150 research outputs found
Five-member ensemble wave forecast for the R/V Mirai 2023 Arctic Ocean expedition using different sea ice forcing
Get PDFThe 14th Symposium on Polar Science/Interdisciplinary sessions [IA] Arctic Research, Thu. 16 Nov. / 2F Auditorium, National Institute of Polar Researchconference objec
Phase-suppressed hydrodynamics of solitons on constant-background plane wave
Get PDFSoliton and breather solutions of the nonlinear Schr\"odinger equation (NLSE)
are known to model localized structures in nonlinear dispersive media such as
on the water surface. One of the conditions for an accurate propagation of such
exact solutions is the proper generation of the exact initial phase-shift
profile in the carrier wave, as defined by the NLSE envelope at a specific time
or location. Here, we show experimentally the significance of such initial
exact phase excitation during the hydrodynamic propagation of localized
envelope solitons and breathers, which modulate a plane wave of constant
amplitude (finite background). Using the example of stationary black solitons
in intermediate water depth and pulsating Peregrine breathers in deep-water, we
show how these localized envelopes disintegrate while they evolve over a long
propagation distance when the initial phase shift is zero. By setting the
envelope phases to zero, the dark solitons will disintegrate into two gray-type
solitons and dispersive elements. In the case of the doubly-localized Peregrine
breather the maximal amplification is considerably retarded; however locally,
the shape of the maximal focused wave measured together with the respective
signature phase-shift are almost identical to the exact analytical Peregrine
characterization at its maximal compression location. The experiments,
conducted in two large-scale shallow-water as well as deep-water wave
facilities, are in very good agreement with NLSE simulations for all cases.Comment: (14 pages, 12 figures
Spectral downshift of Three-wave system and Bichromatic waves under “sea ice”
Get PDFThe 14th Symposium on Polar Science/Interdisciplinary sessions [IA] Arctic Research, Thu. 16 Nov. / 2F Auditorium, National Institute of Polar Researchconference objec
Editorial-The 4th International Workshop on Modeling the Ocean (IWMO 2012)
Get PDFThe 4th International Workshop on Modeling the Ocean (IWMO; http://www.jamstec.go.jp/frcgc/jcope/htdocs/e/ iwmo2012.html) was held on May 21–24, 2012 in the vibrant city of Yokohama on the Tokyo Bay, Japan. The Workshop was hosted by Japan Agency for Marine-Earth Science and Technology (JAMSTEC)—the home of the famous “Earth Simulator”—one of the world\u27s most powerful supercomputers dedicated for simulating the complex interactive processes of the earth and its environment
Observation of wave propagation over 1,000 km into Antarctica winter pack ice
Full text linkA drifting wave-ice buoy, which was configured by mounting the OpenMetBuoy on
an ad hoc floating platform that we named Medusa, was deployed at the
L\"utzow-Holm Bay (LHB) marginal ice zone in Antarctica on 4 Feb 2022 during
the 63rd Japanese Antarctica research expedition. The wave-ice buoy,
Medusa-766, survived the Antarctica winter as the measurement duration reached
333 days. During the winter months, it was located deep in the ice cover with
the shortest distance to the ice-free Southern Ocean over 1,000 km; at this
time, there was evidence of ocean wave signals at the buoy position. Using the
directional wave spectra obtained from the ECMWF's reanalysis, we show that the
Medusa-766 observed waves were likely generated by an extratropical cyclone in
the Southern Ocean. Wave-induced ice breakup potential for such an event could
extend 100s km into the ice field. When Medusa-766 was in LHB in the summer
months, it did not detect sizeable wave energy despite the low sea ice
concentration extent even during on-ice waves events. Characterising the
considerable differences in the wave attenuation at LHB is needed to elucidate
the relative contribution of ocean waves to the unstable LHB fast ice. The
success of Medusa-766 demonstrates the robustness of the general design,
hardware, firmware, and the high sensitivity of the sensor used. The result is
promising for future LHB wave-ice interaction research
An affordable and customizable wave buoy for the study of wave-ice interactions: design concept and results from field deployments
Full text linkIn the polar regions, the interaction between waves and ice has a crucial
impact on the seasonal change in the sea ice extent. However, our comprehension
of this phenomenon is restricted by a lack of observations, which, in turn,
results in the exclusion of associated processes from numerical models. In
recent years, availability of the low-cost and accurate Inertial Motion Units
has enabled the development of affordable wave research devices. Despite
advancements in designing innovative open-source instruments optimized for
deployment on ice floes, their customizability and survivability remain
limited, especially in open waters. This study presents a novel design concept
for an affordable and customizable wave buoy, aimed for wave measurements in
marginal ice zones. The central focus of this wave buoy design is the
application of 3D printing as rapid prototyping technology. By utilizing the
high customizability offered by 3D printing, the previously developed
solar-powered wave buoy was customized to install a battery pack to continue
the measurements in the high latitudes for more than several months.
Preliminary results from field deployments in the Pacific and Arctic Oceans
demonstrate that the performance of the instruments is promising. The accuracy
of frequency wave spectra measurements is found to be comparable to that of
considerably more expensive instruments. Finally, the study concludes with a
general evaluation of using rapid prototyping technologies for buoy designs and
proposes recommendations for future designs
An affordable and customizable wave buoy for the study of wave-ice interactions: design concept and results from field deployments
Get PDFThe interaction between waves and ice has a crucial impact on the seasonal change in the sea ice extent. However, our comprehension of this phenomenon is restricted by a lack of observations. In recent years, availability of the low-cost and accurate Inertial Motion Units has enabled the development of affordable wave research devices. Despite advancements in designing innovative open-source instruments optimized for deployment on ice floes, their customizability and survivability remain limited, especially in open waters. This study presents a novel design concept for an affordable and customizable wave buoy, aimed for wave measurements in marginal ice zones. The central focus of this wave buoy design is the application of 3D printing as rapid prototyping technology. By utilizing the high customizability offered by 3D printing, the previously developed solar-powered wave buoy was customized to install a battery pack. Preliminary results from field deployments in the Pacific and Arctic Oceans demonstrate that the performance of the instruments is promising. The accuracy of frequency wave spectra measurements is found to be comparable to that of considerably more expensive instruments. Finally, the study concludes with a general evaluation of using rapid prototyping technologies for buoy designs and proposes recommendations for future designs
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