Synoptic and sub-synoptic circulation effects on wind resource variability – A case study from a coastal terrain setting in New Zealand

Abstract

This paper investigates linkages between synoptic and sub-synoptic scale atmospheric circulation and temporal wind resource variability, adopting a synoptic weather typing approach. These linkages were examined in a complex terrain, coastal setting in southern New Zealand. Over a 28 month period, approximately 71% of the intermonthly variability in power density was explained by the monthly frequency of a subset of weather types. Within this subset, weather types associated with strong south-west or west orientated pressure gradients were related to enhanced power density, whereas weather types associated with stagnant pressure gradients were related to reduced power density. At the sub-synoptic scale, the effect of the sea breeze on the wind resource was found to be of importance but dependent on both the season and the ambient larger scale atmospheric circulation. Aspects of the sea breeze circulation also appear to be complicated by additional thermal and dynamical influences associated with the larger scale terrain complexity. Similar wind regimes likely occur elsewhere and should be examined specifically in the context of the wind resource.