El Niño/Southern Oscillation Major climatic perturbation on the planet Coupled atmosphere ocean process Key is the western tropical Pacific – Ascending branch of the Walker circulation – Potential energy for Kelvin wave pulse

Coupled Walker/Ocean Circulation

El Niño Conditions

Relation of Sea Level with SOI Statistical relationship with SOI Coastal signals seen in CA Current Ted Strub [OSU]

San Francisco Sea Level

CA Current Effects

San Francisco Sea Level

Kelvin Wave Pulse Kelvin wave pulse Ted Strub [OSU]

Santa Barbara Channel - PnB

Santa Barbara Channel

Primary Production Phytoplankton h CO 2 O2O2 PlantsNUTS Light, carbon & nutrients make plants & O 2

Santa Barbara Channel

Santa Barbara Channel Annual Means – Oct/Oct YearSST ( o C) SSS (psu) SSNO 3 (  M) SSChl (mg m -3 ) T(50m) ( o C) NO 3 (50m) ( o C) Wind Speed (m s -1 ) SCR discharge (Mm 3 /y) 1996 to (2.00) (0.09) 1.81 (2.30) 2.01 (1.68) (0.78) (3.93) 7.12 (2.69) (466.72) 1997 to (5.45) (0.20) 0.80 (1.39) 1.05 (1.16) (2.35) 7.53 (6.87) 5.99 (2.06) ( ) 1998 to (2.76) 33.5 (0.15) 2.21 (2.76) 2.13 (2.22) (1.32) (4.48) 7.77 (1.43) (51.77) 1999 to (1.85) (0.12) 1.52 (1.46) 2.74 (2.89) (0.97) (5.86) 6.70 (2.84) ( ) 2000 to (2.33) (0.13) 0.79 (1.07) 1.70 (2.08) (0.87) (5.23) 6.1 (2.23) ( ) Total15.63 (2.46) (0.15) 1.42 (1.97) 1.94 (2.20) (1.56) (5.51) 6.7 (2.32) ( )

97/98 ENSO in SB Channel Deep thermocline & high SST – Limits nitrate supply & chlorophyll biomass – Chl & nitrate are much lower during ESNO Forcings change – Wind speeds (West channel buoy) are lower – Santa Clara River discharges are >> normal

Ocean Color 97/98 ENSO Kahru & Mitchell [2000; GRL]

More low Chl regions during ENSO

Fewer occurrences of low SST during ENSO

Comparisons with the ENSO

97/98 ENSO in Central CA Biological processes are much lower Winds are roughly the same Upwelling still happens – but it is less “ useful ” water upwelling

El Niño & CA Current Kelvin wave pulse propagates north – Propagates 40,000 km in 6 months (2-3 m/s) Depresses thermocline & raises SST – Thermocline is depressed 30 to 70 m Winds are not affected in some places not others Role of thermocline depth is critical – reduced nutrient supply and lower chlorophyll

El Niño & Global NPP

El Niño & NPP Global primary production rates are a funtion of thermal stratification Strong relationship with Multi-ENSO Index (MEI) – MEI is like the SOI Global NPP is related to ENSO

Ecosystem Regime Shifts - PDO Climate oscillators besides ENSO – Pacific decadal oscillation - PDO Ecosystem effects of “ regime shifts ” – 1977 (have we flipped back??) – Food web & fishery responses

Pacific Decadal Oscillation Warm Cool

Pacific Decadal Oscillation

Southern Oscillation Index SOI = Tahiti - Darwin air pressure  ’ s Low SOI = El Niño conditions

Pacific Decadal Oscillation

PDO vs. ENSO

Pacific Decadal Oscillation Warm Cool

Southern Oscillation Index SOI = Tahiti - Darwin air pressure  ’ s Low SOI = El Niño conditions

Pacific Decadal Oscillation

ENSO

Pacific Decadal Oscillation

Pink Coho Chum Chinook Sockeye Salmon

PDO and Salmon Yields September 1972 (National Fisherman 1972) "Bristol Bay [Alaska] salmon run a disaster." "Gillnetters in the Lower Columbia [Washington and Oregon] received an unexpected bonus when the largest run of spring chinook since counting began in 1938 entered the river." 1995 Yearbook (Pacific Fishing 1995) "Alaska set a new record for its salmon harvest in 1994, breaking the record set the year before." "Columbia [Washington and Oregon] spring chinook fishery shut down; west coast troll coho fishing banned."

