Challenges in modeling spatiotemporally varying phytoplankton blooms in the  Northwestern Arabian Sea and Gulf of Oman

Marvasti, S. Sedigh; Gnanadesikan, Anand; Bidokhti, A. A.; Dunne, John; Ghader, Sarmad

doi:10.5194/bg-13-1049-2016

Cited by 10 publications

(4 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent studies have delved into the biological and chemical parameters of the Persian Gulf and Oman Sea, employing coupled physical-biological ROMS models and satellite data to explore various facets of marine ecology [24][25][26][27][28][29]. However, there remains a gap in our understanding of the behavior of biological parameters with seasonal changes in the Oman Sea region, especially in the context of basin hydrodynamics and atmospheric forces.…”

Section: Current Japanmentioning

confidence: 99%

See 1 more Smart Citation

Seasonal Patterns in Phytoplankton and Zooplankton across the North of Gulf of Oman: A Numerical Study

Samini,

Aliakbari Bidokhti,

Ezam

et al. 2024

Pol. J. Environ. Stud.

View full text Add to dashboard Cite

Climate change, a global phenomenon, has been at the forefront of scientific discourse due to its profound implications on both marine and freshwater environments [1][2][3]. These implications are not just limited to rising temperatures or altered precipitation patterns; they extend to the very fabric of aquatic ecosystems, influencing the dynamics of the marine food web and the organisms that constitute it.Zooplankton, microscopic organisms that drift with ocean currents, play a pivotal role in marine ecosystems [1][2][3]. Serving as a crucial link in the pelagic food web, they connect primary producers, primarily phytoplankton, to higher trophic levels, such as fish. This intermediary role means that any change in the abundance, distribution, or community structure of zooplankton can have cascading effects on the entire

show abstract

Section: Current Japanmentioning

confidence: 99%

“…However, it's also a region in flux, undergoing structural and functional changes due to a combination of climate change and anthropogenic activities [19][20][21]. The hydrodynamics of this region are intricate, influenced by a myriad of processes, including biogeochemical processes typical of upwelling, oligotrophic, and low-oxygen environments [22][23][24].…”

mentioning

confidence: 99%

Seasonal Patterns in Phytoplankton and Zooplankton across the North of Gulf of Oman: A Numerical Study

Samini,

Aliakbari Bidokhti,

Ezam

et al. 2024

Pol. J. Environ. Stud.

View full text Add to dashboard Cite

show abstract

“…The model reproduces a well-developed SLD, characterised by negative SLA (-10 cm) embedded within the cyclonic circulation east of Sri Lanka, consistent with the AVISO observations. The TOPAZ ecosystem model simulates well the mean distribution of oceanic productivity (Sarmiento et al, 2010;Pastor et al, 2013;Marvasti et al, 2016) Oscillation Gnanadesikan et al, 2014). The model provides a realistic representation of the monsoonal biophysical interactions in the Indian Ocean and has been used to explain the bloom dynamics of northwestern BoB during the summer monsoon (Thushara and Vinayachandran, 2016) and northeastern Arabian Sea during winter (Vijith et al, 2016).…”

Section: Model Simulationmentioning

confidence: 99%

Interactive comment on “Vertical distribution of chlorophyll in dynamically distinct regions of the southern Bay of Bengal” by Venugopal Thushara et al.

