iz .G Gd - AstroBio Group cell Ferrel cell Polar cell Easterly wind Westerly wind Earth Venus Mars Titan Summer Winter Easterly wind Westerly wind Hadley cell Ferrel cell ... Taylor–Proudman

!"# $ $%

( ( ( ( ( ( ((

=,8*,'(>$??!@

!

$?AB

($?AC

<,DDE2 (

F( (F(<,DDE2 ((

(F( (

> G(!%%H@(>I38E2G($??B@

<,DDE2

•!

(

•!

(

•! <,DDE2(

J I

<,DDE2(-7K,+430,'(+3-5.D

((((((

(

L = NHf

!(L( ("(L( (#(M(!$/,D(" :"(L(

N3+347*7+(D*.-2(,K(*O7(3*4,DPO7+5/(/5+/.830,'(,K(Q3+*OR85S7(P83'7*D(T5*O(97'7+38(/5+/.830,'(4,-78D(>UV6D@

Williams (1988)

Latitude

Pres

sure

W3D*(+,*30,'

I8,T(+,*30,'

Latitude

Pres

sure

Fast rotation

Slow rotation

Latitude

Pres

sure

Fast rotation

Slow rotation

243 1 10

( BHS4 !"#B%

&S3*D.S5('73+R)<(>!;%!µ4@(54397D

•!(

•!

(!"#$

F

(

V3DD5'5R=.297'D

( $B $%

Hadley cell

Ferrel cell

Polar cell

Easterly wind

Westerly wind

Earth Venus

Mars Titan

Summer

Winter

Easterly wind

Westerly windHadley cell

Ferrel cell

Super-rotation

Super-rotation

•! A"%X ?%X (•! B%H%S4 !HAHS4

Y! !"# $B (Y! (Y! #% $%% (

(U57+3D/OG($?A"Z(<,DD,T([(\588534DG($?A?

! (\588534D(3'-(<,DD,T( $?A?@(

(

(

F

(

(

!;C (

(

(

(

$$;H (

(

(

(

$A;!

•!(

•! (•! (

]7E,'',5D(7*(38;(>!%$$@

(>W78D([(]5'-^7'($?A"@

J7T43'([(]7,_2(>$??!@(

(

(

(

(

(

(

UV6

(M(B#A%(S4 (M(##?%(S4

N,883/S(7*(38;(>$??%@

((

(_D;( ((

Taylor–Proudman theorem•! In a fluid that is steadily rotated, the fluid velocity will be

uniform along any line parallel to the axis of rotation.

d! v dt

+ 2! " #! v + 1

$%p +%& = 0

Momentum equation in rotational frame

Assuming non-compressivity and d/dt=0, the curl is applied to give

! " # $

! v = 0

Taking z-axis along the planet’s rotational axis,

"! v "z

= 0

z

yz

! "

>I/O'75-7+([(]5.G(!%%?@

(

^,'38(_78,/5*2

(+7830_7(_,+0/5*2(,K(O,+5^,'*38(`,T

Qa.3*,+538(D.P7++,*30,'(5'(*O7(I.'

<,*;(+3*7(M(!H(-32D(,'(*O7(7a.3*,+(((((((((((((((((((((#B(-32D('73+(*O7(P,87D

J.47+5/38(4,-785'9(>657D/O(!%%%@

b7+0/38(_78,/5*2(3*(+(M(%;?H(<

Qa.3*,+T3+-(3'9.83+(4,47'*.4(*+3'DP,+*(E2(D83'*(/,'_7/0,'(c(

<,*30,'(+3*7D(+7_7387-(E2(O785,D75D4,8,92(

(>X+3./.'3D([(=3+*43''G(!%%H@

( UV6

((((

(

!

•!(

•! !

•!

(•!

