1. inertial period (惯性周期P135):4 t2 n: N* w7 a1 U* S+ z1 _& K
It is one half the time required for the rotation of a local plane on Earth’s surface
1 k, l) y4 a+ y5 p2. geostrophic balance (地转平衡P151):
& x: Z. Q4 e5 aWithin the ocean’s interior away from the top and bottom Ekman layers, for horizontal distances exceeding a few tens of kilometers, and for times exceeding a few days, horizontal pressure gradients in the ocean almost exactly balance the Coriolis force resulting from horizontal currents. This balance is known as the geostrophic balance.; x' |- \) G' K6 E7 F
3. pressure gradient (压力梯度):; Q& V+ x# M3 j
In atmospheric sciences (meteorology, climatology and related fields), the pressure gradient (typically of air, more generally of any fluid) is a physical quantity that describes which direction and at what rate the pressure changes the most rapidly around a particular location. The pressure gradient is a dimensional quantity expressed in units of pressure per unit length. The SI unit is pascal per metre (Pa/m).
2 D5 z' e0 S& i0 t" ~5 i4 S+ r4. mixed layer (混合层P81) :7 t: k7 F2 v/ \/ ]& Z1 |
Wind blowing on the ocean stirs the upper layers leading to a thin mixed layer at the sea surface having constant temperature and salinity from the surface down to a depth where the values differ from those at the surface. The magnitude of the difference is arbitrary, but typically the temperature at the bottom of the layer must be no more than 0.02–0.1? colder than at the surface./ The oceanic or limnological mixed layer is a layer in which active turbulence has homogenized some range of depth/ d: @, f9 ?* u# x1 z
5. Physical Oceanography(物理海洋学P8):
7 ^4 w# ?' `. b4 P/ N1 Q% ~8 |: ]Physical Oceanography is the study of physical properties and dynamics of the ocean. The primary interests are the interaction of the ocean with the atmosphere, the oceanic heat budget, water mass formation, currents, and coastal dynamics. Physical Oceanography is considered by many to be a subdiscipline of geophysics.1 G& [* @4 j# C, R: y
6. The Ekman number(埃克曼数P139)is a dimensionless number used in describing geophysical phenomena in the oceans and atmosphere. It characterises the ratio of viscous forces in a fluid to the fictitious forces arising from planetary rotation. It is named after the Swedish oceanographer Vagn Walfrid Ekman.3 h0 V1 S# a0 I; A& G
7. thermocline (温跃层P82):
8 V# F9 m/ c& I9 E8 EBelow the mixed layer, water temperature decreases rapidly with depth except at high latitudes. The range of depths where the rate of change, the gradient of temperature, is large is called the# `* Y) F7 V8 ~2 J
8. double diffusion (双扩散P130-131):
$ W5 } k! p# ~7 k# X9 FHere's what happens. Heat diffuses across the interface faster than salt, leading to a thin, cold, salty layer between the two initial layers. The cold salty layer is more dense than the cold, less-salty layer below, and the water in the layer sinks. Because the layer is thin, the fluid sinks in fingers 1-5cm in diameter and 10s of centimeters long, not much different in size and shape from our fingers. This is salt fingering. Because two constituents diffuse across the interface, the process is called double diffusion.p131* T0 n# ]( z8 i" R9 K
9. salinity(盐度)P73-75)
# Q7 ~2 b1 \/ e) q3 [0 jAt the simplest level, salinity is the total amount of dissolved material ingrams in one kilogram of sea water. Thus salinity is a dimensionless quantity. It has no units.
9 x1 |( V0 q2 k10. Reynolds number (雷诺数P116) :
) B- i: ?3 V3 x7 v6 |In fluid mechanics, the Reynolds number (Re) is a dimensionless number that gives a measure of the ratio of inertial forces to viscous forces and consequently quantifies the relative importance of these two types of forces for given flow conditions.. |% j5 ^' ]2 T/ ^% t
11. Coriolis Force (科氏力P133-134)
. A( I H$ w" P# \* P& B9 MIs the dominant pseudo-force influencing motion in a coor-dinate system fixed to the earth.
9 V0 u) h+ j& X" p; c12.Potential Temperature(位温P85)
& E( O7 R& J3 ^% @; t$ CPotential temperature Θis defined as the temperature of a parcel of water at the sea surface after it has been raised adiabatically from some depth in the ocean.: u5 n+ c1 m; ~
13.青藏高原对气候的意义及附近海洋的影响(P42-43)" }- ^$ d* q2 m- a; m. \0 K* d
Maps of surface winds change somewhat with the seasons. The largest changes are in the Indian Ocean and the western Pacific Ocean.Both regions are strongly influenced by the Asian monsoon. In winter, the cold air mass over Siberia creates a region of high pressure at the surface, and cold air blows southeastward across Japan and on across the hot Kuroshio, extracting heat from the ocean. In summer, the thermal low over Tibet draws warm, moist air from the Indian Ocean leading to the rainy season over India.
