Current Status of Accomplishment or Milestone: A first draft of the manuscript is complete and is currently undergoing friendly review.
The results of this work have been presented at several scientific meetings (PACLIM, EPOC, AGU).
Background: The 1997-98 El Niņo was one of the strongest on record, and appeared to be linked to large anomalies in the northeast Pacific Ocean (e.g. SST, sea level). However many of these anomalies appeared prior to the onset of equatorial El Niņo conditions, leading us to believe that more regional factors, possibly unrelated to El Niņo, were responsible for the unusual environmental conditions seen off the west coast.
Purpose of Activity/Goal of Project: We analyze and interpret the patterns in northeast Pacific Ocean fields during this event, and prepared a manuscript that summarizes the results. Since similar anomaly patterns are related to decadal North Pacific variations, the study of this El Niņo event may help us understand what mechanisms lead to the observed climate shifts in environment and fisheries time series.
Description of Accomplishment and Significant Results: The Pacific Ocean changed rapidly from La Niņa conditions in February 1997 to very strong El Niņo conditions in July 1997. This transition was supported by exceptionally weak sea level pressures in the North Pacific High, between Hawaii and British Columbia. During May-September 1997, the impacts of the El Niņo were clear in many parts of the world, but not in the extratropical North Pacific. Contrary to some reports, the warm sea surface temperature anomalies (SSTAs) off the US west coast in May-September 1997 were probably not due to the El Niņo but to several other locally and remotely driven processes.
Significance of Accomplishment (e.g., to the Center, to Management, and to NMFS Strategic plan Goals): Shifts in the abundance and distribution of a number of commercial fish stocks in the California Current coincided with the 1997-1998 El Nino. Our study provided many insights into the mechanisms responsible for climatic change in the North Pacific. These insights have, in turn, suggested a number of new ways to monitor the climatic changes that may be most significant to populations of salmon and other organisms.
Key Contact: Frank Schwing (831-648-9034, fschwing@pfeg.noaa.gov)