Articles | Volume 31, issue 10
https://doi.org/10.5194/angeo-31-1817-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
https://doi.org/10.5194/angeo-31-1817-2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Directionality and spread of shallow water waves along the eastern Arabian Sea
V. Sanil Kumar
Ocean Engineering, CSIR-National Institute of Oceanography (Council of Scientific & Industrial Research), Dona Paula, Goa, 403 004, India
T. R. Anoop
Ocean Engineering, CSIR-National Institute of Oceanography (Council of Scientific & Industrial Research), Dona Paula, Goa, 403 004, India
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Surface wind-waves properties during Indian summer monsoon is investigated based on measured data at 9-15 m water depth at 4 sites in nearshore waters of the eastern Arabian Sea. Significant wave height varied from 0.7 to 5.5 m with average ratio of crest height of wave to height of the same wave as 0.58 to 0.67. Extreme crest height is 1.23 to 1.35 times significant wave height. Measured waves were predominantly swell. Numerical wave model could estimate the wave height well during wave growth.
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Inter-annual variations in wave spectrum are examined at 9m water depth from 2009 to 2012 based on measured data. Variations in the wave spectrum are observed inter-annually from January to February, May and October to November due to the changes in wind sea. Average wave spectrum during the monsoon is single peaked; during non-monsoon period, two peaks are observed. Due to sea breeze an increase in spectral energy of the wind-sea part is observed between 15 and 18 UTC from February to April.
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Ocean Sci. Discuss., https://doi.org/10.5194/os-2017-84, https://doi.org/10.5194/os-2017-84, 2017
Revised manuscript has not been submitted
Short summary
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Surface wind-waves properties during Indian summer monsoon is investigated based on measured data at 9-15 m water depth at 4 sites in nearshore waters of the eastern Arabian Sea. Significant wave height varied from 0.7 to 5.5 m with average ratio of crest height of wave to height of the same wave as 0.58 to 0.67. Extreme crest height is 1.23 to 1.35 times significant wave height. Measured waves were predominantly swell. Numerical wave model could estimate the wave height well during wave growth.
T. Muhammed Naseef and V. Sanil Kumar
Nat. Hazards Earth Syst. Sci., 17, 1763–1778, https://doi.org/10.5194/nhess-17-1763-2017, https://doi.org/10.5194/nhess-17-1763-2017, 2017
Short summary
Short summary
Assessment of design waves is performed using generalized extreme value (GEV) and generalized Pareto distribution (GPD) based on buoy data for 8 years and ERA-Interim reanalysis data for 38 years. The initial distribution method underestimates return levels compared to GPD. Intercomparison of return levels by block maxima and r-largest method for GEV theory shows that return level for 100 years is 7.24 m by r-largest series. A single storm can cause a large difference in the 100-year Hs value.
M. M. Amrutha and V. Sanil Kumar
Ocean Sci., 13, 703–717, https://doi.org/10.5194/os-13-703-2017, https://doi.org/10.5194/os-13-703-2017, 2017
Short summary
Short summary
Waves measured at 12 m in the near-shore waters of the Gulf of Mannar for a 1-year period are used to examine the predominance of wind seas and swells through spectral characterization. The waves of the study region are under the control of sea breeze, with the maximum in the late evening and the minimum in the early morning. A total of 53 % of the surface height variance in the study area results from swells from the southeast and south; the remainder are wind seas from the east and southeast.
M. Anjali Nair and V. Sanil Kumar
Ocean Sci., 13, 365–378, https://doi.org/10.5194/os-13-365-2017, https://doi.org/10.5194/os-13-365-2017, 2017
Short summary
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The information on wave spectral shapes that is required for designing marine structures is presented based on wave data collected from January 2011 to December 2015 in the coastal waters of the eastern Arabian Sea. The variations in the high-frequency tail of the wave spectrum in different months are presented. The slope of the high-frequency tail of the monthly average wave spectra is high during the Indian summer monsoon period (June–September) compared to other months.
