Variability of tropical cyclones over the southwest Pacific Ocean using a high-resolution climate model
Variability of tropical cyclones over the southwest Pacific Ocean using a high-resolution climate model
复制标题
使用高分辨率气候模型研究西南太平洋热带气旋的变化
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
B. Buckley
中科院分区：
文献类型：
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作者：
L. Leslie;D. Karoly;M. Leplastrier;B. Buckley
摘要了解热带气旋 (TC) 频率和分布的变化对于确定自然或人为气候变化可能产生的影响至关重要。这种变化可以利用现有的 TC 数据库并通过对过去和未来的气候进行长期气候模型模拟来研究。耦合海洋-大气气候模型（此处称为 OU-CGCM）被描述并应用于西南太平洋地区的更高分辨率（50km）嵌套域。 OU-CGCM 的六元系综模拟已经运行了 80 年，从 1970 年到 2050 年。在 1970 年到 2000 年期间，OU-CGCM 的运行与观测到的 TC 数据库进行了比较。在2000-2050年期间，进行了两次集合模拟，一次是温室气体浓度恒定，第二次是温室气体浓度增加。OU-CGCM很好地模拟了1970-2000年期间西南太平洋观测到的TC频率和分布。它还在 2000 年至 2050 年期间的固定和增强温室气体模拟中产生了明显的年际和年代际 TC 变化。 TC频率的变异性与TC频率平静期和活跃期出现的典型大气和海温异常模式相关。2000-2050年期间增强温室气体情景的主要发现是：相对于对照运行，TC的平均年代际数量没有变化，但在最严重的WMO 4和5类中，TC的平均年代际数量显着增加了约15％；未来 50 年期间澳大利亚地区发生热带气旋的可能性比以往任何时候都更加强烈； TC 轨道向极地延伸； TC成因区向极移超过2度纬度。
SummaryKnowledge of the variability in tropical cyclone (TC) frequency and distribution is essential in determining the possible impact of natural or human-induced climate change. This variability can be investigated using the available TC data bases and by carrying out long-term climate model simulations for both past and future climates.A coupled ocean-atmosphere climate model (referred to here as the OU-CGCM) is described and applied with a higher resolution (50 km) nested domain in the southwest Pacific region. Six-member ensembles of simulations with the OU-CGCM have been run for 80 years, from 1970 to 2050. During the period 1970–2000, the OU-CGCM runs were compared with the observed TC data base. For the period 2000–2050, two ensembles of simulations were performed, one with constant greenhouse gas concentrations and the second with increasing greenhouse gases.The OU-CGCM simulated well the observed TC frequency and distribution in the southwest Pacific during the period 1970–2000. It also produced clear interannual and interdecadal TC variability in both the fixed and enhanced greenhouse gas simulations during the period 2000–2050. The variability in TC frequencies was associated with the typical atmospheric and SST anomaly patterns that occur in periods of quiet and active TC frequencies.The main findings from the enhanced greenhouse gas scenario for the period 2000–2050 are: no change in the mean decadal number of TCs relative to the control run, but a marked increase of about 15% in the mean decadal number of TCs in the most severe WMO categories 4 and 5; the likelihood of TCs during the next 50-year period that are more intense than ever previously experienced in the Australian region; a poleward extension of TC tracks; and a poleward shift of over 2 degrees of latitude in the TC genesis region.