* ?. h+ F8 k* b4 U5 p9 b! k* D* ?3 u- v14. 科氏力推导
( T5 y9 T2 q& |$ s$ H/ k9 U' j; Y# ]: I8 c8 l4 Z" z4 b$ B4 `+ u
, P5 [, v6 o% L4 S U% d' g6 T0 ?- R* c( ~" G
15. 压强梯度力推导:压强梯度力并不是真正意义上的力,它实际是由于气压不同而产生的空气加速度(即单位质量所受的力)。它是产生从高气压向低气压的空气加速度的原因,产生风。常指空气的水平运动。
. |+ }$ y; t% b4 X
3 X* T# U; y: `7 w, r' q
- I4 u+ h" k$ S4 U 5 V4 z3 M/ j1 T1 ?+ i9 g) u
16. 地转流
5 D8 j. v4 E! G% Q0 t0 U水平压强梯度力和科氏力达到平衡时的稳定海流,叫做地转流。 一、地转流的成因: V( O* {1 P3 @" g
斜压场→水平压强梯度力→海水在受力方向上运动→科氏力→水平压强梯度力.......=.科氏力...→地转流
. P: T6 ]9 e! l6 \5 t, x二、地转流方程及其解% J4 Z- c" o3 t. r
* ~3 C" ?4 q6 Q8 L7 g
/ t6 f& c! a ^- }/ k* R
* X" E: F: K# Y Ex F w v x p
- Z' u" `4 k0 A) s) X* a" y; S/ M6 J, V# }1 }( |8 d
z u w y u v x u u t u +-+-=+++)cos sin (21??ω??ρ???????? y F u y6 N# \' S# q* O! P% H4 h
p
7 c6 {/ Z1 Q5 vz v w y v v x v u t v +--=+++?ω??ρ????????sin 21 z w w w w p
) R8 |) l8 H" p: Q9 C$ K1u v w 2u cos g F t x y z z E y* M, x3 ]0 p; `! v
?????+++=-+ω?-+????ρ?
& V0 v. c( V0 U设等压面只沿x 方向倾斜,夹角为β,则有
3 Q/ [- s. }+ [: t' `8 S1 H-+?=120ρ??ω?p x
9 K% m8 l0 y3 m4 c" ^5 x5 T6 k: \' w+ R
v sin (6-22) 01=--. ~" I8 ~2 w6 ?* k8 X& I
g z
7 n1 Z9 y; C$ O# d% mp0 ~7 S I% w* `# P; a' m
??ρ (6-23)
3 p3 p4 |3 r# @: O & A1 A' z1 f7 {9 b5 E
由(6-22)得 x! c8 W' i, V# \7 [
p f x p v ?ρ???ρω?==1sin 218 ^# ^! u; c! U- z2 i: p7 `3 B
(6-24)
) o) f9 c/ M+ u根据等压面方程dp 0=,有 0p p
u, f' i; h1 T- v/ L! tdp dx dz x z7 }1 V: w6 z( t: K: W3 s6 ]
????=
: V7 n! A- k' A) S2 E& `+=
- e) z( g" ]- W% _4 \) ^/ ]dx4 q( W; S: H0 u6 n. I
dz7 U5 Y4 F! v- a8 W% m
z p x p ????-& A$ {* A7 K: ~! }+ m
= (6-25) 利用式(6—23)可得1 w6 g8 K3 O! i6 c
??ρp
' ~# s! k. o3 Sz4 H3 N; @" ]" M! v
g =- 由图可知 dz
- \) B% ~* G; `tan dx8 \2 [' y w# `- ~) d
=β (6-27) 所以 ββρρρρtan )tan (1)(11f
4 v4 B* c) Z7 U2 v" Y @! bg Q M. i. F4 O u) R3 ?$ @: b* Y
g f dx dz z p f x p f v =?=??-=??=/ d n) ^: b' P; C
(6-28)0 N& L z5 V; |1 Y+ h
βtan f
6 i" J9 v( l9 @. c4 `( y/ n/ Vg2 E3 f, x' G- f, J) }3 \
v =; Q7 r" k3 q0 t' ~6 T7 ]
∴ 由(6— 28)式知:
# u9 b. N. m0 A- c4 ~% F内压场引起的地转流流速v :与等压面倾角的正切成正比;与科氏参量f 成反比;随深度增大而减小;
* Z1 t1 Q3 d* _7 @& c& s等压面与等势面平行时,流速为零 在赤道处:
U9 a" c2 C' i6 o$ z2 O??==00,sin ,f=0,式(6—28)不适用。
! M5 t' c# k+ Y; I* l+ Y4 ]5 P外压场引起的地转流(倾斜流):自表至底(不考虑底摩擦)流速相同 地转流流向:在等压面与等势面的交线上流动;9 }9 b$ g7 v8 ] K- @6 s8 F! T* S
在北半球垂直指向压强梯度力的右方;观测者顺流而立时,右侧等压面高,左侧低。 在南半球正好相反。
& M7 p& n0 S5 I! s7 y5 } ; H2 U, Z; x! O5 T+ B5 u4 M. h! X
17. 风海流
/ u- B% r- V& J一. 无限深海风海流' `+ h& Z1 e r' `
1.基本假定:0 c! N* \" @8 n9 w
北半球;稳定风场;无限广阔;海面水平;
0 K* }. @0 [9 W+ n0 l∞→t 、∞→h 、ρ、f 、A z 为常量。
) m/ k `# Z; q0 O J. R
' N* e& Q2 o0 r. a+ M8 m2.运动方程、边界条件及解的形式 动量方程:6 Y( x: F5 K& J, T! K8 w4 ?4 \' L
x F w v x p
; s' B; S8 P1 i2 Zz u w y u v x u u t u +-+-=+++)cos sin (21??ω??ρ???????? (1) y F u y3 ?0 }: a2 B! s+ A
p, t% k- b9 @$ \% M0 f+ }1 g
z v w y v v x v u t v +--=+++?ω??ρ????????sin 21 (2)2 s, x- ~$ l9 I6 h4 e- P w
分析:流速为常量;方程左边均为0; 只考虑切应力(摩擦力)与科氏力.
