OpenIFS@home: ensemble of forecast simulations from Ex-tropical cyclone Karl case study

This dataset contains the 2000-member original validation test case for OpenIFS@home as presented in Sparrow et al 2021, GMD. These are results from an ensemble of forecast simulations of the tropical cyclone Karl from September 2016, studied during the NAWDEX field campaign. This cyclone underwent extratropical transition and intensified in mid-latitudes to give rise to an intense jet-streak near Scotland and heavy rainfall over Norway. The OpenIFS@Home data comprises output from the European Centre for Medium Range Weather Forecasts (ECMWF) OpenIFS model run under the BOINC framework and managed by http://climateprediction.net/ at the University of Oxford. OpenIFS is derived from ECMWF's IFS operational forecast model. The dataset consists of a 2000 member ensemble of the ECMWF OpenIFS cycle 40 release 1 model, run on the OpenIFS@home volunteer framework. The spatial resolution of the dataset is approximately 125km at the equator (corresponding to a spectral resolution of T159) with 60 vertical levels The model output data format is WMO GRIB. Single level parameters and surface fields use GRIB-1 format whilst multi-level upper air fields use GRIB-2 format To work with GRIB files requires the ECMWF ecCodes package. This software provides command line tools for linux/macOS for inspecting the contents of these files, such as listing parameters and meta-information The model output files are on the native IFS grid, the so-called reduced Gaussian grid, rather than a regular latitude-longitude grid commonly used in plotting. The ECMWF metview application can be used to produce plots directly from the model output files without the need to interpolate first. Other applications exist, such as the Climate Data Operators (CDO) that can be used to first convert the GRIB model output files to netCDF for use in other plotting packages. The data is arranged into subdirectories (one per ensemble member), each containing a zip file of the output GRIB data for that simulation. These follow the standard OpenIFS output format and represent 6 hourly snapshots throughout the forecast. The number in the filename denotes the hour of the forecast contained in each respective GRIB file

本数据集包含Sparrow等人2021年发表于《Geoscientific Model Development》（GMD）期刊的OpenIFS@home项目的2000个原始验证测试用例。这些结果来自2016年9月热带气旋卡尔（Karl）的集合预报模拟，该模拟是在NAWDEX外场试验期间开展的研究内容。
该气旋经历了温带变性过程，并在中纬度地区增强，在苏格兰附近形成强烈急流核，同时在挪威引发强降雨。
OpenIFS@Home数据由欧洲中期天气预报中心（European Centre for Medium Range Weather Forecasts, ECMWF）的OpenIFS模式产出，基于BOINC框架运行，并由牛津大学的http://climateprediction.net/项目负责管理。OpenIFS脱胎于ECMWF的业务化IFS预报模式。
本数据集由ECMWF OpenIFS周期40版本1的2000个集合成员模拟组成，基于OpenIFS@home志愿者计算框架运行。该数据集在赤道处的空间分辨率约为125km（对应光谱分辨率T159），共包含60个垂直层。
模式输出数据采用世界气象组织（World Meteorological Organization, WMO）制定的GRIB格式。其中单级参数与地表场数据使用GRIB-1格式，多层高空场数据则采用GRIB-2格式。
处理GRIB文件需要使用ECMWF的ecCodes工具包，该软件为Linux与macOS系统提供命令行工具，用于检视文件内容，例如列出参数与元数据信息。
模式输出文件采用IFS原生网格——即所谓的缩减高斯网格（reduced Gaussian grid），而非常规绘图中常用的规则经纬网格。
ECMWF的Metview应用可直接基于模式输出文件生成可视化绘图，无需先进行插值操作。另有其他工具可供使用，例如气候数据运算符（Climate Data Operators, CDO），可先将GRIB格式的模式输出文件转换为netCDF格式，以适配其他绘图工具。
数据以子目录形式组织，每个集合成员对应一个独立子目录，每个子目录内包含对应模拟的GRIB输出数据压缩包。这些文件遵循标准OpenIFS输出格式，包含预报过程中每6小时一次的状态快照。文件名中的数字代表该GRIB文件所包含的预报时效小时数。