Summary of first meeting of ENSOs and Regime Shifts group

 

Date of Meeting: 20 August 1997

Place: Univ. of Wash. South Campus Center

 

Present at the meeting:

Steven Hare (IPHC), Lou Botsford (UC), Ray Hilborn (UW), Loh-Lee Low (NMFS), Brian Bigler (Wards Cove), Jim Anderson (UW), Ric Brodeur (NMFS), Warren Wooster (UW), Kerim Aydin (UW), Bill Pinnix (UW), Curt Ebbesmeyer (Evans-Hamilton), Jim Ingraham (NMFS), David Salinger (UW), Rich Hinrichson (UW), Bob Iwamoto (NMFS), John Williams (NMFS).

 

Meeting organized by Hare per following rationale:

 

1) There is a large ENSO event brewing in the mid-Pacific

2) Alaska’s spring/summer has been decidedly anomalous

3) Bristol Bay and other AK salmon stocks are having their worst year in 25 years

4) There’s been talk of a regime shift to pre-1977 conditions

5) There is a great deal of scientific and public interest in the first 4 items

 

Discussion initially focused on current 1997 ENSO event and then on Bristol Bay sockeye salmon run "failure." Mention was also made of seabird mortalities. Several participants remarked that the weather in Alaska this spring could not be due to the current El Niño since the effects are generally felt the winter following an event.

For the remainder of the time most of the discussion was on the possibility of a 1995 North Pacific regime shift back to pre-1977 conditions. The initial impetus for this view was 1) the small return of 2-ocean sockeye salmon to Bristol Bay and 2) the large return of 2-ocean chinook to the Columbia River. The current regime shift model predicts that Alaska salmon and West Coast salmon should vary inversely.

 

Other evidence brought up supporting the notion of a winter 1995 regime shift:

 

  1. Weakening of the Aleutian Low for the winters of 1995, 1996, 1997.
  2. Decrease in precipitation in Alaska for 1995-1997 compared to 1994
  3. Increase in precipitation in Pacific Northwest for the last three years.
  4. Mean size of salmon (Alaska and Columbia River) has increased for return years 1995 and 1996
  5. 1995 was biggest ice year in Bering Sea in 20 years

 

The group agreed to meet again and bring disparate datasets to test the hypothesis that the climate and ecosystem(s) of the North Pacific underwent a regime shift in 1995.

 

Other regime shifts in this century were discussed and event sin the mid-40s (from warm to cool), mid 20s (from cool to warm) and 00s (from warm to cool) were pointed out. Discussion was also made of Beamish’s belief that a regime shift (from warm to warmer) occurred around 1990.

 

All agreed that the developing El Niño would have effects opposite to that occurring with the hypothesized 1995 regime shift.

 

It was pointed out that jellyfish populations (in the Bering?) have skyrocketed since 1990.

 

A forecast: 3-ocean fish returning to the Columbia will be "huge". The 1996 jacks and 1997 two-ocean fish were both substantially larger than average.

 

There was a US Globec meeting held to discuss monitoring of the 1997-8 ENSO. A "white paper" on the discussions held at that meeting is available on the web at the US GLOBEC home page:

 

http://www.usglobec.berkeley.edu/usglobec/globec.homepage.html

 

Next meeting scheduled for:

 

3 September 1997, 9 AM

Pacific Halibut Commission conference room