Eos, V o l . 67, N o . 9, March 4, 1986 References B a r b e r , R. T . , a n d F. C h a v e z , Biological con s e q u e n c e s of El N i n o , Science, 226, 1 2 0 3 , 1983. B a r b e r , R. T . , a n d R. S m i t h , Coastal upwell i n g ecosystem, in Analysis of Marine Ecosys tems, e d i t e d by A. R. L o n g h u r s t , p p . 31—68, Academic, New York, 1981. B r o w n , O., R. E v a n s , J . B r o w n , H . G o r d o n , R. S m i t h , a n d K. B a k e r , B l o o m i n g off t h e U.S. East Coast: A satellite d e s c r i p t i o n , in Global Ocean Flux Study: Proceedings of a Workshop, B o a r d o n O c e a n Science a n d Pol icy, N a t i o n a l R e s e a r c h C o u n c i l , p p . 6 7 - 8 4 , N a t i o n a l A c a d e m y Press, W a s h i n g t o n , D.C., 1984. C h a v e z , F., R. B a r b e r , J . Kogelschatz, V. T h a y e r , a n d B. C a i , El N i n o a n d p r i m a r y p r o d u c t i v i t y : P o t e n t i a l effects o n a t m o s p h e r i c c a r b o n d i o x i d e a n d fish p r o d u c tion, Trop. Oceans Atmos. Newslett., 28, 1, 1984. C h e l t o n , D. B., P. A . B e r n a l , a n d J . A. M c G o w a n , Large-scale i n t e r a n n u a l physical a n d biological i n t e r a c t i o n in t h e California C u r r e n t , / . Mar. Res., 40, 1095, 1982. Cowles, T . , R. B a r b e r , a n d O . Guillen, Bio logical c o n s e q u e n c e s of t h e 1975 El N i n o , Science, 195, 2 8 5 , 1977. D o n g u y , J . R., C. H e n i n , A. M o r l i e r e , J . P. R e b e r t , a n d G. M e y e r s , A p p e a r a n c e s in t h e W e s t e r n Pacific o f p h e n o m e n a i n d u c e d by El N i n o in 1 9 7 9 - 8 0 , Trop. Oceans Atmos. Newslett., 10, 1, 1982. D u g d a l e , R. C , a n d J . J . G o e r i n g , U p t a k e of n e w a n d r e g e n e r a t e d f o r m s of n i t r o g e n in p r i m a r y p r o d u c t i v i t y , Limnol. Oceanogr., 12, 196, 1967. E p p l e y , R., R e l a t i o n s b e t w e e n p r i m a r y p r o duction and ocean chlorophyll determined by satellites, in Global Ocean Flux Study: Pro ceeding of a Workshop, B o a r d o n O c e a n Sci e n c e a n d Policy, N a t i o n a l R e s e a r c h C o u n cil, p p . 8 5 - 1 0 2 , N a t i o n a l A c a d e m y Press, W a s h i n g t o n , D.C., 1984. E p p l e y , R., E. S t e w a r t , M. A b b o t t , a n d R. Owen, Estimating ocean production from satellite-derived c h l o r o p h y l l : I n s i g h t s f r o m t h e E A S T R O P A C d a t a set, p a p e r p r e s e n t e d at t h e S y m p o s i u m o n Vertical M o t i o n in t h e E q u a t o r i a l U p p e r O c e a n a n d its Effects U p o n Living R e s o u r c e s a n d t h e A t m o s p h e r e , Sci. C o m m . o n O c e a n . R e s . / U N E S C O , Paris, May 1 9 8 5 . Information Report Is There a Global Scale Ocean Circulation? P A G E S 109, 110 4 T h e w o r d " g l o b a l " is t h e 'in" w o r d in to day's o c e a n o g r a p h y . W e h a v e a l r e a d y h a d "ecology" a n d " e n v i r o n m e n t , " a n d p e r h a p s e v e n t h e r e c e n t " c l i m a t e " buzz w o r d giving way to t h e m o r e g e n e r a l d e s i g n a t i o n of "glob al." W e a r e faced w i t h t h e T r o p i c a l O c e a n a n d Global A t m o s p h e r e p r o g r a m ( T O G A ) , the World Ocean Circulation Experiment ( W O C E ) , a n d t h e Global F l u x E x p e r i m e n t ; A G U has e n t e r e d t h e "global" stage with a 0 0 9 6 - 3 9 4 1 / 8 6 / 6 7 0 9 - 0 1 0 9 $ 1.00 Copyright 1 9 8 6 by t h e A m e r i c a n Geophysical U n i o n m o n i t o r i n g u s i n g satellite o b s e r v a t i o n s , Rep. UHMET 81-01, D e p . of M e t e o r o l . , U n i v . of H a w a i i , H o n o l u l u , 1 9 8 1 . Schott, G., D e r P e r u - S t r o m u n d s e i n e n o r d l i c h e n N a c h b a r g e b i e t e in n o r m a l e r a n d a b n o r m a l e r A u s b i l d u n g , Ann. Hydrogr. Mar. Meteorol, 59, 1 6 1 , 1 9 3 1 . S m i t h , R. C , a n d K. B a k e r , T h e bio-optical state of o c e a n w a t e r s a n d r e m o t e s e n s i n g , Limnol. Oceanogr., 23, 2 4 7 , 1978. S m i t h , R. C , R. E p p l e y , a n d K. B a k e r , C o r r e lation of p r i m a r y p r o d u c t i o n as m e a s u r e d a b o a r d s h i p in s o u t h e r n C a l i f o r n i a coastal w a t e r s a n d as e s t i m a t e d f r o m satellite chlo r o p h y l l i m a g e s , Mar. Biol, 66, 2 8 1 , 1982. S m i t h , R. L., U p w e l l i n g . , Oceanogr. Mar. Biol Ann. Rev., 6, 1 1 , 1968. S m i t h , W., G. H e b u r n , R. B a r b e r , a n d J . J . O ' B r i e n , R e g u l a t i o n of p h y t o p l a n k t o n c o m m u n i t i e s by physical p r o c e s s e s in u p w e l l i n g e c o s y s t e m s , / . Mar. Res., 41, 5 3 9 , 1 9 8 3 . T h o m p s o n , J . D., C l i m a t e , u p w e l l i n g , a n d biological p r o d u c t i v i t y , in Resource Manage ment and Environmental Uncertainty: Lessons From Coastal Upwelling Fisheries, e d i t e d by M. G l a n t z a n d J . D. T h o m p s o n , p p . 13—33, J o h n Wiley, N e w Y o r k , 1 9 8 1 . Walsh, J., T . W h i t l e d g e , W. Esaias, R. S m i t h , S. H u n t s m a n , H . S a n t a n d e r , a n d B . D e M e n d i o l a , T h e s p a w n i n g h a b i t a t of t h e P e r u v i a n a n c h o v y (Engraulis ringens), Deep Sea Research, 27a, 1, 1980. Y e n t s c h , C. S., R e m o t e s e n s i n g of biological s u b s t a n c e s , in Remote Sensing Applications in Marine Science and Technology, e d i t e d by A. P. C r a c k n e l l , p p . 2 6 3 - 2 9 7 , D. R e i d e l , H i n g h a m , Mass., 1 9 8 3 . Y o s h i d a , K. C i r c u l a t i o n in t h e e a s t e r n t r o p i c a l o c e a n s with special r e f e r e n c e s to u p w e l l i n g a n d u n d e r c u r r e n t s , Jpn.J. Geophys., 4, 1, 1967. Z u t a , S., a n d J . Q u i s p e , H y d r o g r a p h i c fea t u r e s off P e r u in 1 9 7 9 - 1 9 8 0 , in Recent Pro gress in Equatorial Oceanography, e d i t e d by J . M c C r e a r y , J r . , D. M o o r e , a n d J . W i t t e , p p . 6 1 - 7 3 , Nova University Press, Fort L a u d e r d a l e , Fla., 1 9 8 1 . Z u t a , S., T . R i v e r a , a n d A. B u s t a m a n t e , H y d r o l o g i c aspects of t h e m a i n u p w e l l i n g ar eas off P e r u , Upwelling Ecosystems, e d i t e d by R. Boje a n d M. T o m s z a k , p p . 2 3 5 - 2 5 7 , S p r i n g e r - V e r l a g , N e w Y o r k , 1978. F a h r b a c h , E., C. B r o c k m a n n , N . L o s t a u n a u , a n d W. U r q u i z o , T h e n o r t h e r n P e r u v i a n u p w e l l i n g system d u r i n g t h e E S A C A N ex p e r i m e n t , in Coastal Upwelling, e d i t e d by F. A. R i c h a r d s , p p . 1 3 4 - 1 4 5 , Coast. Estuar. Ser., vol. 1, A G U , W a s h i n g t o n , D.C., 1 9 8 1 . F e l d m a n , G., Satellite o b s e r v a t i o n s of p h y t o p l a n k t o n variability in t h e e a s t e r n e q u a t o r i al Pacific, P h . D . d i s s e r t a t i o n , 2 1 7 p p . , M a r . Sci. Res. C t r . , State U n i v . of N e w Y o r k at Stony B r o o k , 1985. F e l d m a n , G., D. C l a r k , a n d D. H a l p e r n , Sat ellite color o b s e r v a t i o n s of t h e p h y t o p l a n k t o n d i s t r i b u t i o n in t h e e a s t e r n e q u a t o r i a l Pacific d u r i n g t h e 1 9 8 2 - 1 9 8 3 El N i n o , Sci ence, 226, 1069, 1984. G o r d o n , H . , D. C l a r k , J . B r o w n , O . B r o w n , R. E v a n s , a n d W . B r o e n k o w , P h y t o p l a n k t o n p i g m e n t c o n c e n t r a t i o n s in t h e M i d d l e Atlantic B i g h t : C o m p a r i s o n of s h i p d e t e r m i n a t i o n s a n d C Z C S e s t i m a t e s , Appl. Opt., 22, 2 0 , 1 9 8 3 . Guillen, O., C h e m i c a l characteristics a n d p r o ductivity off P e r u d u r i n g El N i n o 1 9 8 2 - 8 3 , p a p e r p r e s e n t e d at t h e S y m p o s i u m o n V e r tical M o t i o n in t h e E q u a t o r i a l U p p e r O c e a n a n d its Effects U p o n Living R e s o u r c e s a n d t h e A t m o s p h e r e , Sci. C o m m . o n O c e a n . R e s . / U N E S C O , Paris, May 1 9 8 5 . Guillen, O., a n d R. C a l i e n e s , U p w e l l i n g off C h i m b o t e , in Coastal Upwelling, e d i t e d by F. A. R i c h a r d s , p p . 