scholarly journals Observation of a giant nonlinear wave-packet on the surface of the ocean

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Miguel Onorato ◽  
Luigi Cavaleri ◽  
Stephane Randoux ◽  
Pierre Suret ◽  
Maria Isabel Ruiz ◽  
...  
Keyword(s):  
Wave Packet ◽  
Extreme Events ◽  
Ocean Waves ◽  
Bay Of Biscay ◽  
New Paradigm ◽  
Dispersive Waves ◽  
Physical Systems ◽  
North East ◽  
The North ◽  
Correct Design

AbstractIn many physical systems such as ocean waves, nonlinear optics, plasma physics etc., extreme events and rare fluctuations of a wave field have been widely observed and discussed. In the field of oceanography and naval architecture, their understanding is fundamental for a correct design of platforms and ships, and for performing safe operations at sea. Here, we report a measurement of an impressive and unique wave packet recorded in the Bay of Biscay in the North-East of the Atlantic Ocean. An analysis of the spatial extension of the packet that includes three large waves reveals that it extents for more than 1 km, with individual crests moving faster than 100 km/h. The central and largest wave in the packet was 27.8 m high in a sea with significant wave height of 11 m. A detailed analysis of the data using the nonlinear Fourier analysis reveals that the wave packet is characterized by a non trivial nonlinear content. This observation opens a new paradigm which requires new understanding of the dynamics of ocean waves and, more in general, of nonlinear and dispersive waves.

Octomagelona bizkaiensis (Polychaeta: Magelonidae) a new genus and species from the Capbreton Canyon (Bay of Biscay, north-east Atlantic)

2001 ◽  
Vol 81 (2) ◽  
pp. 221-224 ◽  
Author(s):  
Florencio Aguirrezabalaga ◽  
Argiloa Ceberio ◽  
Dieter Fiege
Keyword(s):  
New Genus ◽  
Bay Of Biscay ◽  
New Genus And Species ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
The Family ◽  
North Eastern

Octomagelona bizkaiensis (Annelida: Polychaeta), a new genus and species of the family Magelonidae is described from the north-eastern Atlantic. The specimens were collected from the Capbreton Canyon, Bay of Biscay, at a depth of 1000–1040 m. The new genus and species differs from all known genera and species of the family Magelonidae by the presence of eight instead of nine thoracic chaetigers.

scholarly journals Citizen science in the marine environment: A case-study estimating common dolphin densities in the north-east Atlantic

2019 ◽  
Author(s):  
James R Robbins ◽  
Lucy Babey ◽  
Clare B Embling
Keyword(s):  
Citizen Science ◽  
Common Dolphin ◽  
Bay Of Biscay ◽  
English Channel ◽  
East Atlantic ◽  
Science Data ◽  
North East ◽  
The North ◽  
Celtic Sea ◽  
Common Dolphins

Background. Citizen science is increasingly popular and has the potential to collect extensive datasets at lower costs than traditional surveys. Ferries have been used to collect data on cetacean populations for decades, providing long-term time series allowing for monitoring of cetacean populations. One cetacean species of concern is the common dolphin, which have been found stranded around the north-east Atlantic in recent years, with high numbers on French coasts being attributed to fisheries bycatch. We estimate common dolphin densities in north-east Atlantic and investigate the power of citizen science data to identify changes in marine mammal densities and areas of importance. Materials & Methods. Data were collected by citizen scientists on ferries between April and October in 2006 - 2017. Common dolphin sightings data from two ferry routes in the Bay of Biscay (n= 569), Celtic Sea (n= 260), and English Channel (n= 75) were used to estimate detection probabilities with detection functions. Density Surface Models estimated density across ferry routes, accounting for the influence of environmental (chlorophyll a, sea surface temperature, depth, and slope), spatial (latitude and longitude) and temporal terms (year and Julian day). Results. Overall detection probability was highest in the English Channel (0.384) and Bay of Biscay (0.348), and lowest in the Celtic Sea (0.158). Common dolphins were estimated to occur in higher densities in the Celtic Sea (0.400 per km) and the Bay of Biscay (0.319 per km), with low densities in the English Channel (0.025 per km). Densities in the Celtic Sea have been relatively stable on the ferry route since 2006 with a slight decrease in 2017. Densities peaked in the Bay of Biscay in 2013 with lower numbers since. The general trend in the English Channel is for increasing densities of common dolphins over time since 2009. Discussion. This study highlights the effectiveness of citizen science data to investigate the distribution and density of cetaceans. The densities and temporal changes shown by this study are representative of those from wider-ranging robust estimates. We highlight the ability of citizen science to collect data over extensive periods of time which complements traditional surveys. Such long-term data are important to identify changes within a population; however, citizen science data may, in some situations, present challenges. We provide recommendations to ensure high-quality data which can be used to inform management and conservation of cetacean populations.

