4 Energy: Winds, Waves, and Tides

2020 ◽  
pp. 65-83
Keyword(s):  
Waves And Tides

scholarly journals The nonlinear effects on the characteristics of gravity wave packets: dispersion and polarization relations

2000 ◽  
Vol 18 (10) ◽  
pp. 1316-1324 ◽  
Author(s):  
S.-D. Zhang ◽  
F. Yi ◽  
J.-F. Wang
Keyword(s):  
Gravity Wave ◽  
Gravity Waves ◽  
Middle Atmosphere ◽  
Wave Packets ◽  
Nonlinear Effects ◽  
Wave Theory ◽  
Nonlinear Propagation ◽  
Waves And Tides ◽  
Time Variations ◽  
Isothermal Atmosphere

Abstract. By analyzing the results of the numerical simulations of nonlinear propagation of three Gaussian gravity-wave packets in isothermal atmosphere individually, the nonlinear effects on the characteristics of gravity waves are studied quantitatively. The analyses show that during the nonlinear propagation of gravity wave packets the mean flows are accelerated and the vertical wavelengths show clear reduction due to nonlinearity. On the other hand, though nonlinear effects exist, the time variations of the frequencies of gravity wave packets are close to those derived from the dispersion relation and the amplitude and phase relations of wave-associated disturbance components are consistent with the predictions of the polarization relation of gravity waves. This indicates that the dispersion and polarization relations based on the linear gravity wave theory can be applied extensively in the nonlinear region.Key words: Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides)

Evidence for nonlinear coupling of planetary waves and tides in the Antarctic mesopause

1997 ◽  
Vol 102 (D4) ◽  
pp. 4437-4446 ◽  
Author(s):  
F. Kamalabadi ◽  
J. M. Forbes ◽  
N. M. Makarov ◽  
Yu. I. Portnyagin
Keyword(s):  
Planetary Waves ◽  
Nonlinear Coupling ◽  
Waves And Tides ◽  
The Antarctic

scholarly journals Spectral characteristics of spring arctic mesosphere dynamics

1998 ◽  
Vol 16 (12) ◽  
pp. 1607-1618 ◽  
Author(s):  
C. M. Hall ◽  
A. H. Manson ◽  
C. E. Meek
Keyword(s):  
Energy Dissipation ◽  
Middle Atmosphere ◽  
Spectral Characteristics ◽  
Turbulent Energy ◽  
Energy Dissipation Rate ◽  
Spectral Signature ◽  
Upper Limits ◽  
Waves And Tides ◽  
Signal Fading ◽  
Mf Radar

Abstract. The spring of 1997 has represented a stable period of operation for the joint University of Tromsø / University of Saskatchewan MF radar, being between refurbishment and upgrades. We examine the horizontal winds from the February to June inclusive and also include estimates of energy dissipation rates derived from signal fading times and presented as upper limits on the turbulent energy dissipation rate, ε. Here we address the periodicity in the dynamics of the upper mesosphere for time scales from hours to one month. Thus, we are able to examine the changes in the spectral signature of the mesospheric dynamics during the transition from winter to summer states.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; turbulence; waves and tides).

Determinants of pelagic metabolism in the Timor Sea during the inter-monsoon period

2011 ◽  
Vol 62 (2) ◽  
pp. 130 ◽  
Author(s):  
A. D. McKinnon ◽  
J. H. Carleton ◽  
S. Duggan
Keyword(s):  
Gross Primary Production ◽  
Vertical Mixing ◽  
Community Respiration ◽  
New Production ◽  
Net Community Production ◽  
Monsoon Period ◽  
Hydrocarbon Seeps ◽  
Timor Sea ◽  
Waves And Tides ◽  
High Production

