Mesoscale and local climates in New Zealand

Abstract

New Zealand is a country of marked local and regional environmental variability. The complexity of the terrain and significant relief of this island nation surrounded by extensive areas of ocean produce rapid changes of climate over relatively short distances. This article provides a selective review of recent research into the mesoscale and local climates of this interestingly varied environment. Research completed on energy budgets of the varying surface types provides the starting point for an assessment of thermal effects on the atmospheric boundary layer and airflow. The dynamic effects of surface topography are also seen to have a major impact on regional and local airflow patterns, as well as on mesoscale variations of convection and precipitation. It is clear that the interaction of mid-latitude synoptic weather systems with the mountains of New Zealand produces distinct patterns of wind and rainfall that have a major impact on the physical and human environment of the country. The föhn nor'wester and southerly changes are significant local meteorological phenomena, while mesoscale climate processes are increasingly recognized as important for agricultural activities, the management of hydrological systems and in dealing with environmental problems such as air pollution.