CMIP5 global cyclone tracks

This folder contains cyclone tracks generated for Pepler and Dowdy (2021) These anticyclones were identified using the Murray and Simmonds (1991) and Simmonds et al. (1999) cyclone tracking scheme. The source code and documntation is available at https://cyclonetracker.earthsci.unimelb.edu.au/<br>Tracks are provided for ERA5 during 1979-2019 and for 10 CMIP5 models from historical simulations for 1979-2005, and rcp45 and rcp85 for 2070-2099<br>Surface cyclones are tracked using 6-hourly MSLP, and upper cyclones are tracked using daily 500 hPa geopotential height<br>Cyclone tracks are provided based on the weakest intensity threshold, with the thresholds used in post-processing provided in Supplementary Table S1 from the published paper. For more details on the parameters used for detection and tracking see the files *incycloc and *intrack which are used as inputs for the tracking scheme.<br>A separate track file is provided for each year, beginning on 1 December of the previous year, to allow for the identification of cross-year tracks when relevant.<br>Column headings:ID Track IDFix Instance within trackDate Date* (UTC)Time Time (UTC)Open/closed Is there closed circulation (0) or an "open" ridge. Not used.Lon LongitudeLat LatitudeMSLP Central pressure (hPa)Laplacian Laplacian of MSLP (hPa. Deg.lat^2), which represents the curvature of the MSLP. This is a better indicator of the strength of a systemDepth Depth of anticyclone (hPa)Radius Radius of anticyclone (degrees)Up Steering velocity (U)Vp Steering velocity (V)<br>*Dates are two digit years, and in some cases are wrong because of the way the tracking scheme works (e.g. 1999-2001).<br>References:<br>Murray, R. J., and I. Simmonds, 1991: A numerical scheme for tracking cyclone centres from digital data. Part I: Development and operation of the scheme. Aust. Meteorol. Mag., 39, 155166.<br>Simmonds, I., R. J. Murray, and R. M. Leighton, 1999: A refinement of cyclone tracking methods with data from FROST. Aust. Meteorol. Mag., (special edition), 3549.<br>Pepler, A. and Dowdy, A. 2021: Deep cyclones in the global midlatitudes likely to become less common but cause more intense rainfall本文件夹包含为Pepler与Dowdy（2021）研究所生成的气旋轨迹。本研究中的反气旋采用Murray与Simmonds（1991）及Simmonds等人（1999）提出的气旋追踪方案进行识别。该追踪方案的源代码与文档可通过https://cyclonetracker.earthsci.unimelb.edu.au/获取。 本次提供的轨迹数据涵盖1979-2019年的ERA5再分析资料，以及10个CMIP5（Coupled Model Intercomparison Project Phase 5）模式在1979-2005年历史模拟试验、2070-2099年rcp45（典型浓度路径4.5，Representative Concentration Pathway 4.5）与rcp85（典型浓度路径8.5，Representative Concentration Pathway 8.5）情景下的模拟气旋轨迹。 地面气旋通过每6小时一次的平均海平面气压（MSLP, Mean Sea Level Pressure）资料进行追踪，高空气旋则采用每日一次的500 hPa位势高度场资料进行追踪。 本数据集的气旋轨迹基于最低强度阈值生成，后处理过程中使用的强度阈值详见已发表论文的补充表S1。关于探测与追踪所用参数的更多细节，可参阅作为追踪方案输入文件的*incycloc与*intrack。 每个年份对应一个独立的轨迹文件，文件起始时间为前一年的12月1日，以便在必要时识别跨年度气旋轨迹。 各列字段说明如下： ID：轨迹编号 Track IDFix：轨迹固定标识 Instance within track：轨迹内的实例序号 Date：日期（UTC） Time：时间（UTC） Open/closed：表征是否存在闭合环流（0代表闭合）或“开放”脊线，该字段未实际使用 Lon：经度 Lat：纬度 MSLP：中心气压（单位：百帕hPa） Laplacian：海平面气压的拉普拉斯算子（单位：hPa·(纬度度数)²），用于表征海平面气压的曲率，是衡量系统强度的更优指标 Depth：反气旋深度（单位：hPa） Radius：反气旋半径（单位：经度度数） U：引导气流的U分量速度 Vp：引导气流的V分量速度 *注：日期采用两位年份格式，部分日期因追踪方案的运行逻辑出现错误（例如1999-2001这类情况）。 参考文献： 1. Murray, R. J. 与 I. Simmonds, 1991：用于从数字化资料中追踪气旋中心的数值方案 第一部分：方案的开发与运行. 《澳大利亚气象学杂志》(Aust. Meteorol. Mag.), 39, 155-166. 2. Simmonds, I., R. J. Murray, 与 R. M. Leighton, 1999：基于FROST资料的气旋追踪方法改进. 《澳大利亚气象学杂志》(Aust. Meteorol. Mag., 特刊), 35-49. 3. Pepler, A. 与 Dowdy, A., 2021：全球中纬度深层气旋发生概率或将降低，但引发的降雨强度或将增强。