3 1 2 - 3 2 6 , Coast. Estuar. Ser., vol. 1, A G U , W a s h i n g t o n , D.C., 1 9 8 1 . L o v e , C. M., E A S T R O P A C Atlas, U.S. Dep. Commer. Circ. 330, 1972. L u k a s , R., T h e t e r m i n a t i o n of t h e e q u a t o r i a l u n d e r c u r r e n t in t h e e a s t e r n Pacific, P h . D . d i s s e r t a t i o n , 126 p p . , U n i v e r s i t y of H a w a i i , H o n o l u l u , 1981. M a n g u m , L., a n d S. H a y e s , T h e vertical s t r u c t u r e of t h e z o n a l p r e s s u r e g r a d i e n t in t h e e a s t e r n e q u a t o r i a l Pacific, Geophys. Res., 89, 1 0 4 4 1 , 1984. Piatt, T . , a n d A. H e r m a n , R e m o t e s e n s i n g of p h y t o p l a n k t o n in t h e sea: Surface-layer c h l o r o p h y l l as a n e s t i m a t e of w a t e r - c o l u m n c h l o r o p h y l l a n d p r i m a r y p r o d u c t i o n , Int. J. Remote Sens., 4, 3 4 3 , 1 9 8 3 . Piatt, T . , a n d W . G. H a r r i s o n , C a r b o n a n d o x y g e n fluxes in t h e o p e n o c e a n , p a p e r p r e s e n t e d at t h e S y m p o s i u m o n Vertical M o t i o n in t h e E q u a t o r i a l U p p e r O c e a n a n d its Effects U p o n Living R e s o u r c e s a n d t h e A t m o s p h e r e , Sci. C o m m . o n O c e a n . Res./ U N E S C O , Paris, May 1985. S a d l e r , J . C , a n d B . J . Kilonsky, T r a d e w i n d G e n e C a r l F e l d m a n is with the National Aero nautics and Space Administration Goddard Space Flight Center, Greenbelt, Md. n e w j o u r n a l called Global Biogeochemical Cycles (which covers it all), a n d t h e r e was t h e wella t t e n d e d E a r t h System Science: N e w Views a n d Plans s y m p o s i u m at t h e 1985 A G U Fall m e e t i n g in S a n F r a n c i s c o , Calif., last D e c e m ber. W h y all t h e i n t e r e s t in t h e global scale? It's safe to say t h a t t h e i m p o r t a n t p r e s e n t c o n c e r n s of t h e e a r t h sciences, s u c h as climate stability a n d t h e o c e a n ' s c o n t i n u e d p o t e n t i a l to a b s o r b civilization's c h e m i c a l wastes, a r e global issues a n d m u s t be viewed in t h a t c o n text if we a r e to a d d r e s s t h e m p r o p e r l y . A n o t h e r factor is t h a t for t h e first t i m e , t h r o u g h satellite t e c h n o l o g y , we h a v e t h e capability of g a t h e r i n g global scale d a t a o n a truly synoptic basis. So, as in t h e past, a p p l i c a t i o n of n e w t e c h n o l o g y allows u s to d e f i n e n e w h o r i z o n s a n d a d d r e s s a n e w r a n g e of r e s e a r c h q u e s tions. I n a d d i t i o n to t h e s e factors, t h e r e is also t h e historical e v o l u t i o n of o c e a n o g r a p h y , w h i c h m a k e s t h e global p r o s p e c t i v e p a r t i c u larly a p p e a l i n g at this t i m e . T h e scientific e x p l o r a t i o n of t h e o c e a n in t h e late 19th a n d early 2 0 t h c e n t u r y was d o m i n a t e d by g r e a t n a t i o n a l e x p e d i t i o n s t h a t gave us t h e first g l i m p s e of vast a r e a s of t h e o c e a n . As t h e m o s t g e n e r a l p i c t u r e of t h e o c e a n ' s large-scale s t r u c t u r e e m e r g e d , a t t e n tion was d i r e c t e d t o w a r d s specific r e g i o n s of t h e o c e a n , s u c h as t h e G u l f S t r e a m , u p w e l l i n g r e g i m e s , etc., t h e field of r e g i o n a l o c e a n o g r a p h y evolved. N o w a r m e d with a r e a s o n a b l y g o o d p i c t u r e of t h e r e g i o n s a n d with t h e n e c essary t e c h n o l o g y to view t h e global in its e n tirety, we a r e g u i d e d t o w a r d t h e i m p o r t a n t global scientific c o n c e r n s of t o d a y . It's t i m e to p u t t h e r e g i o n a l pieces of t h e j i g s a w puzzle t o g e t h e r to d e t e r m i n e h o w t h e y i n t e r a c t with o n e a n o t h e r a n d with t h e a t m o s p h e r e in es- ; Eos, Vol. 67, N o . 