M. M. Amrutha and V. Sanil Kumar
Ann. Geophys., 34, 1197–1208, https://doi.org/10.5194/angeo-34-1197-2016, https://doi.org/10.5194/angeo-34-1197-2016, 2016
Short summary
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This study examines variation in wave power off the central west coast of India at water depths 30, 9 and 5 m based on buoy measured data. The study shows a significant reduction (~ 10–27 %) in wave power at 9 m depth compared to 30 m and the power at 5 m depth is 20–23 % less than that at 9 m. At 9 m water depth, the mean annual wave power is 6 kW m−1 and interannual variations up to 19.3 % are observed during 2009–2014; 75 % of the total annual wave energy is from this narrow directional sector.
V. Sanil Kumar and Jesbin George
Ann. Geophys., 34, 871–885, https://doi.org/10.5194/angeo-34-871-2016, https://doi.org/10.5194/angeo-34-871-2016, 2016
Short summary
Short summary
Influence of monsoon variability on the surface waves using measured data covering 7 years and reanalysis data from 1979 to 2015 during the Indian summer monsoon in the eastern Arabian Sea is examined. A high positive correlation (r ~ 0.84) between average low-level jet for the block 0–15° N, 50–75° E and wave height of eastern Arabian Sea is observed in all months except August. The monsoon seasonal average wave height is found to be relatively low during the strong El Niño years.
T. R. Anoop, V. Sanil Kumar, P. R. Shanas, J. Glejin, and M. M. Amrutha
Ocean Sci., 12, 369–378, https://doi.org/10.5194/os-12-369-2016, https://doi.org/10.5194/os-12-369-2016, 2016
Short summary
Short summary
Using measured, modeled and reanalysis wave data and reanalysis wind data, we show that the Indian Ocean Dipole (IOD) plays a role in the variability of wave climate of the eastern Arabian Sea (AS). The change in wind field over the AS due to IOD influences the generation or dissipation of wave field and hence causes the decrease in northwest short period waves during positive IOD and increase during negative IOD.
M. M. Amrutha, V. Sanil Kumar, and J. Singh
Ann. Geophys., 34, 215–226, https://doi.org/10.5194/angeo-34-215-2016, https://doi.org/10.5194/angeo-34-215-2016, 2016
Short summary
Short summary
The nearshore wave characteristics are presented during the active sea/land breeze period based on data measured at 5 m and 15 m water depth in the eastern Arabian Sea. Prior to the sea breeze, the wave field is dominated by swell and during the sea breeze, wind-sea dominates with superimposed swell. Reduction in the wave height of wind-sea is around 20 % and that of the swell is around 10 % from 15 m to 5 m water depth.
V. Sanil Kumar and M. Anjali Nair
Ann. Geophys., 33, 159–167, https://doi.org/10.5194/angeo-33-159-2015, https://doi.org/10.5194/angeo-33-159-2015, 2015
Short summary
Short summary
Inter-annual variations in wave spectrum are examined at 9m water depth from 2009 to 2012 based on measured data. Variations in the wave spectrum are observed inter-annually from January to February, May and October to November due to the changes in wind sea. Average wave spectrum during the monsoon is single peaked; during non-monsoon period, two peaks are observed. Due to sea breeze an increase in spectral energy of the wind-sea part is observed between 15 and 18 UTC from February to April.
M. M. Amrutha, V. Sanil Kumar, T. R. Anoop, T. M. Balakrishnan Nair, A. Nherakkol, and C. Jeyakumar
Ann. Geophys., 32, 1073–1083, https://doi.org/10.5194/angeo-32-1073-2014, https://doi.org/10.5194/angeo-32-1073-2014, 2014
P. R. Shanas and V. Sanil Kumar
Nat. Hazards Earth Syst. Sci., 14, 1371–1381, https://doi.org/10.5194/nhess-14-1371-2014, https://doi.org/10.5194/nhess-14-1371-2014, 2014
J. Glejin, V. Sanil Kumar, T. M. Balakrishnan Nair, and J. Singh
Ocean Sci., 9, 343–353, https://doi.org/10.5194/os-9-343-2013, https://doi.org/10.5194/os-9-343-2013, 2013