Current Status of Accomplishment or Milestone: The manuscript retitled to "Mid-latitude Wind Stress: The Energy Source for Climatic Regimes in the North Pacific Ocean" was submitted for publication to Science in June 1997.
Background: Analyses of historical surface observations demonstrate extensive decadal-scale variations in winter, mid-latitude atmospheric forcing, which is shown to greatly affect North Pacific Ocean circulation patterns. Following the 1976 climatic shift, wind-stress on the subtropical side of the North Pacific Current increased dramatically resulting in extensive physical environmental alteration of the entire West Wind Drift region as well as the downstream California and Alaska Currents. Marine fishery production in the California and Alaska Currents changed at this time as well, suggesting that natural environmental variation could preclude sustainable yields from many North Pacific fisheries.
Purpose of Activity/Goal of Project: To assess the large-scale natural variability of the Eastern North Pacific Ocean which can be used to predict alterations in the productivity of regional fisheries.
Description of Accomplishment and Significant Results: This paper describes the key climatic mechanisms envolved in the environmental regime shift which occured in the North Pacific in 1976-77. This regime shift which is forced by alterations in the magnitude and location of winter winds over the midlatitudes of the North Pacific has been shown to have strong temporal relationships with the productivity of a wide range of fisheries in the North Pacific, including the present critical status of many Pacific Salmon stocks.
Significance of Accomplishment (e.g., to the Center, to Management, and to NMFS Strategic plan Goals): The milestone demonstrates that decade, or regime scale, environmental variation occurs over the entire North Pacific basin. This scale of environmental variation will cause extensive departures from mean productivity which have the potential to result in fishery productivity changes significant enough to necessitate alterations of fishery management plans.
Problems: Subsurface oceanographic data were not available for decade scale analyses.
Key Contact: Richard Parrish (831-648-9033)