scholarly journals A study of tides and storm surges in offshore waters of the Meghna estuary using a finite element model

MAUSAM ◽  
2021 ◽  
Vol 48 (4) ◽  
pp. 519-530
Author(s):  
R.F. HENRY ◽  
D. S. DUNCALF ◽  
R. S. WALTERS ◽  
M. J. OSBORNE ◽  
T. S. MURTY
Keyword(s):  
Bay Of Bengal ◽  
East Coast ◽  
High Tide ◽  
Storm Surges ◽  
Element Model ◽  
Considerable Extent ◽  
Andaman Sea ◽  
Tidal Elevation ◽  
The North ◽  
Coastal Land

Tropical Cyclones which develop in the Andaman Sea and the Bay of Bengal during the inter monsoon months (April-May, October-December), move either westwards affecting the east coast of India or recurve to the north or northeast and eventually cross the coast of Bangladesh or Myanmar. Extensive damage is caused to the life and property by the storm surge as much of  the coastal land around the Bay of Bengal is densely populated. The damage caused by a cyclone induced surge depends to a considerable extent on whether the surge peaks at or close to high tide. The main purpose of the present study was to develop a combined time-surge model for the off-shore waters in the Meghna estuary. It seems clear that the strong, predominantly southward current measured at Site A, south of Sandwip Island, has substantial magnifying and delaying effect on tidal elevation and current. But the areal extent of this modification of the tide is unknown at present. Further, it is impossible to say whether the fast southward current forms a narrow jet or a broad current many kilometers wide, but it is important to know which is the case before the effect can be modelled satisfactorily.      

Review of the Indian Ocean spikefish genus Mephisto (Tetraodontiformes: Triacanthodidae)

Zootaxa ◽  
2020 ◽  
Vol 4802 (1) ◽  
pp. 82-98
Author(s):  
KATHERINE E. BEMIS ◽  
JAMES C. TYLER ◽  
PETER N. PSOMADAKIS ◽  
LAUREN NEWELL FERRIS ◽  
APPUKUTTANNAIR BIJU KUMAR
Keyword(s):  
Indian Ocean ◽  
Bay Of Bengal ◽  
East Coast ◽  
Andaman Sea ◽  
Micro Ct ◽  
Tooth Replacement ◽  
Color Photograph ◽  
Replacement Pattern ◽  
The Indian Ocean ◽  
Ct Data

We redescribe the triacanthodid spikefish Mephisto fraserbrunneri Tyler 1966 based upon eight specimens (five newly reported herein) and the first color photographs of freshly collected specimens; these data are compared with that of the single specimen of the recently described M. albomaculosus Matsuura, Psomadakis, and Mya Than Tun 2018. Both species are found in the Indian Ocean, with M. fraserbrunneri known from the Arabian Sea off the east coast of Africa to the eastern Bay of Bengal, and M. albomaculosus confirmed only from the type locality in the Andaman Sea (a color photograph of an individual M. cf. albomaculosus from the Bay of Bengal that was not retained is also presented). We describe and diagnose the genus Mephisto and provide a key to the two species based upon all available specimens. We also provide a distribution map for both species and summarize literature records. Using micro-CT data, we show that Mephisto fraserbrunneri replaces teeth intraosseously, which suggests this tooth replacement pattern is plesiomorphic for Tetraodontiformes. 

Intertidal ostracod (Crustacea: Ostracoda) abundance and assemblage structure within and between four shores in north-east England

1999 ◽  
Vol 79 (6) ◽  
pp. 1045-1051 ◽  
Author(s):  
Susan L. Hull
Keyword(s):  
Cluster Analysis ◽  
East Coast ◽  
Tidal Elevation ◽  
North East ◽  
The North ◽  
Significant Difference ◽  
Exposed Shore ◽  
High Degree ◽  
Degree Of Similarity ◽  
Ostracod Species

Triplicate samples of rockpool algae were collected at each of three tidal elevations (upper, mid and low) from four shores on the north-east coast of England. Two moderately exposed (Ravenscar, the exposed shore at Filey Brigg), and two moderately sheltered (Selwicks Bay, the sheltered shore at Filey Brigg) shores were sampled during one week of spring tides during June 1996. A total of 6866 individual ostracods comprising of 26 ostracod species were recovered from the algal samples. Some species showed significant differences in abundance with tidal elevation across the four shores, e.g. Hirschmannia viridis was significantly more abundant in the upper shore pools. Other species, e.g. Heterocythereisalbomaculata, showed no significant difference in abundance either with tidal elevation or between shores. Significant differences in abundance occurred between shores at a given tidal height in some species, e.g. Semicytherura nigrescens was absent from Selwicks Bay but abundant on the remaining shores. Other species had markedly disjunct distributions, e.g. Callistocythere badia only occurred in the exposed upper shore pools at Filey Brigg. Ostracods were significantly less abundant in the low shore pools. Cluster analysis showed that low shore samples had a high degree of similarity between the four shores whereas the upper and mid-shore samples clustered primarily to shore. A two-way ANOSIM indicated that there was a significant difference in assemblage similarity between the four shores and also between the different tidal elevations.

