caa a22 4500 469052694 CHVBK 20180323132834.0 cr unu---uuuuu 170328e19920601xx s 000 0 eng 10.1007/BF01025619 doi (NATIONALLICENCE)springer-10.1007/BF01025619 Sturman A. Department of Geography, University of Canterbury, 1, Christchurch, New Zealand aut Dynamic and thermal effects on surface airflow associated with southerly changes over the South Island, New Zealand [Elektronische Daten] [A. Sturman] Summary: The Southerly Change Experiment (SOUCHEX) was conducted to examine the influence of the New Zealand Southern Alps on the structure and evolution of cold fronts, locally called southerly changes, as they travel up the east coast. The extensive data obtained by the augmented surface weather station network is used to examine in detail the mesoscale wind field associated with the events observed during the experiment. A comparison of the wind fields observed during the different events illustrates the influence of local dynamic and thermal factors. In particular, lee trough-induced northeasterlies and thermally developed diurnal wind systems are seen to interact with the wind field created by the passage of the front over the Southern Alps. It is apparent that the wind field associated with southerly changes responds to a variety of factors as the cold fronts propagate northwards. For example, there is a tendency for the flow to turn onshore producing a southeast wind during daytime over the Canterbury Plains south of Banks Peninsula probably due to diabatic heating of the mountains and plains. This onshore flow is in direct opposition to pre-frontal foehn northwesterly flow which often continues in the mountain regions and aloft after the front has moved up the coast. The interaction of these air masses over Canterbury creates difficulties for local forecasting. Also, the nocturnal passage of a southerly change is often difficult to detect in surface anemograph traces because of the decoupling of the boundary layer air from that above, producing low level drainage flow over the Canterbury Plains. The overall effect is to create a complex mesoscale wind field resulting from interaction of cold fronts with regional orographic and thermal influences. Springer-Verlag, 1992 Meteorology and Atmospheric Physics Springer-Verlag 47/2-4(1992-06-01), 229-236 0177-7971 47:2-4<229 1992 47 703 https://doi.org/10.1007/BF01025619 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01025619 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Sturman A. Department of Geography, University of Canterbury, 1, Christchurch, New Zealand aut NATIONALLICENCE 773 0- Meteorology and Atmospheric Physics Springer-Verlag 47/2-4(1992-06-01), 229-236 0177-7971 47:2-4<229 1992 47 703 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer