Statistical Analysis of Coastal Currents from HF Radar Along the North-Western Bay of Bengal
Highly accurate ocean current measurements are very much important in the field of ocean engineering. Over the past decades, the High-Frequency (HF) Radars are known to be one of the important marine instruments for oceanographic studies. The present work focuses mainly on statistical analysis of HF radar-measured ocean surface current along the Odisha coast, north-western Bay of Bengal during 2015. The observations indicate that northward propagating Western Boundary Current (WBC) and southward propagating East India Coastal Current (EICC) can reach up to 1.8 m/s and 1.0 m/s, respectively. The zonal (meridional) components vary in the range −0.8 to 0.8 (−0.6 to 0.7) m/s along with standard deviation of 0.25 m/s for both the components with 99% significance level. The boxplot analysis shows the extreme values of both the zonal and meridional currents along with the negative medians; however, certain outliers are observed only for zonal currents. The 25th percentile is less than −0.20 m/s for the meridional currents, whereas opposite result for zonal currents. The zonal and meridional currents follow normal distribution, whereas the current magnitude and kinetic energy follow Weibull distribution. The Weibull shape parameter (β) varies for both the parameters: current magnitude (β > 1) and kinetic energy (0 < β < 1) due to the variations in moments, which indicates that in case of kinetic energy (current magnitude), the failure rate decreases (increases) over time. This circulation variability can be attributed predominantly to the winds and the coastal dynamics.
KeywordsBay of Bengal HF radar Ocean currents Statistics and tides
We acknowledge the financial support given by the ESSO-INCOIS, Ministry of Earth Sciences (MoES), and Science and Engineering Research Board (SERB) of Department of Science and Technology (DST), Government of India. Also, we sincerely thank Coastal and Environmental Engineering Group, NIOT, Chennai for constant monitoring of the HF Radars and making the data availability efficient. We also acknowledge IITBBS for providing the research facility.
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