scholarly journals The Fishes collected by the “Huxley” from the North Side of the Bay of Biscay in August, 1906

1907 ◽  
Vol 8 (1) ◽  
pp. 1-5
Author(s):  
L. W Byrne
Keyword(s):  
The Other ◽  
Bay Of Biscay ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
North Side

Only one species met with on this cruise appears to have been previously undescribed.Although all the other species were already known from similar localities in the North-east Atlantic, attention may be called to an interesting series of the young of Synaphobranchus pinnatus and to the capture of numerous young examples of Onus biscayensis.When compared with the results of the hauls taken by H.M.S. Research, a little farther south and over very much deeper soundings, the list of species taken by the Huxley is chiefly remarkable for the entire absence of Stomias boa, Gonostoma microdon, and G. bathyphilum, the range of none of which seems to extend into waters as shallow as those fished by the Huxley.

scholarly journals Ecological Trap or Favorable Habitat? First Evidence That Immature Sea Turtles May Survive at Their Range-Limits in the North-East Atlantic

2021 ◽  
Vol 8 ◽  
Author(s):  
Philippine Chambault ◽  
Philippe Gaspar ◽  
Florence Dell’Amico
Keyword(s):  
Endangered Species ◽  
Sea Turtles ◽  
Thermal Conditions ◽  
Ecological Trap ◽  
Bay Of Biscay ◽  
East Atlantic ◽  
Marine Animals ◽  
North East ◽  
The North ◽  
Environmental Events

Unusual environmental events can push marine animals outside their physiological tolerances through changes in trophic and/or thermal conditions. Such events typically increase the risk of stranding. Rescue Centers offer a unique opportunity to report animals in distress and satellite track rehabilitated individuals to identify potential new habitats and support an effective conservation of these endangered species. By combining sightings (1988–2020) and tracking data (2008–2020) collected along the French Atlantic and English Channel coasts, our study assessed if the Bay of Biscay is an ecological trap or a favorable habitat for immature sea turtles. The largest tracked individuals migrated westward to pelagic waters, likely toward their natal beaches, while smaller individuals remained within the Bay of Biscay (BoB) and crossed colder (mean: 17.8 ± 3.0°C) but more productive waters. The turtles’ directions differed from the ones of ocean currents, excluding a passive advection to these unexpected habitats. Although the BoB might be thermally unsuitable in winter, the higher micronekton biomass predicted in this region could offer a productive foraging habitat for immature turtles. However, the majority of the sightings referred to individuals stranded alive (75%), suggesting this area could also act as an ecological trap for the smallest individuals that are mostly reported in winter suffering cold-stunning. Assumed to be outside the species range, our results reveal a potential foraging ground in the North-East Atlantic for these young turtles, confirming the crucial role of the rehabilitation centers and the need to continue prioritizing conservation of these endangered species, particularly vulnerable at this stage and at such temperate latitudes.

Three sightings of Mesoplodon species in the Bay of Biscay: first confirmed True's beaked whales (M. mirus) for the north-east Atlantic?

