Abstract
The deep ocean temperatures from 6 years of CTD profiling at the Hawaii Ocean Time-series series exhibit robust interannual variations. A total of 63 (62) casts were made which reached to at least 3600 (4500) dbar between October 1988 and November 1994. In the North Pacific Deep Water between 3500 and 3600 dbar, potential temperature (θ) had a mean value of 1.2°C, with variations over a range of 54.0 m°C and a standard deviation of 10.8 m°C. In the Pacific Bottom Water between 4400 and 4500 dbar, the mean θ was 1.115°C, with variations over a range of 11.0 m°C, and a standard deviation of 2.1 m°C. Smoothing splines fitted to the time series in each pressure interval are used to separate interannual variability from instrumental and natural high frequency noise. In the Deep Water, the interannual variability had an RMS value of 7.4 m°C, with a signal-to-noise ( S N ) ratio of 1.1. In the Bottom Water, interannual variations had an RMS value of 1.5 m°C with an S N ratio of 1.3. The interannual variations of 0 were not coherent between the Deep Water and the Bottom Water. The apparent dominant time scale in the Deep Water was near 2 years, and close to 3 years in the Bottom Water. Previous observations of interannual baroclinic Rossby waves in the North Pacific are suggested as an explanation for the deep ocean interannual temperature variability.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call