Seasonal variability of the mixed layer in the central Bay of Bengal and associated changes in nutrients and chlorophyll

Narvekar, Jayu; Kumar, Sanjeev

doi:10.1016/j.dsr.2006.01.012

Cited by 109 publications

(55 citation statements)

References 24 publications

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“…The cumulative discharge of these 6 rivers during this period (Fig.14b) amounted to a voluminous 3.46 x 10 12 m 3 . Note that the precipitation peaks in July (Fig.9 of Narvekar and Prasanna Kumar, 2006), while the river discharge peaks in August (Fig.14a).…”

Section: Discussionmentioning

confidence: 99%

“…This high surface salinity arises from positive E-P, which is in excess of 40 mm/month (Fig.9 of Narvekar and Prasanna Kumar, 2006) coupled with marginal river discharge during spring intermonsoon (Fig.14a). SST during spring intermonsoon along the central Bay transect was 1 o C warmer in the north, but towards the south it was 2 o C warmer.…”

Section: Discussionmentioning

confidence: 99%

“…The thermohaline structures obtained from the in situ hydrographic of Narvekar and Prasanna Kumar, 2006). In addition to the oceanic precipitation there is also a large amount of freshwater input from peninsular rivers.…”

Section: Discussionmentioning

confidence: 99%

“…In the present paper we examine the hydrographic data collected during fall and spring intermonsoons in the Bay of Bengal to identify the signature of eddies and explore their role in altering the biological productivity. The spring (MarchApril) and the fall (September-October) intermonsoon seasons represent the primary and secondary heating season in the Bay of Bengal during which the winds are weak and variable (Narvekar and Prasanna Kumar, 2006). The fresh water discharge from peninsular rivers is the least during spring intermonsoon, while it is at its peak during end of summer and beginning of fall intermonsoon (August-September).…”

Section: Introductionmentioning

confidence: 99%

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Eddy-mediated biological productivity in the Bay of Bengal during fall and spring intermonsoons

Kumar

Murukesh

Ramaiah

et al. 2007

Deep Sea Research Part I: Oceanographic Research Papers

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173

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The signature of cold-core eddies and their role in altering the biological productivity of the Bay of Bengal was examined using two recent sets of hydrographic data collected along the central and western Bay of Bengal during fall (14 September -12 October, 2002) and spring (12 April -7 May, 2003) intermonsoons under the Bay of Bengal Process Studies (BOBPS) programme. Based on the thermohaline structure and the satellite-derived sea-level anomaly maps 9 cyclonic eddies were identified. Out of this, 4 cyclonic eddies -2 each along the central Bay and along the western boundary -occurred during fall intermonsoon 2002, while 5 occurred -3 along the central Bay and 2 along the western boundary -during spring intermonsoon. The eddy depressed the temperature, which varied from 3 o C to 7 o C at 120 m depth. Maximum depression of temperature was associated with spring-time eddies in the northern Bay, where subsurface stability was low. The reduced water column stability in spring leads to greater eddypumping, thereby cooling the water to a greater extent. However, the cyclonic eddies were unable to break the stratification of the top 20m layer, thereby curtailing their effects below this depth during both seasons. Eddypumping not only cooled the water column but also enhanced the nutrient concentrations. This in turn increased the biological productivity of the Bay to 1½-2 times. In addition, the subsurface chlorophyll maximum (SCM), which is generally located between 40 and 70 m in fall and 60 and 90 m in spring intermonsoons, shallowed under the influence of the eddies and also enhanced the chlorophyll concentration in the SCM to more than double. Thus, eddy-pumping of nutrients controls the biological productivity of the Bay of Bengal during both the seasons. In the fall intermonsoon, however, the riverine input of nutrients and sediments in the northern Bay also plays a role in altering the biological productivity. This has an overall implication to the basin-wide new production and export flux and, at least partly, resolves the reason for the comparable annual fluxes of organic carbon

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Eddy-mediated biological productivity in the Bay of Bengal during fall and spring intermonsoons

Kumar

Murukesh

Ramaiah

et al. 2007

Deep Sea Research Part I: Oceanographic Research Papers

Self Cite

173

View full text Add to dashboard Cite

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“…In the BOB, the winds are weak and variable during FIM and SpIM, representing 238 the primary and secondary heating seasons (Narvekar and Prasanna Kumar, 2006). 239…”

Section: Discussion 237mentioning

confidence: 99%

Nutrient regimes and their effect on distribution of phytoplankton in the Bay of Bengal

Paul

Ramaiah

Sardessai

2008

Marine Environmental Research

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Examining features of enhanced phytoplankton biomass in the Bay of Bengal using a coupled physical‐biological model

et al. 2016

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KEY POINTS: Coupled Bio-Physical Model configured for the Indian Ocean Description of areas of enhanced phytoplankton biomass validated by remotely sensed chlorophyll a Model provides vertical cross sections of phytoplankton not available by remote sensing ABSTRACT A coupled bio-physical ocean model is used to describe areas of enhanced phytoplankton biomass, seen remotely sensed observations, in the otherwise oligotrophic environment of the Bay of Bengal. The model is based on the Naval Coastal Ocean Model (NCOM), which is oneway coupled to the 13-component Carbon, Silicate, and Nitrogen Ecosystem (CoSiNE) model and configured for the Indian Ocean. Model results are compared and evaluated against a set of in situ shipboard observations as well as ocean color data acquired from several remote sensing platforms. The model is shown to successfully simulate the seasonal cycle of phytoplankton, the markedly contrasting scenarios of phytoplankton distribution in the north versus the south Bay of Bengal, and the biological impact from the 1997/1998 Indian Ocean Dipole (IOD) event. The model simulation provides us with vertical cross sections of phytoplankton biomass from summer and winter blooms in the southwest of the bay; information not found in remotely sensed data. It also successfully reproduces the timing of the onset of the blooms and their spatial extent, thereby providing a measure of its potential for augmenting in situ and remotely sensed observations to improve understanding of the dynamics of primary producers and carbon cycling in one of the most poorly sampled regions of the world's oceans.

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Seasonal variability of the mixed layer in the central Bay of Bengal and associated changes in nutrients and chlorophyll

Cited by 109 publications

References 24 publications

Eddy-mediated biological productivity in the Bay of Bengal during fall and spring intermonsoons

Eddy-mediated biological productivity in the Bay of Bengal during fall and spring intermonsoons

Nutrient regimes and their effect on distribution of phytoplankton in the Bay of Bengal

Examining features of enhanced phytoplankton biomass in the Bay of Bengal using a coupled physical‐biological model

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