Sub-surface temperature oscillations and associated flow in the western Bay of Bengal

Antony, M.K.; Murty, C.S.; Reddy, G. V.; Rao, K. H.

doi:10.1016/0272-7714(85)90076-9

Cited by 9 publications

(5 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These features were especially notable below regions of elevated chlorophyll feature. The internal wave climate of the BoB is poorly characterized, apart from relatively sparse measurements of the semidiurnal tides and high-frequency waves obtained over the past several decades (e.g., Wijeratne et al 2010;Jackson 2007;Antony et al 1985;Osborne and Burch 1980;Perry and Schimke 1965). ASIRI observations provide new insights into the internal wavefield through the NRL mooring array (Fig.…”

Section: Modeling Program Continuedmentioning

confidence: 99%

ASIRI: An Ocean–Atmosphere Initiative for Bay of Bengal

Wijesekera

Shroyer

Tandon

et al. 2016

Bulletin of the American Meteorological Society

View full text Add to dashboard Cite

Air–Sea Interactions in the Northern Indian Ocean (ASIRI) is an international research effort (2013–17) aimed at understanding and quantifying coupled atmosphere–ocean dynamics of the Bay of Bengal (BoB) with relevance to Indian Ocean monsoons. Working collaboratively, more than 20 research institutions are acquiring field observations coupled with operational and high-resolution models to address scientific issues that have stymied the monsoon predictability. ASIRI combines new and mature observational technologies to resolve submesoscale to regional-scale currents and hydrophysical fields. These data reveal BoB’s sharp frontal features, submesoscale variability, low-salinity lenses and filaments, and shallow mixed layers, with relatively weak turbulent mixing. Observed physical features include energetic high-frequency internal waves in the southern BoB, energetic mesoscale and submesoscale features including an intrathermocline eddy in the central BoB, and a high-resolution view of the exchange along the periphery of Sri Lanka, which includes the 100-km-wide East India Coastal Current (EICC) carrying low-salinity water out of the BoB and an adjacent, broad northward flow (∼300 km wide) that carries high-salinity water into BoB during the northeast monsoon. Atmospheric boundary layer (ABL) observations during the decaying phase of the Madden–Julian oscillation (MJO) permit the study of multiscale atmospheric processes associated with non-MJO phenomena and their impacts on the marine boundary layer. Underway analyses that integrate observations and numerical simulations shed light on how air–sea interactions control the ABL and upper-ocean processes.

show abstract

Section: Modeling Program Continuedmentioning

confidence: 99%

ASIRI: An Ocean–Atmosphere Initiative for Bay of Bengal

Wijesekera

Shroyer

Tandon

et al. 2016

Bulletin of the American Meteorological Society

View full text Add to dashboard Cite

show abstract

“…However, significant energy can also be seen at subtidal (> 0.5cph) frequencies, although it falls in this band by 1 to 2 orders as compared to the energy at 0.08 cph, indicating the importance of high-frequency (subtidal) IW. Antony et al (1985) and Shenoi and Antony (1991) also observe similar energy peaks at 0"5 to 1-0cph in the coastal waters of Machilipatnam and Karwar respectively. At the sites T1 and T2 the IW spectra do not show any clear tendency of energy decay with depth.…”

Section: 3bmentioning

confidence: 58%

“…The data collected during the MONEX program by Russian research vessels and subsequent field programmes by Indian scientists have created an important base for carrying out studies related to different aspects of the IW. Accordingly, several investigations (Varkey 1980;Antony et al 1985;Sanil Kumar et al 1989;Rao et al 1991;Shenoi and Antony 1991) made attempts to understand the general characteristics and harmonic composition of IW.…”

