Data_Sheet_1_Modulations of Synoptic Weather Patterns on Warm-Sector Heavy Rainfall in South China: Insights From High-Density Observations With Principal Component Analysis.pdf

Based on hourly high-density precipitation data in Guangdong Province, China, 134 warm-sector heavy rainfall (WSHR) events were selected from 2016 to 2018. The synoptic weather patterns of these WSHR events were objectively classified using T-mode principal component analysis. Six WSHR weather patterns were identified, as follows: Type 1-southwest (T1-SW), Type 2-southeast (T2-SE), Type 3-coastal jets I (T3-CJI), Type 4-coastal jets II (T4-CJ II), Type 5-western low vortex (T5-WL), and Type 6-high-pressure (T6-HP). Three high-occurrence WSHR centers were finally extracted: the areas of Yangjiang and Shanwei, and the urban agglomeration of Guangdong–Hong Kong–Macao Greater Bay Area (GBA). Compared with the other five patterns, T6-HP is a newly identified WSHR weather pattern, which is related to a local/small-scale weather system in the context of anomalous northward movement of the western Pacific subtropical high. Notably, the precipitation area of the T6-HP type of WSHR event is smaller, which can only be captured by high-density observations. In addition, the occurrence locations of six large-scale extreme precipitation events were closely associated with the urban agglomerations in GBA, implying that urbanization plays an important role in extreme magnitudes of large-scale WSHR events and their occurrence centers.

基于广东省2016年至2018年每小时高密度降水数据，选取了134次暖区强降水事件（WSHR）。通过对这些WSHR事件的天气图象进行客观分类，采用T模态主成分分析，共识别出六种WSHR天气型：类型1-西南（T1-SW）、类型2-东南（T2-SE）、类型3-沿海急流I（T3-CJI）、类型4-沿海急流II（T4-CJ II）、类型5-西部低压涡旋（T5-WL）和类型6-高压（T6-HP）。最终提取出三个高发WSHR中心：阳江和汕尾地区，以及广东-香港-澳门大湾区（GBA）的城市集聚区。与其它五种型式相比，T6-HP是一种新识别的WSHR天气型，与西太平洋副热带高压异常北移背景下的局部/小尺度天气系统相关。值得注意的是，T6-HP型WSHR事件的降水区域较小，只能通过高密度观测捕获。此外，六次大规模极端降水事件的发生地点与GBA的城市集聚区密切相关，这表明城市化在大规模WSHR事件的极端强度及其发生中心方面发挥着重要作用。