Time series analysis of data measured in the nearshore area

[摘要] ENGLISH ABSTRACT : Factors that lead to the generation of currents in the nearshore area within theNatal Bight were investigated. The investigation was carried out on data thatspans from the 6th June 2012 to the 16th January 2013. The data comprisedcurrent measurements, wave measurements, water level measurements, as wellas wind measurements. The measurements were decomposed into different directioncomponents in order to study their impacts on corresponding currentmeasurements. Current measurements were resolved into tidal currents andnon-tidal currents through the use of harmonic analysis. Stokes drift was estimatedusing a monochromatic spectrum to obtain the wave induced current.The effect of the wind on the currents was analysed through the use of windroses and duration analysis. The study was completed with an explorationof the contribution of the Agulhas current. It was found that the waters arecharacterized by a semi-diurnal, micro-tidal system and tides have a limitedcontribution to the generation of currents. The contribution of Stokes driftto the overall currents is less than that of tides. Wind is the most significantgenerator of the nearshore currents.

[发布机构] Stellenbosch University