Seasonal Variability and Large-scale Correlation in the California Current:

1993-2004Andrew Davis

The California Current is a mean alongshore equatorward flow that shows variability on all time scales.

Quarterly measurements were taken on cruises by Theresa Chereskin using ADCP’s (Acoustic Doppler Current Profilers).

Local vs. Remote Forcing

Two general categories exist for the explanation of CCS variability: local and remote forcing.

Local effects would be largely atmospheric and simultaneous relative to the resolution of the data.

Remote effects would be associated with waves propagating from other regions.

We will limit ourselves here to local effects.

Examining the Possibility of Local Forcing

• First we will determine whether this low-resolution data displays any periodicities, specifically at yearly frequencies.

• Then we will check for large scale correlation, implying simultaneous atmospheric influence.

• We will concentrate our analysis on the strongest regions of the California Current on lines 90 and 93.

Line 90 LSSA

alongshore

ross-shelf

Line 93 LSSA

alongshore

cross-shelf

2623

22

24

25

27

V line 90R2 analysis

2623

22

24

25

27

V line 93R2 analysis

U line 93R2 analysis

22

23 24

Conclusions

• No detectable periodicities at this resolution over this range. Yearly periodicity was particularly sought, and no evidence was found.

• A degree of large scale correlation was found, but it was minor and relatively local