Section: Introductionmentioning

confidence: 99%

Internal wave characteristics in the eastern Arabian Sea during summer monsoon

Murthy

Sharma²,

James

et al. 1992

J Earth Syst Sci

View full text Add to dashboard Cite

The time series BT profiles and surface winds and atmospheric pressure, collected in the deep waters off Ratnagiri and Karwar during summer monsoon were utilized to document the characteristics of internal waves (IW). Low-frequency (~< 2 cycle per day (cpd)) IW off Ratnagiri are found to propagate at 83 cm/s with wavelengths of 45 km and wave heights upto 40 m. These parameters for high-frequency (> 2 cpd) IW off Karwar correspond to 99cm/s, 3km and 23m. The IW off Karwar appear to leave the station at 70 ~ (+ 10 ~ (measured from the horizontal). The data sets were further analysed to address the harmonic composition of the IW and identify the possible sources for the observed IW fields. Power spectra of the IW indicated energy peaks at inertial (0.6 cpd) and tidal (1 and 2 cpd) frequencies off Ratnagiri and in the high-frequency band of 0.5-2'0 cycles per hour off Karwar. The coherence between the IW and wind/tide is found to be good at several frequencies within the IW spectrum. This feature probably suggests tides as a source for the IW of tidal frequencies and winds and tides as a joint source for the IW at the remaining frequencies.

show abstract

“…Accordingly, unusual temperature variations at subsurface depths were noticed (Antony et al 1985) while making continuous observations on temperature, salinity and currents at a point in the vicinity of river Krishna. However, during winter time, the incursion of low saline waters through EICC from the north dominates any remnants of freshwater discharge of the monsoon time.…”

Section: The Wearing Of Thermal Inversions Along the East Coastmentioning

confidence: 97%

Impact of stratification on internal waves and differential wearing of thermal inversions on the east coast of India

et al. 2010

View full text Add to dashboard Cite

The surface layers of the Bay of Bengal along the east coast of India exhibit intricate stratification owing to the differential distribution of freshwaters. The winter (January-February) cooling of the salinity-induced stable layers results in the development of thermal inversions that deteriorate toward the end of the season. The study focuses on the behavior of the thermal inversions in the light of the variable stratification and the monsoon imposed reversing coastal current. To address the associated processes, a threedimensional Princeton Ocean Model is applied for the east coast of India, and numerical experiments carried out to study the means by which the thermal inversions tend to perish with the passage of winter. The model domain with variable curvilinear grid uses input fields that comprise realistic bathymetry and initial temperature/salinity conforming to winter/specified stratification. The surface forcing comprises wind stress and diurnal pattern air-sea heat fluxes. The body forcing is derived from the periodic tidal elevations at the open boundaries. It has been found that the thermal inversions tend to sustain as the equator-ward flowing East India Coastal Current (EICC) traps the cool low saline waters between Paradip and Kakinada. The current off Paradip is weak and variable and is not a part of EICC. Consequently, in the absence of replenishment of cool and freshsurface waters, the temperature/salinity gradients get eroded steadily. No thermal inversions are noticed south of Kakinada because of relatively weak current with diminished vertical salinity gradient. As the nature of stratification encountered in the bay is highly variable due to diverse reasons, the behavior of internal waves under different stratification scenarios is also addressed. Numerical experiments indicate that the energy/amplitude of the internal waves are comparable in the surface layers for any stratification, where as it is certain orders exalted in the deeper waters of the strong stratification scenario. Further, it is found that the energies and pattern of the temperature oscillations conform to the nature of mixed tide at the corresponding latitude. The underneath stratification is found to be more responsible for the generation of internal waves compared to the local stratification. This implies that the body forcing emanating from below is the cardinal contributor for the generation of internal waves. The numerical experiment with a flat and uniform bottom showing weak manifestation of internal waves endorses the same. This connotes that the continental slopes are an effective generator of the internal waves and the energy flux conversion of the barotropic tide to internal waves seems to be heavily dependent on the shoaling bottom.

show abstract

Sub-surface temperature oscillations and associated flow in the western Bay of Bengal

Cited by 9 publications

References 3 publications

ASIRI: An Ocean–Atmosphere Initiative for Bay of Bengal

ASIRI: An Ocean–Atmosphere Initiative for Bay of Bengal

Internal wave characteristics in the eastern Arabian Sea during summer monsoon

Impact of stratification on internal waves and differential wearing of thermal inversions on the east coast of India

Contact Info

Product

Resources

About