ERA5 monthly averaged data on single levels from 1940 to present|气候数据数据集|再分析数据集

ERA5 is the fifth generation ECMWF reanalysis for the global climate and weather for the past 8 decades.
Data is available from 1940 onwards.
ERA5 replaces the ERA-Interim reanalysis.
Reanalysis combines model data with observations from across the world into a globally complete and consistent dataset using the laws of physics. This principle, called data assimilation, is based on the method used by numerical weather prediction centres, where every so many hours (12 hours at ECMWF) a previous forecast is combined with newly available observations in an optimal way to produce a new best estimate of the state of the atmosphere, called analysis, from which an updated, improved forecast is issued. Reanalysis works in the same way, but at reduced resolution to allow for the provision of a dataset spanning back several decades. Reanalysis does not have the constraint of issuing timely forecasts, so there is more time to collect observations, and when going further back in time, to allow for the ingestion of improved versions of the original observations, which all benefit the quality of the reanalysis product.
ERA5 provides hourly estimates for a large number of atmospheric, ocean-wave and land-surface quantities.
An uncertainty estimate is sampled by an underlying 10-member ensemble
at three-hourly intervals. Ensemble mean and spread have been pre-computed for convenience.
Such uncertainty estimates are closely related to the information content of the available observing system which
has evolved considerably over time. They also indicate flow-dependent sensitive areas.
To facilitate many climate applications, monthly-mean averages have been pre-calculated too,
though monthly means are not available for the ensemble mean and spread.
ERA5 is updated daily with a latency of about 5 days (monthly means are available around the 6th of each month). In case that serious flaws are detected in this early release (called ERA5T), this data could be different from the final release 2 to 3 months later. In case that this occurs users are notified.
The data set presented here is a regridded subset of the full ERA5 data set on native resolution.
It is online on spinning disk, which should ensure fast and easy access.
It should satisfy the requirements for most common applications.
An overview of all ERA5 datasets can be found in this article.
Information on access to ERA5 data on native resolution is provided in these guidelines.
Data has been regridded to a regular lat-lon grid of 0.25 degrees for the reanalysis and 0.5 degrees for
the uncertainty estimate (0.5 and 1 degree respectively for ocean waves).
There are four main sub sets: hourly and monthly products, both on pressure levels (upper air fields) and single levels (atmospheric, ocean-wave and land surface quantities).
The present entry is "ERA5 monthly mean data on single levels from 1940 to present".

ERA5为欧洲中期天气预报中心（ECMWF）第五代全球气候与天气再分析产品，涵盖了过去八十年间的数据。数据自1940年起提供。ERA5取代了先前的ERA-Interim再分析产品。再分析将模型数据与全球范围内的观测数据相结合，依据物理定律构建一个全球范围内完整且一致的数据集。这一原则被称为数据同化，其方法源自数值天气预报中心，每隔数小时（在ECMWF为12小时）将先前预报与新的观测数据以最优化方式结合，生成新的最佳大气状态估计，即分析，并据此发布更新、改进的预报。再分析以降低的分辨率进行，以便提供覆盖数十年数据集。再分析不受发布及时预报的约束，因此有更多时间收集观测数据，并在追溯至更早时间时，允许摄入原始观测数据的改进版本，从而全面提升再分析产品的质量。ERA5提供了大量大气、海洋波和地表数量的每小时估计值。基于10成员集合体的不确定性估计通过每三小时进行一次采样。为方便起见，已预先计算了集合平均和分布。此类不确定性估计与可用观测系统的信息含量密切相关，并随时间显著演变。它们还指示了流相关的敏感区域。为了便于众多气候应用，已预先计算了月平均值，尽管集合平均和分布的月平均值不可用。ERA5每日更新，约滞后5天（月平均值在每月6号左右可用）。如果在早期发布版（称为ERA5T）中发现严重缺陷，则此数据可能与2至3个月后发布的最终版本2有所不同。在此情况下，用户将收到通知。此处呈现的数据集是全ERA5数据集在原生分辨率上的重网格化子集。它存储在旋转磁盘中，这应确保快速便捷的访问。它应满足大多数常见应用的需求。所有ERA5数据集的概述可在此篇文章中找到。有关访问原生分辨率ERA5数据的指南提供在这些指导原则中。数据已重网格化至0.25度（再分析）和0.5度（不确定性估计）的规则经纬网格，对于海洋波分别是0.5度和1度。主要分为四个子集：小时和月度产品，包括压力层（高空场）和单层（大气、海洋波和地表数量）。本条目是“自1940年至现在的ERA5单层月平均数据”。”}