scholarly journals Impact of wave physics on ocean–wave coupling in CMEMS-IBI Part B: Validation study

2019 ◽  
Author(s):  
Romain Rainaud ◽  
Lotfi Aouf ◽  
Alice Dalphinet ◽  
Marcos Garcia Sotillo ◽  
Enrique Alvarez-Fanjul ◽  
...  
Keyword(s):  
Positive Impact ◽  
Wave Model ◽  
Ocean Waves ◽  
Ocean Model ◽  
Ocean Wave ◽  
Wave Coupling ◽  
In Situ Observations ◽  
The Waves ◽  
Horizontal Grid

Abstract. This work aims to evaluate the ocean/waves coupling based on input from the wave modelMFWAM. 1-year coupled runs including seasonal variability has been performed for the IberianBiscay and Ireland domain. We investigated the consequences of improvement in wave physics onthe mixed layer of the ocean with a fine horizontal grid size of 1/36°. The ocean model NEMO andthe wave model MFWAM have been used for this study to prepare the use of coupling operationallyin the IBI Copernicus Marine Service and Monitoring Evironment (CMEMS). Two wave physicsversions have been discussed in this study. The validation of sea surface temperature, surfacecurrents have been implemented in comparison with satellite and in-situ observations. The resultsshow a positive impact of the waves forcing on surface key parameters. For storm cases it has beendemonstrated a good skill of the ocean/wave coupling to capture the peak of surge event such as theone observed for Petra storm.

scholarly journals Terrestrial aurora: astrophysical laboratory for anomalous abundances in stellar systems

2014 ◽  
Vol 32 (2) ◽  
pp. 77-82 ◽  
Author(s):  
I. Roth
Keyword(s):  
Solar Flares ◽  
Heavy Ions ◽  
Electromagnetic Waves ◽  
Stellar System ◽  
Decay Product ◽  
Early Solar System ◽  
Physical Processes ◽  
In Situ Observations ◽  
The Waves

Abstract. The unique magnetic structure of the terrestrial aurora as a conduit of information between the ionosphere and magnetosphere can be utilized as a laboratory for physical processes at similar magnetic configurations and applied to various evolutionary phases of the solar (stellar) system. The most spectacular heliospheric abundance enhancement involves the 3He isotope and selective heavy elements in impulsive solar flares. In situ observations of electromagnetic waves on active aurora are extrapolated to flaring corona in an analysis of solar acceleration processes of 3He, the only element that may resonate strongly with the waves, as well as heavy ions with specific charge-to-mass ratios, which may resonate weaker via their higher gyroharmonics. These results are applied to two observed anomalous astrophysical abundances: (1) enhanced abundance of 3He and possibly 13C in the late stellar evolutionary stages of planetary nebulae; and (2) enhanced abundance of the observed fossil element 26Mg in meteorites as a decay product of radioactive 26Al isotope due to interaction with the flare-energized 3He in the early solar system.

Ocean Surface Modeling in Vary Wind Field

2011 ◽  
Vol 480-481 ◽  
pp. 1452-1456
Author(s):  
Li Bo ◽  
Zhong Yi Li ◽  
Yue Jin Zhang
Keyword(s):  
Wind Field ◽  
Wave Spectrum ◽  
Wave Model ◽  
Ocean Surface ◽  
Ocean Waves ◽  
Surface Modeling ◽  
Ocean Wave ◽  
Statistical Characteristics ◽  
Linear Wave ◽  
Wave Models

In ocean surface modeling a popular method of wave modeling is making use of ocean wave spectrum, which is a physical wave model and based on linear wave theories. The ocean waves produced in this way can reflect the statistical characteristics of the real ocean well. However, few investigations of ocean simulation have been focused on turbulent fluid under vary wind field in this way, while all ocean wave models are built with the same wind parameters. In order to resolve the problem of traditional method, we proposed a new method of dividing the ocean surface into regular grids and generating wave models with different parameters of wind in different location of view scope. The method not only preserves the fidelity of statistical characteristics, but also can be accelerated with the processing of GPU and widely used in VR applications.

scholarly journals Investigation of the Anisotropic Patterns in the Altimeter Backscatter Measurements Over Ocean Wave Surfaces