Environmental magnetic and petroleum hydrocarbons records in sediment cores from the north east coast of Tamilnadu, Bay of Bengal, India

2011 ◽  
Vol 62 (4) ◽  
pp. 681-690 ◽  
Author(s):  
R. Venkatachalapathy ◽  
S. Veerasingam ◽  
N. Basavaiah ◽  
T. Ramkumar ◽  
K. Deenadayalan
Keyword(s):  
Bay Of Bengal ◽  
Petroleum Hydrocarbons ◽  
East Coast ◽  
Sediment Cores ◽  
North East ◽  
The North

Bottlenose dolphins around Aberdeen harbour, north-east Scotland: a short study of habitat utilization and the potential effects of boat traffic

2005 ◽  
Vol 85 (6) ◽  
pp. 1547-1554 ◽  
Author(s):  
M.I. Sini ◽  
S.J. Canning ◽  
K.A. Stockin ◽  
G.J. Pierce
Keyword(s):  
East Coast ◽  
Bottlenose Dolphins ◽  
High Tide ◽  
Habitat Utilization ◽  
Late Afternoon ◽  
North East ◽  
The North ◽  
Early Afternoon ◽  
Boat Traffic

The aim of this study was to investigate the factors that affect the patterns of occurrence and habitat utilization of bottlenose dolphins around Aberdeen harbour, on the north-east coast of Scotland (UK), and their responses to boat traffic. Land-based surveys were conducted over a period of nine weeks, between early May and late July, 2002. During this time 83 sightings of bottlenose dolphins were recorded. Dolphins occurred more frequently around midday and early afternoon, while their abundance was greater around high tide and late afternoon. Foraging was the most commonly observed activity.Dolphins were usually concentrated around the entrance of Aberdeen harbour. Their responses to boats varied considerably according to boat size, activity and speed, but there is evidence of habituation to boat traffic.

scholarly journals Glacial fluctuations of the Indian monsoon and their relationship with North Atlantic abrupt climate change: new data and climate experiments

2012 ◽  
Vol 8 (6) ◽  
pp. 6269-6308 ◽  
Author(s):  
C. Marzin ◽  
N. Kallel ◽  
M. Kageyama ◽  
J.-C. Duplessy ◽  
P. Braconnot
Keyword(s):  
North Atlantic ◽  
Bay Of Bengal ◽  
Indian Monsoon ◽  
Hydrological Cycle ◽  
Meridional Overturning Circulation ◽  
Andaman Sea ◽  
Freshwater Flux ◽  
Chinese Loess ◽  
The North ◽  
The North Atlantic

Abstract. Several paleoclimate records such as Chinese loess and speleothem sequences or upwelling indicators present large variations of the Asian monsoon system during the last glaciation. Here, a unique record in the northern Andaman Sea (core MD77-176) is used to reconstruct the variations of the hydrological cycle of the Bay of Bengal. The high resolution salinity record displays large millennial scale oscillations over the period 40 000 to 11 000 yr BP that are synchronous with the Greenland ice core record of changes in polar air temperature during the last glaciations. Events of high (resp. low) salinity in the Bay of Bengal, i.e. weak (resp. strong) Indian monsoon, correspond to cold (resp. warm) events in the North Atlantic. We use the IPSL_CM4 model to study the processes that can explain the relationship between the Indian monsoon and the North Atlantic climate. A modelling experiment represents such a rapid event in the North Atlantic under glacial conditions by increasing the freshwater flux in the North Atlantic and reducing the intensity of the Atlantic meridional overturning circulation. This freshwater hosing results in a weakening of the Indian monsoon rainfall and circulation. The changes in the continental runoff and local hydrological cycle are responsible for the changes in salinity of the Bay of Bengal in the model. This is a favourable comparison with the new salinity record presented here. Additional sensitivity experiments are produced with the LMDZ atmospheric model to analyse the teleconnection mechanisms between the North Atlantic and the Indian monsoon. The changes over the tropical Atlantic are shown to be essential in triggering perturbations of the subtropical jet over Eurasia that in turn affect the intensity of the Indian monsoon.

