des.
Mid
-lat
itude
cyc
lone
s ha
ve ty
pica
l spa
tial
scal
es o
f w
aven
umbe
rs 5
-6 a
nd h
ave
typi
cal
time
scal
e of
7-1
0 da
ys.
Mid
-lat
itude
cyc
lone
s ar
e m
arke
d by
wel
l-de
fine
d fr
onts
sep
arat
ing
the
war
m a
ir m
ass
from
the
sout
h an
d th
e co
ld a
ir m
ass
from
th
e no
rth.
(V
ery
diff
eren
t fro
m tr
opic
al
hurr
ican
es, w
hich
do
not h
ave
fron
tal
feat
ures
).
(Fro
m W
eath
er &
Cli
mat
e)
ESS
200A
Pro
f. J
in-Y
i Yu
Col
d an
d W
arm
Fro
nts
cold fr
ont
war
m fr
ont
Mid
-Lat
itude
Cyc
lone
(Fro
m W
eath
er &
Cli
mat
e)
ESS
200A
Pro
f. J
in-Y
i Yu
How
Cyc
lone
Gro
ws?
(Fro
m W
eath
er &
Cli
mat
e)
Pot
entia
l Ene
rgy
Ava
ilab
le P
. Ene
rgy
(col
d/w
arm
air
mov
es s
outh
/nor
th)
(V*T
* >
0)
Ava
ilab
le E
nerg
y K
inet
ic E
nerg
y
(col
d/w
arm
air
mov
es d
own/
up)
(W*T
*>0)
4
ESS
200A
Pro
f. J
in-Y
i Yu
Ava
ilabl
e Po
tent
ial E
nerg
y
ESS
200A
Pro
f. J
in-Y
i Yu
Lif
e C
ycle
of
Mid
-Lat
itude
Cyc
lone
Cyc
loge
nesi
s
Mat
ure
Cyc
lone
Occ
lusi
on
(fro
m W
eath
er &
Cli
mat
e)
ESS
200A
Pro
f. J
in-Y
i Yu
Tro
pica
l Hur
rica
ne
The
hur
rica
ne is
ch
arac
teri
zed
by a
str
ong
ther
mal
ly d
irec
t cir
cula
tion
with
the
risi
ng o
f w
arm
air
ne
ar th
e ce
nter
of
the
stor
m
and
the
sink
ing
of c
oole
r ai
r ou
tsid
e.
The
war
m c
ore
of th
e hu
rric
ane
serv
es a
s a
rese
rvoi
r of
pot
enti
al e
nerg
y,
whi
ch is
con
tinu
ousl
y be
ing
conv
erte
d in
to k
inet
ic
ener
gy b
y th
e th
erm
ally
di
rect
cir
cula
tion.
(fro
m W
eath
er &
Cli
mat
e)
ESS
200A
Pro
f. J
in-Y
i Yu
The
y A
re th
e Sa
me
Thi
ngs…
Hur
rica
nes:
extr
eme
trop
ical
sto
rms
over
Atl
antic
and
eas
tern
Pac
ific
O
cean
s.
Typ
hoon
s:ex
trem
e tr
opic
al s
torm
s ov
er w
este
rn P
acif
ic O
cean
.
Cyc
lone
s:ex
trem
e tr
opic
al s
torm
s ov
er I
ndia
n O
cean
and
Aus
tral
ia.
(fro
m W
eath
er &
Cli
mat
e)
5
ESS
200A
Pro
f. J
in-Y
i Yu
Air
Par
cel E
xpan
ds A
s It
Ris
es…
Air
pre
ssur
e de
crea
ses
with
ele
vati
on.
If a
hel
ium
bal
loon
1 m
in d
iam
eter
is
rele
ased
at
sea
leve
l, it
expa
nds
as it
fl
oats
upw
ard
beca
use
of t
he p
ress
ure
decr
ease
. The
bal
loon
wou
ld b
e 6.
7 m
in
diam
eter
as
a he
ight
of
40 k
m.
(fro
m T
he B
lue
Pla
net)
ESS
200A
Pro
f. J
in-Y
i Yu
Adi
abat
ic L
apse
Rat
e
Adi
abat
ic la
pse
rate
= 1
0°C
/km
or
1°C
/100
m
= a
ir t
empe
ratu
re in
a r
isin
g ba
lloon
dro
ps 1
°C e
very
100
m.
(fro
m U
nder
stan
ding
Wea
ther
& C
lim
ate)
ESS
200A
Pro
f. J
in-Y
i Yu
Wat
er V
apor
In
the
Air
Eva
pora
tion
:th
e pr
oces
s w
here
by m
olec
ules
bre
ak f
ree
of t
he li
quid
vol
ume.
Con
dens
atio
n:w
ater
vap
or m
olec
ules
ran
dom
ly c
ollid
e w
ith t
he w
ater
sur
face
and
bo
nd w
ith a
djac
ent
mol
ecul
es.
(fro
m U
nder
stan
ding
Wea
ther
& C
lim
ate)
Satu
rati
on
ESS
200A
Pro
f. J
in-Y
i Yu
Spec
ific
.vs.
Rel
ativ
e H
umid
ity
Spe
cifi
c H
umid
ity:
How
man
y gr
ams
of w
ater
vap
or i
n on
e ki
logr
amof
air
(in
uni
t of
gm
/kg)
.
Rel
ativ
e H
umid
ity:
The
per
cent
age
of c
urre
nt m
oist
ure
cont
ent t
oth
e sa
tura
ted
moi
stur
e am
ount
(in
un
it o
f %
).