The Timor Sea is a major conduit of the Indonesian Throughflow characterised by large internal waves and tides. To ascertain whether these result in high pelagic productivity, we conducted experiments to determine the metabolic balance between net community production (NCP) and community respiration (CR) on the Sahul Shelf, the Sahul Shoals and the Yampi Shelf, an area of active hydrocarbon seeps. The barrier to vertical mixing of subthermocline nutrients represented by the halocline allowed new production to dominate in March 2004, whereas production in June 2005 depended on recycled nutrients. CR was correlated with dissolved organic carbon (DOC) in 2004, but with chlorophyll in 2005, suggesting that respiration was dominated by microheterotrophs in 2004 but by autotrophs in 2005. Overall, area-specific CR averaged 120 ± 92 (s.d.), 101 ± 52 and 61 ± 6 mmol O2 m–2 day–1, NCP averaged 109 ± 85 (s.d.), 32 ± 41 and 57 ± 10 mmol O2 m–2 day–1, and average gross primary production (= CR+NCP) : R ratios were 1.9, 1.4 and 1.9 on the shelf, at the Sahul Shoals and the Yampi Shelf, respectively. We suggest that differences in water column structure and internal wave activity drive intermittent high production events in a predominantly oligotrophic sea.

scholarly journals A Thermodynamic Model of the Formation, Growth, and Decay of First-Year Sea Ice

1987 ◽  
Vol 33 (113) ◽  
pp. 105-119 ◽  
Author(s):  
R. Gabison
Keyword(s):  
Sea Ice ◽  
Thermodynamic Model ◽  
Model Performance ◽  
Melting Process ◽  
The Arctic ◽  
First Year ◽  
Climatological Data ◽  
Oceanic Tides ◽  
Waves And Tides ◽  
Improved Model

AbstractThe formulation and application of a onedimensional sea-ice thermodynamic model is presented in this paper. The model’s sensitivity to changes in oceanic and atmospheric parameters is analyzed and compared with previous studies. The model is next applied to three locations in the Arctic: Cambridge Bay, Frobisher Bay, and Alert Inlet to study the model’s ability to simulate the annual cycle of first-year ice. The model’s results are compared with available climatological data and discussed in terms of the main thermodynamic processes, the combined effects of oceanic tides, and of sea-ice deterioration by melting on the break-up of sea ice.It is shown that the model is effective in simulating the climatology of the first-year ice thickness at the three Arctic locations. The study also suggests that improved model performance can be expected from additional research and application of flexural forcing of the ice by waves and tides, and of deterioration of ice strength during the melting process.

scholarly journals Mangrove Rehabilitation at Alo Beach (Karakelang Islands, Talaud) Using Propagul of Rhizophora mucronata Lamk

Jurnal Wasian ◽  
2017 ◽  
Vol 4 (2) ◽  
pp. 69
Author(s):  
Ady Suryawan
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Rhizophora Mucronata ◽  
Randomized Design ◽  
Waves And Tides ◽  
Survival And Growth ◽  
Mangrove Rehabilitation ◽  
Main Factor

This study aimed to know the dynamic of survival rate and growth of Rhizophora mucronata Lamk which planted by using propagules at Alo Beach, Karakelang Island, Talaud. The study was conducted from June 2013 to April 2017, used a complete randomized design with 6 treatments i.e. K1, K2, K3, K4, K5, K6. The amount of propagules in every treatment were 100 pieces each. The parameter observed were characteristic of substrat, survival rate,height and diameter of the plant’s in age of 1.5 months and 48 months. The results showed that treatment had a significant effect on survival rate and growth of Rhizophora mucronata plants. The rehabilitation was categorized as success at 1.5 months old, but it was failed inthe 48 months. Beside waves and tides, low substrat nutrition became the main factor that affect the success of mangrove rehabilitation in Alo Beach.The K5 treatment has the highest survival and growth rate of the plant. The K5 treatment using pnematophore as brace, while planting without brace/K1 has lowest survival and growth rate since months old.Keywords: mangroves, rehabilitation, Rhizophora mucronata, Talaud

scholarly journals Mesospheric front observations by the OH airglow imager carried out at Ferraz Station on King George Island, Antarctic Peninsula, in 2011

2018 ◽  
Vol 36 (1) ◽  
pp. 253-264 ◽  
Author(s):  
Gabriel Augusto Giongo ◽  
José Valentin Bageston ◽  
Paulo Prado Batista ◽  
Cristiano Max Wrasse ◽  
Gabriela Dornelles Bittencourt ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Near Infrared ◽  
Middle Atmosphere ◽  
Convective Cloud ◽  
Atmospheric Composition ◽  
Secondary Wave ◽  
King George Island ◽  
Composition And Structure ◽  
Waves And Tides ◽  
Energy And Momentum