2004 ◽  
Vol 84 (5) ◽  
pp. 1095-1099 ◽  
Author(s):  
Caroline R. Weir ◽  
Jonathan Stokes ◽  
Clive Martin ◽  
Pablo Cermeño
Keyword(s):  
Water Depth ◽  
Bay Of Biscay ◽  
Beaked Whale ◽  
East Atlantic ◽  
North East ◽  
The North ◽  
Beaked Whales

Three sightings of Mesoplodon beaked whales are reported from the Bay of Biscay, north-east Atlantic. All sightings comprised one or two animals, breaching repeatedly in proximity to the survey vessel, and occurred at between 2200 and 4100 m water depth. Descriptive and photographic data are compared with published accounts of Mesoplodon species in the north-east Atlantic, and the identification of the animals as True's beaked whale (Mesoplodon mirus) concurs with all observed features. Within the north-east Atlantic, True's beaked whale is the only Mesoplodon species that could produce the single, closely-spaced parallel-paired scar observed on one animal. Our observations are consistent with the first live sightings of True's beaked whale in the Bay of Biscay, and only the second documented record worldwide.

scholarly journals Assessing Future Changes of Climate Extreme Events in the CORDEX-MENA Region Using Regional Climate Model ALADIN-Climate

2020 ◽  
Vol 4 (3) ◽  
pp. 477-492
Author(s):  
Fatima Driouech ◽  
Khalid ElRhaz ◽  
Willfran Moufouma-Okia ◽  
Khadija Arjdal ◽  
Saloua Balhane
Keyword(s):  
Regional Climate Model ◽  
Extreme Events ◽  
Climate Model ◽  
Heat Waves ◽  
Regional Climate ◽  
Domain Model ◽  
Climate Extreme ◽  
Mena Region ◽  
North East ◽  
The North

Abstract This study investigates future changes of temperature, precipitation, and associated extreme events in the MENA region using Regional Climate Model ALADIN-Climate over the CORDEX-MENA domain. Model capabilities to reproduce key observed regional climate features are first assessed, including heat waves, drought and high precipitation extremes. Projected changes indicate the intensification of heat waves number, duration and magnitude, and contrasted precipitation changes. A drying is projected in the north-west and moistening in the north-east along the Mediterranean side of the region. Projected regional warming is found at the rate of about 0.2 °C/decade to 0.5 °C/decade over land depending on the scenario. Drought is expected to increase in the northern half of the region independently from the index used, but with a higher rate in the case of the index accounting for both the effect of precipitation and temperature changes. ALADIN-Climate results corroborate previous studies projecting the MENA region to host global hot spots for drought in the late twenty-first century.

scholarly journals Use of Topographic Map Evidence From Drainage Divides Surrounding Wyoming’s Great Divide Basin to Compare Two Fundamentally Different Regional Geomorphology Paradigms

2020 ◽  
Vol 9 (1) ◽  
pp. 45 ◽  
Author(s):  
Eric Clausen
Keyword(s):  
Scientific Discipline ◽  
Mountain Range ◽  
Topographic Map ◽  
New Paradigm ◽  
Geologic History ◽  
North East ◽  
The North ◽  
Continental Divide ◽  
Great Divide ◽  
East West

Divide crossings (or low points or gaps) notched into the North American east-west continental divide segments completely encircling Wyoming’s Great Divide Basin interior drainage region (as observed on detailed topographic maps) are used to compare the commonly accepted regional geomorphology paradigm with a fundamentally different and new regional geomorphology paradigm. Paradigms are sets of rules governing how a scientific discipline conducts its research and are judged on their ability to explain observed evidence. Published literature is used to contrast an accepted paradigm interpretation that east-oriented drainage previously flowed across what is now the Great Divide Basin with the new paradigm basic requirement that mountain range and continental divide uplift occurred while immense south-oriented floods flowed across them. Numerous divide crossings are notched into the continental divide segments now completely encircling the relatively flat-floored Great Divide Basin interior drainage area and divide crossings observed along each of the Great Divide Basin’s north, east, south, and west margins are described and interpreted first from the accepted paradigm perspective (using published literature interpretations to the extent possible) and second from the new paradigm perspective. The published literature does not mention most of the described divide crossings, much less provide explanations for their origins, perhaps because the accepted paradigm cannot satisfactorily explain those origins. In contrast the new paradigm successfully explains most if not all of the described (and observed, but undescribed) divide crossings, although the new paradigm requires a completely different middle and late Cenozoic regional geologic history than what most published regional geology literature describes.

scholarly journals Citizen science in the marine environment: A case-study estimating common dolphin densities in the north-east Atlantic

2019 ◽  
Author(s):  
James R Robbins ◽  
Lucy Babey ◽  
Clare B Embling
Keyword(s):  
Citizen Science ◽  
Common Dolphin ◽  
Bay Of Biscay ◽  
English Channel ◽  
East Atlantic ◽  
Science Data ◽  
North East ◽  
The North ◽  
Celtic Sea ◽  
Common Dolphins