9, March 4, 1986 SOUTHERN OCEAN NORTH THE TWO GLOBAL SCALE THERMOHALINE ATLANTIC CELLS Fig. 1. S c h e m a t i c r e p r e s e n t a t i o n of t h e two d o m i n a n t global scale t h e r m o h a l i n e circulation cells a l o n g a m e r i d i o n a l p l a n e . T h e m a g n i t u d e of t h e f o r m a t i o n r a t e s of Antarctic Bottom water a n d N o r t h Atlan tic D e e p w a t e r a r e " b a l l p a r k " values. tablishing t h e climate system, its stability a n d variability, a n d t h e delicate b a l a n c e of t h e global b i o g e o c h e m i c a l system. W i t h all this i n t e r e s t a b o u t t h e global scale, it's n a t u r a l to ask: Is t h e r e really a global scale o c e a n circulation? H o w a r e t h e r e g i o n a l circulation cells l i n k e d t o g e t h e r ? W h i l e t h e r e g i o n a l systems a r e g e n e r a l l y t h o u g h t to be w i n d - d r i v e n f e a t u r e s , t h e global scale circula tion is of t h e m o r e sluggish t h e r m o h a l i n e cir culation t y p e , d r i v e n by large-scale b u o y a n c y fluxes b e t w e e n o c e a n a n d a t m o s p h e r e . P e r h a p s t h e m o s t influential global scale t h e r m o h a l i n e circulation t h e o r y is t h a t for t h e abyssal circulation, p r o p o s e d by Stommel and Axons [ I 9 6 0 ] . T h i s e n d u r i n g yet s i m p l e con cept, in w h i c h s t r o n g m e r i d i o n a l flow within t h e w e s t e r n b o u n d a r i e s of t h e o c e a n is bal a n c e d in b o t h mass a n d vorticity by t h e slug gish i n t e r i o r flow, h a s b e e n well verified by o b s e r v a t i o n s . It h a s b e e n e x t e n d e d , u s i n g m o r e realistic o c e a n b a t h y m e t r y , a n d its valid ity to o c e a n b a s i n - r i d g e scale has b e e n estab lished ( d u e largely to t h e w o r k of B r u c e W a r r e n of W o o d s H o l e O c e a n o g r a p h i c Institu tion, W o o d s H o l e , Mass.). T h e global p r o s p e c t i v e is often t a k e n in s t u d y of t h e s o u t h e r n o c e a n , w h e r e t h e m a j o r o c e a n s a r e linked by t h e d e e p r e a c h i n g circum a n t a r c t i c belt in t h e 5 0 ° - 6 0 ° S r a n g e . W i t h in this belt is t h e e a s t w a r d flowing A n t a r c t i c C i r c u m p o l a r C u r r e n t . P e r h a p s it's u n f a i r to call this a global c u r r e n t , since it encircles t h e l o n g i t u d e s at h i g h l a t i t u d e s , b u t it s h o u l d b e n o t e d t h a t with its p a t h of 2 4 , 0 0 0 k m a n d t r a n s p o r t of 125 Sv (Sv = 1 0 m / s ) it is t h e s t r o n g e s t , m o s t d o m i n a n t c u r r e n t of t h e w o r l d o c e a n . It is t h e m o s t i m p o r t a n t factor in d i m i n i s h i n g t h e differences b e t w e e n o c e a n s . H o w e v e r , this is p r o b a b l y b e c a u s e it is t h e t h e r m o h a l i n e p a r t of t h e s o u t h e r n o c e a n t h a t h a s t h e g r e a t e s t i m p a c t at t h e global scale. I n t e n s e w a t e r m a s s a l t e r a t i o n a r o u n d A n t a r c t i c a o c c u r s as t h e relatively w a r m Cir c u m p o l a r D e e p w a t e r upwells to i n t e r a c t with t h e p o l a r a t m o s p h e r e , t h e sea, a n d t h e glacial ice to f o r m d e n s e A n t a r c t i c B o t t o m w a t e r . T h i s w a t e r mass c r e e p s n o r t h w a r d , r e a c h i n g well i n t o t h e n o r t h e r n h e m i s p h e r e . It has b e e n said (in partial j e s t , of course) t h a t t h e Atlantic, Pacific, a n d I n d i a n o c e a n s a r e m e r e e s t u r a r i e s of t h e s o u t h e r n o c e a n . 