FUTURE CHANGES OF EXPLOSIVE CYCLONES AND THEIR IMPACT ON JAPANESE COASTAL WAVES USING MRI-AGCM 150-YEAR PROJECTION

Abstract. We investigate the rapidly changing equilibrium between the momentum sources and sinks during the passage of a single two-peak storm over the Catalan inner shelf (NW Mediterranean Sea). Velocity measurements at 24 m water depth are taken as representative of the inner shelf, and the cross-shelf variability is explored with measurements at 50 m water depth. During both wind pulses, the flow accelerated at 24 m until shortly after the wind maxima, when the bottom stress was able to compensate for the wind stress. Concurrently, the sea level also responded, with the pressure-gradient force opposing the wind stress. Before, during and after the second wind pulse, there were velocity fluctuations with both super- and sub-inertial periods likely associated with transient coastal waves. Throughout the storm, the Coriolis force and wave radiation stresses were relatively unimportant in the along-shelf momentum balance. The frictional adjustment timescale was around 10 h, consistent with the e-folding time obtained from bottom drag parameterizations. The momentum evolution at 50 m showed a larger influence of the Coriolis force at the expense of a decreased frictional relevance, typical in the transition from the inner to the mid-shelf.

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The concurrence of Atmospheric Rivers and explosive cyclogenesis in the North Atlantic and North Pacific basins

10.5194/esd-2017-76 ◽

2017 ◽

Author(s):

Jorge Eiras-Barca ◽

Alexandre M. Ramos ◽

Joaquim G. Pinto ◽

Ricardo M. Trigo ◽

Margarida L. R. Liberato ◽

...

Keyword(s):

North Atlantic ◽

North Pacific ◽

Reanalysis Data ◽

Water Vapour Flux ◽

Atmospheric Rivers ◽

The North ◽

Explosive Cyclones ◽

The North Atlantic ◽

Characteristic Features ◽

Western Side

Abstract. The explosive cyclogenesis of extra-tropical cyclones and the occurrence of atmospheric rivers are characteristic features of baroclinic atmospheres, and are both closely related to extreme hydrometeorological events in the mid-latitudes, particularly on coastal areas on the western side of the continents. The potential role of atmospheric rivers in the explosive cyclone deepening has been previously analysed for selected case studies, but a general assessment from the climatological perspective is still missing. Using ERA-Interim reanalysis data for 1979–2011, we analyse the concurrence of atmospheric rivers and explosive cyclogenesis over the North Atlantic and North Pacific Basins for the extended winter months (ONDJFM). Atmospheric rivers are identified for almost 80 % of explosive deepening cyclones. For non-explosive cyclones, atmospheric rivers are found only in roughly 40 % of the cases. The analysis of the time evolution of the high values of water vapour flux associated with the atmospheric river during the cyclone development phase leads us to hypothesize that the identified relationship is the fingerprint of a mechanism that raises the odds of an explosive cyclogenesis occurrence and not merely a statistical relationship. This insight can be helpful for the predictability of high impact weather associated with explosive cyclones and atmospheric rivers.

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Modeling of a Tsunami Described by Charles Darwin and Coastal Waves

Evolution of Extreme Waves and Resonances ◽

10.1201/9781003038504-12 ◽

2020 ◽

pp. 301-328

Author(s):

Shamil U. Galiev

Keyword(s):

Charles Darwin ◽

Coastal Waves

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Coastal Wave Extremes around the Pacific and Their Remote Seasonal Connection to Climate Modes

Climate ◽

10.3390/cli9120168 ◽

2021 ◽

Vol 9 (12) ◽

pp. 168

Author(s):

Julien Boucharel ◽

Loane Santiago ◽

Rafael Almar ◽

Elodie Kestenare

Keyword(s):

Large Scale ◽

Wind Wave ◽

Boreal Summer ◽

Opposite Hemisphere ◽

Ocean Surface Waves ◽

First Order ◽

Coastal Waves ◽

The Pacific ◽

Wide Range ◽

The Tropics

At first order, wind-generated ocean surface waves represent the dominant forcing of open-coast morpho-dynamics and associated vulnerability over a wide range of time scales. It is therefore paramount to improve our understanding of the regional coastal wave variability, particularly the occurrence of extremes, and to evaluate how they are connected to large-scale atmospheric regimes. Here, we propose a new “2-ways wave tracking algorithm” to evaluate and quantify the open-ocean origins and associated atmospheric forcing patterns of coastal wave extremes all around the Pacific basin for the 1979–2020 period. Interestingly, the results showed that while extreme coastal events tend to originate mostly from their closest wind-forcing regime, the combined influence from all other remote atmospheric drivers is similar (55% local vs. 45% remote) with, in particular, ~22% coming from waves generated remotely in the opposite hemisphere. We found a strong interconnection between the tropical and extratropical regions with around 30% of coastal extremes in the tropics originating at higher latitudes and vice-versa. This occurs mostly in the boreal summer through the increased seasonal activity of the southern jet-stream and the northern tropical cyclone basins. At interannual timescales, we evidenced alternatingly increased coastal wave extremes between the western and eastern Pacific that emerge from the distinct seasonal influence of ENSO in the Northern and SAM in the Southern Hemisphere on their respective paired wind-wave regimes. Together these results pave the way for a better understanding of the climate connection to wave extremes, which represents the preliminary step toward better regional projections and forecasts of coastal waves.

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