Downscaled Alaskan Climate Data (CCSM)

<b>The dataset in this record is the output of the CCSM4 (Community Climate System Model version 4).</b> Please see the collection reference below for outputs from the other models described here.<br>These data are the outputs of three general circulation climate models (GCMs), CCSM4, MRI-CGCM3, and IPSL-CM5A-LR for the period 1950-2100. Runs of each GCM were carried out as part of the fifth phase of the Coupled Model Intercomparison Project. Future runs were forced with the RCP 8.5 emissions scenario. They were downscaled to a one km spatial resolution using a quantile matching approach. The three GCMs were chosen because they were shown to recreate climate well in Alaska during the last few decades and because they span the range of potential conditions during the 21^stcentury as projected by all climate models included in the IPCC AR5. Variables include daily minimum and maximum Temperature (°C), daily sum of precipitation (mm), daily sum of shortwave radiation (Mj m^-2), and mean VPD (kPa). <br><b>This dataset includes the following files. </b>The gridded netCDFs are provided as compressed .tar.gz files.<b> </b>Extensive metadata is embedded within each netCDF.<br>CCSM4-hist-prcp.tar.gz : Daily precipitation (mm) for 1950-2005 from the CCSM4 GCM. CCSM4-future-prcp.tar.gz : Daily precipitation (mm) for 2006-2100 from the CCSM4 GCM.CCSM4-hist-srad.tar.gz : Daily shortwave radiation (mJ m^-2) for 1950-2005 from the CCSM4 GCM. CCSM4-future-srad.tar.gz : Daily shortwave solar radiation (mJ m^-2) for 2006-2100 from the CCSM4 GCM.CCSM4-hist-tmax.tar.gz : Daily maximum temperature (deg C) for 1950-2005 from the CCSM4 GCM. CCSM4-future-tmax.tar.gz : Daily maximum temperature (deg C)for 2006-2100 from the CCSM4 GCM.CCSM4-hist-tmin.tar.gz : Daily minimum temperature (deg C) for 1950-2005 from the CCSM4 GCM. CCSM4-future-tmin.tar.gz : Daily minimum temperature (deg C)for 2006-2100 from the CCSM4 GCM.CCSM4-hist-vap.tar.gz : Daily vapor pressure (kPa) for 1950-2005 from the CCSM4 GCM. CCSM4-future-vap.tar.gz : Daily vapor pressure (kPa) for 2006-2100 from the CCSM4 GCM.<br><br>

<b>本记录中的数据集为CCSM4（Community Climate System Model version 4，社区气候系统模型第4版）的输出结果。</b>
请参阅下方的集合引用，以获取本文提及的其他模型的输出数据。
这些数据为三种通用环流气候模型 (General Circulation Climate Model, GCM) 的输出结果，分别为CCSM4、MRI-CGCM3与IPSL-CM5A-LR，时间跨度为1950年至2100年。每个GCM的模拟运行均作为耦合模型比对项目第五阶段 (Coupled Model Intercomparison Project Phase 5, CMIP5) 的一部分开展。未来情景模拟以RCP 8.5（典型浓度路径8.5，Representative Concentration Pathway 8.5）排放情景作为强迫场。随后通过分位数匹配法将数据降尺度至1千米空间分辨率。选择这三种GCM的原因在于：它们能够较好地重现过去数十年阿拉斯加地区的气候状况，且覆盖了政府间气候变化专门委员会第五次评估报告 (Intergovernmental Panel on Climate Change Assessment Report 5, IPCC AR5) 中所有气候模型所预估的21世纪潜在气候情景范围。变量包含每日最低气温、最高气温（单位：摄氏度）、每日降水总量（单位：毫米）、每日短波辐射总量（单位：兆焦耳每平方米，Mj m⁻²）以及平均水汽压亏缺 (Vapor Pressure Deficit, VPD)。
<b>本数据集包含以下文件。</b>
网格化的netCDF (Network Common Data Form) 文件以压缩的.tar.gz格式提供。每个netCDF文件中均嵌入了丰富的元数据。
CCSM4-hist-prcp.tar.gz：来自CCSM4模型的1950-2005年每日降水数据（单位：毫米）
CCSM4-future-prcp.tar.gz：来自CCSM4模型的2006-2100年每日降水数据（单位：毫米）
CCSM4-hist-srad.tar.gz：来自CCSM4模型的1950-2005年每日短波辐射数据（单位：兆焦耳每平方米）
CCSM4-future-srad.tar.gz：来自CCSM4模型的2006-2100年每日短波太阳辐射数据（单位：兆焦耳每平方米）
CCSM4-hist-tmax.tar.gz：来自CCSM4模型的1950-2005年每日最高气温数据（单位：摄氏度）
CCSM4-future-tmax.tar.gz：来自CCSM4模型的2006-2100年每日最高气温数据（单位：摄氏度）
CCSM4-hist-tmin.tar.gz：来自CCSM4模型的1950-2005年每日最低气温数据（单位：摄氏度）
CCSM4-future-tmin.tar.gz：来自CCSM4模型的2006-2100年每日最低气温数据（单位：摄氏度）
CCSM4-hist-vap.tar.gz：来自CCSM4模型的1950-2005年每日水汽压数据（单位：千帕）
CCSM4-future-vap.tar.gz：来自CCSM4模型的2006-2100年每日水汽压数据（单位：千帕）