COL map based on JMA-GSM analysis and forecasts

"Cutoff low" (COL) is a low-pressure system that develops between the middle (~5000 m altitude) and the upper troposphere (~10000 m altitude). It propagates holding cold air derived from polar air inside. The cold, heavy air moving over the upper troposphere destabilizes the atmosphere below, and often accompanies localized weather disasters such as tornadoes and quasi-linear convective systems. The dataset provides COLs variables(center coordinates, intensity, size, and background gradient) analyzed from JMA-GSM with methods based on Kasuga et al. (2021). Analysis tools and details are available at https://gitlab.com/naos1/colindex.切断低压（Cutoff low，COL）是一类形成于中层（约5000米高度）与对流层上层（约10000米高度）之间的低压系统。其移动过程中会裹挟源自极地气团的冷空气。当这类携带着寒冷重空气的系统移至对流层上层时，会使下方大气层结变得不稳定，且常伴随龙卷风、准线性对流系统等局地气象灾害。 本数据集基于Kasuga等人（2021）提出的分析方法，通过JMA-GSM（日本气象厅全球谱模式）分析得到切断低压相关变量，涵盖中心坐标、强度、尺度及背景梯度。 相关分析工具与详细信息可访问：https://gitlab.com/naos1/colindex。