Projected Monthly and Derived Precipitation Products - 771m CMIP5/AR5

This set of files includes downscaled projections of monthly totals, and derived annual, seasonal, and decadal means of monthly total precipitation (in millimeters, no unit conversion necessary) from Jan 2006 - Dec 2100 at 771x771 meter spatial resolution. Each set of files originates from one of five top ranked global circulation models from the CMIP5/AR5 models and RPCs, or is calculated as a 5 Model Average. The downscaling process utilizes PRISM climatological datasets from 1971-2000. Brief descriptions of the datasets: Monthly precipitation totals: The total precipitation, in mm, for the month. For Decadal outputs: 1. Decadal Average Total Monthly Precipitation: 10 year average of total monthly precipitation. Example: All January precipitation files for a decade are added together and divided by ten. 2. Decadal Average Seasonal Precipitation Totals: 10 year average of seasonal precipitation totals. Example: MAM seasonal totals for every year in a decade are added together and divided by ten. 3. Decadal Average Annual Precipitation Totals: 10 year average of annual cumulative precipitation. For seasonal means, the four seasons are referred to by the first letter of 3 months making up that season: * `JJA`: summer (June, July, August) * `SON`: fall (September, October, November) * `DJF`: winter (December, January, February) * `MAM`: spring (March, April, May) Please note that these maps represent climatic estimates only. While we have based our work on scientifically accepted data and methods, uncertainty is always present. Uncertainty in model outputs tends to increase for more distant climatic estimates from present day for both historical summaries and future projections.本数据集包含2006年1月至2100年12月期间、空间分辨率为771×771米的逐月降水总量降尺度投影结果，以及由此衍生的年、季、年代际尺度月降水总量均值（单位：毫米，无需进行单位转换）。 每组文件要么源自CMIP5/AR5模式中排名前五的全球环流模型与典型浓度路径（RPCs），要么为5个模式的平均结果。 本次降尺度过程采用了1971-2000年的PRISM气候数据集。 数据集简要说明如下： 逐月降水总量：对应自然月的总降水量，单位为毫米。 针对年代际输出项： 1. 年代际月降水总量均值：逐月降水总量的10年平均值。示例：将某十年内所有1月的降水文件求和后除以10，即得到该年代1月的降水均值。 2. 年代际季降水总量均值：季降水总量的10年平均值。示例：将某十年内每年的MAM季降水总量求和后除以10，即得到该年代春季降水总量的10年均值。 3. 年代际年降水总量均值：年累计降水量的10年平均值。 季均值采用由3个月份首字母组合命名的四季标识： * `JJA`：夏季（6月、7月、8月） * `SON`：秋季（9月、10月、11月） * `DJF`：冬季（12月、1月、2月） * `MAM`：春季（3月、4月、5月） 请注意，本数据集仅为气候预估结果。尽管本研究基于学界公认的数据与方法开展，但不确定性始终存在。相较于当前时段，无论是历史气候总结还是未来气候预估，模式输出的不确定性会随预估时段距当前越远而显著增加。