1 `- k" V* j8 h- F; O) X0=??x
4 T7 B. Y( ?0 C. w6 u Np (3); 221z u; ]9 W2 s4 A/ @
A z u A z F z z x ??=????=1 T* d/ v2 q* Z B3 R- P x
ρρ (5)
. v q3 q: D4 v+ l2 G. a, Q) g6 C5 O
" Q0 j- q3 I I3 U
0=??y p (4); 221z
: M! ~) [6 ^9 h7 M6 }3 Zv
. d+ `1 d' N- t$ Y* \A z v A z F z z y ??=????=ρρ (6) (1)、(2)式简化为:: f0 ~: ~! s* c4 O6 t0 x# j! c- p6 P
1 F4 H% w0 ^0 p# q$ ? W$ ~???% t4 ?+ `; S4 E- S
?! Z( d! [ M0 Y/ v) F
?
6 k9 f* ]: {( _3 F1 O: i, z$ g??=+?-=+?0sin 20sin 22: j9 `$ {' y) q
222z d v$ y0 D) w% ^0 m
d A u z d u
3 ^2 G0 k# [6 b0 kd A v z z ρ?ωρ?ω (7) 以
5 W" C4 C5 e/ D0 D# b2 @; Y?ωsin 2=f 代上式得 022=+v A f6 E# b ^3 s3 m, l, L5 ?( c |
: A& ~, `; P wdz# b' L; u' x0 A0 b$ q. P& ]# r
u d Z ρ (8)8 \- A: {4 c& ~0 D* v
02
4 \* B1 J) ?% P$ C+ C ~2=-u A f dz v d Z ρ (9) 引入复平面 令 vi u V+ [. b# ^! v) g
+= , z- R6 @3 }+ t( }" q5 N% m( n
A f
+ [! T$ s3 `( A9 G; y/ `a 22
* R3 i$ b3 O3 @. P- d8 Q, t) Lρ=+ c0 V" K4 _/ b( S7 z' _
3 q- `4 I. L! ?& M# z
复平面
, O1 X( u( M( Y: j% q+ z3 v$ {8 k(9)×I + (8)得
% k) }# x5 n9 H9 Z$ A9 A* X9 p3 n# Q0)(2)(26 `2 b* q4 \% v( j' O, b
2
" C" G" b2 m% \9 N& R* V% ~) p# ^3 {& v: U B
2=+-+vi u i a dz vi u d 0)1(2
' s9 v! F$ y6 S' V: I22% j7 u/ }: o( g$ T. }5 p
2=+-V a i dz V d 02
) l- g+ p" B, g' ?2: m; _3 ^3 o/ m, h
2=-V j dz
( X* s7 M. {7 c2 _0 b! }4 sV d (10) 解方程得
; s8 r. G7 n2 B/ ?a i j )1(+=
2 _* C/ z! ?* q. tV = A jz jz Be e -+ (11)
' c. L( D) z" t在海底: -∞=z ;V=0 ; B=05 f, _/ e: Y% D' J2 J8 k, z
在海面: 设风只沿 y 轴方向吹,则海面的边界条件为
6 U, I ~! H" }/ M% ndz dv A Z
6 X. @+ D% b4 s# M: j. ~5 zy =τ ; 0==dz du A z: W$ y9 f- j3 U {1 b$ F! J
x τ ;0=dz du (11)式对z 求导 jz jAe dz
0 y! | u# x* R/ x3 zdV
/ I) X; z1 h4 u4 h= (12) 由上式得 z=0时 11()y z
1 P: F; t3 f: |/ k8 r- N2 \4 jdV d u iv i dv i A j dz j dz j dz j A τ+====
7 |) K5 J- ?. ~, ^jz, \% d" q) Z3 |# X6 ]" @) e
Ae V =∴2 ]% M( |! y0 M! q
jz z5 ]+ j) p, J/ g4 F* Z! d- {3 z
z
4 O9 W% K* H- S8 V: `2 Oy e jA i V τ=
5 e7 E( R1 T8 }; ?1 B∴
; a2 R4 c5 i" c, P$ b! y. Yvi
' c8 ^' h% K }3 m/ m6 H1 Y" l1 Xu# i( Z$ |- u4 D4 p, @. s
6 V7 A2 S& c4 l; |0 {" W
=+=+=+=++=+=a i a i ia i i a i i i a i i j i 2)1(22212)1()1()1()1(2a
