Rainfall Estimates on a Gridded Network based on all station data v1-2019

A global land-based gridded dataset of daily precipitation at 1 degree X 1 degree resolution from 1950 to 2016. Two datasets are available under the REGEN moniker. This dataset interpolates all daily precipitation stations available regardless of completeness of station timeseries. A second related dataset available here (update link) interpolates only the long-term stations (stations with at least 40 complete years of data). Besides the grid cell average precipitation amount per day (mm/day), the Yamamoto standard deviation per grid cell (mm/day), the kriging error per grid cell (%) and number of stations per grid cell variables are also included.Currently, there are two major data archives of global in situ daily rainfall data: 1. The Global Historical Station Network (GHCN-Daily) hosted by National Oceanic and Atmospheric Administration (NOAA) and 2. The Deutscher Wetterdienst (DWD) Global Precipitation Climatology Centre (GPCC). These two data archives are combined along with additional station data acquired from other researchers. The merged archive is quality controlled and the flagged stations are removed to create a long term high quality archive of raw station data, which is then interpolated using ordinary block kriging by this dataset. The REGEN long-term dataset instead only interpolates a long-term station subset of this high quality merged archive.The output consists of a separate CF-compliant netcdf file for each year, each containing the four aforementioned variables. These values are available for global land areas with the exception of Antarctica. The time dimension of the netcdf ranges from 1950-01-01 to 2016-12-31. Each dataset (All station based and long-term station based) is in classic netcdf format and occupies around 350MB of disk space for each year with the combined total of all years being around 26GB. Besides these two netcdfs, two additional netcdfs containing a mask indicating the high data quality grid cells of each dataset (all station and long-term) are also available. These netcdf files have the same grid descriptions as the original data but contain only one timestep for the entire period. This is an updated version of REGEN V1.0 (Rainfall Estimates on a GriddEd Network). REGEN V1-2019 adds another 3 years of data, now spanning 1950 to 2016. This was done by utilising an updated gridded monthly product - GPCC Full Data Monthly Version 2018, for retrieving absolute daily precipitation values from interpolated anomaly fields. In contrast REGEN V1.0 used GPCC Full Data Monthly Version 7. REGEN V1.0 is identical to REGEN V1-2019 in every other aspect.

本数据集为1950年至2016年期间、分辨率为1°×1°的全球陆面逐日降水格点数据集。目前有两款以REGEN为标识的数据集可供使用。其中一款数据集会对所有可用的逐日降水观测台站进行插值处理，不考虑台站时间序列的完整性；另一款相关数据集（可通过此处的更新链接获取）则仅对长期台站（即拥有至少40个完整观测年份数据的台站）进行插值。除逐日格点平均降水量（单位：毫米/日，mm/day）外，数据集还包含以下变量：单格点的山本（Yamamoto）标准差（mm/day）、单格点的克里金（kriging）误差（%）以及单格点对应的观测台站数量。当前，全球逐日原位降雨数据主要来自两大档案库：1. 由美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）维护的全球历史台站网络（Global Historical Station Network, GHCN-Daily）；2. 德国国家气象局（Deutscher Wetterdienst, DWD）下属的全球降水气候学中心（Global Precipitation Climatology Centre, GPCC）。研究人员将这两大档案库的数据与其他渠道获取的台站数据进行了整合。整合后的数据集经过质量控制，剔除了带有标记的不合格台站，最终构建出一套长期高质量的原始台站数据档案；本数据集即基于该档案，通过普通块克里金插值方法生成格点数据。而REGEN长期台站数据集则仅基于该高质量整合档案中的长期台站子集进行插值。数据集输出为按年份分存的、符合CF（Climate and Forecast）规范的NetCDF文件，每个文件均包含前文提及的四个变量。数据覆盖全球陆地区域（南极洲除外）。NetCDF文件的时间维度覆盖1950年1月1日至2016年12月31日。两款数据集（全台站版与长期台站版）均采用经典NetCDF格式，单年份文件大小约为350MB，所有年份的总存储量约为26GB。除上述两款NetCDF数据集外，还额外提供两款NetCDF掩码文件，分别对应两款主数据集的高质量格点区域。此类掩码文件与原始数据采用相同的格点定义，但仅包含覆盖全时段的单一时次数据。本数据集为REGEN V1.0（格点网络降水估算数据集，Rainfall Estimates on a GriddEd Network）的更新版本。REGEN V1-2019新增了3年的数据，使数据集时间跨度扩展至1950年至2016年。该版本通过使用更新后的格点逐月产品——GPCC全数据逐月版本2018（GPCC Full Data Monthly Version 2018），从插值得到的距平场中反演得到逐日绝对降水量。与之相比，REGEN V1.0采用的是GPCC全数据逐月版本7（GPCC Full Data Monthly Version 7）；两款数据集在其余所有方面均保持一致。