September 1915 (Pacific Fisherman 1915) "Never before have the Bristol Bay [Alaska] salmon packers returned to port after the season's operations so early." "The spring [chinook salmon] fishing season on the Columbia River [Washington and Oregon] closed at noon on August 25, and proved to be one of the best for some years." 1939 Yearbook (Pacific Fisherman 1939) "The Bristol Bay [Alaska] Red [sockeye salmon] run was regarded as the greatest in history." "The [May, June and July chinook] catch this year is one of the lowest in the history of the Columbia [Washington and Oregon]."

PDO and Fish Yields

PDO and … Mantua et al…

Pacific Decadal Oscillation

PDO and … TABLE 3: Percent change in mean catches of four Alaskan salmon stocks following major PDO sign changes in 1947 and salmon stock1947 step1977 step western Alaska sockeye-37.2%+242.2% central Alaska sockeye-33.3%+220.4% central Alaska pink-38.3%+251.9% southeast Alaska pink-64.4%+208.7%

PDO and …

Salmon and the PDO Two Hypotheses for signal –First feeding of smolts entering ocean & PDO_altered primary production – Streamflow alterations drive salmon habitat availability Consensus is the first feeding…

PDO and …

Bristol Bay Salmon Stocks Studied / Modeled Extensively Study concluded Biocomplexity preserved by setting regional guidelines– not just protecting economically viable stock BUT- where does PDO fit in? The largest harvest of sockeye salmon in the world occurs in the Bristol Bay area of southwestern Alaska where 10 million to more than 30 million sockeye salmon may be caught each year during a short, intensive fishery lasting only a few weeks.

Freshwater Life: Half of the Cycle Sockeye: “Simply put, the adults spawn at a date that, given the average thermal regime, will allow the embryos to complete embryonic development and emerge in time to feed on aquatic insects and zooplankton the following spring” Hilborn et. al. 2003

Bristol Bay Hydrology & PDO Above average mean annual discharge warm-PDO Below average mean annual discharge cool-PDO In general, high streamflow = favorable reproductive conditions

Bristol Bay Catch History Dominant location varies PDO-flux influences general productivity? Stock spawning ground, adaptations influence success of individual runs PDO-related population change not evident in 1920’s to 1940’s?

Bristol Bay Stock History Regional Stock have variety of adaptations to mean hydrologic & ecologic conditions Number of recruits per spawner: Total # adult salmon returning from a spawning year divided by # fish spawned in that brood year Increase in recruits = higher survival rates

Pacific Decadal Oscillation

Salmon and the PDO Spawners passing Bonneville Dam Hatchery returns PDO

PREDICTIONS? Spring Chinook returns correlated with a “ food chain ” indicator of ocean conditions, with a two year lag Columbia River coho returns correlated with the same indicator but with one year lag Ocean Entry 2005

“ Cool ” Phase A working mechanistic hypothesis: source waters...  Transport of cold water, phytoplankton and boreal zooplankton into the NCC from Gulf of Alaska  Transport of warm water, phytoplankton and sub-tropical zooplankton into NCC from offshore and from the south “ Warm ” Phase

Salmon and the PDO Two Hypotheses for signal –First feeding of smolts entering ocean & PDO_altered primary production – Streamflow alterations drive salmon habitat availability Consensus is the first feeding…

Predicting CA/OR Coho & Chinook Runs for 2012/2013

Predicting CA/OR Coho & Chinook Runs for 2012/2013

Predicting CA/OR Coho & Chinook Runs for 2012/2013

Predicting CA/OR Coho & Chinook Runs for 2011/2012

Pacific Decadal Oscillation

PDO from Tree Rings Biondi, Gershunov & Cayan, 2001 North Pacific Decadal Climate Variability Since AD Journal of Climate, 14, Used tree rings from Jeffrey Pine & Douglas Fir

PDO from Tree Rings

Pacific Decadal Oscillation

Decadal scale variations in patterns over Pacific Warm phase – Alaska moist, salmon up (freshwater habitat is good) – Oregon/Washington dry, salmon down – Patterns throughout Pacific basin Cool phase opposite Fisheries response (time scales match)