Characteristics of Mesoscale Convective Complexes over Northeastern Brazil

Abstract The main purpose of this study was to analyze the Mesoscale Convective Complexes (MCC) physical characteristics over the Northeastern Brazil between 2008 to 2017. To create a short-term weather forecast, understanding and detailing of these systems is necessary. This is of great importance for the population, since MCC often cause adverse phenomena leading to socio-economic losses for the whole society. The MCC identification and all calculations of their physical characteristics were performed with the aid of an MCC automatic analysis and detection algorithm, based on the standards proposed by Maddox. METEOSAT satellites Infrared enhanced images were used for the processing algorithm. Sixty-five MCCs occurred mainly in the autumn and summer seasons were identified. MCC development started between late evening and early morning (between 00-03 UTC). An interval of approximately four hours was observed between genesis and maximum development, when MCC reach maximum extension area. The average coverage area of these MCCs was 120,000 km2, the largest of the reported cases had a total area of about 427,926 km2.

摘要
本研究旨在分析2008年至2017年巴西东北部地区的中尺度对流复合体（Mesoscale Convective Complexes，MCC）物理特征。开展短期天气预报需充分认知并精细化解析这类天气系统，而由于中尺度对流复合体常引发灾害性现象，给全社会造成社会经济损失，因此相关研究对民众而言具有重要意义。
本研究基于马多克斯（Maddox）提出的标准，借助中尺度对流复合体自动分析与检测算法，完成了所有目标系统的识别及其物理特征计算。处理算法采用静止气象卫星（METEOSAT）的红外增强影像作为数据源。
本研究共识别出65个中尺度对流复合体，这些系统主要发生在秋季与夏季。中尺度对流复合体的生成时段多为深夜至凌晨（协调世界时00时至03时）；从生成到达到最大发展阶段的间隔约为4小时，此时其覆盖面积将达到峰值。此类中尺度对流复合体的平均覆盖面积为120000平方千米，其中已报道的最大个例总面积约为427926平方千米。