IPCC Climate Change Data: 1961-1990, Precipitation

From the IPCC website: The CRU Global Climate Dataset
available through the IPCC DDC consists of a multi-variate 0.5º
latitude by 0.5º longitude resolution mean monthly climatology
for global land areas, excluding Antarctica, strictly
constrained to the period 1961-1990. The mean 1961-1990
climatology comprises a suite of eleven surface variables:
precipitation (PRE) and wet-day frequency (WET); mean, maximum
and minimum temperature (TMP, TMX, TMN); diurnal temperature
range (DTR); vapour pressure (VAP;) global radiation (RAD;)
cloud cover (CLD); frost frequency (FRS); and wind speed (WND).
The mean climate surfaces have been constructed from a new
dataset of station 1961-1990 climatological normals, numbering
between 19,800 (precipitation) and 3615 (windspeed). The station
data were interpolated as a function of latitude, longitude and
elevation using thin-plate splines. The accuracy of the
interpolations are assessed using cross-validation and by
comparison with other climatologies. this data-set has been
decsribed in: New,M., Hulme,M. and Jones,P.D. (1999)
Representing twentieth century space-time climate variability.
Part 1: development of a 1961-90 mean monthly terrestrial
climatology J.Climate 12, 829-856.

数据源自政府间气候变化专门委员会（IPCC，Intergovernmental Panel on Climate Change）官网：英国气候研究单位（CRU，Climatic Research Unit）全球气候数据集可通过IPCC数据分发中心（DDC，Data Distribution Centre）获取。该数据集为覆盖全球陆地区域（不含南极洲）的多变量逐月气候平均场，空间分辨率为0.5°纬度×0.5°经度，时间范围严格限定于1961-1990年。这套1961-1990年的气候平均场包含11项地表气象变量：降水量（PRE，precipitation）、雨日频率（WET，wet-day frequency）；平均气温、最高气温与最低气温（分别对应TMP、TMX、TMN）；气温日较差（DTR，diurnal temperature range）；水汽压（VAP，vapour pressure）；全球辐射（RAD，global radiation）；云量（CLD，cloud cover）；霜冻日频率（FRS，frost frequency）；以及风速（WND，wind speed）。该气候平均场基于1961-1990年的台站气候常态值新数据集构建，台站数量区间为19800个（降水量）至3615个（风速）。台站数据以纬度、经度与海拔作为插值因子，通过薄板样条法完成空间插值。插值精度通过交叉验证法以及与其他气候数据集对比的方式进行评估。该数据集的相关研究成果已发表于：New, M.、Hulme, M.与Jones, P.D.（1999年）《表征20世纪时空气候变率 第一部分：1961-1990年逐月陆地气候平均场的构建》，《气候学报》（*J. Climate*）第12卷，第829-856页。