caa a22 4500 605473153 CHVBK 20210128100341.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s00382-014-2169-6 doi (NATIONALLICENCE)springer-10.1007/s00382-014-2169-6 Relating changes in synoptic circulation to the surface rainfall response using self-organising maps [Elektronische Daten] [Christopher Lennard, Gabriele Hegerl] The climate of a particular region is governed by factors that may be remote, such as the El Nino Southern Oscillation or local, such as topography. However, the daily weather characteristics of a region are controlled by the synoptic-scale atmospheric state. Therefore changes in the type, frequency, duration or intensity of particular synoptic states over a region would result in changes to the local weather and long-term climatology of the region. The relationship between synoptic-scale circulation and the rainfall response is examined for a 31-year period at two stations in different rainfall regimes in South Africa. Dominant rain-bearing synoptic circulations are identified for austral winter and summer as mid-latitude cyclones and convective systems respectively whereas no circulations are dominantly associated with spring and autumn rainfall. Over the 31-year period a statistically significant increase in the frequency of characteristic summer circulation modes is observed during summer, winter and spring. During autumn a statistically significant shift towards characteristically winter circulation modes is evident. Seasonal rainfall trends computed at each station corroborate those of the circulation data. Extreme rainfall is associated with particular circulation modes and trends in both circulation and station data show an earlier occurrence of extreme rainfall during the rainy season. Springer-Verlag Berlin Heidelberg, 2014 Self-organising maps nationallicence Circulation archetypes nationallicence Rainfall response nationallicence Extreme rainfall nationallicence Downscaling nationallicence Lennard Christopher Climate System Analysis Group, Environmental and Geographical Science Department, South Lane, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa aut Hegerl Gabriele School of Geosciences, University of Edinburgh, Edinburgh, Scotland, UK aut Climate Dynamics Springer Berlin Heidelberg 44/3-4(2015-02-01), 861-879 0930-7575 44:3-4<861 2015 44 382 https://doi.org/10.1007/s00382-014-2169-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-014-2169-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Lennard Christopher Climate System Analysis Group, Environmental and Geographical Science Department, South Lane, University of Cape Town, Rondebosch, 7701, Cape Town, South Africa aut NATIONALLICENCE 700 1- Hegerl Gabriele School of Geosciences, University of Edinburgh, Edinburgh, Scotland, UK aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 44/3-4(2015-02-01), 861-879 0930-7575 44:3-4<861 2015 44 382