DOI: 10.1007/s00382-012-1368-2
Scopus记录号: 2-s2.0-84862991399
论文题名: The simulation of cutoff lows in a regional climate model: Reliability and future trends
作者: Grose M.R. ; Pook M.J. ; McIntosh P.C. ; Risbey J.S. ; Bindoff N.L.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2012
卷: 39, 期: 2017-01-02 起始页码: 445
结束页码: 459
语种: 英语
英文关键词: Atmospheric blocking
; Climate change
; Climate models
; Cutoff low
; Regional climate models
; Split jet
英文摘要: Cutoff lows are an important source of rainfall in the mid-latitudes that climate models need to simulate accurately to give confidence in climate projections for rainfall. Coarse-scale general circulation models used for climate studies show some notable biases and deficiencies in the simulation of cutoff lows in the Australian region and important aspects of the broader circulation such as atmospheric blocking and the split jet structure observed over Australia. The regional climate model conformal cubic atmospheric model or CCAM gives an improvement in some aspects of the simulation of cutoffs in the Australian region, including a reduction in the underestimate of the frequency of cutoff days by more than 15 % compared to a typical GCM. This improvement is due at least in part to substantially higher resolution. However, biases in the simulation of the broader circulation, blocking and the split jet structure are still present. In particular, a northward bias in the central latitude of cutoff lows creates a substantial underestimate of the associated rainfall over Tasmania in April to October. Also, the regional climate model produces a significant north-south distortion of the vertical profile of cutoff lows, with the largest distortion occurring in the cooler months that was not apparent in GCM simulations. The remaining biases and presence of new biases demonstrates that increased horizontal resolution is not the only requirement in the reliable simulation of cutoff lows in climate models. Notwithstanding the biases in their simulation, the regional climate model projections show some responses to climate warming that are noteworthy. The projections indicate a marked closing of the split jet in winter. This change is associated with changes to atmospheric blocking in the Tasman Sea, which decreases in June to November (by up to 7. 9 m s-1), and increases in December to May. The projections also show a reduction in the number of annual cutoff days by 67 % over the century, together with an increase in their intensity, and these changes are strongest in spring and summer. © 2012 Springer-Verlag. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/55227
Appears in Collections: 过去全球变化的重建
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作者单位: Antarctic Climate and Ecosystems Cooperative Research Centre (ACE CRC), University of Tasmania, Private Bag 80, Hobart, TAS 7000, Australia; Centre for Australian Weather and Climate Research (CAWCR), CSIRO Marine and Atmospheric Research, Castray Esplanade, Hobart, TAS 7000, Australia; Institute of Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bag 129, Hobart, TAS 7001, Australia
Recommended Citation:
Grose M.R.,Pook M.J.,McIntosh P.C.,et al. The simulation of cutoff lows in a regional climate model: Reliability and future trends[J]. Climate Dynamics,2012-01-01,39(2017-01-02)