throughout the world, but mainly in the Equatorial Pacific. Finally, the PDO has
cycles of 20—30 years, and is responsible for processes in the North and Central
Pacific. Because of the length of its cycles we are not in a position to predict
whether global change is affecting its periodicity.
Case Study 1: The North Atlantic Oscillation
The NAO is a basin-wide scale atmospheric alternation of atmospheric mass,
reflecting the changes in sea level pressure over the North Atlantic region. The
standard NAO index (Figure 6) is the difference in normalized sea level pressures
between the subtropical high pressures centred on the Azores and the sub-polar
low pressures centred over Iceland, during the winter season (December to
March). Its state determines the speed and direction of the westerlies across the
north Atlantic as well as the level and direction of moisture transport and winter
temperatures on both sides of the basin. A high NAO index is associated with
J. P. Barry, C. H. Baxter, R. D. Sagarin and S. E. Gilman, Science, 1995, 267, 672—675.
A. M. Breeman, in J. J. Beukema and J. J. W. M. Brouns (eds.) Expected Effects of Climatic Change
on Marine Coastal Ecosystems, 1990, Kluwer Academic Press, pp. 69—76.
K. T. Frank, I. Perry and K. F. Drinkwater, Trans. Am. Fish. Soc., 1990, 119, 353—365.
J. Lubchenco, S. A. Navarrete, B. N. Tissot and J. C. Castilla, in H. A. Mooney, E. R. Fuentes and
B. I. Kronberg, Earth System Responses to Global Change, 1993, pp. 147—166.
S. A. Murawski, Trans. Am. Fish. Soc., 1993, 122, 647—658.
A. J. Southward, J. Mar. Biol. Assoc. UK, 1967, 47, 81—95.
A. J. Southward, S. J. Hawkins and M. T. Burrows, J. Therm. Biol., 1995, 20, 127—155.
D. H. Cushing, Climate and Fisheries, Academic Press, London, 1982, 387 pp.
M. R. Heath, J. O. Backhaus, K. Richardson, E. Mckenzie, D. Slagstad, D. Beare, J. Dunn, J. G.
Fraser, A. Gallego, D. Hainbucher, S. Hay, S. Jonasdottir, H. Madden, J. Mardaljevic and A.
Schacht, Fish. Oceanogr., 1999, 8(Supp. 1), 163—176.
B. Planque and A. H. Taylor, ICES J. Mar. Sci., 1998, 55, 644—654.
D. G. Ainley, W. J. Sydeman and J. Norton, Mar. Ecol. Prog. Ser., 1996, 118, 69—79.
K. J. Kuletz, D. B. Irons, B. A. Angler and J. F. Piatt, Proc. Int. Symp. Role of Forage Fishes in Mar.
Ecosys., 1997, 703—706.
J. M. Napp, K. O. Coyle, T. E. Whitledge, D. E. Varela, M. V. Flint, N. Shiga, D. M. Schell and
S. M. Henrichs, in Report of the FOCI International Workshop on Recent Conditions in the Bering
Sea, ed. S. A. Macklin, 1999, Contribution 2044 from NOAA/Pacific Marine Environmental
Laboratory, Contribution B358 from Fisheries-Oceanography Coordinated Investigations.
I. Stirling, N. J. Lunn and J. Iacozza, Arctic, 1999, 52, 294—306.
R. R. Veit, P. Pyle and J. A. McGowan, Mar. Ecol. Prog. Ser., 1996, 139, 11—18.
J. P. Croxall, K. Reid and P. A. Prince, Mar. Ecol. Progr. Ser., 1999, 177, 115—131.
W. R. Fraser, W. Z. Trivelpiece, D. G. Ainley and S. G. Trivelpiece, Pol. Biol., 1992, 11, 525—531.
D. Lluch-Belda, S. Hernandez-Vazquez, D. B. Lluch-Cota, C. A. Salinas-Zavala and R. A.
Schwartzlose, CalCOFI Rep., 1992, 33, 50—59.
N. P. Holliday and P. C. Reid, ICES J. Mar. Sci., 2001, 58, 270—274.
W. A. Montevecchi and R. A. Myers, ICES J. Mar. Sci., 1997, 54, 608—614.
P. C. Reid, M. de Fatima Borges and E. Svendsen, Fish. Res., 2001, 50, 163—171.
R. D. Sagarin, J. P. Barry, S. E. Gilman and C. H. Baxter, Ecol. Monographs, 1999, 69, 465—490.
C. Wilkinson, O. Linden, H. Cesar, G. Hodgson, J. Rubens and A. E. Strong, Ambio, 1999, 28, 188—196.
J. P. Gattuso, D. Allemand and M. Frankignoulle, Am. Zool., 1999, 39, 160—183.
J. A. Kleypas, R. W. Buddemeir, D. Archer, J. P. Gattuso, C. Langdon and B. N. Opdyke, Science,
1999, 284, 118—120.
A. Timmermann, J. Oberhuber, A. Bacher, M. Esch, M. Latif and E. Roeckner, Nature, 1999, 398,
694—696.
