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Development of a High-Resolution Multiscale Modeling and Prediction System for Bay of Bengal, Part I: Climatology-Based Simulations  [PDF]
Arun Chakraborty, Avijit Gangopadhyay
Open Journal of Marine Science (OJMS) , 2016, DOI: 10.4236/ojms.2016.61013
Abstract: A high-resolution (10 km × 10 km) multiscale ocean modeling system was developed for short-term (1 - 2 weeks) ocean state hindcasting/forecasting in the Bay of Bengal (BOB) region. This paper is Part I of a two-part series of studies. The Regional Ocean Modeling System (ROMS) was implemented and initialized with Levitus 1/4° climatological fields for short-term forecasting. The results from these climatology-based model simulations for three representative months (February, June and October) in three different seasons (winter, summer and autumn) are discussed herein. This high-resolution model implementation simulates most of the observed dominant circulation features. The multiscale features during February include an anticyclonic basin-scalegyre with a strong western boundary current (WBC) in the western basin, the formation of several shallow mesoscale eddies in the head of the Bay and a cyclonic sub-basin-scale Myanmar Gyre in the northeast. During June, no well-defined boundary current is simulated along the Indian coast; instead, alternating cyclonic and anticyclonic eddies appear along the east coast with cross-basin eastward flow to support a deep cyclonic Andaman Gyre. In October, a basin-scale cyclonic gyre with a continuous well-defined East India Coastal Current (EICC), weak inflow from the Malacca Strait to the Andaman Sea and advection of BOB water into the Arabian Sea via the Palk Strait are simulated well by the model. A number of mesoscale eddies appear on the eastern half of the basin during October. Physical pattern of simulated eddies and transports across selected sections are validated against available drifter climatology, ARGO data and previous observations. Application of this system to synoptic short-term predictions for October 2008 will be presented in
The Onset of the Monsoon over the Bay of Bengal:The Observed Common Features for 2008-2011
The Onset of the Monsoon over the Bay of Bengal: The Observed Common Features for 2008–2011

YU Wei-Dong,SHI Jian-Wei,LIU Lin,LI Kui-Ping,LIU Yan-Liang,WANG Hui-Wu,
YU Wei-Dong
,SHI Jian-Wei,LIU Lin,LI Kui-Ping,LIU Yan-Liang,WANG Hui-Wu

大气和海洋科学快报 , 2012,
Abstract: In situ buoy observation data spanning four years(2008-2011) were collected and used to perform a composite analysis of the monsoon onset process in the Bay of Bengal(BoB).The sea surface temperature(SST) in the central BoB increases dramatically during the monsoon transition period and reaches its annual maximum just before the onset of the monsoon.This process is illustrated by the northward-propagating deep convection phase of the intraseasonal oscillation and the establishment of a steady southwest wind.It is argued that the SST peak plays a potential role in triggering the onset of the monsoon in the BoB and its vicinity.The general picture of the BoB monsoon onset summarized here reveals the possibility of regional land-ocean-atmosphere interaction.This possibility deserves further examination.
Modulation of Low-Latitude West Wind on Abnormal Track and Intensity of Tropical Cyclone Nargis (2008) in the Bay of Bengal

LI Wei-Wei,WANG Chunzai,WANG Dongxiao,YANG Lei,DENG Yi,

大气科学进展 , 2012,
Abstract: Tropical cyclone (TC) Nargis (2008) made landfall in Myanmar on 02 May 2008, bringing a storm surge, major flooding, and resulting in a significant death toll. TC Nargis (2008) displayed abnormal features, including rare eastward motion in its late stage, rapid intensification before landing. Using reanalysis data and a numerical model, we investigated how a low-latitude westerly wind modulated TC Nargis' (2008) track and provided favorable atmospheric conditions for its rapid intensification. More importantly, we found a possible counterbalance effect of flows from the two hemispheres on the TC track in the Bay of Bengal. Our analysis indicates that a strong westerly wind burst across the Bay of Bengal, resulting in TC Nargis' (2008) eastward movement after its recurvature. This sudden enhancement of westerly wind was mainly due to the rapidly intensified mid-level cross-equatorial flow. Our results show that a high-pressure system in the Southern Hemisphere induced this strong, mid-level, cross-equatorial flow. During the rapid intensification period of TC Nargis (2008), this strong and broad westerly wind also transported a large amount of water vapor to TC Nargis (2008). Sufficient water vapor gave rise to continuously high and increased mid-level relative humidity, which was favorable to TC Nargis' (2008) intensification. Condensation of water vapor increased the energy supply, which eventuated the intensification of TC Nargis (2008) to a category 4 on the Saffir-Simpson scale.
