南海海洋温度锋面时空特征遥感分析

Remote Sensing Analysis of Temporal and Spatial Characteristics of Ocean Temperature Fronts in the South China Sea

摘要:

使用 2010–2020 年微波和红外融合 SST 数据，利用温度梯度法计算总温度梯度，获取了南海海面温度的水平变化梯度，开展了锋面位置、锋面平均强度及中心线长度的研究。利用锋面信息结果，开展了南海锋面气候态分布特征和年际变化分析和锋面强度与海面风场的相关性分析。结果发现：南海区域探测到的 8 个锋面多为河口锋和陆架锋，均有明显的季节态变化。1–2 月检测到的锋面数量最多，所有锋面均可被检测；3–4 月有较小幅度地减少，主要体现在马来西亚–菲律宾西侧沿岸锋和泰国湾锋的消失；5–9 月呈现持续减少的趋势，并在 9 月达到最小值，仅检测到台湾海峡及广东福建沿岸锋和越南沿岸锋；10–12 月开始有所回升，南海北部沿岸锋面开始被检测到。台湾海峡及广东福建沿岸锋平均梯度全年与风速的相关程度都在 0.48 以上，越南沿岸锋与纬向风相关系数最低为 0.021。相比较夏季来说，冬季平均梯度与风速的相关程度较高。

Abstract:

Based on sea surface temperature（SST）data of microwave infrared fusion data from 2010 to 2020， the total temperature gradient is calculated using the temperature gradient method，the horizontal change gradient of sea surface temperature in the South China Sea is obtained，and the research on the location of fronts，the average intensity of fronts，and the length of the centerline is carried out. Based on the results of the frontal survey，the distribution characteristics and interannual variations of the South China Sea frontal climate patterns and the correlation between the intensity of the fronts and the monsoon are analyzed. The results show that the eight fronts detected in the South China Sea region are mostly estuarine fronts and shelf fronts，all of which have obvious seasonal patterns. The number of fronts detected in January and February is the highest，and all fronts can be detected. There is a small decrease from March to April，mainly due to the disappearance of the Shelf-Slope Front and the Gulf of Thailand Front. A continuous decreasing trend is observed from May to September，with a minimum value reached in September，and only the Taiwan Strait and Guangdong-Fujian Fronts and the Vietnam coastal front are detected. From October to December，the number of fronts is increased，and fronts are detected in the north of the South China Sea. The correlation coefficient between the mean gradient and wind speed in the Taiwan Strait and GuangdongFujian Fronts is above 0.48 throughout the year，while the lowest correlation coefficient between the Vietnam Coastal Front and latitudinal winds is 0.021. The correlation coefficient in winter is higher in comparison with that in summer.