The overall goal of this study is to identify the teleconnection mechanisms that underlie ENSO-Antarctic climate links. Initially time series plots and cross correlation analysis of Antarctic surface and upper air climate data are used to search for high latitude atmospheric signals during Pacific Ocean warm (ENSO) and cold (La Nina) events. Consistent increases (decreases) in pressure were found during warm (cold) events, with a variable response in temperature. Upper air data demonstrate consistent changes in windspeed, cloud cover geopotential height" wind speeds and direction, temperature and relative humidity during ENSO events. Spatial anomaly plots, Hovmoller, harmonic and cluster analyses are used to identify ENSO related climate anomaly wavetrains, teleconnections and propagation mechanisms that link Southern Hemisphere low and high latitudes. Although inter-warm and cold event variability is a characteristic, strong meridional anomaly contrasts, equatorward and poleward anomaly propagation, and distinct jetstream behaviour were apparent in all events studied. In warm (cold) events subtropical jet strength increases (decreases) and polar jet strength decreases (increases) resulting in a decrease (increase) in poleward moving cyclonicity. The jetstreams are considered to play a major role in ENSO related climate anomaly propagations.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:417865 |
| Date | January 1999 |
| Creators | Houseago, Richenda Elouise |
| Publisher | University of Birmingham |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://etheses.bham.ac.uk//id/eprint/5254/ |
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