Clo
uds
form
whe
n th
e re
lati
ve h
umid
ity
reac
hes
100%
.
spec
ific
hum
idit
y6
gm/k
g
satu
rate
dsp
ecif
ic h
umid
ity
10 g
m/k
g
satu
rate
dsp
ecif
ic h
umid
ity
20 g
m/k
gR
elat
ive
hum
idit
y 6/
20 x
100
%=
30 %
Rel
ativ
e hu
mid
ity
6/10
x 1
00%
=60
%
6
ESS
200A
Pro
f. J
in-Y
i Yu
Why
Clo
uds
For
m?
Clo
uds
form
whe
n ai
r ri
ses
and
beco
mes
sat
urat
ed in
res
pons
e to
ad
iaba
tic
cool
ing.
ESS
200A
Pro
f. J
in-Y
i Yu
Clo
ud T
ype
Bas
ed O
n Pr
oper
ties
Four
bas
ic c
loud
cat
egor
ies:
Cir
rus
---
thin
, wis
py c
loud
of
ice.
Stra
tus
---
laye
red
clou
dC
umul
us--
-cl
ouds
hav
ing
vert
ical
dev
elop
men
t.N
imbu
s--
-ra
in-p
rodu
cing
clo
ud
The
se b
asic
clo
ud ty
pes
can
be c
ombi
ned
to
gene
rate
ten
diff
eren
t clo
ud ty
pes,
suc
h as
ci
rros
trat
us c
loud
s th
at h
ave
the
char
acte
rist
ics
of
cirr
us c
loud
s an
d st
ratu
s cl
ouds
.
ESS
200A
Pro
f. J
in-Y
i Yu
Clo
ud T
ypes
Bas
ed O
n H
eigh
t
If b
ased
on
clou
d ba
se h
eigh
t, th
e te
n pr
inci
pal c
loud
type
s ca
nth
en g
roup
ed
into
fou
r cl
oud
type
s:
Hig
h cl
ouds
--ci
rrus
, cir
rost
ratu
s, c
irro
scum
ulus
.
Mid
dle
clou
ds–
alto
stra
tus
and
alto
cum
ulus
Low
clo
uds
–st
ratu
s, s
trat
ocum
ulus
, and
nim
bost
artu
s
Clo
uds
wit
h ex
tens
ive
vert
ical
dev
elop
men
t–cu
mul
us a
nd c
umul
onim
bus.
(fro
m “
The
Blu
e P
lane
t”)
ESS
200A
Pro
f. J
in-Y
i Yu
Clo
ud C
lass
ific
atio
ns
(fro
m “
The
Blu
e P
lane
t”)
7
ESS
200A
Pro
f. J
in-Y
i Yu
Hig
h C
loud
s
Hig
h cl
ouds
hav
e lo
w c
loud
te
mpe
ratu
re a
nd lo
w w
ater
con
tent
an
d co
nsis
t mos
t of
ice
crys
tal.
1. C
irru
s C
loud
s
2. C
irro
stra
tus
Clo
uds
3. C
irro
cum
ulus
Clo
uds
(fro
m A
ustr
alia
n W
eath
er S
ervi
ce)
ESS
200A
Pro
f. J
in-Y
i Yu
Mid
dle
Clo
uds
Mid
dle
clou
ds a
re u
sual
ly c
ompo
site
of
liqui
d dr
ople
ts.
The
y bl
ock
mor
e su
nlig
ht to
the
surf
ace
than
the
hig
h cl
ouds
.
5. A
ltocu
mul
us C
loud
s4.
Alto
stra
tus
Clo
uds
(fro
m A
ustr
alia
n W
eath
er S
ervi
ce)
ESS
200A
Pro
f. J
in-Y
i Yu
Low
Clo
uds
Low
, thi
ck, l
ayer
ed c
loud
s w
ith la
rge
hori
zont
al e
xten
ds, w
hich
can
exc
eed
that
of
seve
ral s
tate
s.
6. S
trat
usC
loud
s
7. S
trat
ocum
ulus
Clo
uds
8. N
imbo
stra
tus
Clo
uds
(fro
m A
ustr
alia
n W
eath
er S
ervi
ce)
ESS
200A
Pro
f. J
in-Y
i Yu
Clo
uds
With
Ver
tical
Dev
elop
men
t
The
y ar
e cl
ouds
with
sub
stan
tial v
ertic
al d
evel
opm
ent a
nd o
ccur
whe
n th
e ai
r is
ab
solu
te o
r co
ndit
iona
lly u
nsta
ble.
9. C
umul
us C
loud
s10
. Cum
ulon
imbu
s C
loud
s
(fro
m A
ustr
alia
n W
eath
er S
ervi
ce)
8
ESS
200A
Pro
f. J
in-Y
i Yu
Mid
-Oce
an E
ddie
sT
he G
ulf
Str
eam
and
the
Kur
oshi
o sp
in o
ff lo
ng-l
ived
edd
ies
via
baro
clin
ic a
nd b
arot
ropi
c in
stab
ilitie
s.
The
rol
e of
edd
ies
for
heat
tran
spor
t in
the
ocea
n is
like
ly m
uch
less
than
in
the
atm
osph
ere.
The
oce
anic
edd
ies
are
best
de
velo
ped
wel
l pol
ewar
d of
the
latit
ude
of th
e m
axim
um o
cean
ic
tran
spor
t.
The
win
d-dr
iven
and
ther
moh
alin
e ci
rcul
atio
ns a
re li
kely
to p
rovi
de
muc
h m
ore
impo
rtan
t con
trib
utio
ns to
th
e m
erid
iona
l hea
t flu
x in
the
subt
ropi
cs.
(Fig
ure
from
Oce
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