((

(]77(>$???@ V3E3887+,(3'-(6;(=.E7+(>!%$%@(

&*4,DPO7+5/(/5+/.830,'(,K(7d,P83'7*D

•! e5-3882R8,/S7-(P83'7*D(D774(*,(E7(.E5a.5*,.D(5'(*O7(.'5_7+D7;(eO,D7(P83'7*D(3+7(/,'D5-7+7-(*,(E7(D8,T(+,*3*,+(85S7(b7'.D;()*(5D(P,DD5E87(*O3*(D.P7+R+,*30,'(+7-5D*+5E.*7D(*O7+438(7'7+92(38,'9(*O7(8,/38(047(,'(D./O(P83'7*D;(

=,*(-32D5-7(V,8-('59O*D5-7

I8,T(/5+/.830,' W3D*(/5+/.830,'

6,-7+3*7(/8543*7(

V7'*+38(D*3+

V7'*+38(D*3+

Atmospheres of Synchronously Rotating Terrestrial Planets Orbiting M Dwarfs (Joshi et al., 1997)

•! Planets within the habitable zones of M dwarfs are likely to be synchronous rotators; in other words, one side is permanently illuminated while the other side is in perpetual darkness.

•! Simulation with a rotation rate similar to that of Titan

<3-530_7(047(/,'D*3'*(,K(4,-7+'(b7'.D(3*4,DPO7+7

N,883/S([(f,.'9(>$?AH@

"(!%%%%(-32D

"(!(-32D

"($%%(-32D(>gQ3+*O@

(!%%%

%&'()&*+,$-"&#+..+%(#"()/$+)0$+1&*2'(*'

%&'()&*+,$-"&#+33+%(#"()/$+)0$+1&*2'(*'

I.ED,83+R*,R3'0D,83+(/5+/.830,'

&d5RD2447*+5/(/5+/.830,'

b7'.D(432(O3_7(O3-(3(DO388,T(85a.5-RT3*7+(,/73'(3'-(O3E5*3E87(D.+K3/7(*74P7+3*.+7D(K,+(.P(*,(!(E5885,'(273+D(,K(5*D(73+82(O5D*,+2G(3//,+-5'9(*,(/,4P.*7+(4,-785'9(,K(*O7(P83'7*hD(3'/57'*(/8543*7(E2(D/57'0D*D(3*(J&I&hD(U,--3+-()'D0*.*7(K,+(IP3/7(I*.-57D(>U)II@(5'(J7T(f,+S;((eO7(i'-5'9DG(P.E85DO7-(*O5D(T77S(5'(*O7(j,.+'38(U7,PO2D5/38(<7D73+/O(]7k7+DG(T7+7(,E*35'7-(T5*O(3(4,-78(D54583+(*,(*O7(*2P7(.D7-(*,(P+7-5/*(K.*.+7(/8543*7(/O3'97(,'(Q3+*O;

I54(&(I,83+(`.dL($;"B(d(Q3+*OG((<,*;(P7+5,-L(6,-7+'(b7'.D(

((

•! U8,E38(473'(D.+K3/7(35+(*74P7+3*.+7(,K($$lV(-7DP5*7(3'(5'/5-7'*(D,83+(`.d(3*(b7'.DhD(,+E5*(g"Bm(O59O7+(*O3'(*O3*(+7/75_7-(E2(4,-7+'(Q3+*O(

•! eO7(-32D5-7(,K(*O7(P83'7*(5D(384,D*(/,4P87*782(/8,.-2;((

Surface air temperature Cloudiness

Surface level winds

4(5+$'+(67+89:;<=+>4(2+?$*@2+'A$+B-2'+A(C"'(C6$+D&-6#+&E+&@-+2&6(-+252'$0F+>

\O3*(5D(O3PP7'5'9(5'(I54(&(c

•! eO7(O59OR87_78(/8,.-5'7DD(,'(*O7(-32D5-7(,K(I54(&(O3D(_38.7D(3D(O59O(3D($%%m;(eO5D(5D(*O7(+7D.8*(,K(*O5D(T,+8-hD(D8,T(+,*30,'(TO5/O(97'7+3*7D(3(D*+,'9(/5+/.830,'(T5*O(+5D5'9(4,0,'(3'-(3//,4P3'25'9(O59O(*O5/S(/8,.-D(,'(*O7(-32D5-7(*O3*(+7`7/*(3(D.ED*3'038(K+3/0,'(,K(*O7(5'/5-7'*(D.'859O*;(

•! eO7D7(O59O82(+7`7/0_7(*O5/S(3+73882(7d*7'D5_7(/8,.-D(3+7(K,+47-(K+,4(D43887+(D/387(P3+347*7+5^7-(/,'_7/0_7(/8,.-D(*O3*(/3++2(T3*7+(_3P,+(3'-(/,'-7'D7-(T3*7+(*,(O59O(380*.-7D(5'(E.,23'*(.P-+3nD;(

(!%%%