Climatology of Borneo Vortices in the HadGEM3-GC3.1 General Circulation Model
Climatology of Borneo Vortices in the HadGEM3-GC3.1 General Circulation Model
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DOI：
10.1175/jcli-d-20-0604.1
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发表时间：
2021-01
影响因子：
4.9
通讯作者：
Junyi Liang;J. Catto;M. Hawcroft;K. Hodges;M. Tan;J. Haywood
中科院分区：
文献类型：
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作者：
Junyi Liang;J. Catto;M. Hawcroft;K. Hodges;M. Tan;J. Haywood
婆罗洲涡是一种冬季强降水风暴，它与深对流和强降水密切相关，在赤道南海上空发展，对西太平洋大陆的天气和气候产生强烈影响。在这项研究中，哈德利中心全球环境模型3-全球耦合，版本3.1（HadGEM 3-GC3.1），全球气候模型模拟气候学的BV在不同的水平分辨率的能力进行了检查，使用客观的功能跟踪算法。水平分辨率为N512（25 km）的HadGEM 3-GC 3.1模拟的BV具有良好的代表性特征，包括其频率、空间分布和对流层下部结构，与气候再分析中识别的BV相比，而N96（~135 km）和N216（~65 km）模拟的BV要弱得多，频率也低得多。此外，N512模拟更好地捕捉到的贡献，在婆罗洲和马来半岛的冬季降水与降水从再分析数据和观测相比，而N96和N216模拟低估了这一贡献，因为太弱的低层收敛的模拟BV。N512模拟还表现出更好的能力，再现调制BV活动的东北冷涌和活跃阶段的Madden-Julian振荡在该地区的发生，包括增加BV轨道密度，强度和寿命。因此，一个足够高的模式分辨率被认为是重要的现实模拟与BV的当前气候降水极端和研究他们可能的变化，在温暖的气候。
Borneo vortices (BVs) are intense precipitating winter storms that develop over the equatorial South China Sea and strongly affect the weather and climate over the western Maritime Continent because of their association with deep convection and heavy rainfall. In this study, the ability of the Hadley Centre Global Environment Model 3–Global Coupled, version 3.1 (HadGEM3-GC3.1), global climate model to simulate the climatology of BVs at different horizontal resolutions is examined using an objective feature-tracking algorithm. The HadGEM3-GC3.1 at the N512 (25 km) horizontal resolution simulates BVs with well-represented characteristics, including their frequency, spatial distribution, and lower-tropospheric structures when compared with BVs identified in a climate reanalysis, whereas the BVs in the N96 (~135 km) and N216 (~65 km) simulations are much weaker and less frequent. Also, the N512 simulation better captures the contribution of BVs to the winter precipitation in Borneo and the Malay Peninsula when compared with precipitation from a reanalysis data and from observations, whereas the N96 and N216 simulations underestimate this contribution because of the overly weak low-level convergence of the simulated BVs. The N512 simulation also exhibits an improved ability to reproduce the modulation of BV activity by the occurrence of northeasterly cold surges and active phases of the Madden–Julian oscillation in the region, including increased BV track densities, intensities, and lifetimes. A sufficiently high model resolution is thus found to be important to realistically simulate the present-climate precipitation extremes associated with BVs and to study their possible changes in a warmer climate.