ERA5 Reanalysis Model Level Data

After many years of research and technical preparation, the production of a new ECMWF climate reanalysis to replace ERA-Interim is in progress. ERA5 is the fifth generation of ECMWF atmospheric reanalyses of the global climate, which started with the FGGE reanalyses produced in the 1980s, followed by ERA-15, ERA-40 and most recently ERA-Interim. ERA5 will cover the period January 1950 to near real time.

ERA5 is produced using high-resolution forecasts (HRES) at 31 kilometer resolution (one fourth the spatial resolution of the operational model) and a 62 kilometer resolution ten member 4D-Var ensemble of data assimilation (EDA) in CY41r2 of ECMWF's Integrated Forecast System (IFS) with 137 hybrid sigma-pressure (model) levels in the vertical, up to a top level of 0.01 hPa. Atmospheric data on these levels are interpolated to 37 pressure levels (the same levels as in ERA-Interim). Surface or single level data are also available, containing 2D parameters such as precipitation, 2 meter temperature, top of atmosphere radiation and vertical integrals over the entire atmosphere. The IFS is coupled to a soil model, the parameters of which are also designated as surface parameters, and an ocean wave model. Generally, the data is available at an hourly frequency and consists of analyses and short (12 hour) forecasts, initialized twice daily from analyses at 06 and 18 UTC. Most analyses parameters are also available from the forecasts. There are a number of forecast parameters, e.g. mean rates and accumulations, that are not available from the analyses.

Improvements to ERA5, compared to ERA-Interim, include use of HadISST.2, reprocessed ECMWF climate data records (CDR), and implementation of RTTOV11 radiative transfer. Variational bias corrections have not only been applied to satellite radiances, but also ozone retrievals, aircraft observations, surface pressure, and radiosonde profiles.

Please note: DECS is producing a CF 1.6 compliant netCDF-4/HDF5 version of ERA5 for the CISL RDA at NCAR. The netCDF-4/HDF5 version is the de facto RDA ERA5 online data format.

历经多年之研究与技术准备，旨在取代ERA-Interim的欧洲中期天气预报中心（ECMWF）新型气候再分析的生产工作正在进行中。ERA5是ECMWF全球气候大气再分析的第五代产品，其起源可追溯至20世纪80年代生产的FGGE再分析，继之以ERA-15、ERA-40，直至最近的ERA-Interim。ERA5将涵盖从1950年1月至今的近实时时段。ERA5采用高分辨率预报（HRES）在31公里分辨率（为运行模型空间分辨率的四分之一）下生产，并使用ECMWF综合预报系统（IFS）的CY41r2版本中62公里分辨率的十成员4D-Var数据同化（EDA）集合，垂直方向上包含137个混合sigma压力（模型）层次，直至0.01 hPa的顶层。大气数据在这些层次上进行插值至37个压力层次（与ERA-Interim相同）。同时，也提供表面或单层数据，包括降水、2米温度、大气顶辐射以及整个大气层的垂直积分等二维参数。IFS与土壤模型耦合，其参数亦被指定为表面参数，以及海洋波浪模型。通常，数据以每小时频率提供，包括分析和短期（12小时）预报，每日两次从06 UTC和18 UTC的分析中初始化。大多数分析参数也来自预报。存在一些预报参数，例如平均速率和累积量，这些参数无法从分析中获得。与ERA-Interim相比，ERA5的改进之处包括采用HadISST.2、重新处理过的ECMWF气候数据记录（CDR）以及实施RTTOV11辐射传输。不仅对卫星辐射进行了变分偏差校正，还包括了对臭氧反演、飞机观测、地表压力和探空资料剖面。请注意：DECS正在为NCAR的CISL RDA生产符合CF 1.6规范的netCDF-4/HDF5版本的ERA5，该版本已成为RDA ERA5在线数据格式的实际标准。

搜集汇总

背景与挑战

背景概述

ERA5 Reanalysis Model Level Data是欧洲中期天气预报中心（ECMWF）生产的第五代全球气候再分析数据集，覆盖1979年至2025年（每月更新），提供高时空分辨率（水平分辨率约31公里，垂直137个模型层）的每小时气象数据，包括比湿、表面压力、风分量和温度等关键变量，数据格式为netCDF4，总体积达391.33 TB，适用于气候建模和分析。