2021 ◽  
Vol 9 ◽  
Author(s):  
Xi-Yu Xu ◽  
Ke Xu ◽  
Maofei Jiang ◽  
Bingxu Geng ◽  
Lingwei Shi
Keyword(s):  
Wave Model ◽  
Ocean Surface ◽  
Ocean Waves ◽  
Ocean Wave ◽  
Altimeter Data ◽  
Wave Surface ◽  
Wave Direction ◽  
Backscatter Coefficient ◽  
Wave Surfaces ◽  
Operational Modes

This article attempts to analyze the influence of the anisotropic effects of the ocean wave surface on SAR altimetry backscatter coefficient (Sigma-0) measurements, which has not been intensively addressed in publications. Data of Sentinel-3A, Cryosat-2, and Jason-3 altimeters allocated by the WW3 numeric wave model were analyzed, and the patterns of Sigma-0 with respect to the wave direction were acquired under ∼2 m significant wave height. The ocean waves were classified into six categories, among which the moderate swell and short win-wave cases were analyzed intensively. Swell-dominated ocean surface shows less randomness than the wind-wave-dominated ocean surface. Clear and significant sinusoid trends are found in the Sigma-0 and SSB patterns of both operational modes (SAR mode and PLRM mode) of the Sentinel-3A altimeter for the moderate swell case, indicating the sensitivity of Sigma-0 and SSB measurements to the anisotropic features of the altimeter measurements. The anisotropic pattern in the Sentinel-3A PLRM Sigma-0 is somewhat counterintuitive, but the analysis of Jason-3 altimeter data would show similar results. Additionally, by comparing the anisotropic patterns of two orthogonally polarized SAR altimeters (Sentinel-3A and Cryosat-2), we could draw the conclusion that the Sigma-0 measurements are not sensitive to the polarization mode. As for the SSHA patterns, no clear sinusoid could be identified for the moderate swell. A possible explanation is that the SSB pattern may be overwhelmed in the complicated factors that can influence the SSHA pattern.

Seasonal fluctuations in the secondary microseism wavefield recorded offshore Ireland

2020 ◽  
Author(s):  
Florian Le Pape ◽  
Christopher J. Bean
Keyword(s):  
Wave Model ◽  
Ocean Waves ◽  
Ocean Wave ◽  
Ocean Bottom ◽  
Ocean Bottom Seismometer ◽  
Storm Activity ◽  
Directional Spectrum ◽  
Sea Bottom ◽  
Ocean Wave Model ◽  
Obs Data

<p><span>Generated in the ocean, secondary microseisms result from the interaction of opposing ocean wave fronts and represent the strongest ambient seismic noise level measured on land. The recorded noise energy will vary with seasons due to changes in storm activity and associated secondary microseism source locations. Here, ocean bottom seismometer (OBS) data collected offshore Ireland in 2016 have been processed to look into the seasonal variations of the ambient noise wavefield recorded at the seafloor. Daily cross-correlations of OBS pairs located on top of thick sediments in deep water highlight seasonal changes between Rayleigh waves fundamental mode and first overtone for winter and summer months. Comparisons with ocean wave directional spectrum data derived from ocean wave model hindcasts suggest those variations are correlated with changing patterns in ocean waves interactions and therefore microseism source locations. In order to understand those observations in detail, we use 3D numerical simulations to show how the water column but also the subsurface structure below the sea bottom will affect the recorded wavefield at the seafloor for different stations and sources locations. Compared to land stations, the secondary microseism wavefield observed in the ocean and in particular changes in the excitation of Rayleigh modes due to site effects can help characterize the microseism source locations that fluctuate through the seasons.</span></p>

In situ observations of instabilities in the mesopause region using foil chaff technique during the Waves in Airglow Structures Experiment (WAVE) campaigns

2009 ◽  
Vol 114 (D20) ◽  
Author(s):  
Yoshiko Koizumi ◽  
Minoru Kubota ◽  
Yasuhiro Murayama ◽  
Makoto Abo ◽  
Michihiro Uchiumi ◽  
...  
Keyword(s):  
Mesopause Region ◽  
In Situ Observations ◽  
The Waves

scholarly journals Simulation of convective moistening of extratropical lower stratosphere using a numerical weather prediction model

2019 ◽  
Author(s):  
Zhipeng Qu ◽  
Yi Huang ◽  
Paul A. Vaillancourt ◽  
Jason N. S. Cole ◽  
Jason A. Milbrandt ◽  
...  
Keyword(s):  
Water Vapor ◽  
High Resolution ◽  
Lower Stratosphere ◽  
Water Vapor Content ◽  
Grid Spacing ◽  
Stratospheric Water Vapor ◽  
In Situ Observations ◽  
Horizontal Grid ◽  
Resolution Simulation

