Thermodynamic Response of a High-Resolution Tropical Indian Ocean Model to TOGA COARE Bulk Air–Sea Flux Parameterization: Case Study for the Bay of Bengal (BoB)

2020 ◽  
Vol 177 (8) ◽  
pp. 4025-4044 ◽  
Author(s):  
Subrat Kumar Mallick ◽  
Neeraj Agarwal ◽  
Rashmi Sharma ◽  
K. V. S. R. Prasad ◽  
S. S. V. S. Ramakrishna
Keyword(s):  
High Resolution ◽  
Indian Ocean ◽  
Bay Of Bengal ◽  
Tropical Indian Ocean ◽  
Ocean Model ◽  
Toga Coare ◽  
Flux Parameterization

scholarly journals SENSITIVITY OF UPPER OCEAN DYNAMICS IN HIGH-RESOLUTION TROPICAL INDIAN OCEAN MODEL TO DIFFERENT FLUX PARAMETERIZATION: CASE STUDY FOR THE BAY OF BENGAL (BOB)

2018 ◽  
Vol XLII-5 ◽  
pp. 839-847 ◽  
Author(s):  
S. K. Mallick ◽  
N. Agarwal ◽  
R. Sharma ◽  
K. V. S. R. Prasad
Keyword(s):  
High Resolution ◽  
Indian Ocean ◽  
Bay Of Bengal ◽  
Tropical Indian Ocean ◽  
Ocean Dynamics ◽  
Sea Surface ◽  
Upper Ocean ◽  
Wind Component ◽  
Strong Wind ◽  
Flux Parameterization

<p><strong>Abstract.</strong> Simulation experiments using a high-resolution ocean general circulation model (OGCM) of the tropical Indian Ocean (TIO) were carried out to assess the model’s sensitivity to different flux parameterization. The flux formulation proposed by Kara et al. (2000) is used in the control run (CR). One more experiment differing in the bulk fluxes formulation for the computation of momentum, freshwater and heat is carried out. In the first experiment (CR), actual wind is used for the computation of the exchange coefficient in air-sea bulk flux formulation. In the second experiment (E1), model surface current is used in the wind stress formulation to compute the turbulent air-sea fluxes for TIO region. The formulation used in E1 is the same as it is used in CR, instead of actual wind, relative wind component is used in flux formulas. Both experiments are carried out for the period 2014&amp;ndash;2016. The OGCM is forced using the daily fields of winds, radiation and freshwater fluxes obtained from ERA-Interim Reanalysis. In this study, we examine and quantify the performance of the above-mentioned experiments with respect to observations from ARGO, satellite-based sea surface temperature (SST) and sea surface salinity (SSS) for the year 2015. We observe that the upper ocean dynamics is significantly modulated by different flux algorithms. The errors in simulated SST is reduced by &amp;sim;8% to 10% in E1 compared to CR, respectively. The temperature errors in the top 20<span class="thinspace"></span>m depth are reduced by 8% in E1. It is found that this flux formulation using relative winds is effective in accurately simulating the upper ocean dynamics in strong wind regimes of the Bay of Bengal.</p>

scholarly journals Wind-Driven Response of the Northern Indian Ocean to Climate Extremes*

2007 ◽  
Vol 20 (13) ◽  
pp. 2978-2993 ◽  
Author(s):  
Tommy G. Jensen
Keyword(s):  
Indian Ocean ◽  
Ocean Circulation ◽  
Bay Of Bengal ◽  
El Niño ◽  
Arabian Sea ◽  
El Nino ◽  
Ocean Model ◽  
La Niña ◽  
Northern Indian Ocean ◽  
La Nina

