Temporal variability of tsunami arrival detection distance revealed by virtual tsunami observation experiments using numerical simulation and 1-month HF radar observation

To investigate the transient electromagnetic method of response characteristics in the tunnel geological prediction, the finite element numerical simulation of unfavorable geological body of different location, different resistivity sizes, different shapes, and different volume size were carried out by ANSYS finite element software. The results show that secondary electromagnetic field of different location of unfavorable geological body have same decay rate, when detection distance from 30m to 70m, transient electromagnetic responses are strongest, followed distance from 10m to 30m and from 70m to 90m. The shape, volume and resistivity of unfavorable geological body have strong influence on transient electromagnetic response, unfavorable geological body more sleek, the greater the volume and the smaller the resistivity of unfavorable geological body, the secondary electromagnetic field decay slower.

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HF Radar Observation of Wave Directional Spectra in a Strong Current Regime

OCEANS 2007 - Europe ◽

10.1109/oceanse.2007.4302281 ◽

2007 ◽

Cited By ~ 1

Author(s):

Brian K. Haus ◽

Mei Wang ◽

Lynn K. Shay ◽

Lucy R. Wyatt

Keyword(s):

Hf Radar ◽

Radar Observation ◽

Current Regime ◽

Strong Current

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HF Radar Observation of Longwang Typhoon in the Taiwan Strait

Chinese Journal of Geophysics ◽

10.1002/cjg2.1167 ◽

2007 ◽

Vol 50 (6) ◽

pp. 1474-1481 ◽

Cited By ~ 1

Author(s):

Zi-Ping GONG ◽

Heng-Yu KE ◽

Zhi-Fei DONG ◽

Xiong-Bin WU ◽

Feng CHENG

Keyword(s):

Taiwan Strait ◽

Hf Radar ◽

Radar Observation ◽

The Taiwan Strait

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HF radar observation of tidal current over the Beibu Gulf, South China Sea

Wuhan University Journal of Natural Sciences ◽

10.1007/s11859-015-1058-0 ◽

2015 ◽

Vol 20 (1) ◽

pp. 55-58

Author(s):

Yingwei Tian ◽

Biyang Wen ◽

Jian Tan ◽

Zili Li

Keyword(s):

South China Sea ◽

South China ◽

Tidal Current ◽

Hf Radar ◽

Radar Observation ◽

Beibu Gulf ◽

China Sea

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The M2 Internal Tide off Oregon: Inferences from Data Assimilation

Journal of Physical Oceanography ◽

10.1175/2397.1 ◽

2003 ◽

Vol 33 (8) ◽

pp. 1733-1757 ◽

Cited By ~ 69

Author(s):

Alexander L. Kurapov ◽

Gary D. Egbert ◽

J. S. Allen ◽

Robert N. Miller ◽

Svetlana Y. Erofeeva ◽

...

Keyword(s):

Data Assimilation ◽

Temporal Variability ◽

Internal Tide ◽

Inverse Model ◽

Hf Radar ◽

Surface Velocity ◽

Open Boundary ◽

Spatial And Temporal Variability ◽

Computational Domain ◽

Energy Propagation

Abstract A linearized baroclinic, spectral-in-time tidal inverse model has been developed for assimilation of surface currents from coast-based high-frequency (HF) radars. Representer functions obtained as a part of the generalized inverse solution show that for superinertial flows information from the surface velocity measurements propagates to depth along wave characteristics, allowing internal tidal flows to be mapped throughout the water column. Application of the inverse model to a 38 km × 57 km domain off the mid-Oregon coast, where data from two HF radar systems are available, provides a uniquely detailed picture of spatial and temporal variability of the M2 internal tide in a coastal environment. Most baroclinic signal contained in the data comes from outside the computational domain, and so data assimilation (DA) is used to restore baroclinic currents at the open boundary (OB). Experiments with synthetic data demonstrate that the choice of the error covariance for the OB condition affects model performance. A covariance consistent with assumed dynamics is obtained by nesting, using representers computed in a larger domain. Harmonic analysis of currents from HF radars and an acoustic Doppler profiler (ADP) mooring off Oregon for May–July 1998 reveals substantial intermittence of the internal tide, both in amplitude and phase. Assimilation of the surface current measurements captures the temporal variability and improves the ADP/solution rms difference. Despite significant temporal variability, persistent features are found for the studied period; for instance, the dominant direction of baroclinic wave phase and energy propagation is always from the northwest. At the surface, baroclinic surface tidal currents (deviations from the depth-averaged current) can be 10 cm s–1, 2 times as large as the depth-averaged current. Barotropic-to-baroclinic energy conversion is generally weak within the model domain over the shelf but reaches 5 mW m–2 at times over the slopes of Stonewall Bank.

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