Changes in Tropical Cyclone Activity due to Global Warming: Results from a High-Resolution Coupled General Circulation Model
Changes in Tropical Cyclone Activity due to Global Warming: Results from a High-Resolution Coupled General Circulation Model
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DOI：
10.1175/2008jcli1921.1
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发表时间：
2008-10-01
影响因子：
4.9
通讯作者：
Navarra, A.
中科院分区：
文献类型：
--
作者：
Gualdi, S.;Scoccimarro, E.;Navarra, A.
热带气旋（TC）的特征。该分析是使用完全耦合的高分辨率全球大气环流模型进行的情景气候模拟进行的。模式的能力，以再现一个合理的现实TC气候学进行了评估，通过比较模式的结果，从模拟的20世纪的观测。该模型似乎能够模拟热带气旋样涡与许多功能相似的观察TC。模拟的TC活动具有现实的地理分布，季节调制和年际变化，这表明该模式是能够再现的主要基本机制，连接TC的发生与大尺度环流。气候情景的结果表明，当大气中CO2浓度增加一倍和四倍时，TC频率普遍大幅降低。这种减少在热带西北太平洋和北大西洋尤为明显。在数值预报中，较弱的TC活动似乎与对流不稳定性的减少有关。在ATL区域，较弱的TC活动似乎是由于大气稳定性的增加和更强的垂直风切变。尽管TC活动普遍减少，但有证据表明与模拟气旋相关的降雨量增加。最后，TC的活动仍然很好地局限于热带地区，TC数量的峰值仍然在两个半球的赤道20度纬度，尽管热带上层海洋的整体变暖和暖SST向极地扩展。
characteristics of tropical cyclones (TCs). The analysis has been performed using scenario climate simulations carried out with a fully coupled high-resolution global general circulation model. The capability of the model to reproduce a reasonably realistic TC climatology has been assessed by comparing the model results from a simulation of the twentieth century with observations. The model appears to be able to simulate tropical cyclone-like vortices with many features similar to the observed TCs. The simulated TC activity exhibits realistic geographical distribution, seasonal modulation, and interannual variability, suggesting that the model is able to reproduce the major basic mechanisms that link TC occurrence with large-scale circulation. The results from the climate scenarios reveal a substantial general reduction of TC frequency when the atmospheric CO2 concentration is doubled and quadrupled. The reduction appears particularly evident for the tropical western North Pacific (WNP) and North Atlantic (ATL). In the NWP the weaker TC activity seems to be associated with reduced convective instabilities. In the ATL region the weaker TC activity seems to be due to both the increased stability of the atmosphere and a stronger vertical wind shear. Despite the generally reduced TC activity, there is evidence of increased rainfall associated with the simulated cyclones. Finally, the action of the TCs remains well confined to the tropical region and the peak of TC number remains equatorward of 20 degrees latitude in both hemispheres, notwithstanding the overall warming of the tropical upper ocean and the expansion poleward of warm SSTs.