Evidence for large-scale eddy-driven gyres in the North Atlantic

Science

Volumn 277, Issue 5324, 1997, Pages 361-364

  Lozier, M Susan ^a  

^a DUKE UNIVERSITY   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

AIR/SEA INTERACTION; CIRCULATION; CLIMATE DATABASE; EDDIES; EDDY; GYRE; GYRES; LARGE-SCALE RECIRCULATION SYSTEM; OCEAN CIRCULATION;

ARTICLE; CLIMATE; DATA BASE; GEOGRAPHY; PRIORITY JOURNAL; SEA; WATER FLOW;

ATLANTIC, (NORTH);

EID: 0030771950     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.277.5324.361     Document Type: Article

References (43)

1. M. S. Lozier, W. B. Owens, R. G. Curry, Prog. Oceanogr. 36, 1 (1995).
2. S. Levitus, NOAA Prof. Pap. 13 (Government Printing Office, Washington, DC, 1982); S. Levitus and T. P. Boyer, World Ocean Atlas 1994, vol. 4, Temperature, NOAA Atlas NESDIS 4 (National Oceanic and Atmospheric Administration, Washington, DC, 1994).
3. S. Levitus, NOAA Prof. Pap. 13 (Government Printing Office, Washington, DC, 1982); S. Levitus and T. P. Boyer, World Ocean Atlas 1994, vol. 4, Temperature, NOAA Atlas NESDIS 4 (National Oceanic and Atmospheric Administration, Washington, DC, 1994).
4. -3. The reference pressure divided by 1000 dbar is denoted by n. The depth of the potential density anomaly surface is approximated by its pressure, because 1 dbar ∼ 1 m.
5. W. J. Schmitz, J. Mar. Res. 38, 111 (1980).
6. Because the detailed signature of the recirculation was created by isobars contoured between 25 and 50 dbar, it is important to note that the standard errors for the pressure field on this surface are∼10 to 20 dbar for the western North Atlantic.
7. An earlier analysis of a collection of historical hydrographic lines [J. L. Reid, Prog. Oceanogr. 33, 1 (1994)] showed a large-scale anticyclonic gyre in the general vicinity of the gyre shown in Fig. 1C. However, Reid's gyre and the one depicted in Fig. 1C have substantial differences in their vertical structure and horizontal substructure.
8. Southward flow of North Atlantic Deep Water on the eastern side of the Mid-Atlantic Ridge is supported by P. M. Saunders [J. Mar. Res. 40, 641 (1982)], S. Gana and C. Provost [J. Mar. Syst. 4, 67 (1993)], and J. Paillet and H. Mercier (Deep-Sea Res., Part I, in press).
9. Southward flow of North Atlantic Deep Water on the eastern side of the Mid-Atlantic Ridge is supported by P. M. Saunders [J. Mar. Res. 40, 641 (1982)], S. Gana and C. Provost [J. Mar. Syst. 4, 67 (1993)], and J. Paillet and H. Mercier (Deep-Sea Res., Part I, in press).
10. Southward flow of North Atlantic Deep Water on the eastern side of the Mid-Atlantic Ridge is supported by P. M. Saunders [J. Mar. Res. 40, 641 (1982)], S. Gana and C. Provost [J. Mar. Syst. 4, 67 (1993)], and J. Paillet and H. Mercier (Deep-Sea Res., Part I, in press).
11. Topographic sill depths of ∼1000 m are a barrier for flow of this density into the Nordic Seas.
12. L. V. Worthington, Johns Hopkins Oceanogr. Stud. 6, (1976); R. A. Clarke, H. W. Hill, R. F. Reininger, B. A. Warren, J. Phys. Oceanogr. 10, 25 (1980); M. S. McCartney, Prog. Oceanogr. 29, 283 (1992); W. J. Schmitz and M. S. McCartney, Rev. Geophys. 31, 29 (1993).
13. L. V. Worthington, Johns Hopkins Oceanogr. Stud. 6, (1976); R. A. Clarke, H. W. Hill, R. F. Reininger, B. A. Warren, J. Phys. Oceanogr. 10, 25 (1980); M. S. McCartney, Prog. Oceanogr. 29, 283 (1992); W. J. Schmitz and M. S. McCartney, Rev. Geophys. 31, 29 (1993).
14. L. V. Worthington, Johns Hopkins Oceanogr. Stud. 6, (1976); R. A. Clarke, H. W. Hill, R. F. Reininger, B. A. Warren, J. Phys. Oceanogr. 10, 25 (1980); M. S. McCartney, Prog. Oceanogr. 29, 283 (1992); W. J. Schmitz and M. S. McCartney, Rev. Geophys. 31, 29 (1993).