6 3 H o w e v e r , t h e global s p r e a d of A n t a r c t i c B o t t o m w a t e r is n o t t h e only t h e r m o h a l i n e "show in t o w n . " T h e r e a r e two global scale circulation cells ( F i g u r e 1), o n e c o m p o s e d of A n t a r c t i c B o t t o m w a t e r , c o m p e n s a t e d by r e t u r n to t h e s o u t h e r n o c e a n as t h e s o m e w h a t w a r m e r saltier C i r c u m p o l a r D e e p water, a n d t h e o t h e r d r i v e n by N o r t h Atlantic events, as u p p e r layer o r t h e r m o c l i n e w a t e r is c o n v e r t e d to N o r t h Atlantic D e e p w a t e r ( N A D W ) . T h e full e x t e n t of t h e N A D W / t h e r m o c l i n e t h e r m o h a l i n e cell has n o t really b e e n e x p l o r e d in t h e l i t e r a t u r e , a l t h o u g h t h e global s p r e a d i n g of t h e salinity m a x i m u m of N A D W [Reid and Lynn, 1971] is firmly p a r t of i n t r o d u c t o r y c o u r s e s of Physical O c e a n o g r a p h y . As N A D W s p r e a d s t h r o u g h o u t t h e o c e a n , slow u p w e l l i n g r e t u r n s w a t e r to t h e u p p e r layer (a la Stommel and Arons [I960]) which initially fed t h e initial p r o d u c t i o n of N A D W . N a t u r a l l y , t h e u p p e r layer water m u s t flow back to t h e N o r t h Atlantic to b a l a n c e t h e ex p o r t of d e e p w a t e r . T h i s t h e r m o h a l i n e cell is so well d e v e l o p e d t h a t it is clearly seen in t h e inverse s o l u t i o n s for N o r t h Atlantic t r a n s p o r t a l o n g t h e m e r i d i o n a l p l a n e [Roemmich and Wunsch, 1985]: u p p e r layer water within t h e t h e r m o c l i n e flows n o r t h w a r d to b a l a n c e a p p r o x i m a t e l y 17 Sv of s o u t h w a r d t r a n s p o r t within t h e d e e p w a t e r . T h i s f e a t u r e m u s t be p a r t of a global system; h o w e v e r , t h e p a t h of t h e r e t u r n flow h a s n o t b e e n identified. A clue exists within t h e S o u t h Atlantic: o c e a n i c h e a t flux across 30° S is d i r e c t e d t o w a r d t h e e q u a t o r (talk a b o u t t a k i n g coals to Newcastle)! A c c o r d i n g to Hastenrath [1982] at a r a t e of 6 9 x 1 0 W. Since it is n o t likely t h a t this h e a t is i n t r o d u c e d to t h e Atlantic from t h e a t m o s p h e r e s o u t h of 30°S, w h e r e d o e s it c o m e f r o m ? I believe it c o m e s f r o m t h e I n d i a n O c e a n t h e r m o c l i n e a n d is p a r t of t h e global scale N A D W / t h e r m o c l i n e circulation cell. 1 3 If realistic values for N A D W t e m p e r a t u r e a n d v o l u m e flux (2°C a n d 17 Sv, respectively) a n d for t h e Brazil C u r r e n t flow across 30°S (18°C a n d 10 Sv, respectively; see Gordon [1986]) a r e u s e d , it can be seen t h a t t h e n o r t h w a r d flowing u p p e r layer w a t e r m u s t have a n a v e r a g e t e m p e r a t u r e of 12°-14° C, far t o o w a r m to b e d e r i v e d f r o m t h e D r a k e Passage. It c a n only be d e r i v e d f r o m t h e I n dian Ocean. An Indian Ocean thermocline s o u r c e for this u p p e r layer flow is s u p p o r t e d by r e c e n t o b s e r v a t i o n s t h a t indicate l e a k a g e of t h e A g u l h a s C u r r e n t (within t h e w a r m e r u p p e r layers) to t h e S o u t h Atlantic s u b t r o p i cal g y r e [Gordon, 1985], a l t h o u g h m o s t (80— © UPWELLING SINKING DEEP WATER FLOW COLD"WATER T R A N S F E R INTO A T L A N T I C OCEAN "WARM"UPPER LAYER FLOW Fig- 2- M a p view of t h e N o r t h Atlantic D e e p w a t e r t h e r m o c l i n e circulation cell [Gordon, 1986]. T h e circled values r e f e r to t r a n s p o r t in S v e r d r u p u n i t s r e q u i r e d to m a t c h globally u n i f o r m u p w e l l i n g of a 20-Sv p r o d u c t i o n of N A D W . Eos, V o l . 6 7 , N o . 