The North Pacific Gyre Oscillation (NPGO) is a climate pattern that emerges as the 2nd dominant mode of sea surface height variability (2nd EOF SSH) in the Northeast Pacific. The NPGO is significantly correlated with previously unexplained fluctuations of salinity, nutrients and chlorophyll-a measured in long-term observations in the California Current (CalCOFI) and Gulf of Alaska (Line P). We use the term NPGO because its fluctuations reflect changes in the intensity of the central and eastern branches of the North Pacific gyre circulations as evident from the NPGO SSHa anomalies. Fluctuations in the NPGO are driven by regional and basin-scale variations in wind-driven upwelling and horizontal advection- the fundamental processes controlling salinity figure and nutrient figure concentrations. Nutrient fluctuations drive concomitant changes in phytoplankton concentrations, and may force similar variability in higher trophic levels. The NPGO thus provides a strong indicator of fluctuations in the mechanisms driving planktonic ecosystem dynamics.
cciea_OC_NPGOA data frame with 847 rows and 5 variables:
Time (seconds since 1970-01-01T00:00:00Z) [-6.31152E8, 1.5935616E9]
NPGO Index () [-3.646516, 2.956047]