The surface wind field during winter smog nights in Christchurch and coastal Canterbury, New Zealand

• DOI: 10.1002/joc.981
• Publication Date: 2004-01-22T08:02:35Z
• Authors: Meinolf Kossmann; Andrew Sturman
• Keywords: Peninsula; Prevailing winds; Sea breeze; Anticyclone; Global wind patterns

Abstract In Christchurch and other Canterbury towns on the east coast of New Zealand's South Island, poor dispersion conditions high emissions particulate matter carbon monoxide regularly lead to build‐up smog during anticyclonic weather in wintertime. This study analyses surface wind fields nights using data collected Air Pollution Study 2000 (CAPS2000). Westerly land breezes drainage winds from foothills Southern Alps Plains are evident all coastal towns, but local terrain features often complicate fields. holds particularly for Christchurch, where Banks Peninsula causes flow splitting both any superimposed larger scale winds. Furthermore, stagnation airflow over is caused by convergence localized southeasterly down western part (Port Hills) with regional‐scale northwesterly Plains. Results illustrate interaction cold air although unusually frequency synoptic‐scale easterly period appeared reduce effects these sources pollution concentrations. The topographically induced non‐stationary urban identified here have not previously been studied detail internationally should receive greater attention future. Copyright © 2004 Royal Meteorological Society