Record-breaking SST over mid-North Atlantic and extreme high temperature over the Jianghuai-Jiangnan region of China in 2013

In July 2013, the Jianghuai-Jiangnan region of China experienced a persistent extreme high temperature, and the surface air temperature (SAT) over many areas of the region set a new record, which had a profound impact on people's lives. This study explored the possible mechanism for this extreme climate phenomenon. The results show that the sea surface temperature (SST) over the mid-North Atlantic in July 2013 was the warmest observed over the past 160 years. The strong anomaly of the SST connects to the East Asian upper level westerly and western Pacific subtropical high (WPSH) via the teleconnection wave train and further contributes to the SAT variability over the Jianghuai-Jiangnan region; this connection could be one possible mechanism for the formation of the record-breaking extreme hot event (EHE) over the Jianghuai-Jiangnan region in July 2013. In addition, for the EHE over the Jianghuai-Jiangnan region, the role of the WPSH was generally emphasised. This study found that the variability of the upper level westerly over the Jianghuai-Jiangnan region is also an important climate factor impacting the SAT of the region. In particular, the record-breaking weakness of the upper level westerly corresponded to the record-breaking SAT over the Jianghuai-Jiangnan region in July 2013. These results indicate that the role of the upper level westerly should be emphasised in addition to the WPSH, according to both the variability in the summer air temperature and the EHE over the Jianghuai-Jiangnan region.