Background. Citizen science is increasingly popular and has the potential to collect extensive datasets at lower costs than traditional surveys. Ferries have been used to collect data on cetacean populations for decades, providing long-term time series allowing for monitoring of cetacean populations. One cetacean species of concern is the common dolphin, which have been found stranded around the north-east Atlantic in recent years, with high numbers on French coasts being attributed to fisheries bycatch. We estimate common dolphin densities in north-east Atlantic and investigate the power of citizen science data to identify changes in marine mammal densities and areas of importance. Materials & Methods. Data were collected by citizen scientists on ferries between April and October in 2006 - 2017. Common dolphin sightings data from two ferry routes in the Bay of Biscay (n= 569), Celtic Sea (n= 260), and English Channel (n= 75) were used to estimate detection probabilities with detection functions. Density Surface Models estimated density across ferry routes, accounting for the influence of environmental (chlorophyll a, sea surface temperature, depth, and slope), spatial (latitude and longitude) and temporal terms (year and Julian day). Results. Overall detection probability was highest in the English Channel (0.384) and Bay of Biscay (0.348), and lowest in the Celtic Sea (0.158). Common dolphins were estimated to occur in higher densities in the Celtic Sea (0.400 per km) and the Bay of Biscay (0.319 per km), with low densities in the English Channel (0.025 per km). Densities in the Celtic Sea have been relatively stable on the ferry route since 2006 with a slight decrease in 2017. Densities peaked in the Bay of Biscay in 2013 with lower numbers since. The general trend in the English Channel is for increasing densities of common dolphins over time since 2009. Discussion. This study highlights the effectiveness of citizen science data to investigate the distribution and density of cetaceans. The densities and temporal changes shown by this study are representative of those from wider-ranging robust estimates. We highlight the ability of citizen science to collect data over extensive periods of time which complements traditional surveys. Such long-term data are important to identify changes within a population; however, citizen science data may, in some situations, present challenges. We provide recommendations to ensure high-quality data which can be used to inform management and conservation of cetacean populations.

scholarly journals Interannual evolution of (sub)mesoscale dynamics in the Bay of Biscay

Ocean Science ◽  
2017 ◽  
Vol 13 (5) ◽  
pp. 777-797 ◽  
Author(s):  
Guillaume Charria ◽  
Sébastien Theetten ◽  
Frédéric Vandermeirsch ◽  
Özge Yelekçi ◽  
Nicole Audiffren
Keyword(s):  
Mixed Layer ◽  
Large Scale ◽  
Mixed Layer Depth ◽  
Relative Vorticity ◽  
Circulation System ◽  
Western Boundary ◽  
Bay Of Biscay ◽  
Coastal System ◽  
North East ◽  
The North

Abstract. In the north-east Atlantic Ocean, the Bay of Biscay is an intersection between a coastal constrained dynamics (wide continental shelf and shelf break regions) and an eastern boundary circulation system. In this framework, the eddy kinetic energy is 1 order of magnitude lower than in western boundary systems. To explore this coastal complex system, a high-resolution (1 km, 100 vertical sigma layers) model experiment including tidal dynamics over a period of 10 years (2001–2010) has been implemented. The ability of the numerical environment to reproduce main patterns over interannual scales is demonstrated. Based on this experiment, the features of the (sub)mesoscale processes are described in the deep part of the region (i.e. abyssal plain and continental slope). A system with the development of mixed layer instabilities at the end of winter is highlighted. Beyond confirming an observed behaviour of seasonal (sub)mesoscale activity in other regions, the simulated period allows exploring the interannual variability of these structures. A relationship between the winter maximum of mixed layer depth and the intensity of (sub)mesoscale related activity (vertical velocity, relative vorticity) is revealed and can be explained by large-scale atmospheric forcings (e.g. the cold winter in 2005). The first submesoscale-permitting exploration of this 3-D coastal system shows the importance of (sub)mesoscale activity in this region with its evolution implying a potentially significant impact on vertical and horizontal mixing.

Sign in / Sign up

Export Citation Format

Share Document