Heat Waves in Southern China: Synoptic Behavior, Long-Term Change, and Urbanization Effects
Heat Waves in Southern China: Synoptic Behavior, Long-Term Change, and Urbanization Effects
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DOI：
10.1175/jcli-d-16-0269.1
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发表时间：
2017-01-01
影响因子：
4.9
通讯作者：
Lau, Ngar-Cheung
中科院分区：
文献类型：
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作者：
Luo, Ming;Lau, Ngar-Cheung
利用再分析资料和地面观测资料，研究了1979 - 2010年中国南方地区热浪的特征。中国广东省（GDPC）是作为一个例子。结果表明，西北太平洋副热带高压的西移是影响广东省大尺度大风的主要因素。当HW发生时，华南地区的大气柱普遍炎热干燥。该地区被异常沉降所覆盖，导致变暖，天空晴朗，导致更大的太阳能加热。高湿伴随着异常高压中心和近地面的反气旋，伴随着异常的海陆西北气流，从而减少了海陆之间的水汽输送，使陆地上空的大气干燥。高压异常和高温的演变与西北偏西副高的西移有关，500 hPa高度场有显著的正距平向西移。这些特征与华南地区和中南半岛部分地区的高温极端事件相吻合。还观察到HW频率（+0.19事件十年（-1））、HW天数（+2.86天十年（-1））、最长事件持续时间（+0.38天十年（-1））和最热事件的最高温度（+0.23摄氏度十年（-1））显著增加。这些上升趋势在珠江三角洲（珠三角）地区更为突出，城市化对珠三角地区HW频率增加的贡献接近50%。研究还发现，HWs开始较早，结束较晚，城市化可能会提前HWs事件的爆发时间。
The characteristics of heat waves (HWs) in southern China in 1979-2010 are studied by using both reanalysis and station datasets. Guangdong Province of China (GDPC) is taken as an example. It is found that the westward movement of the western North Pacific subtropical high (WNPSH) is the primary factor for large-scale HWs occurring in GDPC. When an HW occurs, a hot and dry atmospheric column prevails over southern China. The region is overlaid by anomalous subsidence, which leads to warming, and clear sky, which causes greater solar heating. HWs are accompanied by an anomalous high pressure center and anticyclone near the surface, with anomalous land-sea northwesterly flow, thus reducing sea-land moisture transport and drying the atmosphere over land. The evolution of the high pressure anomaly and high temperature is associated with the westward displacement of WNPSH, with a prominent positive anomaly in 500-hPa height migrating westward. All these features associated with HWs in GDPC coincide with high-temperature extremes in the whole region of southern China and parts of Indochina. Significant increases in HW frequency (+0.19 events decade(-1)), HW days (+2.86 days decade(-1)), the duration of the longest event (+0.38 days decade(-1)), and the hottest temperature of the hottest event (+0.23 degrees C decade(-1)) are also observed. These upward trends are more prominent in the Pearl River delta (PRD) region, and urbanization contributes to nearly 50% of the increase in HW frequency in PRD. It is also noticed that HWs are commencing earlier and ending later, and urbanization may advance the timing of the onset of HW events.