9, March 4, 1 9 8 6 90%) of t h e A g u l h a s flow curls back i n t o t h e I n d i a n O c e a n as p a r t of t h e A g u l h a s R e t r o flection. T h e s u b t r o p i c a l g y r e of t h e S o u t h Atlantic is m o s t u n i q u e in t h a t t h e r e is a h e a t s o u r c e at its p o l e w a r d - e a s t e r n c o r n e r a n d as Olson and Evans [1986] p o i n t o u t , t h e A g u l h a s c o n n e c t i o n also m a y s u p p l y significant a m o u n t of anticyclonic vorticity i n t o t h e S o u t h Atlantic. W i t h a n I n d i a n - A t l a n t i c t h e r m o c l i n e link in m i n d , a global p a t t e r n for t h e N A D W t h e r mocline circulation cell is p r o p o s e d ( F i g u r e 2; See also Gordon [1986]): N A D W s p r e a d s into each o c e a n , w h e r e it is e v e n t u a l l y i n t r o d u c e d into t h e t h e r m o c l i n e (it is likely t h a t t h e u p welling a r o u n d A n t a r c t i c a a n d t h e p r o d u c tion of A n t a r c t i c i n t e r m e d i a t e w a t e r plays a n i m p o r t a n t role), a n d t h e t h e r m o c l i n e w a t e r b e g i n s its l o n g t r i p b a c k to t h e N o r t h Atlantic to c o m p l e t e t h e cycle. T h e N A D W , e n t e r i n g t h e Pacific t h e r m o cline, feeds w e s t w a r d flow i n t o t h e I n d i a n O c e a n t h r o u g h t h e I n d o n e s i a n seas. Esti m a t e s of t h e v o l u m e flux r e p o r t e d in t h e lit e r a t u r e h a v e a n o r d e r to m a g n i t u d e r a n g e : 1.5 Sv [Wyrtki, 1961] to 14 Sv [Poila and Gor don, 1984]. D u r i n g t r a n s i t of t h e I n d o n e s i a n seas t h e r e is e v i d e n c e of a n o m a l o u s l y h i g h vertical m i x i n g within t h e t h e r m o c l i n e : t h e surface w a t e r t e m p e r a t u r e d e c e a s e s d e s p i t e s t r o n g a t m o s p h e r e t o o c e a n h e a t flux. T h e N o r t h Pacific s u b s u r f a c e salinity m a x i m u m is a n n i h i l a t e d d u r i n g p a s s a g e , a n d t h e vertical n u t r i e n t g r a d i e n t across t h e t h e r m o c l i n e is greatly r e d u c e d . T h e Pacific to I n d i a n t r a n s fer of tropical w a t e r a n d t h e s t r o n g vertical m i x i n g within t h e I n d o n e s i a n seas s h o u l d h a v e s o m e i m p o r t a n t larger-scale effects o n t h e h e a t , fresh w a t e r , a n d n u t r i e n t b u d g e t s . T h e s p r e a d of t h e low-salinity Pacific w a t e r across t h e e n t i r e I n d i a n O c e a n a l o n g 10° S is clearly seen in t h e v a r i o u s t h e r m o c l i n e m a p s p r e s e n t e d by Wyrtki [1971]. T h e similarity of t h e t h e r m o c l i n e within t h e I n d i a n O c e a n n o r t h of 10° S in r e g a r d to t h e low vertical sa linity g r a d i e n t a n d h i g h n e a r - s u r f a c e n u t r i e n t c o n c e n t r a t i o n s suggests s o m e c o n n e c t i o n with t h e I n d o n e s i a n flow-through a n d m i x i n g event. H o w e v e r , t h e Pacific-derived w a t e r in t h e tropical I n d i a n O c e a n eventually slips southward through the Mozambique Channel to feed (as a m i n o r c o m p o n e n t ) t h e A g u l h a s C u r r e n t , which in t u r n i n t r o d u c e s I n d i a n O c e a n t h e r m o c l i n e w a t e r into t h e S o u t h At lantic. W h i l e t h e p o l e w a r d flux within t h e M o z a m b i q u e C h a n n e l is s u g g e s t e d by t h e wa ter mass characteristics, t h e r e is n o s t r o n g evi d e n c e t h a t t h e r e is a p o l e w a r d mass flux at t h e a p p r o x i m a t e l y 10-Sv level, as r e q u i r e d by t h e global scale p a t t e r n . O n c e in t h e Atlantic, t h e u p p e r layer t h e r mocline w a t e r passes to t h e n o r t h within t h e subtropical g y r e a n d crosses t h e e q u a t o r , p r o b a b l y o n t h e w e s t e r n side, a l t h o u g h s o m e i n v o l v e m e n t with t h e c o m