scholarly journals Near-surface circulation and tidal currents of the Okhotsk Sea observed with satellite-tracked drifters

2002 ◽  
Vol 107 (C11) ◽  
Author(s):  
Kay I. Ohshima
Keyword(s):  
Tidal Currents ◽  
Okhotsk Sea ◽  
Near Surface ◽  
Surface Circulation

ADCP Observation and Numerical Model Prediction of Tidal Currents Near Kozu Island

2018 ◽  
Author(s):  
Tsubasa Kodaira ◽  
Takuji Waseda
Keyword(s):  
Numerical Model ◽  
Model Prediction ◽  
Vertical Profile ◽  
General Circulation ◽  
Circulation Model ◽  
Tidal Currents ◽  
Ocean Current ◽  
Near Surface ◽  
The Kuroshio ◽  
Adcp Observation

Izu island chain south of Tokyo, Japan has been considered as a prospective area for ocean renewable energy development because of relatively strong tidal currents, and the Kuroshio current. An Acoustic Doppler Current Profiler (ADCP) measurement near one of the islands, Kozu island, was conducted to know ocean current variability. The ADCP, Signature500, was installed 700m away from the coast and the water depth is 32m there. The observation period is for a month from January 8th, 2017. Vertical profile of the currents was recorded every 1 m at 1 minute interval. Based on the observation, the peak tidal currents were often more than 1m/s, and the maximum total speed exceeded 2m/s. The maximum flow is probably related to the Kuroshio intrusion because temperature increased abruptly. Typical vertical profile of the current follows the logarithmic law except for the near surface area. To study the spatial distribution of the current around Kozu island, a numerical model is developed based on MIT General Circulation Model (MITgcm). The model prediction of tidal sea surface variation is in a good agreement with the observation. The model underestimated the tidal currents, but the phase is in a reasonable agreement with the ADCP observation result.

The near-surface circulation of the North Pacific using satellite tracked drifting buoys

1983 ◽  
Vol 88 (C12) ◽  
pp. 7507 ◽  
Author(s):  
Gerard J. McNally ◽  
William C. Patzert ◽  
A. D. Kirwan ◽  
Andrew C. Vastano
Keyword(s):  
North Pacific ◽  
Near Surface ◽  
The North ◽  
Surface Circulation ◽  
The North Pacific ◽  
Drifting Buoys

Rule-of-Thumb Formulas for Extending the Versatility of Tidal Current Tables

2000 ◽  
Vol 34 (2) ◽  
pp. 18-21
Author(s):  
Ben J. Korgen
Keyword(s):  
Tidal Current ◽  
Critical Value ◽  
Tidal Currents ◽  
Current Speed ◽  
Time Interval ◽  
Local Conditions ◽  
Near Surface ◽  
Rule Of Thumb ◽  
Safety Margins ◽  
Scientific Results

Four rule-of-thumb formulas have been derived for use in conjunction with existing tidal current tables. For near-surface tidal currents, these formulas yield 1) the percent of time current speed is above a critical value, 2) the percent of time current speed is below a critical value, 3) the time interval when current speed is above a critical value, and 4) the time interval when current speed is below a critical value. The formulas presented require as inputs the near-surface tidal current speed predictions found in standard tidal current tables. Intended for making rough approximations, these formulas may be useful in planning operations for which information on near-surface tidal currents is important. They are not scientific results or predictive models on which anyone’s life should depend. They should be used only with generous safety margins and if possible, with in situ current measurements, since local conditions may vary considerably.

scholarly journals Attenuation of wind-induced pressure perturbations in alpine snow

2016 ◽  
Vol 62 (234) ◽  
pp. 674-683 ◽  
Author(s):  
STEPHEN A. DRAKE ◽  
HENDRIK HUWALD ◽  
MARC B. PARLANGE ◽  
JOHN S. SELKER ◽  
ANNE W. NOLIN ◽  
...  
Keyword(s):  
High Frequency ◽  
Pressure Measurements ◽  
Near Surface ◽  
Surface Circulation ◽  
Surface Snow ◽  
Theoretical Predictions ◽  
Air Mixing ◽  
Perturbation Pressure ◽  
The Impact ◽  
Lower Frequencies

ABSTRACTWindpumping has been identified as a process that could potentially enhance sublimation of surface snow at high forcing frequency and spawn air movement deeper in firn at lower frequencies. We performed an experiment to examine the relationship between high-frequency wind and pressure measurements within the top meter of an alpine snowpack and compared experimental results with two theoretical predictions. We find that both theoretical predictions underestimate high-frequency perturbation pressure attenuation with depth in the near-surface snowpack and the discrepancy between theory and measurement increases with perturbation pressure frequency. The impact of this result for near-surface snow is that potential enhanced sublimation will occur over a shallower snow depth than these two theories predict. Correspondingly, interstitial air mixing at depth in firn will be driven by lower frequencies than these two theories predict. While direct measurement of these energy-rich lower frequencies is beyond the scope of this paper, stationary pressure measurements validate the presence of a pressure field that could drive near-surface circulation.

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