Abstract Composites of Florida State University winds (1970–99) for four different climate scenarios are used to force an Indian Ocean model. In addition to the mean climatology, the cases include La Niña, El Niño, and the Indian Ocean dipole (IOD). The differences in upper-ocean water mass exchanges between the Arabian Sea and the Bay of Bengal are investigated and show that, during El Niño and IOD years, the average clockwise Indian Ocean circulation is intensified, while it is weakened during La Niña years. As a consequence, high-salinity water export from the Arabian Sea into the Bay of Bengal is enhanced during El Niño and IOD years, while transport of low-salinity waters from the Bay of Bengal into the Arabian Sea is enhanced during La Niña years. This provides a venue for interannual salinity variations in the northern Indian Ocean.

scholarly journals ASIRI: An Ocean–Atmosphere Initiative for Bay of Bengal

2016 ◽  
Vol 97 (10) ◽  
pp. 1859-1884 ◽  
Author(s):  
Hemantha W. Wijesekera ◽  
Emily Shroyer ◽  
Amit Tandon ◽  
M. Ravichandran ◽  
Debasis Sengupta ◽  
...  
Keyword(s):  
Boundary Layer ◽  
High Resolution ◽  
Indian Ocean ◽  
Bay Of Bengal ◽  
Regional Scale ◽  
Ocean Dynamics ◽  
Coastal Current ◽  
Northeast Monsoon ◽  
Low Salinity ◽  
Salinity Water

Abstract 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.

scholarly journals The sensitivity of the Seychelles–Chagos thermocline ridge to large-scale wind anomalies

2009 ◽  
Vol 66 (7) ◽  
pp. 1455-1466 ◽  
Author(s):  
Juliet C. Hermes ◽  
Chris J. C. Reason
Keyword(s):  
Indian Ocean ◽  
Large Scale ◽  
Regional Climate ◽  
Austral Summer ◽  
Tropical Indian Ocean ◽  
Ocean Model ◽  
The South ◽  
South Indian Ocean ◽  
Southwest Indian Ocean ◽  
South Indian

Abstract Hermes, J. C., and Reason, C. J. C. 2009. The sensitivity of the Seychelles–Chagos thermocline ridge to large-scale wind anomalies. – ICES Journal of Marine Science, 66: 1455–1466. The Seychelles–Chagos thermocline ridge (SCTR) in the southwest tropical Indian Ocean is important for regional climate, the Madden–Julian Oscillation, as well as upper-ocean nutrients and related phytoplankton and zooplankton densities. Subsurface variability in this region has been proved to influence the overlying sea surface temperatures, which in turn can influence eastern African rainfall. There is evidence that austral summers with a deeper (shallower) SCTR tend to have more (less) tropical cyclone (TC) days in the Southwest Indian Ocean. The importance of this relationship was underlined during the 2006/2007 austral summer, when areas of Madagascar and central Mozambique experienced devastating floods, because of ten named tropical storms, including several intense TCs, effecting on these areas. At the same time, the SCTR during this season was anomalously deep, partly because of a downwelling Rossby wave that propagated across the South Indian Ocean during the previous austral winter/spring. In this paper, a regional ocean model is used to investigate the effect of remote forcing on this region and to study the sensitivity of the SCTR to changes in the large-scale winds over the South Indian Ocean, with a particular focus on the events of the 2006/2007 austral summer.

The impact of northern Indian Ocean rivers on the Bay of Bengal using NEMO global ocean model

2020 ◽  
Vol 39 (3) ◽  
pp. 45-55
Author(s):  
Atul Srivastava ◽  
Anitha Gera ◽  
Imran M. Momin ◽  
Ashis Kumar Mitra ◽  
Ankur Gupta
Keyword(s):  
Indian Ocean ◽  
Bay Of Bengal ◽  
Ocean Model ◽  
Global Ocean ◽  
Northern Indian Ocean ◽  
The Impact

Precipitable water over the tropical Indian Ocean derived from NIMBUS 7 satellite data ? A case study

1993 ◽  
Vol 66 (3) ◽  
pp. 325-330
Author(s):  
M. R. Ramesh Kumar ◽  
P. M. Muralidharan ◽  
P. V. Sathe
Keyword(s):  
Indian Ocean ◽  
Satellite Data ◽  
Tropical Indian Ocean ◽  
Precipitable Water
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