Ocean fronts are areas of increased primary productivity susceptible to climate induced ocean warming. Quantifying the spatial and temporal variability of thermal fronts in rapidly warming parts of the ocean is needed. Frontal frequency (FF) in SST imagery was examined in the coastal upwelling region of South-Central Vietnam, a known marine hotspot. Level-1 daily MODIS data between 2003 and 2018 was used to generate level-3 mapped SST products. The Cayula and Cornillon single image edge detection (SIED) algorithm was used to extract fronts from the SST imagery. Two types of fronts were found in the area, both strongly influenced by seasonal monsoons. Upwelling fronts were found along the southeast coast of Vietnam and extending eastward from the upwelling center during the SW monsoon. Shelf fronts, running along the 100 m – 200 m isobath, separate the cold-water current from the north with the open ocean during the NE monsoon. An upward trend of SST was recorded at approximately 0.05 °C/year throughout the 16-year period (p < 0.05), with rates of increase being higher during the Southwest (SW) monsoon period (May-September). The two longest marine heatwaves (MHW) occurred during El Niño years, nine days in 2010 and 16 days in 2016 with highest maximum intensity of 2.95 °C. The results show that FF trend is increasing significantly in region with shelf fronts and that this increase is associated with a positive SST trend. Additionally, El Niño/La Niña is associated with variability of fronts in this small-scale marine hotspot over the last 16 years.

海洋前沿是初级生产力增加的区域，容易受到气候引起的海洋变暖的影响。需要量化海洋快速变暖部分的热锋的空间和时间变化。在已知的海洋热点越南中南部的沿海上升流区域检查了 SST 图像中的锋面频率 (FF)。使用 2003 年至 2018 年期间的 1 级每日 MODIS 数据生成 3 级映射 SST 产品。Cayula 和 Cornillon 单图像边缘检测 (SIED) 算法用于从 SST 图像中提取前沿。在该地区发现了两种类型的锋，都受到季节性季风的强烈影响。在西南季风期间，沿越南东南海岸发现了上升流锋，并从上升流中心向东延伸。货架前沿，沿着 100 m – 200 m 等深线延伸，在东北季风期间，将冷水流从北方与开阔的海洋分开。在整个 16 年期间，SST 的上升趋势约为 0.05 °C/年（p  < 0.05)，在西南 (SW) 季风期间（5 月至 9 月），增长率更高。两次最长的海洋热浪 (MHW) 发生在厄尔尼诺年，2010 年为 9 天，2016 年为 16 天，最高强度为 2.95 °C。结果表明，FF 趋势在具有陆架前沿的区域显着增加，并且这种增加与正 SST 趋势相关。此外，厄尔尼诺/拉尼娜现象与过去 16 年来这个小规模海洋热点的锋面变化有关。