2 s% A3 v- @- S$ v! P2 we a i i 224sin 4cos 4π2 y' {1 L% b& |$ c. z
π
( ^+ Y" O/ `3 y. W: v2 [π=+ az# G" D1 y1 s N) ]9 K
i z
2 o ]# U* |! m( E/ \y
* E$ t6 r- @+ @' V; p" yi; b: U! O/ B2 t v# E1 S6 H
e
# n8 g' |; o: u: A/ O" gA a e
, _6 j/ g2 T' N0 i6 u( N* hV )1(4 s' U0 y+ L- O+ k: r7 f
2+=
( J5 ^% j0 Z0 J6 y% d6 i# E4 Uτπ5 x9 a! b5 i# _8 J# w& C i
==
6 Z/ }9 ^) _% \ E+ U++Z
* X7 @2 r5 G: N& t5 Y& Xz
9 f, M2 o! E4 R Q* b% [az i az y A A f
: H5 J: w7 z) T- [# A( }8 ^. U/ Ee: P+ i, t( q' Q0 j5 ` h0 L( K
228 t$ Q* u U# O" ] i
)
) e0 o/ f5 e8 c2 d: F& r" f4
+ ~: h" ~6 f" S# X" f(ρτπ
4 O) Y* W* j; X?9 k$ f5 E- _$ t% S
ωρτρτππ# b' m& {& I1 r' |3 M' q
sin 2)()9 w; m- W/ C8 N0 V- { Z6 C
41 |6 N3 J( m. L6 p& Q+ ]6 w( u
(4
\: R6 j1 Q8 GZ az i az/ S9 d X3 g' u' u; Z V
y z
' c+ y% _- U" ^/ `; F$ }& daz i az y A e
/ r9 \* M+ x: ?$ Be fA e
0 L/ M: D% `. [' Y+++=
& Z. o6 I2 W* E" i=6 f! p- z/ I/ x, V
iv
1 {: } C8 m1 v, ou az i az e V az +=+++=)]45sin()45[cos(000. D T+ N5 I# ]/ a# u
8 ^+ T g- M7 b- D/ D M$ n+ x! ~7 vu V e az az =+00 ?# \" n( S; `, e3 J2 S
45cos() 式中: a A z
v6 @ { k! e! z# x2
4 S% p0 F( i, [& p& s O+ W=
7 [( a& R W6 Iρω?
, ^' f% `! r& p @% `8 usin (z2 L, n# G8 ]( ?) |9 \+ x; n
A f
6 }1 n' O- K: ^, R; r7 ]a 224 G% F- E; [4 Q' i0 u' [- \
ρ=6 K- ^8 I2 X) i" F+ I& y. J# _
)2 M$ @( ?/ j; |0 z/ p# K! D
v V e az az =+0045sin()
8 z) J3 r- v9 l8 O) X?( f- H) y9 n/ g& L4 [
ωρτρτsin 22
3 y8 N9 b: X7 ]* E20z y
; R, {+ t, c' K6 D) {& O; K. Nz
+ z" k' V6 }* ?/ P3 g* Y2 q; o* My A fA v u V =* V1 M4 e# E3 w
=* l2 H% h, a6 E& d3 u# g
+=∴
3 f) _# n; \" V7 [4 N0 p& _: n8 E$ h2 R3. 对解的讨论
% f, D9 E3 h+ s( ]- @(1)流速的量值V e
3 V' i$ \" f' A! { Z: o# i1 Y$ d5 Waz
; g5 _' j* f7 u" N: t- ]0,随深度呈指数减小
! Y& p& J' f" @ p, b(2)流矢量与x 轴的夹角: (450+ ?/ _* }, G I' E! q
+az) (3)z =0时:流速为V 0,与y τ成正比,在风矢量右方4507 v/ L; ^0 H& H: ~; r. `. v
(在南半球则左偏)/ P# y W# E) Q
(4)z a
0 e- m; L; a% `( @7 v, R=-& C& V6 p8 h4 I; x1 N$ f7 j
π7 i* o4 M" \ n2 m% s. A
时:
/ i7 v+ ? q0 ?& W流速为00043.0V e
. q; s4 E I9 V4 o$ x; B1 XV -=-π; j5 [7 ~3 ~' _7 r8 {
; a* i! `' l. N r4 g1 ^
π
8 A; D$ F: D4 n- v4 |+ m6 K4 r为摩擦深度,用D 表示
