Separation of Short Time Series of Currents into 'Fluctuations,' 'Tides,' and 'Mean' Flow
| Autor: | Ann E. Gargett, Dana K. Savidge |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Atmospheric Science
010504 meteorology & atmospheric sciences 010505 oceanography Turbulence Flow (psychology) Ocean Engineering Forcing (mathematics) Internal wave Atmospheric sciences 01 natural sciences Current (stream) Current meter Climatology Mean flow Extraction (military) Geology 0105 earth and related environmental sciences |
| Zdroj: | Journal of Atmospheric and Oceanic Technology. 33:1089-1095 |
| ISSN: | 1520-0426 0739-0572 |
| DOI: | 10.1175/jtech-d-15-0232.1 |
| Popis: | With standard low-frequency velocity data from current meter moorings, pressure gradient–driven mean flow is determined by low-pass filtering, while tides are estimated by fitting tidal constituents, with accuracy and numbers of constituents determined by record length. With the advent of higher-frequency measurements from cabled coastal ocean observatories, current data also include supertidal variability (fluctuation) associated with a variety of turbulent and internal wave processes. To examine the relationships of such fluctuations to variability of the tides and/or potentially time-variable mean flows within which they are embedded, it is highly desirable to find a method whereby these flow components can be separated over relatively short periods of intensified event-scale forcing. A method is presented that first isolates “fluctuations” and then separates the remaining longer time-scale variability into “tides” and a remaining “mean,” without recourse to extraction of a fitted tide with the error inherent in such a fit over short data records. |
| Databáze: | OpenAIRE |
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