Abstract. Stratospheric water vapor (SWV) is a climatically important atmospheric constituent due to its impacts on the radiation budget and atmospheric chemical composition. Despite the important role of SWV in the climate system, the processes controlling the distribution and variation of water vapor in the upper troposphere and lower stratosphere (UTLS) are not well understood. In order to better understand the mechanism of transport of water vapor through the tropopause, this study uses the high resolution Global Environmental Multiscale model of the Environment and Climate Change Canada, to simulate a lower stratosphere moistening event over North America. Satellite remote sensing and aircraft in situ observations are used to evaluate the quality of model simulation. The main focus of this study is to evaluate the processes that influence the lower stratosphere water vapor budget, particularly the direct water vapor transport and the moistening due to the ice sublimation. In the high-resolution simulations with horizontal grid-spacing less than 2.5 km, it is found that the main contribution to lower-stratospheric moistening is the upward transport caused by the breaking of gravity waves. In contrast, for the lower-resolution simulation with horizontal grid-spacing of 10 km, the lower-stratospheric moistening is dominated by the sublimation of ice. In comparison with the aircraft in situ observations, the high-resolution simulations predict well the water vapor content in the UTLS, while the lower resolution simulation over-estimates the water vapor content. This overestimation is associated with the overly abundant ice in the UTLS along with too-high sublimation rate in the lower stratosphere. The results of this study affirm the strong influence of overshooting convection on the lower-stratospheric water vapor and highlight the importance of both dynamics and microphysics in simulating the water vapor distribution in the UTLS region.

Directional Wind–Wave Coupling in Fully Coupled Atmosphere–Wave–Ocean Models: Results from CBLAST-Hurricane

2013 ◽  
Vol 70 (10) ◽  
pp. 3198-3215 ◽  
Author(s):  
Shuyi S. Chen ◽  
Wei Zhao ◽  
Mark A. Donelan ◽  
Hendrik L. Tolman
Keyword(s):  
Surface Waves ◽  
Surface Stress ◽  
Prediction Models ◽  
Wind Wave ◽  
Coupled Model ◽  
Ocean Waves ◽  
Ocean Model ◽  
Wave Coupling ◽  
Surface Exchange ◽  
Fully Coupled

Abstract The extreme high winds, intense rainfall, large ocean waves, and copious sea spray in hurricanes push the surface-exchange parameters for temperature, water vapor, and momentum into untested regimes. The Coupled Boundary Layer Air–Sea Transfer (CBLAST)-Hurricane program is aimed at developing improved coupling parameterizations (using the observations collected during the CBLAST-Hurricane field program) for the next-generation hurricane research prediction models. Hurricane-induced surface waves that determine the surface stress are highly asymmetric, which can affect storm structure and intensity significantly. Much of the stress is supported by waves in the wavelength range of 0.1–10 m, which is the unresolved “spectral tail” in present wave models. A directional wind–wave coupling method is developed to include effects of directionality of the wind and waves in hurricanes. The surface stress vector is calculated using the two-dimensional wave spectra from a wave model with an added short-wave spectral tail. The wind and waves are coupled in a vector form rather than through the traditional roughness scalar. This new wind–wave coupling parameterization has been implemented in a fully coupled atmosphere–wave–ocean model with 1.67-km grid resolution in the atmospheric model, which can resolve finescale features in the extreme high-wind region of the hurricane eyewall. It has been tested in a number of storms including Hurricane Frances (2004), which is one of the best-observed storms during the CBLAST-Hurricane 2004 field program. This paper describes the new wind–wave coupling parameterization and examines the characteristics of the coupled model simulations of Hurricane Frances (2004). Observations of surface waves and winds are used to evaluate the coupled model results.

scholarly journals The Theory of Trapped-Fetch Waves with Tropical Cyclones—An Operational Perspective

2005 ◽  
Vol 20 (3) ◽  
pp. 229-244 ◽  
Author(s):  
Peter J. Bowyer ◽  
Allan W. MacAfee
Keyword(s):  
Tropical Cyclones ◽  
Wave Model ◽  
Ocean Waves ◽  
Resonance Phenomenon ◽  
High Wave ◽  
Almost All ◽  
High Degree ◽  
The Waves ◽  
Real Time Application ◽  
Operational Assessment