Abstract. The main goals of this work are to characterize and investigate the potential wave sources of four mesospheric fronts identified in the hydroxyl near-infrared (OH-NIR) airglow images, obtained with an all-sky airglow imager installed at Comandante Ferraz Antarctic Station (EACF, as per its Portuguese acronym) located on King George Island in the Antarctic Peninsula. We identified and analyzed four mesospheric fronts in 2011 over King George Island. In addition, we investigate the atmospheric background environment between 80 and 100 km altitude and discuss the ducts and propagation conditions for these waves. For that, we used wind data obtained from a meteor radar operated at EACF and temperature data obtained from the TIMED/SABER satellite. The vertical wavenumber squared, m2, was calculated for each of the four waves. Even though no clearly defined duct (indicated by positive values of m2 sandwiched between layers above and below with m2  < 0) was found in any of the events, favorable propagation conditions for horizontal propagation of the fronts were found in three cases. In the fourth case, the wave front did not find any duct support and it appeared to dissipate near the zenith, transferring energy and momentum to the medium and, consequently, accelerating the wind in the wave propagation direction (near to south) above the OH peak (88–92 km). The likely wave sources for these four cases were investigated by using meteorological satellite images and in two cases we could find that strong instabilities were potential sources, i.e., a cyclonic activity and a large convective cloud cell. In the other two cases it was not possible to associate troposphere sources as potential candidates for the generation of such wave fronts observed in the mesosphere and secondary wave sources were attributed to these cases. Keywords. Atmospheric composition and structure (airglow and aurora) – meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides)

Geochemical evidence of tropical cyclone controls on shallow-marine sedimentation (Pliocene, Taiwan) 

2021 ◽  
Author(s):  
Shahin Dashtgard ◽  
Ludvig Löwemark ◽  
Pei-Ling Wang ◽  
Romy Setiaji ◽  
Yu-Yen Pan ◽  
...  
Keyword(s):  
Foreland Basin ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Shallow Marine ◽  
Sediment Reworking ◽  
Virtual Absence ◽  
Marine Strata ◽  
Marine Sedimentation ◽  
Weather Events ◽  
Waves And Tides

&lt;p&gt;&amp;#160;Shallow-marine sediment typically contains a mix of marine and terrestrial organic mate&amp;#173;rial (OM). Most terrestrial OM enters the ocean through rivers, and marine OM is incorpo&amp;#173;rated into the sediment through both suspension settling of marine plankton and sediment reworking by tides and waves under fairweather conditions. River-derived terrestrial OM is delivered year-round, although sediment and OM delivery from rivers is typically highest during extreme weather events that impact river catchments. In Taiwan, tropical cyclones (TCs) are the dominant extreme weather event, and 75% of all sediment delivered to the surrounding ocean occurs during TCs.&lt;/p&gt;&lt;p&gt;Lower Pliocene shallow-marine sedimentary strata in the Western Foreland Basin of Taiwan comprises mainly completely bioturbated intervals that transi&amp;#173;tion upward into strata dominated by tidally generated sedimentary structures, indicating extensive sediment reworking under fairweather conditions. Physical evidence of storm deposition is limited. However, lower Pliocene strata contain OM that is effectively 100% terrestrial OM in sediment that accumulated in estimated water depths &lt;35 m. The overwhelming contribution of terrestrially sourced OM is attributed to the dominance of TCs on sedimentation, whereby &amp;#8764;600,000 TCs are estimated to have impacted Taiwan during accumulation of a ~200 m long succession. In contrast, the virtual absence of marine OM indicates that organic contributions from suspension settling of marine OM is negligible regardless of the preserved evidence of extensive reworking via fairweather processes (i.e., waves and tides). These data suggest that (1) even in the absence of physical expressions of storm deposition, TCs still completely dominate sedimentation in shallow-marine environments, and (2) the organic geochemical signal of preserved shallow-marine strata is not reflective of day-to-day depositional conditions in the environment.&lt;/p&gt;

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