Articles | Volume 33, issue 2
https://doi.org/10.5194/angeo-33-159-2015
https://doi.org/10.5194/angeo-33-159-2015
Regular paper
 | 
03 Feb 2015
Regular paper |  | 03 Feb 2015

Inter-annual variations in wave spectral characteristics at a location off the central west coast of India

V. Sanil Kumar and M. Anjali Nair

Abstract. The inter-annual variations in wave spectrum are examined based on the wave data measured at 9 m water depth off the central west coast of India from 2009 to 2012 using a wave rider buoy. The temporal variation of the spectral energy density over a calendar year indicates similar variation in all the four years studied. The inter-annual variations in wave spectrum are observed in all months with larger variations during January to February, May and October to November due to the changes in wind-sea. The seasonal average wave spectrum during the monsoon (June–September) is single-peaked and the swell component is high in 2011 compared to other years. The annual averaged wave spectrum had higher peak energy during 2011 due to the higher spectral energy present during the monsoon period. During the non-monsoon period, two peaks are predominantly observed in the wave spectra; with the average peak at 0.07 Hz corresponding to the swells from the Indian Ocean and another at 0.17 Hz due to the local wind field.

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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.