Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea
DRS at CSIR-National Institute of Oceanography
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Title |
Influence of Indian summer monsoon variability on the surface waves in the coastal regions of eastern Arabian Sea
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Creator |
SanilKumar, V.
Jesbin, G. |
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Subject |
Meteorology and climatology
Oceanography and limnology Oceanography and limnology |
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Description |
We assess the influence of monsoon variability on the surface waves using measured wave data covering 7 years and reanalysis data from 1979 to 2015 during the Indian summer monsoon (JJAS) in the eastern Arabian Sea. The inter-annual comparison shows that the percentage of higher wave heights (>2.5m) is higher (~26%) in 2014 than in other years due to the higher monsoon wind speed (average speed ~7.3ms-1) in 2014. Due to the delayed monsoon, monthly average significant wave height (Hm0) of June was lowest (~1.5m) in 2009. The spectral peak shifted to lower frequencies in September due to the reduction of wind seas as a result of decrease in monsoon intensity. The study shows high positive correlation (r~0.84) between average low-level jet (LLJ) for the block 0-15°N, 50-75°E and Hm0 of eastern Arabian Sea in all the months except in August (r~0.66). The time series data on wave height shows oscillations with periods 5 to 20 days. Wavelet coherence analysis indicates that the LLJ and Hm0 are in-phase related (phase angle 0°) almost all the time and LLJ leads Hm0. The monsoon seasonal anomaly of Hm0 is found to have a negative relationship with the Oceanic Nino Index indicating that the monsoon average Hm0 is relatively low during the strong El Nino years
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Date |
2016-12-02T11:49:13Z
2016-12-02T11:49:13Z 2016 |
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Type |
Journal Article
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Identifier |
Annales Geophysicae, vol.34(10); 2016; 871-885
http://drs.nio.org/drs/handle/2264/5051 |
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Language |
en
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Rights |
This is an open access article under the CC BY-NC-ND license© Author(s) 2016. CC Attribution 3.0 License (CC BY-NC-SA 3.0)
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Publisher |
Copernicus
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