Wind-driven upwelling and surface chlorophyll blooms in Greater Cook Strait |
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Authors: | Stephen M Chiswell John R Zeldis Mark G Hadfield Matthew H Pinkerton |
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Institution: | 1. National Institute of Water and Atmospheric Research, Wellington, New Zealands.chiswell@niwa.cri.nz;3. National Institute of Water and Atmospheric Research, Wellington, New Zealand |
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Abstract: | We present the results of a combined observational and numerical study to investigate cool plumes of nutrient-rich upwelled water that emanate near the Kahurangi Shoals and extend into Greater Cook Strait. Surface temperature and chlorophyll are mapped using satellite observations to produce surface climatologies, to validate a numerical simulation and to show the utility of using spatial temperature differences as a measure of upwelling. We find upwelling near the Kahurangi Shoals is strongly wind-driven in the weather band. Upwelling occurs at all times of the year, but its surface signature is only visible in summer months. The upwelled nutrient-rich water supports increased primary production compared to surrounding waters, particularly in summer when the water column is more stratified and surrounding surface waters are presumably nutrient depleted. |
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Keywords: | Upwelling primary production New Zealand satellite observations numerical simulation |
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