J. W. Hurrell, Science, 1995, 269, 676—679.
Influence of Climate Variability and Change on Marine Ecosystems
65
cycles of 20—30 years, and is responsible for processes in the North and Central
Pacific. Because of the length of its cycles we are not in a position to predict
whether global change is affecting its periodicity.
Case Study 1: The North Atlantic Oscillation
The NAO is a basin-wide scale atmospheric alternation of atmospheric mass,
reflecting the changes in sea level pressure over the North Atlantic region. The
standard NAO index (Figure 6) is the difference in normalized sea level pressures
between the subtropical high pressures centred on the Azores and the sub-polar
low pressures centred over Iceland, during the winter season (December to
March). Its state determines the speed and direction of the westerlies across the
north Atlantic as well as the level and direction of moisture transport and winter
temperatures on both sides of the basin. A high NAO index is associated with
J. P. Barry, C. H. Baxter, R. D. Sagarin and S. E. Gilman, Science, 1995, 267, 672—675.
A. M. Breeman, in J. J. Beukema and J. J. W. M. Brouns (eds.) Expected Effects of Climatic Change
on Marine Coastal Ecosystems, 1990, Kluwer Academic Press, pp. 69—76.
K. T. Frank, I. Perry and K. F. Drinkwater, Trans. Am. Fish. Soc., 1990, 119, 353—365.
J. Lubchenco, S. A. Navarrete, B. N. Tissot and J. C. Castilla, in H. A. Mooney, E. R. Fuentes and
B. I. Kronberg, Earth System Responses to Global Change, 1993, pp. 147—166.
S. A. Murawski, Trans. Am. Fish. Soc., 1993, 122, 647—658.
A. J. Southward, J. Mar. Biol. Assoc. UK, 1967, 47, 81—95.
A. J. Southward, S. J. Hawkins and M. T. Burrows, J. Therm. Biol., 1995, 20, 127—155.
D. H. Cushing, Climate and Fisheries, Academic Press, London, 1982, 387 pp.
M. R. Heath, J. O. Backhaus, K. Richardson, E. Mckenzie, D. Slagstad, D. Beare, J. Dunn, J. G.
Fraser, A. Gallego, D. Hainbucher, S. Hay, S. Jonasdottir, H. Madden, J. Mardaljevic and A.
Schacht, Fish. Oceanogr., 1999, 8(Supp. 1), 163—176.
B. Planque and A. H. Taylor, ICES J. Mar. Sci., 1998, 55, 644—654.
D. G. Ainley, W. J. Sydeman and J. Norton, Mar. Ecol. Prog. Ser., 1996, 118, 69—79.
K. J. Kuletz, D. B. Irons, B. A. Angler and J. F. Piatt, Proc. Int. Symp. Role of Forage Fishes in Mar.
Ecosys., 1997, 703—706.
J. M. Napp, K. O. Coyle, T. E. Whitledge, D. E. Varela, M. V. Flint, N. Shiga, D. M. Schell and
S. M. Henrichs, in Report of the FOCI International Workshop on Recent Conditions in the Bering
Sea, ed. S. A. Macklin, 1999, Contribution 2044 from NOAA/Pacific Marine Environmental
Laboratory, Contribution B358 from Fisheries-Oceanography Coordinated Investigations.
I. Stirling, N. J. Lunn and J. Iacozza, Arctic, 1999, 52, 294—306.
R. R. Veit, P. Pyle and J. A. McGowan, Mar. Ecol. Prog. Ser., 1996, 139, 11—18.
J. P. Croxall, K. Reid and P. A. Prince, Mar. Ecol. Progr. Ser., 1999, 177, 115—131.
W. R. Fraser, W. Z. Trivelpiece, D. G. Ainley and S. G. Trivelpiece, Pol. Biol., 1992, 11, 525—531.
D. Lluch-Belda, S. Hernandez-Vazquez, D. B. Lluch-Cota, C. A. Salinas-Zavala and R. A.
Schwartzlose, CalCOFI Rep., 1992, 33, 50—59.
N. P. Holliday and P. C. Reid, ICES J. Mar. Sci., 2001, 58, 270—274.
W. A. Montevecchi and R. A. Myers, ICES J. Mar. Sci., 1997, 54, 608—614.
P. C. Reid, M. de Fatima Borges and E. Svendsen, Fish. Res., 2001, 50, 163—171.
R. D. Sagarin, J. P. Barry, S. E. Gilman and C. H. Baxter, Ecol. Monographs, 1999, 69, 465—490.
C. Wilkinson, O. Linden, H. Cesar, G. Hodgson, J. Rubens and A. E. Strong, Ambio, 1999, 28, 188—196.
J. P. Gattuso, D. Allemand and M. Frankignoulle, Am. Zool., 1999, 39, 160—183.
J. A. Kleypas, R. W. Buddemeir, D. Archer, J. P. Gattuso, C. Langdon and B. N. Opdyke, Science,
1999, 284, 118—120.
A. Timmermann, J. Oberhuber, A. Bacher, M. Esch, M. Latif and E. Roeckner, Nature, 1999, 398,
694—696.
J. W. Hurrell, Science, 1995, 269, 676—679.
Influence of Climate Variability and Change on Marine Ecosystems
65