Abstract The majority of high wave events and almost all cases of extreme or phenomenal wave growth are the result of a high degree of synchronicity between moving storms and the waves that they generate. This wave containment or resonance phenomenon, referred to as trapped-fetch waves, has been known for generations, but not always well understood by forecasters. The twofold threat of trapped-fetch waves is that they have the potential for extreme growth, yet are unheralded by leading swell. Conceptual and numerical Lagrangian reference frame experiments on wave containment are presented, illustrating the influence on tropical cyclone ocean waves by three storm parameters: storm speed, wind speed, and fetch length. To further illustrate the concepts and provide real-time application, a simple, desktop Lagrangian trapped-fetch wave model, used for training and operational assessment of trapped-fetch waves, is described in a companion article.

scholarly journals On the cross-tropopause transport of water by tropical convective overshoots: a mesoscale modelling study constrained by in-situ observations during TRO-Pico field campaign in Brazil

2021 ◽  
Author(s):  
Abhinna K. Behera ◽  
Emmanuel D. Riviere ◽  
Sergey M. Khaykin ◽  
Virginie Marecal ◽  
Melanie Ghysels ◽  
...  
Keyword(s):  
Large Scale ◽  
Mesoscale Model ◽  
Deep Convection ◽  
Grid Point ◽  
Meteorological Model ◽  
Brazilian Version ◽  
Radar Echo ◽  
In Situ Observations ◽  
Horizontal Grid

Abstract. Deep convection overshooting the lowermost stratosphere is well known for its role in the local stratospheric water vapour (WV) budget. While it is seldom the case, local enhancements of WV associated with stratospheric overshoots are often published. Nevertheless, one debatable topic prevails on the global impact of this event with respect to the temperature-driven dehydration of air parcels entering the stratosphere. As a first step, it is crucial to quantify their role at a local scale before assessing their impact at a large-scale in a meteorological model. It would lead to a forcing scheme for overshoots in the global models. This paper reports on the local enhancements of WV linked to stratospheric overshoots, observed during the TRO-Pico campaign conducted in March 2012 in Bauru, Brazil, using the BRAMS (Brazilian version of RAMS) mesoscale model. Since numerical simulation depends on the choice of several preferred parameters, each having its uncertainties, we vary the microphysics or the vertical resolution while simulating the overshoots. Thus, we produce a set of simulations illustrating the possible variations in representing the stratospheric overshoots. To resolve better the stratospheric hydration, we opt for simulations with the 800-m-horizontal-grid-point presentation. Next, we validate these simulations against the Bauru S-band radar echo tops and the TRO-Pico balloon-borne observations of WV and particles. Two of the three simulations' setups yield results compatible with the TRO-Pico observations. From these two simulations, we determine approximately 333 t to 2000 t of WV mass prevailing in the stratosphere due to an overshooting plume depending on the simulation setup. About 70 % of the ice mass remains between the 380 K to 385 K isentropic levels. The overshooting top comprises pristine ice and snow, while aggregates only play a role just above the tropopause. Interestingly, the horizontal cross-section of the overshooting top is about 450 km2 at 380 K isentrope, which is similar to the horizontal-grid-point resolution of a simulation that cannot compute overshoots explicitly. These results could establish a forcing scheme of overshooting hydration or dehydration in a large-scale simulation.

scholarly journals OBSERVATIONS OF TIE TRANSFORMATION OF OCEAN WAVE CHARACTERISTICS NEAR COASTS BY USE OF ANCHORED BUOYS

1966 ◽  
Vol 1 (10) ◽  
pp. 6
Author(s):  
Haruo Higuchi ◽  
Tadao Kakinuma
Keyword(s):  
Shallow Water ◽  
Ocean Waves ◽  
Transformation Process ◽  
Long Waves ◽  
Ocean Wave ◽  
Wave Characteristics ◽  
Wave Observation ◽  
The Waves

In order to clarify the transformation process of ocean waves in shallow water, a series of wave observations were carried out along some coasts in Japan by photographing two or three convenient buoys aligned m the direction of the waves with two 16 urn cine-cameras. The equipment and methods used in observations and analyses are here described together with some of the results obtained. By examining the motion of the buoys off the coast at Shirahama it was found that the method of wave observation by means of anchored buoys was very useful in the case of comparatively long waves.

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