+ g4 F( V& v# e) c2 z6 @, ~流向为4504 O5 x9 c3 l/ k/ }: V
—π=-1350
0 i% X0 x! `) V+ \1 H8 I,恰与表面流向相反。 4. 求0V 的经验公式 f v V ?/ ]& P/ S# ?9 F, l$ L, T2 d4 q
sin 0127.00=5 s6 P& }! ~) z+ r# I
7 {3 j- p, X, h8 r7 N" U! m求z A 的经验公式 A z =4.32! q! c, K& z/ z, B! E& `
f v8 z% K- i5 |' O
二、浅海风海流8 J" r# Q. \4 |. U& N" I/ {
h/D ↓→流矢量与风矢量的方向趋于一致; h/D >0.5与无限深海相似; h/D >2 可作为无限深海处理。" n( B4 S a) Z; q/ u0 r
/ a. ~* ~0 `2 z# S7 j8 {% y; z9 C
# V/ s. d8 y/ h( L
三. 风海流的体积运输3 D9 ?5 _' V& y/ I$ c/ M
在x与 y方向上通过单位宽度自表面到流动消失处的体积运输分别为
- o5 p$ p: d S1 F' D0 |??& U- a- @9 K. ]/ A: w$ i# a
∞9 y3 H0 ~0 Q* K( x7 j5 ]( P$ T" b
-∞
/ q; \) c/ m1 X) Z* o" y-
; ~3 }7 S& }$ K2 V% h+
" T' _/ i( J/ F5 |=, F. i1 q+ U, }+ ]/ Q1 D
=* Z3 X, Y2 w4 R: C& Y' W
00
' _# `! \+ j7 Q, b4 e; K5 H
! k! |4 f, j1 i6 [; p( U# B)
' y: P6 o( L: j9 X7 X* s. w9 Y4
7 G1 W8 V" B Q/ L" X' {4 S; rcos(dz3 F b. |# d! @+ _- ]! E/ w
az
! A8 Q4 y2 n* X9 c7 p, Z) b3 `, ]e
, @+ r) ]8 j: n, L% ?V
! z, m+ H( {$ @# d* i+ fudz7 Y& S5 y1 R4 `' X
M az# I) h* ~: Z& T) r# n
x
4 U0 t( b% }. F: n9 qπ( `* d3 _% D9 V+ P7 ~4 E0 Q7 n
利用分步积分公式: ∫udv = uv - ∫vdu有:
) D: P( A$ ?+ F# U/ p?/ U# B+ B# w( L0 k; |: O% h
?+
3 z3 ]6 Q S$ Q; L6 C4 G# w-
9 @6 q( Y4 M3 z, e: @7 _2 E5 F+
C, V% C7 O; K! U, S) N=
/ h/ S1 a( Z# ~ w+dz
/ `# G8 }8 M9 L( U! p7 ?az
3 G9 i- d5 a* Q7 `, zae( v4 i& A) N$ b" I
a0 D2 O5 X3 Q# k
az6 ^. c7 g- M: Q6 D( {$ o
e3 y# ~ z( L4 `; }0 A& {7 W M
a; Y# B' X+ E, S- y3 m
dz. `" Y1 x- u$ [3 X0 W8 K& l/ \
az
; W2 m, P" r) a; v9 _, f! Pe az
+ C( k6 N" Q2 x9 p1 F) ]* B* Waz
4 z! n" h2 U# O+ N) ] yaz)
3 @$ }# n- C( s( }! m; r4% v5 H4 j7 j7 v {' L; {+ ] s) d
sin(, x( Y6 }3 `; g. f, l
1- W5 t" U8 i) Y# X U9 W1 [
)+ i2 ^4 b* {/ u$ U. V' @
4
5 }; j" N4 I6 _sin(1 Z6 d3 f% Y- u) W3 d |
1
, \3 L3 F m5 L8 z7 ~9 N' ^' D)! _1 d! U2 i" Y. J
45 j6 G3 {$ l! ^3 e/ s+ K$ _1 A
cos(5 ^) c4 I- t; {1 S
π
& u) r! S8 |) q8 \9 B, B6 ]π8 @1 L% D) p: F: g9 F3 l
π
* i# P% s4 e9 O6 Q1 {8 i" Y?+1 v" ?9 V) `; ^$ |1 e
++ h4 S# r5 q6 B& f( m0 X' t
+
J/ U W# ^& V% w: j1 U7 _-! [, B }5 j: f$ t
-6 g4 h5 s) r8 I
+% s4 B; v3 Z @3 }* u8 e. v
=] y3 K- \2 |! K9 z* t# ?
