Velocity of climate change for North America based on CMIP6 GCMs

This dataset represents velocity of climate change for North America, based on Parameter Regression of Independent Slopes Model (PRISM) climate data from the historical normal period, and climate change projections of the Coupled Model Intercomparison Project phase 6 (CMIP6) database corresponding to the 5th and 6th IPCC Assessment Reports for future projections. The data has been prepared for AdaptWest (adaptwest.databasin.org).The velocity of climate change is an analytical concept that can be used to evaluate the exposure of organisms to climate change. As originally proposed, velocity is calculated by dividing the rate of climate change by the rate of spatial climate variability to obtain a speed at which species must migrate over the surface of the earth to maintain constant climate conditions. We provide velocity surfaces for a multivariate PCA implementation that searches for climate matches based on the first 2 axes derived from a PCA of 11 biologically relevant climate variables. Values represent climate velocity in km/yr from the histroical normal period (here 1961-1990) and the relevant future multi-decadal period (2041-2070 or 2071-2100). Areas of no-analog (inbound velocity) and disappearing (outbound velocity) climates are shown as NODATA in the velocity rasters. Values showing the proportion of runs in which a cell was characterized as no-analog or disappearing are given in additional rasters disappearing climate subfolder, filename includes ‘disp’. Typically, the two related rasters (velocity and disappearing climates) would be viewed and analyzed together.本数据集表征北美洲的气候变化速率，数据基础为历史基准期的独立斜率参数回归模型（Parameter Regression of Independent Slopes Model, PRISM）气候数据，以及对应第五、第六次联合国政府间气候变化专门委员会（Intergovernmental Panel on Climate Change, IPCC）评估报告的耦合模式比较计划第六阶段（Coupled Model Intercomparison Project Phase 6, CMIP6）数据库的未来气候预估结果。本数据集为AdaptWest（adaptwest.databasin.org）项目制备。 气候变化速率是一项用于评估生物群落受气候变化影响程度的分析性概念。按照最初提出的定义，该速率通过将气候变化速率除以气候空间变率计算得到，其物理意义为物种为维持恒定气候环境而需在地球表面迁移的速度。 本数据集提供基于多变量主成分分析流程的气候速率表面：该分析通过对11个具有生物学相关性的气候变量执行主成分分析，选取前两个主成分轴以匹配气候条件。数据值代表以千米/年为单位的气候速率，时间范围涵盖历史基准期（此处为1961-1990年）以及相关的未来年代际时段（2041-2070年或2071-2100年）。 气候无类比区域（对应入向速率）与气候消失区域（对应出向速率）在速率栅格中以无数据（NODATA）标记。额外的栅格数据存储于"disappearing climate"子文件夹中，文件名包含"disp"，用于表征各栅格单元被归类为无类比或消失气候的模拟运行占比。通常，这两类相关栅格（气候速率栅格与消失气候栅格）需结合开展可视化与分析工作。