Table 2.
Information on environmental covariates used in dynamic factor analysis including how data were summarized and used in the model (e.g., mean winter, spring, and summer SST).
| Covariate | Data summary | Station location | Source |
|---|---|---|---|
| Sea surface temperature (SST) | Seasonal means: Winter (win) = Jan–Mar, Spring (spr) = Apr–Jun, Summer (sum) = Jul–Aug | Race Rocks, Strait of Juan de Fuca | http://www.pac.dfo‐mpo.gc.ca/science/oceans/data‐donnees/lightstations‐phares/data/RaceRocksDailySalTemp.txt |
| Sea surface salinity (SSS) | Annual mean | Race Rocks, Strait of Juan de Fuca | http://www.pac.dfo‐mpo.gc.ca/science/oceans/data‐donnees/lightstations‐phares/data/RaceRocksDailySalTemp.txt |
| Skagit River outflow (flow) | Seasonal means: Spr = Mar–Jun, Sum = Jul–Sep | Site # 12200500 Mt. Vernon, Washington | http://waterdata.usgs.gov/nwis/dv |
| Air temperature (AirTemp) | Annual mean | Puget Sound lowlands | https://www.ncdc.noaa.gov/cag/time‐series/ |
| North Pacific Gyre Oscillation (NPGO) | Annual mean from Jul to Jun | NA | http://www.oces.us/npgo/npgo.php |
| El Niño (ENSO) | Annual mean from Jul to Jun | NA | http://www.esrl.noaa.gov/psd/enso/mei/table.html |
| Spring transition index (STI) | Date of spring transition from downwelling to upwelling | Fig. 1, off northwestern Washington, “CUI Site” | https://www.pfeg.noaa.gov/products/PFELData/upwell/daily/p06dayac.all |