)
& H& S# Q0 T5 o* V" O: V4
% d) U+ t( {. l8 V- }cos(5 U }) i" \9 }
1
) X0 Q% w8 F* S! D)
% l- Y r) c/ ^cos(
6 S9 r+ v: B: m* {% _2 D[
1 [% }4 J. \7 W5 Z5 ~6 r% ?/ v3 |5 K! Y)
* a, @4 f n. e3 s+ c& w4, f, @' O- ]5 l# O9 A7 _" Q5 w
sin(
; r! P" f a2 i8 ]2 T9 v: ?) M, ^0 o14 s, }% J, h1 y. w
41 H m F6 B$ c1 y* I
1dz: G J2 n. S: B; q
az$ T. u; `0 V2 E8 J6 s
ae$ Y8 ^! t5 d$ v. }8 v
a
& |9 e% a7 c' Daz
6 X& Z, I8 a2 je( t( H3 |! v. R8 ^4 R) y8 h
az
; }- `/ q i& Z7 z' `e
: t& j$ T8 D1 h- v" N1 ea, B H8 A, X( m' Z. \6 ^- T
az$ q" z) q: y# U1 y+ M5 b
az
6 j+ c* L' K# J* }5 N4 @a
2 s! P5 X! r& }9 Y' S& C, maz/ C7 T, [2 X2 P6 w& s, G1 L
π) i9 L$ f/ c" P3 e/ V E. ^3 `' ]
π4 ^4 M r2 x+ {: `+ o& k' M
π
8 i9 Z) B: o m! V0 e2 X)] c7 _2 E$ [ o3 d [% l' K# c
4
! w' \( T& `( dcos(
* | ?* h8 |: g1 n)
1 t7 `2 ?) V: A" B4 ?9 S+ e/ @4- P. t! ]+ v# A, M+ p
[sin(& ?) W6 T7 s3 B$ S8 _9 ^
2: O u" }1 m2 `0 v" |- b7 ^
1* y: E% |2 d+ P- j! S# y
)" f8 z" y. e* R4 D: Y- O
4
S0 f+ ~' A! u' M! pcos(az: }# ^3 {+ q( j* H. q% Z
az
3 J+ J" l( {& Z b6 d6 E& ^$ D# ie
! G% R' `) |9 t& G. h) D& Za
; c' y: E' P. W) E$ I' odz6 H% N/ g9 n( b! q3 q, k
az' N5 f# W7 V. S; R
e az7 K1 ^5 K0 X/ Q, c" k2 B
az+
; [& f) K" d j" f/ x' G9 o- K3 u+
! `8 ?# a: i& a2 _+
, U2 C1 e0 h1 U) d5 t; l=
) ^7 ~/ P( w9 ^! ?" \+! S6 I( G H3 l" r9 D
?π
$ |# V/ a/ p- J% `' Rπ
6 ~$ _$ \/ ?( u- ?π5 b4 A% A# g$ S6 [* T( H- {
a/ g+ ~! R7 I7 u6 t
V
; F1 e, b* ~9 }, N# h& I( Sa
6 P: d8 W6 T% OV
% O4 U, O# ]% S. _, taz
. m' q. s/ c; `$ f! c) X# Raz
( t/ t/ G# k! i% Xe- U' {4 c3 Q9 Q# Q
a# ~: n2 k9 I# m# p+ K! l
V% B* Q& r: c8 n/ C0 X- f
M az7 I) c2 n1 u; r3 R0 ?' I. ^7 W
x26 s! E* |. R' I" `& W) n0 g
27 N* Z% t- O! A$ p
27 r' Q3 \( _' V9 g6 m0 x
) W2 c# ^5 i0 C1 E, R# B)
' U. w8 T+ X% h; g* g, E4
, M; F6 j4 @2 ~# bcos(( z7 @) \9 z/ a
) ^ v3 @4 o3 s8 L6 H( G. Q
4
$ C* }9 y& Q' L& k7 I[sin(, q+ H1 [+ }* T, Z4 @2 c
2
3 E `/ p* J9 [4 ]: d
' d2 d* C R, H i1 C v6 t$ m* m0=
! F m- Q6 x, v5 L7 X# k=
! H4 L! y: k3 y1 o; ]∞( k* X& p+ o0 n: A
-
' R' h- G& @. ]. F( X' E2 [# J* o5 `" v+
, m2 O8 O4 _, K, W; F; L+9 e1 S3 {( D: Z# g9 {1 f
+
& R* ]" _5 ] b- J5 e0 A=7 Y. g6 b( f, |
π
3 \+ n- L y7 z: yπ
( k4 q* k$ Z. u# J1 z$ u1 p3 T??
: f5 ]& f; b, L& F8 P- k∞
: y9 O/ z3 K: t( ?4 K. z" p+ A! V-∞
% g) U: J' m) B3 Z-4 |6 j) f: w+ _! s
=1 f0 H) ^& ^! }: r; V
+; ]. T9 [3 ]& }- |& S1 ^5 }
=: F& X8 L! R4 j# Q) S9 V! M5 y
=
2 F8 G$ q9 Q/ B+ O, Z) h& V007 y6 T- @9 S- J& B! P' z
4 M8 T! c. Y, c& @5 i B' e9 C @)