Vinayachandran¹

2018

Preprint

View full text Add to dashboard Cite

The Bay of Bengal (BoB) generally exhibits surface oligotrophy, due to nutrient limitation induced by strong salinity stratification. Nevertheless, there are hot spots of high chlorophyll in the BoB where the monsoonal forcings are strong enough to break the stratification; one such region being the southern BoB, east of Sri Lanka. A recent field program conducted during the summer monsoon of 2016, as a part of the Bay of Bengal Boundary Layer Experiment (BoBBLE), provides a unique high-resolution dataset of the vertical distribution of chlorophyll in the southern BoB using ocean gliders along with shipboard CTD measurements. Observations were carried out for a duration of 12-20 days, covering the dynamically active regions of the Sri Lanka Dome (SLD) and the Southwest Monsoon Current (SMC). Mixing and upwelling induced by the monsoonal wind forcing enhanced surface chlorophyll concentrations (0.3-0.7 mg m −3). Prominent deep chlorophyll maxima (DCM; 0.3-1.2 mg m −3) existed at intermediate depths (20-50 m), signifying the contribution of subsurface productivity on the biological carbon cycling in the BoB. The shape of chlorophyll profiles varied in different dynamical regimes; upwelling was associated with sharp and intense DCM, whereas mixing resulted in a diffuse and weaker DCM. Within the SLD, open-ocean Ekman suction favoured a substantial increase in chlorophyll. Farther east, where the thermo-1 cline was deeper, enhanced surface chlorophyll was associated with intermittent mixing events. Remote forcing by the westward propagating Rossby waves influenced the upper ocean dynamics and chlorophyll distribution in the southern BoB. Stabilising surface freshening events and barrier layer formation often inhibited the generation of surface chlorophyll. The pathway of the SMC intrusion was marked by a distinct band of chlorophyll, indicating the advective effect of biologically rich Arabian Sea waters. The region of 5 monsoon current exhibits the strongest DCM as well as the highest column-integrated chlorophyll. Observations suggest that the persistence of DCM in the southern BoB is promoted by surface oligotrophy and shallow mixed layers. Results from a coupled physical-ecosystem model substantiate the dominant role of mixed layer processes associated with the monsoon in controlling the nutrient distribution and biological productivity in the southern BoB. The present study provides new insights into the vertical distribution of 10 chlorophyll in the BoB, emphasizing the need for extensive in situ sampling and ecosystem model-based efforts for a better understanding of the bio-physical interactions and the potential climatic feedbacks.

show abstract

“…Hence, evaluation of model physics is not presented here. TOPAZ has been used earlier to reproduce the observed oceanic productivity and its variability Pastor et al, 2013;Marvasti et al, 2016] and to explain the biophysical interactions associated with Indian Ocean Dipole (IOD), El Niño Southern Oscillation (ENSO), and Atlantic Multidecadal Oscillation (AMO) Gnanadesikan et al, 2014]. An analysis of the mechanisms controlling winter phytoplankton bloom in the northeastern Arabian Sea using the same model has been presented in Vijith et al [2016].…”

Section: 1002/2016jc011987mentioning

confidence: 99%

Formation of summer phytoplankton bloom in the northwestern Bay of Bengal in a coupled physical-ecosystem model

Thushara

Vinayachandran

2016

J. Geophys. Res. Oceans

View full text Add to dashboard Cite

The Bay of Bengal (BoB) is considered to be a region of low biological productivity, owing to nutrient limitation, caused by strong salinity stratification induced by the freshwater influx from rivers and precipitation. Satellite and in situ observations, however, reveal the presence of prominent regional blooms in the bay in response to monsoonal forcings. Bloom dynamics of the BoB are presumably determined by freshwater as well as the local and remote effect of winds and remain to be explored in detail. Using a coupled physical‐ecosystem model, we have examined the oceanic processes controlling productivity in the northwestern BoB during the summer monsoon. The region exhibits a prominent bloom lasting for a period of about 2 months, supporting major fishing zones along the northeast coast of India. The ecosystem model simulates the spatial and temporal evolution of the surface bloom in good agreement with Sea‐Viewing Wide Field‐of‐View Sensor (SeaWiFS) observations. Vertical distribution of upper ocean physical and biological tracers and a nitrate budget analysis reveal the dominant role of coastal upwelling induced by alongshore winds in triggering the bloom. Horizontal advection plays a secondary role by supplying nutrients from coastal to offshore regions. The bloom decays with the weakening of winds and upwelling by the end of summer monsoon. The simulated bloom in the northwestern bay remains largely unaffected by the freshwater effects, since the peak bloom occurs before the arrival of river plumes.

show abstract

Challenges in modeling spatiotemporally varying phytoplankton blooms in the Northwestern Arabian Sea and Gulf of Oman

Abstract: Abstract. Recent years have shown an increase in harm-

Cited by 10 publications

References 59 publications

Seasonal Patterns in Phytoplankton and Zooplankton across the North of Gulf of Oman: A Numerical Study

Seasonal Patterns in Phytoplankton and Zooplankton across the North of Gulf of Oman: A Numerical Study

Interactive comment on “Vertical distribution of chlorophyll in dynamically distinct regions of the southern Bay of Bengal” by Venugopal Thushara et al.

Formation of summer phytoplankton bloom in the northwestern Bay of Bengal in a coupled physical-ecosystem model

Contact Info

Product

Resources

About