15. L. V. Worthington, Johns Hopkins Oceanogr. Stud. 6, (1976); R. A. Clarke, H. W. Hill, R. F. Reininger, B. A. Warren, J. Phys. Oceanogr. 10, 25 (1980); M. S. McCartney, Prog. Oceanogr. 29, 283 (1992); W. J. Schmitz and M. S. McCartney, Rev. Geophys. 31, 29 (1993).
16. R. S. Pickart and W. M. Smethie, J. Phys. Oceanogr. 23, 2602 (1993).
17. J. Paillet, M. Arhan, M. S. McCartney, in preparation.
18. P. B. Rhines and W. R. Holland, Dyn. Atmos. Oceans 3, 289 (1979).
19. W. R. Holland, Geophys. Fluid Dyn. 4, 187 (1973).
20. R. Gerdes and C. Köberle, J. Phys. Oceanogr. 25, 2624 (1995).
21. These gyres at intermediate depths are distinct from the smaller scale gyres at abyssal depths that are more clearly associated with the basin topography.
22. P. B. Rhines and W. R. Young, J. Fluid Mech. 122, 347 (1982).
23. W. R. Holland and P. B. Rhines, J. Phys. Oceanogr. 10, 1010 (1980).
24. S. McDowell, P. Rhines, T. Keffer, ibid. 12, 1417 (1982); T. Keffer, ibid. 15, 509 (1985); J. L. Sarmiento, C. G. H. Rooth, W. Roether, J. Geophys. Res. 87, 8047 (1982).
25. S. McDowell, P. Rhines, T. Keffer, ibid. 12, 1417 (1982); T. Keffer, ibid. 15, 509 (1985); J. L. Sarmiento, C. G. H. Rooth, W. Roether, J. Geophys. Res. 87, 8047 (1982).
26. S. McDowell, P. Rhines, T. Keffer, ibid. 12, 1417 (1982); T. Keffer, ibid. 15, 509 (1985); J. L. Sarmiento, C. G. H. Rooth, W. Roether, J. Geophys. Res. 87, 8047 (1982).
27. J. Pedlosky, Ocean Circulation Theory (Springer-Verlag, New York, 1996).
28. o is a constant potential density. The vertical derivative is computed locally over a nominal depth of 100 m. In an effort to approximate neutral surfaces [T. J. McDougall, J. Phys. Oceanogr. 17, 1950 (1987)], potential vorticity was also calculated as f/h, where h is the distance between two locally referenced isopycnals. The differences in the two methods were insignificant to the results of this study; that is, the region and extent of homogenization were the same with either calculation.
29. M. S. McCartney and L. D. Talley, ibid. 12, 1169 (1982).
30. J. O'Dwyer and R. G. Williams (J. Phys. Oceanogr., in press) report, from an analysis of the Levitus data set, possible regions of homogenization at abyssal depths in the western North Atlantic.
31. 3 = 41.45 (at ∼3000 m) as the level of no motion.
32. 3 = 41.45 (at ∼3000 m) as the level of no motion.
33. D. L. Musgrave, J. Geophys. Res. 90, 7037 (1985).
34. 2 = 36.95 show counter-rotating gyres separated by this instability region in the western North Atlantic, which suggests the importance of eddy flux divergence in the forcing of the gyres.
35. J. Pedlosky, J. Phys. Oceanogr. 13, 2121 (1983).
36. N. Hogg, Deep-Sea Res. Part A 30, 945 (1983).
37. P. B. Rhines and W. R. Young, J. Mar. Res. 40, 559 (1982).
38. P. Cessi, G. lertey, W. Young, J. Phys. Oceanogr. 17, 1640 (1987); P. Cessi, ibid. 18, 662 (1988).
39. P. Cessi, G. lertey, W. Young, J. Phys. Oceanogr. 17, 1640 (1987); P. Cessi, ibid. 18, 662 (1988).
40. W. J. Jenkins and P. B. Rhines, Nature 286, 877 (1980); R. S. Pickart, Deep-Sea Res. Part A 39, 1553 (1992); W. M. Smethie, Prog. Oceanogr. 31, 51 (1993).
41. W. J. Jenkins and P. B. Rhines, Nature 286, 877 (1980); R. S. Pickart, Deep-Sea Res. Part A 39, 1553 (1992); W. M. Smethie, Prog. Oceanogr. 31, 51 (1993).
42. W. J. Jenkins and P. B. Rhines, Nature 286, 877 (1980); R. S. Pickart, Deep-Sea Res. Part A 39, 1553 (1992); W. M. Smethie, Prog. Oceanogr. 31, 51 (1993).
43. I thank J. Pedlosky for his aid in the interpretation of these fields and P. Rhines for his comments on the manuscript. Support from NSF (grant OCE-9629489) is gratefully acknowledged.