" E. R* V. V' Z4
5 X: l& v( D) i P1 W) dsin(dz6 H* Z) ?: o. W) s J5 l8 v: k8 M o
az
9 y" i3 W# n, A6 R( Ge4 e5 ~+ {" Y4 K- ^( f; g
V
% ?$ N% l( N9 ^. Y; j5 u- e( N. k% A: Bvdz8 W1 G* ]6 d3 R% t. ? B
M az
! a# H# ~, i. b3 y% Ly
& b/ ^' z0 v7 {% i7 j7 B& @π5 O C6 P# `: E& s8 v; X' Z$ C
结论(北半球):
8 g; Z; o5 H- \9 m深海风海流:体积运输方向与风矢量垂直,指向右方。在南半球相反。
; Y* D' |- s) k! h! e浅海风海流:体积运输在x方向与y方向上都存在;4 p9 |# U: Q1 e$ k
其合成方向偏离风矢量的角度小于900;; e% [" M9 x C2 ~% o! \
水深愈小,偏角愈小。
J( u( W: M4 h2 T5 y8 X; h# z9 c* `8 B
12
7 U8 [; ]/ g# x! C- w1218. 惯性流
) T% }% P# M: Z c只有科氏力作用的海流称为惯性流 一、运动方程 vj ui +=
! \- T+ J# \/ V5 S6 a5 q
" U2 f" J6 j; Y% W3 [: b % k9 J7 o6 p$ s: b4 U
?????-=
% d9 n7 v' N6 S, u- P1 M& L3 R" |* N+ j; z6 I# F* `
=fu
7 `4 k+ A# ?8 Q6 p9 \) ^% J4 h! D8 N: M" L0 f/ |4 d/ _/ }
" G3 B0 r% f( u( Qdt dv fv dt
' ~: a; K& I9 i6 l! f/ L! Idu (1) 由(1)式得: dv3 t7 B0 T8 K4 L& { s$ v3 ?# u! p% I9 K
fu
; w2 H b* U: b& ^dt du fv dt 11-==(2) 即: vdv
7 V2 H0 ~% L2 s2 }5 Yudu dv
. S+ m, N# N0 j! z( afu du fv
0 ?3 T% n4 Z- |; O6 \: Z-=-=11 (3) 积分得: 2) Z: @8 ]8 ^- ?6 Q; @
022
0 P9 g2 E" P/ G A" RV v u
& T3 l! h' u" R' c( `2 n, L) J$ D=++ \5 L5 Z8 A- R; E% c. |% h
又由(1)式得: 2
/ C) o) X& L0 e) M# v' a5 f12/ q" x4 K5 ]" H! I; S* D- a }
2- i s7 O. b8 v
, g* ~# f- }3 S k)0 d1 i7 q4 S8 Q1 G2 o. D
(v u V += (4)1 n% l Z6 \( @5 `
dt; Y- K' R6 H8 g; v" i4 }
dv f u dt dx dt
. V: r9 D/ x' O9 ^8 c2 Zdu f v dt dy 11-==== (5): f6 G/ x, }- }. W
对(5)式积分有
" e% S# v. H3 x0 _* I+ E( ~: Y* hf
! t2 F& _1 a3 @+ \/ G4 R$ T! ]v% m' u3 Y' ~: B8 c% i) U" i2 ?8 {
x x f
; I& ~5 {, e" U; o! C( y5 Fu
0 H5 V7 l& ?" Z% w9 Vy y -9 @. m6 t% X+ Z5 o
=-=
4 p* l! D* m! U1 ^-00 (6)
/ ^) @0 w w) `3 R/ n1 B利用(4)式则(6)式变为: 22
0 }7 p: D+ j$ z T5 _2022# N8 N* L9 [8 X2 r, ^6 F0 m# U
22020)()(r f V f v u y y x x ==+=-+- 该圆为惯性圆,对应的流称为惯性流
! A( N1 R4 v5 v+ n5 H9 k; W水质点运动的半径为:?
$ _ Z r* U1 |" F7 M4 `ωsin 20 l) f. s, x! m; M3 y) R" }
0V f V r ==
0 ` O; @5 }, e6 N速度为:r V ?ωsin 20=
0 j' r5 v; X5 P周期为:
1 I! |' p- W7 ~( Z3 {02r 2r 12! _3 E( X e- t
T ()2V 2sin r sin sin sin 24
7 o/ k1 Z& k, V ]# B5 ~1 u6 Hππππ=
$ ?# T2 H* \! N' g' r D7 A====πω?ω???小时
* e6 w8 v% @$ [/ h二、惯性流实例; P9 e$ C& Z6 E0 F3 w# H
图为1961年在31.50N ,1430. N$ ]* N$ u$ e7 i/ v3 e
E ," a3 G3 r) C8 x6 U2 S; t$ z
于1000~2000m 深处观测的惯性流实例。 vf( O% ?/ E: r9 B/ l7 w! e
F x =uf
0 P$ n9 p# y; }0 P) N4 Y$ @# UF y -=
E6 j6 t4 o6 X §6—4世界大洋上层主要环流6 \+ q A1 E" g, ?6 o& v; w
) B1 i: _4 w b一、主要环流/ M6 p5 Y a* A
1.北太平洋- Y3 {( p2 y- \/ v3 E
