Comparison of dynamic height measurements from an inverted echo sounder and an island tide gauge in the central Pacific

An inverted echo sounder (IES) and deep pressure sensor were deployed within 70 km of a shallow pressure sensor at Palmyra Island (6°N, 162°W) in the central Pacific. These instruments provided yearlong records of acoustic travel time, deep pressure and sea level. Two independent time series of dynamic height are derived from travel time and sea surface elevation, respectively. The spectra of these time series are similar, and at the spectral peaks the coherence between them exceeds 99.9% confidence levels, indicating that travel time can be used to record dynamic height fluctuations. This investigation provides a frequency dependent calibration for the IES in this region. At the energetic low frequencies (periods ∼ 1 month), this calibration agrees with a calibration by the standard method using conductivity‐temperature‐depth (CTD) casts. At higher frequencies (periods of ∼3 days), using the CTD‐derived calibration may underestimate the amplitude of some processes by as much as 30%

Inverted Echo Sounder Measurement of Dynamic Height Through an ENSO Cycle in the Central Equatorial Pacific

A four-year record from an inverted echo sounder, deployed near Palmyra Island at 6—N in the central Pacific Ocean, is compared with a simultaneous record of subsurface pressure from this island\u27s lagoon. A factor m, converting round-trip acoustic travel time to surface dynamic height relative to a deep pressure level, was estimated from the ratio of the spectra of the two records in the energetic synoptic oscillation band. Year-to-year variation in m was not statistically significant. For the overall record, m was found to be - 70 — 8 dyn m s-1, where the error bounds represent a 90% confidence interval. This is consistent with first-baroclinic-mode excitation. © 1990 IEE

Five years’ central pacific sea level from in situ array, satellite altimeter and numerical model: Research note

Temporal and spatial features of central equatorial Pacific Ocean sea‐level variation appear similar, in measurements from two very different systems (one in the ocean and one carried on a satellite), and in results from a numerical model of the region. In particular, there is an interannual cycle: during El Nino, Kelvin waves appear at the equator, and the sea‐surface ridge associated with the equatorial current system shifts southward; in non‐El Nino years, instability waves appear at 6°N (strongest around the end of each calendar year), and the ridge shifts to the north. This three‐way comparison gives support to both measurement systems and to the numerical model. © 1994 Taylor & Francis Group, LLC

Sedimentary furrows and organized flow structure: A study in Lake Superior

This article is in Free Access Publication and may be downloaded using the “Download Full Text PDF” link at right. © 1992, by the Association for the Sciences of Limnology and Oceanography, Inc

Five years’ central pacific sea level from in situ array, satellite altimeter and numerical model: Research note

Temporal and spatial features of central equatorial Pacific Ocean sea‐level variation appear similar, in measurements from two very different systems (one in the ocean and one carried on a satellite), and in results from a numerical model of the region. In particular, there is an interannual cycle: during El Nino, Kelvin waves appear at the equator, and the sea‐surface ridge associated with the equatorial current system shifts southward; in non‐El Nino years, instability waves appear at 6°N (strongest around the end of each calendar year), and the ridge shifts to the north. This three‐way comparison gives support to both measurement systems and to the numerical model. © 1994 Taylor & Francis Group, LLC