Studies of the meteorology and climatology of Ross Island and the Ross Ice Shelf, Antarctica
This thesis documents a series of studies performed on the lower atmosphere over the region of the Ross Ice Shelf, Antarctica, and its surroundings. In particular, much of the thesis focuses on the area in the vicinity of Ross Island, a mountainous protrusion in the far north-west of the permanent f...
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| Format: | Other/Unknown Material |
| Language: | English |
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University of Canterbury. Physics and Astronomy
2013
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| Online Access: | http://hdl.handle.net/10092/8653 https://doi.org/10.26021/6775 |
| Summary: | This thesis documents a series of studies performed on the lower atmosphere over the region of the Ross Ice Shelf, Antarctica, and its surroundings. In particular, much of the thesis focuses on the area in the vicinity of Ross Island, a mountainous protrusion in the far north-west of the permanent floating ice shelf. Weather in both the smaller and larger regions is naturally complex and generated by a range of localised and larger scale interactions. In order to better understand the meteorology of the Ross Ice Shelf, including Ross Island, we produce a synoptic climatology of the region based on surface wind output provided by the ERA Interim reanalysis. Output is taken from 1979 to 2011 and thus represents a much longer time scale than covered by previous studies of Ross Ice Shelf winds. The climatology is generated through a clustering routine based on the widely-used $k$-means technique. The results of the routine are discussed and we find that the reanalysis is capable of representing the previously reported features of the region. Cluster composites are also shown to be coherent between reanalysis output and data collected by in situ monitoring devices. We confirm that the Ross Ice Shelf Air Stream (RAS), a jet of fast-moving air that propagates from the Siple Coast across the ice shelf, is a robust feature of the climatology of the region and we find that it has a large impact on the surface temperature. The analysis is continued with reference to two widely studied modes of internal variability, the Southern Annular Mode (SAM) and El Nino-Southern Oscillation (ENSO), which are known to affect local conditions in the Ross Sea region via modulation of the Amundsen-Bellingshausen Sea low. Reanalysis output and results from the clustering routine allow us to examine the impacts of these modes upon the Ross Ice Shelf and Ross Sea in unprecedented detail. Further, we are able to tie changes in the mean pattern to variability within and between particular clusters, allowing us to ascertain the dominant ... |
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