a.反气旋式环流::由加利福尼亚海流,北赤道流,黑潮,黑潮延续组成" e- S9 k# b7 [+ F* e: K
b.气旋式环流:由黑潮分支,阿拉斯加海流,阿留申海流,亲潮组成。4 t* T, q L6 J M
2.南太平洋环流:由秘鲁海流,北赤道流,东澳大利亚海流,南极绕极环流组成。
( [5 _6 C) f/ l2 U3.印度洋环流:由西澳大利亚海流,南赤道流,莫桑比克海流,南极绕极环流组成。; y4 w8 ~: C5 L
4.北大西洋
, H4 u T) `7 T La.反气旋式环流:由加那利海流,北赤道流,湾流,北大西洋流组成
; R& }1 @; _& l7 G% nb.气旋式环流:由挪威海流,东格陵兰海流,拉布拉多海流,北大西洋流组成
0 |. J5 n7 S4 P, @5 W5.南大西洋环流:由本格拉海流,南赤道流,巴西海流,南极绕极环流组成。' X8 D' K; @: A0 Y: i' L; D
6.南极绕极环流,(自西向东)
! v4 ~6 Q: P' \/ w% d* ^7.北极环流:挪威海流→沿岸流→楚科奇海流→北极东格陵兰海流8 P6 K8 M3 \2 J5 l) r4 i
二、赤道流系
1 X: D1 D8 z% k2 G$ T- q6 [# F" R! [8 P" Z& F8 X
赤道无风带位置:30~100N
* \; y h+ }% {1.北赤道流
$ f& G9 [( k: d# v1 ^- Q+ c范围:100N到20 0~250N。/ O J* I4 x- o$ [. J" E
形成动力:东北信风! h9 ^. ?' j! a' Y- d% g- H
性质:高温(纬度低)、高盐(蒸发强)4 G3 [% d1 V% g. a6 b
2.南赤道流:
' z% P6 Z: E" Q9 ~9 v8 Y范围:200S~30N* l. S. |9 i& t8 Z$ d
形成动力:东南信风
1 ^+ L+ i3 i; V! h& ~性质:高温(纬度低)、高盐(蒸发强)
: Y9 }# e7 \4 [0 J9 n& q* F$ V3.赤道逆流:向东流动
& M2 T9 `" i9 d; s' m范围:30~100N(赤道无风带)* U) a. ^8 Q% C3 Q7 B
形成动力:压强梯度力(大洋海面西高东低。)
/ K' N: T, ?0 H/ ?性质:高温(纬度低)、低盐(低压带,上升流,雨水多)0 m! }& v/ C5 Z6 Q& h: [0 y
4.赤道潜流! E% _; i/ o3 P- s
位置:赤道下方,大洋东部,约50米深处,( {( F2 B3 p; H1 V
大洋西部,约200米深处
: a5 W& @/ ~4 o$ n2 S范围:厚约200m,宽约3O0km) s6 {$ G# M" `$ Y7 o: x% Y- w& P
形成原因:东南信风使表面海水在大洋西岸堆积,导致海面自西向东下倾,从而产生回流所致6 [+ y9 A& P' o( E$ E& \4 u; w6 @* d
三. 西边界流、湾流和黑潮) X1 e# l( O( m. Q3 P+ m/ {
1.西边界流:大洋西侧沿大陆坡从低纬流向高纬的海流。
- @( A- p# `$ c$ U" O有:黑潮、东澳海流,湾流、巴西海流,莫桑比克海流等。" k. Q0 o4 y" j' S% p' W) A
2.湾流流系! |0 w/ s; u7 l
" ]' w5 @/ [6 T1 L$ Ea.佛罗里达海流:北赤道流和南赤道流跨过赤道的部分组成的圭亚那流进入墨西哥湾后的海流
7 {6 z+ Y# l4 o4 k8 z" rb.湾流:流出佛罗里达海峡与安迪列斯海流汇合(湾流起点)进入大西洋的海流
& l2 M( c! l' A P. z# f Dc.北大西洋流:由哈特拉斯角(35°N)转向东北横越大西洋的海流
# b) I- Y1 I# V: l$ vd.湾流的特点:宽度:100~150Km
1 {, m- j& T" n1 H* W水平温度梯度最高处达10℃/20Km$ q |: { D7 I$ _$ V3 _$ G
左侧为高密度冷水,右侧为低密度温暖的马尾藻海水。* e# l# Y' J4 ` ^8 l
; G3 w, \# c6 Q. _# j, I3.黑潮! a0 \. k( {' F2 v# G
(1)黑潮流系
" b1 b- o2 p+ S* t(2)黑潮特点
! \3 {- W* Q5 Z最强流轴宽:约75~90km6 @' P6 _" Q8 ?+ c- P* I4 W% k* {# T+ z
两侧水位相差:lm左右6 t: f% h3 s# x+ f7 u/ M% r4 G9 c s
流速最大可达150~200cm/s
3 l; l w( D4 ?* c( B# q' t 影响深度在1000m以下
9 C* y5 A @# ^四. 西风漂流
* d( u) b$ \6 r1.北大西洋流. v* B/ Y- m* t& A( E0 Q( F
在欧洲海岸附近分为三支:挪威海流;加那利海流;伊尔明格海流。3 Z9 s7 F5 g5 @7 d8 s
2.北太平洋流
0 F) \2 C1 @! b! T2 s
& ^) o$ T8 C4 _- d黑潮延续;加里福尼亚海流;阿拉斯加海流。
\8 k# w4 f( q0 a0 |3.南极绕极环流
* `. O D7 X' G' K5 g2 t) f上部为漂流,下部为地转流。) e1 w& r* g% w- O( R5 U! X0 s
在太平洋东岸的向北分支称为秘鲁海流;) X' H, t& [7 g6 W
在大西洋东岸的向北分支称为本格拉海流;; O% E: G- u5 e8 s; Z! s
在印度洋东部的向北分支称为西澳海流. |