# An Interpretable Deep Learning Approach for Detecting Marine Heatwaves Patterns
## 4 Discussion
### Compared with Existing Research  
[PERSON] and [PERSON] [42] discovered several patterns in the coastal areas of China. The first is that marine heatwave events in the South China Sea primarily occur in the Nansha Islands and the Gulf of Tonkin, related to the weakening of the East Asian winter monsoon and the strengthening of the West Pacific subtropical high pressure and South China Sea high pressure. The second pattern involves an abnormal strengthening of the Northwest Pacific subtropical high-pressure system in summer, an increase in solar shortwave radiation, a weakening of Walker circulation, a reduction in latent heat release at the sea surface, an increase in net heat flux, an extension of the cyclone westward leading to an anomaly in the low-latitude easterlies, the weakening of the southwest summer monsoon, and a reduction or even disappearance of upwelling in the central and western regions of the South China Sea, forming strong basin-scale marine heatwaves in summer. The third pattern appears during El Nino events when the winter cyclonic anomaly in the Northwest Pacific weakens the East Asian winter monsoon; the south wind is relatively strong, increasing the northward transport of warm surface water and reducing the cold surge west of Hainan Island, resulting in marine heatwaves in the Gulf of Tonkin. The fourth is that the South China Sea's high pressure extends westward during El Nino warm events, inhibiting the evaporation process, enhancing the shortwave solar radiation received by the ocean surface, and weakening the wind field, thereby forming marine heatwaves. The fifth pattern is in the East China Sea and Southern Yellow Sea regions, where marine heatwave events are mainly influenced by anomalies in the East Asian summer monsoon, Northwest Pacific anomalous anti-cyclonic circulation, and local ocean dynamic processes. Another pattern involves an anomalous anti-cyclonic circulation over the Northwest Pacific leading to increased sea surface temperatures in the Eastern Indian Ocean equatorial region and the Western Pacific equatorial region, which, due to strong adiabatic sinking motion and solar shortwave radiation, causes extreme high-temperature events in the East China Sea; on the other hand, it also leads to extreme high-temperature events in the East China Sea by enhancing the transport of warm Kuroshio water towards the East China Sea region. It can be observed that there is an overlap between the patterns found in the research and the models discovered by the article. Table 6 lists some studies that coincide with the marine heatwave mechanisms identified in this experiment.  
Research has shown that the South China Sea is dominated by the East Asian monsoon, with a warm and humid southwest wind in the summer [47]. Blocked by the mountains on the eastern coast of the Indo-China Peninsula, the southwest wind surges past the southern end of this range, forming a strong wind jet near southeastern Vietnam [48]. Driven by the early summer monsoon wind, offshore Ekman transport brings up cold subsurface water to the surface near the coast [48,49]. As the wind stress extends eastward, the cold sea surface area continues to expand in July and August into the central part of South China Sea; this phenomenon is known as the midsummer cooling effect. Notably, the cold water range in the upwelling zone of the western-central South China Sea continues to expand, reaching its maximum area in August, while the upwelling zone in the northern South China Sea displays the oppositional trend. In addition, the warm sea surface range in the Gulf of Tonkin enlarges from June to August.  
As shown in Figure 16, the significance of wind speed features markedly increases near the occurrence of marine heatwaves, which verifies our hypothesis and illustrates the pertinence of the Northern Bay marine heatwave generation pattern studied.