Mesoscale circulation of the bay of Bengal and its influence on marine productivity
Thesis (PhD. (Geomatics Engineering))
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| Format: | Thesis |
| Language: | English |
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Universiti Teknologi Malaysia
2023
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| Online Access: | http://openscience.utm.my/handle/123456789/550 |
| _version_ | 1796848879484796928 |
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| author | Rayaroth, Mridula Kuttyattu |
| author_facet | Rayaroth, Mridula Kuttyattu |
| author_sort | Rayaroth, Mridula Kuttyattu |
| collection | OpenScience |
| description | Thesis (PhD. (Geomatics Engineering)) |
| first_indexed | 2024-03-05T17:34:14Z |
| format | Thesis |
| id | oai:openscience.utm.my:123456789/550 |
| institution | Universiti Teknologi Malaysia - OpenScience |
| language | English |
| last_indexed | 2024-03-05T17:34:14Z |
| publishDate | 2023 |
| publisher | Universiti Teknologi Malaysia |
| record_format | dspace |
| spelling | oai:openscience.utm.my:123456789/5502023-08-13T09:00:27Z Mesoscale circulation of the bay of Bengal and its influence on marine productivity Rayaroth, Mridula Kuttyattu Ocean circulation Marine productivity Bengal, Bay of Thesis (PhD. (Geomatics Engineering)) The circulation of the Bay of Bengal is playing a significant role in climate variability and biological productivity. Its surface circulation is subjected to seasonal reversal as well as periodic and non-periodic disturbances including low-frequency planetary wave activity. The present study has derived high resolution mean and instantaneous surface velocity fields of Bay of Bengal combining satellite altimetry and surface drifter observations. Inter-annual variations as well as spatial characteristics and temporal evolution of the surface circulation features is identified. The influence of mesoscale circulation features on marine productivity was determined. Finally, the water characteristics and deep circulation of the Bay of Bengal have also been analysed. This study has employed the satellite altimeter observations, sea surface wind data from satellite scatterometers, satellite-tracked surface drifter data, argo data, SeaWiFs Chlorophyll a data and temperature-salinity data from the Global Temperature-Salinity Profile Program. The surface drifter and altimeter data are combined to estimate the mean surface velocity field. Spatial and temporal variability of Chlorophyll a distribution in the Bay of Bengal is obtained by basin scale trend analysis. The deep circulation of the Bay of Bengal is derived by employing isentropic analysis. Major features observed in the mean velocity field are western boundary East Indian Coastal Current which is intense between 12°N and 16°N, where the speed reaches 1 m/s, weak westward North Equatorial Current with speed ranging between 0.25 m/s and 0.5 m/s and significant eastward flow near the equator. The Equatorial jet is identified both in spring and fall. Besides strong currents, the Bay of Bengal exhibits intense mesoscale eddy activity on the western side. In addition to the current reversal in the equatorial region, significant changes in the western boundary current are occurring in the Bay of Bengal during Indian Ocean Dipole events. During positive Indian Ocean Dipole, the western boundary flow is weak (speed less than 0.6 m/s) and embedded with mesoscale eddies whereas a well organised strong western boundary current with a maximum speed of 1.2 m/s between 5°N and 20°N prevails during negative Indian Ocean Dipole events. The Chlorophyll a distribution shows maximum concentration during south-west monsoon season in the Bay of Bengal, especially in August with a maximum concentration of 0.7 mg/m3 south-east of Sri Lanka. The cyclonic and anticyclonic eddies significantly modifying the Chlorophyll a distribution, particularly in the western part. The inter-annual variation of Chlorophyll a is much influenced by Indian Ocean Dipole events. The vertical distribution of water characteristics along zonal and meridional sections displays the water mass assembly of the Bay of Bengal. Below the low salinity surface water, high salinity (35 psu) Intermediate High Saline Water mass is observed between 200 m to 800 m and Indian Deep Water resides below 800 m. Overall, this study reveals the surface and deep circulation of the Bay of Bengal and its influence on biological productivity with special reference to the Indian Ocean Dipole Faculty of Geoinformation and Real Estate 2023-08-13T00:29:20Z 2023-08-13T00:29:20Z 2017 Thesis Dataset http://openscience.utm.my/handle/123456789/550 en application/pdf application/pdf application/pdf application/pdf Universiti Teknologi Malaysia |
| spellingShingle | Ocean circulation Marine productivity Bengal, Bay of Rayaroth, Mridula Kuttyattu Mesoscale circulation of the bay of Bengal and its influence on marine productivity |
| title | Mesoscale circulation of the bay of Bengal and its influence on marine productivity |
| title_full | Mesoscale circulation of the bay of Bengal and its influence on marine productivity |
| title_fullStr | Mesoscale circulation of the bay of Bengal and its influence on marine productivity |
| title_full_unstemmed | Mesoscale circulation of the bay of Bengal and its influence on marine productivity |
| title_short | Mesoscale circulation of the bay of Bengal and its influence on marine productivity |
| title_sort | mesoscale circulation of the bay of bengal and its influence on marine productivity |
| topic | Ocean circulation Marine productivity Bengal, Bay of |
| url | http://openscience.utm.my/handle/123456789/550 |
| work_keys_str_mv | AT rayarothmridulakuttyattu mesoscalecirculationofthebayofbengalanditsinfluenceonmarineproductivity |