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Using synoptic type analysis to understand New Zealand climate during the Mid-Holocene
Citation
Ackerly, D and Lorrey, A and Renwick, JA and Phipps, SJ and Wagner, S and Dean, S and Singarayer, J and Valdes, P and Abe-Ouchi, A and Ohgaito, R and Jones, JM, Using synoptic type analysis to understand New Zealand climate during the Mid-Holocene, Climate of the Past, 7 pp. 1189-1207. ISSN 1814-9324 (2011) [Refereed Article]
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Copyright Statement
Copyright 2011 The Authors Licensed under Creative Commons Attribution 3.0 Unported http://creativecommons.org/licenses/by/3.0/legalcode
DOI: doi:10.5194/cp-7-1189-2011
Abstract
Diagnosing the climate of New Zealand from
low-resolution General Circulation Models (GCMs) is notoriously
difficult due to the interaction of the complex topography
and the Southern Hemisphere (SH) mid-latitude
westerly winds. Therefore, methods of downscaling synoptic
scale model data for New Zealand are useful to help
understand past climate. New Zealand also has a wealth
of palaeoclimate-proxy data to which the downscaled model
output can be compared, and to provide a qualitative method
of assessing the capability of GCMs to represent, in this case,
the climate 6000 yr ago in the Mid-Holocene.
In this paper, a synoptic weather and climate regime classification
system using Empirical Orthogonal Function (EOF)
analysis of GCM and reanalysis data was used. The climate
regimes are associated with surface air temperature and precipitation
anomalies over New Zealand. From the analysis in
this study, we find at 6000 BP that increased trough activity
in summer and autumn led to increased precipitation, with
an increased north-south pressure gradient ("zonal events")
in winter and spring leading to drier conditions. Opposing
effects of increased (decreased) temperature are also seen in spring (autumn) in the South Island, which are associated
with the increased zonal (trough) events; however, the circulation
induced changes in temperature are likely to have been
of secondary importance to the insolation induced changes.
Evidence from the palaeoclimate-proxy data suggests that
the Mid-Holocene was characterized by increased westerly
wind events in New Zealand, which agrees with the preference
for trough and zonal regimes in the models.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | New Zealand, palaeoclimate |
| Research Division: | Earth Sciences |
| Research Group: | Physical Geography and Environmental Geoscience |
| Research Field: | Palaeoclimatology |
| Objective Division: | Environment |
| Objective Group: | Climate and Climate Change |
| Objective Field: | Effects of Climate Change and Variability on New Zealand (excl. Social Impacts) |
| UTAS Author: | Phipps, SJ (Dr Steven Phipps) |
| ID Code: | 104711 |
| Year Published: | 2011 |
| Web of Science® Times Cited: | 13 |
| Deposited By: | IMAS Research and Education Centre |
| Deposited On: | 2015-11-18 |
| Last Modified: | 2017-10-30 |
| Downloads: | 95 View Download Statistics |
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