Record Details

Co-existence of wind seas and swells along the west coast of India during non-monsoon season

DRS at CSIR-National Institute of Oceanography

View Archive Info
 
 
Field Value
 
Title Co-existence of wind seas and swells along the west coast of India during non-monsoon season
 
Creator Rashmi, R.
Aboobacker, V.M.
Vethamony, P.
John, M.P.
 
Subject swell
winds
seasonal variations
diurnal variations
 
Description An attempt has been made to understand the co-existence of wind seas and swells along the west coast of India during non-monsoon season. Wave data were collected in different years during non-monsoon season (off Goa during May 2005, off Ratnagiri during January-February 2008 and off Dwarka during December 2007-January 2008), which is fairly a calm weather season along these regions. Diurnal variation in wave parameters is noticeable along the central west coast of India (off Goa and Ratnagiri), which is due to the interaction of multidirectional waves (both wind seas and swells) of varying magnitudes and frequencies. Swells are predominantly mature (91 percent) and old (88 percent) during late pre-monsoon and post-monsoon seasons, respectively. Sea Swell Energy Ratio quantifies wind sea, swell and mixed seas prevailing in these regions during non-monsoon season. Intermodal distance (ID) between the energy peaks is moderately separated during non-monsoon season, whereas, during the shamal events, energy peaks are very close to each other (ID approx. 0). However, pure wind seas (ID approx. 1) are weakly present and found to co-exist with the swells almost all the time during non-monsoon season. Wind sea growth has been found while the swell propagates opposite to the direction of the wind and wind sea. Wind seas have minimum angular spreads in multimodal state. Under low winds, the interaction between wind sea and swell dominates and thereby the multimodal state reduces to unimodal state. The fetch available for the evolution of the wind sea spectrum has been estimated, and it is found to be less than 150 km. For the fetch limited condition, a non-dimensional empirical relation has been derived relating the significant wind sea height in terms of wind speed and peak wind sea period, and this relation fits for the west coast of India.
 
Date 2013-04-01T09:55:37Z
2013-04-01T09:55:37Z
2013
 
Type Journal Article
 
Identifier Ocean Science, vol.9; 2013; 281-292
no
http://drs.nio.org/drs/handle/2264/4271
 
Language en
 
Relation Ocean_Sci_9_281.jpg
 
Rights © Author(s) 2013. CC Attribution 3.0 License (CC BY 3.0).
 
Publisher European Geosciences Union