Status of Bay of Bengal: An Ecological Point of View
Pai IK
Atlas Journal of Biology , 2010,
Abstract: The marine resources are a major source of food, a reservoir of minerals, major suppliers of oxygen, regulator of climate. It is also an ultimate dumping ground for the mounting burden of human waste material. Due to unchecked anthropogenic activity in recent years, the physico-chemical and biological status of the marine environments have changed significantly. This has resulted in the changing environmental scenario of the world. The Bay of Bengal, is one of the largest Bay in the world known to receive large flow of sediments from several rivers and other water bodies from India, Bhutan, Bangladesh, Myanmar, Indonesia etc., Many of these rivers bring along with them, a large quantity of effluents from cities / towns located on either side of these rivers, thus making the Bay nutrient rich. This Bay also plays a major role in determining the climatic conditions of India and other South East Asian countries. Thus its ecology is of paramount interest. Further, the Bay is also known for its oligotrophic nature as well low productivity, thus resulting in high diversity of flora and fauna. The ecological status of the Bay has a direct bearing on the lifescape of the Bay, and therefore, a study was undertaken to understand abiotic and biotic factors with special reference to zooplankton. Based on the observations, the study recommends certain appropriate measures to be taken to conserve the ecology of one of the largest Bay in the world.
Natural isotopic composition of nitrogen in suspended particulate matter in the Bay of Bengal
S. Kumar, R. Ramesh, N. B. Bhosle, S. Sardesai,M. S. Sheshshayee
Biogeosciences (BG) & Discussions (BGD) , 2004,
Abstract: We present the first measurement of nitrogen isotopic composition (δ15N) in suspended particulate matter (SPM) of the surface Bay of Bengal (BOB) at 24 different locations during pre- (April–May 2003) and post- (September–October 2002) monsoon seasons. The δ15N of particulate organic nitrogen (PON) in surface suspended matter of coastal as well as northern open BOB shows signatures of a two end-member mixing between continental inputs and marine sources. Dilution by the organic and detrital continental material brought in by rivers leads to consistently lower δ15N, evident from the relationship between surface salinity and δ15N. δ15N of surface PON of open ocean locations during both seasons, and also at coastal locations during pre-monsoon suggest the nitrate from deeper waters as a predominant source of nutrient for planktons. The depth profiles of δ15N of SPM during pre-monsoon season at nine different locations are also presented. These indicate an increase in δ15N by a maximum of 2.8‰ between euphotic depth and 300 m, which is lower than that observed in the eastern Indian Ocean, indicating the role of higher sinking rates of particles ballasted by aggregates of organic and mineral matter in BOB.
Natural isotopic composition of nitrogen in suspended particulate matter in the Bay of Bengal  [PDF]
S. Kumar,R. Ramesh,N. B. Bhosle,S. Sardesai
Biogeosciences Discussions , 2004,
Abstract: We present the first measurement of nitrogen isotopic composition (δ15N) in suspended particulate matter (SPM) of the surface Bay of Bengal (BOB) at 24 different locations during pre- (April–May 2003) and post- (September–October 2002) monsoon seasons. The δ15N of particulate organic nitrogen (PON) in surface suspended matter of coastal as well as northern open BOB shows signatures of a two end-member mixing between continental inputs and marine sources. Dilution by the organic and detrital continental material brought in by rivers leads to consistently lower δ15N, evident from the relationship between surface salinity and δ15N. δ15N of surface PON of open ocean locations during both seasons, and also at coastal locations during pre-monsoon suggest the nitrate from deeper waters as a predominant source of nutrient for planktons. The depth profiles of δ15N of SPM during pre-monsoon season at nine different locations are also presented. These indicate an increase in δ15N by a maximum of 2.8‰ between euphotic depth and 300 m, which is lower than that observed in the eastern Indian Ocean, indicating the role of higher sinking rates of particles ballasted by aggregates of organic and mineral matter in BOB.