p l e x vertical a n d zonal e q u a t o r i a l circulation is possible. T h e Caribbean a n d Gulf Stream features carry the thermocline water further n o r t h into the N A D W production regions. T h e p r o p o s e d N A D W / t h e r m o c l i n e cell in volves m u c h of t h e t h e r m o c l i n e circulation. T h e efficiency of t h e system, a n d p e r h a p s t h e vigor of N A D W p r o d u c t i o n itself, m a y d e p e n d u p o n t h e ability of t h e system to pass t h e r m o c l i n e w a t e r b e t w e e n o c e a n basins. T h e s e links m a y be v u l n e r a b l e to variations d u e to t h e w i n d - d r i v e n circulation. T h e Pacif ic O c e a n to I n d i a n O c e a n sea level difference 0 0 9 6 - 3 9 4 1 / 8 6 / 6 7 0 9 - 0 1 1 0 $ 1.00 Copyright 1 9 8 6 by the A m e r i c a n Geophysical U n i o n across t h e I n d o n e s i a n seas m i g h t vary as t h e large-scale w i n d fields o v e r t h e tropical Pacif ic a n d I n d i a n o c e a n s c h a n g e , p e r h a p s in r e s p o n s e to S o u t h e r n Oscillation e v e n t s . T h e l e a k a g e of I n d i a n O c e a n t h e r m o c l i n e w a t e r into t h e S o u t h Atlantic is effected by t h e local w i n d : m o d e l s show t h a t t h e l e a k a g e g r o w s l a r g e r as t h e m a x i m u m westerlies shift fur t h e r to t h e s o u t h . T h u s t h e s e two links m a y act as " c h o k e " p o i n t s , w h i c h u p o n r e s p o n d i n g to t h e wind affect t h e e n t i r e efficiency of t h e t h e r m o h a l i n e cell. C l i m a t e variability at a va riety of t i m e scales m a y b e r e l a t e d to t h e im p o s e d w i n d d r i v e efficiency of this cell a n d b e a r s investigation. W i t h a global p r o s p e c t i v e in m i n d , t h e o c e a n o g r a p h y of c e r t a i n r e g i o n s , while i n t e r e s t i n g in its o w n r i g h t , takes o n n e w significance. I n t h e s c h e m e p r e s e n t e d above, it is s u g g e s t e d t h a t ventilation of s p e cific t h e r m o c l i n e s m a y n o t b e successfully a p p r o a c h e d in isolation f r o m n e i g h b o r i n g t h e r moclines. W e a r e a b o u t to e n t e r i n t o a n e w p h a s e of o c e a n o g r a p h y as we t a k e o n t h e global p r o spective. A r m e d with g o o d k n o w l e d g e of r e gional o c e a n o g r a p h y a n d with t h e t e c h n o l o g y available to us, I suspect t h a t by t h e y e a r 2 0 0 0 we will b e a m a z e d to l e a r n t h a t all t h e t h i n g s t h a t we h a v e b e e n saying a b o u t t h e im p o r t a n c e of t h e o c e a n to large-scale climate system a r e really t r u e ! Well, w h a t ' s left for t h e 21st c e n t u r y ? I n a d d i t i o n to s e t t i n g m o n i t o r i n g n e t w o r k s to k e e p tabs o n t h e o c e a n , I guess we will g o back a n d get t h e r e g i o n a l and process oceanography d o n e right, and t h e n t h e r e ' s always t h o s e o t h e r b o d i e s in t h e solar system, with liquid a n d ice " o c e a n s . " T h i s w o r k was p r e s e n t e d at t h e A G U / A m e r i c a n Society of L i m n o l o g y a n d O c e a n o g r a p h y O c e a n Sciences M e e t i n g L u n c h e o n , N e w O r l e a n s , La., J a n u a r y 15, 1986. References: G o r d o n , A., I n d i a n - A t l a n t i c t r a n s f e r of t h e r m o c l i n e w a t e r at t h e A g u l h a s Retroflection, Science, 227, 1030, 1985. G o r d o n , A., I n t e r o c e a n e x c h a n g e of t h e r m o cline w a t e r , J. Geophys. Res., in p r e s s , 1986. H a s t e n r a t h , S., O n m e r i d i o n a l h e a t t r a n s p o r t s in t h e w o r l d o c e a n , J. Phys. Oceanogr., 12, 9 2 2 , 1982. O l s o n , D., a n d R. E v a n s , R i n g s of t h e A g u l h a s C u r r e n t , Deep Sea Res., in p r e s s , 1986. Piola, A., a n d A. G o r d o n , Pacific a n d I n d i a n O c e a n u p p e r layer saltinity b u d g e t , J. Phys. Oceanogr. 