Performance of ECCC surge forecasting systems near Canada's East Coast during the passage of hurricane Dorian

2020 ◽  
Author(s):  
Oleksandr Huziy ◽  
Bernier Natacha ◽  
Benoit Pouliot ◽  
Patrick Timko ◽  
Pengcheng Wan ◽  
...  
Keyword(s):  
Atmospheric Pressure ◽  
Lead Time ◽  
East Coast ◽  
High Tide ◽  
Storm Surges ◽  
Water Levels ◽  
Tidal Range ◽  
Safe Navigation ◽  
Prediction Systems ◽  
Protection Of Life

<p>Accurate forecasts of storm surges caused by winds and atmospheric pressure are important for the protection of life and property in coastal regions and also for safe navigation. Therefore, Environment and Climate Change Canada (ECCC) maintains and develops surge prediction systems. This study focuses on the assessment of the timing and amplitude of predicted surges at selected locations during the passage of hurricane Dorian. The systems use barotropic ocean models to simulate water levels and currents at 1/30 and 1/12 degree horizontal resolutions.</p><p>The relatively low tidal range at the time of Dorian’s landfall helped prevent catastrophic flooding. However, with a closer superposition of the peak surge and high tide, the damage could have been more significant. Reasonably well predicted timing of the highest surge by the system helped prevent the over-issuance of warnings. Sensitivity of the forecast quality to the lead time, resolution and atmospheric forcing for the event will be presented.</p>

scholarly journals STORM SURGE PREDICTION IN TIDAL RIVERS: A NEW CONCEPTION

1978 ◽  
Vol 1 (16) ◽  
pp. 57
Author(s):  
Winfried Siefert
Keyword(s):  
Storm Surge ◽  
North Sea ◽  
High Tide ◽  
Storm Surges ◽  
Tidal Dynamics ◽  
The North ◽  
Highly Sensitive ◽  
Tidal Rivers ◽  
The North Sea ◽  
Warning Services

The heights of extreme storm surges in the North Sea rise up to U or 5 m above mean high tide. Warning services are established along the coast, mainly based on empirical connections between weather and tide data. A lot of wrong announcements are given especially for places up the tidal rivers. This can become disasterous for a lot of modern, highly sensitive harbour facilities. Thus storm surges are the famous plagues of the southern North Sea coast. Moreover, the "ten plagues of Germany" occurred during the last 16 years. So recently a new conception for storm surge prediction in tidal rivers was developed - with the result of a lot of new understandings of tidal dynamics in rivers (SIEFERT, 1968). We investigated about 130 storm surges, hindcasting all of them and forecasting about 20 of them, and analysed their behaviour in tidal rivers. Now we are able to forecast the upstream heights and even the shape of the surge curve in the Elbe with an accuracy of ± 2 dm, ' 6 hours in advance.

scholarly journals The band fish Acanthocepola indica (Perciformes: Cepolidae) in the Northern Bay of Bengal, India

2018 ◽  
Vol 10 (1) ◽  
Author(s):  
Alakesh Pradhan ◽  
Bijay K. Mahapatra
Keyword(s):  
Bay Of Bengal ◽  
East Coast ◽  
Single Specimen ◽  
East Coast Of India ◽  
North East ◽  
The North ◽  
Northern Bay Of Bengal ◽  
First Time

A relatively poorly known species of band fish, Acanthocepola indica (Cepolidae), is reported for the first time from the north-east coast of India, Bay of Bengal, based on single specimen 236,86mm long, collected in Digha. We include a detailed, illustrated description of the specimen

Mesolithic Sites of the North East Coast of England

1933 ◽  
Vol 7 (2) ◽  
pp. 188-198
Author(s):  
A. Raistrick
Keyword(s):  
East Coast ◽  
Sand Dunes ◽  
High Tide ◽  
North East ◽  
The North ◽  
Subsequent Period ◽  
Tide Level ◽  
Boulder Clay ◽  
Clay Cover ◽  
Glacial Time

For a distance of four miles north of Newbiggin-on-Sea, Northumberland, the coast presents a stretch of low cliffs and headlands of sandstone, alternating with shallow bays flanked by sand-dunes, the dunes usually resting visibly on a low boulder clay cliff, not usually rising more than 20 ft. above high tide level. The river Lyne reaches the coast now about two miles north of Newbiggin, at Lyne Sands, but in preglacial and early post-glacial time, entered the sea at Newbiggin bay. The old course of the river is occupied by the “Carrs,” a strip of swampy peat, proved at several places by boring, to reach a depth of over twenty feet and to be underlain by river gravel on boulder clay. The basal layers of the peat are proved by pollen analysis to be of latest Boreal age. Between this old channel and the sea, lies Newbiggin Moor, between 30 ft. and 50 ft. OD. a wide stretch of sandstone covered by thin soil, and occasional peat and blown sand. In early Boreal time this would be a headland prolonged southward between the sea on the east and the river Lyne on the west. At a subsequent period the Lyne has broken through its present course to the sea, north of Lyne Sands. The foreshore is made up by a wide stretch of sandstone, flats and skerries overlain by boulder clay, making the low cliff in the southern part, with sand dunes resting directly on the clay. Northward the sandstone gradually rises and towards Cresswell Point makes the whole cliff, with only a thin boulder clay cover on top.

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