Surface buoyancy flux in Bay of Bengal and Arabian Sea
G. Anitha, M. Ravichandran,R. Sayanna
Annales Geophysicae (ANGEO) , 2008,
Abstract: The seasonal variation of thermal, haline, net surface buoyancy flux, the Monin-Obukhov length (M-O length, L) and stability parameter, i.e. the ratio of M-O length to mixed layer depth (h) were studied in the Bay of Bengal (BoB) and the Arabian Sea (AS) for the years 2003 and 2004 using Argo temperature and salinity profiles. The relative quantitative influence of winds to surface buoyancy and the applicability of scaling mixed layer using M-O length in BoB and AS was brought out. Rotation and light penetration modify the mixed layer depth from M-O length during shoaling in spring giving L/h<1.
Pollution in the Bay of Bengal: Impact on Marine Ecosystem  [PDF]
Towhida Rashid, Sirajul Hoque, Sharmin Akter
Open Journal of Marine Science (OJMS) , 2015, DOI: 10.4236/ojms.2015.51006
Abstract: The study focused on heavy metal concentration in sea water, sea sediment and their toxic effect on sea shells, and on oyster along the east coast of the Bay of Bengal. The hierarchy of heavy metals in sea sediment of the bay showed as: Fe > Zn > Ni > Cr > Pb > Cd. The average concentration of nickel exceeded ERL (20.9 μg·g-1) value and the incidence of adverse effects on biological components exceeded 16.7%. The present study showed that the concentration of Cd, Fe, Pb and Cu in sea water were relatively higher than the standard concentration. The study showed a considerable amount of heavy metals (0.035%) such as Zn, Pb, Cu, Fe, and Mg in sea shells, and oyster which may make them toxic. The toxic effect of Pb and Zn may reduce their growth which is a great threat to marine ecosystem.
The struggle for the Bay : the life and times of Sandwip, an almost unknown Portuguese port in the Bay of Bengal in the sixteenth and seventeenth centuries
Rila Mukherjee
Revista da Faculdade de Letras : Historia , 2008,
Abstract: This article places Sandwip, a lesser known salt trading island and port in the Bay of Bengal within the nexus of global trade and politics in the seventeenth century. Sandwip is now a part of Bangladesh but at the time under review it was successively part of the medieval kingdoms of Bengal, Tripura and Arakan. Sandwip was, briefly, held by the Portuguese and is referred to in Portuguese annals as a ‘minor’ settlement, part of their ‘informal empire’ in the Bay. The article argues that we should not read such settlements of the Portuguese in Southasia as ‘formal’ or ‘informal’, ‘minor’ or ‘major’, and make thereby artificial distinctions between categories. We need to, instead, refocus and study Portuguese expansion as a multi pronged enterprise in which local exigencies and imperial vision were braided all over the Bay of Bengal.
Two Dimensional Hydrodynamic Modelling of Northern Bay of Bengal Coastal Waters  [PDF]
Misbah Uddin, Jahir Bin Alam, Zahirul Haque Khan, G. M. Jahid Hasan, Tauhidur Rahman
Computational Water, Energy, and Environmental Engineering (CWEEE) , 2014, DOI: 10.4236/cweee.2014.34015
Abstract: Mathematical models have advancement to a point where they are considered to be an effective tool for simulating natural phenomena in coastal regions. This paper discusses the development of Bay of Bengal Model (BoBM), updating of the model with the recent bathymetry and shore line of islands and coastline and upgrading from rectangular grid to finer size of mesh grids by using latest version of MIKE21 FM modeling system. This model is very useful for the hydrodynamic study in the coastal region of Bangladesh. The article also presents the model set-up, boundary conditions and few calibration results of the model. The model applications clearly show the variation of the flow structure, their speed and direction separately for monsoon and dry season around the model area which covers the northern part of Bay of Bengal.
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