14, 7 4 7 , 1984. Reid, J . a n d R. L y n n , O n t h e influence of t h e N o r w e g i a n - G r e e n l a n d a n d W e d d e l l Seas u p o n t h e b o t t o m w a t e r s of t h e I n d i a n a n d Pacific o c e a n s Deep Sea Res., 18 1 0 6 3 , 1 9 7 1 . R o e m m i c h , D., a n d C. W u n s c h , T w o t r a n s a t lantic sections: M e r i d i o n a l circulation a n d h e a t flux in t h e s u b t r o p i c a l N o r t h Atlantic O c e a n , Deep Sea Res., 32, 6 1 9 , 1985. S t o m m e l , H . , a n d A. A r o n s , O n t h e abyssal circulation of t h e w o r l d o c e a n , 1, S t a t i o n a r y p l a n e t a r y flow p a t t e r n s o n a s p h e r e Deep Sea Res., 6, 140, 1960. W y r t k i , K., Physical o c e a n o g r a p h y of t h e S o u t h e a s t Asian w a t e r s , Naga Rep., Vol. 2, 195 p p . , Univ. of Calif. San D i e g o , S c r i p p s Inst, of O c e a n o g r . , La Jolla, Calif., 1 9 6 1 . W y r t k i , K. Oceanographic Atlas of the Interna tional Indian Ocean Expedition, 531 p p , N a tional Science F o u n d a t i o n , W a s h i n g t o n , D.C., 1 9 7 1 . This item was contributed by A r n o l d L. G o r d o n , Lamont-Doherty Geological Observatory, Pal isades, N.Y. News & Announcements Ocean Sciences Award P A G E 110 T h e O c e a n Sciences A w a r d is p r e s e n t e d by t h e O c e a n Sciences Section of A G U to a n in dividual w h o h a s m a d e o u t s t a n d i n g a n d long s t a n d i n g c o n t r i b u t i o n s to t h e o c e a n sciences. Previous recipients are E u g e n e C. L a F o n d R i c h a r d C. V e t t e r R o b e r t E. Wall F e n n a n D. J e n n i n g s W a y n e V. B u r t W. Stanley Wilson C u r t i s A. Collins 1982 1983 1983 1984 1984 1984 1985 N o m i n a t i o n s a r e solicited for c a n d i d a t e s for t h e O c e a n Sciences A w a r d in 1986. L e t t e r s of n o m i n a t i o n s h o u l d b e s e n t to A r n o l d L. G o r d o n , P r e s i d e n t - E l e c t , O c e a n Sciences Section, L a m o n t - D o h e r t y Geological O b s e r v a t o r y , Pal isades, N Y 10964. T h e d e a d l i n e for n o m i n a tions is May 1, 1986. N o m i n a t i o n s m a y b e ac c o m p a n i e d by s e c o n d i n g n o m i n a t i o n s a n d a r e s u m e of t h e c a n d i d a t e . Black Sea Cruise P A G E 110 T h e National Expeditionary Planning C o m m i t t e e of t h e U n i v e r s i t y - N a t i o n a l O c e a n o g r a p h i c L a b o r a t o r y System ( U N O L S ) h a s d e s i g n a t e d t h e R/V Knorr to s u p p o r t o c e a n o g r a p h i c p r o g r a m s in t h e Black Sea d u r i n g 1987. R e s e a r c h e r s a r e invited to s u b m i t r e q u e s t s for s h i p t i m e in 1987 a n d 1988 to s u p p o r t projects in t h e Black Sea, t h e M e d i t e r r a n e a n Sea, t h e R e d Sea, a n d t h e I n d i a n O c e a n . P r o p o s a l s for t h e s u p p o r t of t h e sci entific p r o g r a m s s h o u l d b e s u b m i t t e d in ac c o r d a n c e with t h e f u n d i n g a g e n c y d e a d l i n e s . R e q u e s t s for s h i p u s e s h o u l d b e s e n t s o o n to J . D. D o n n e l l y , M a n a g e r , M a r i n e O p e r a tions, W o o d s H o l e O c e a n o g r a p h i c I n s t i t u t i o n , Woods Hole, MA 02543 (telephone: 617-5481400, ext. 2 7 3 6 ) , o r to W. D. B a r b e e , E x e c u tive S e c r e t a r y , U N O L S Office, W B - 1 5 , School of O c e a n o g r a p h y , University of W a s h i n g t o n , Seattle, W A 9 8 1 9 5 ( t e l e p h o n e : 2 0 6 - 5 4 3 2283). Meeting Report Ocean Telemetry Workshop P A G E 110 An informal workshop on ocean telemetry a n d p l a t f o r m location was h e l d o n J a n u a r y 15, 1986, d u r i n g t h e A G U O c e a n Sciences M e e t i n g in N e w O r l e a n s , La. P l a n s for t h e w o r k s h o p g r e w f r o m t h e realization t h a t p r e -
© Copyright 2026 Paperzz