STAR-Ensemble SSP2-4.5 Precipitation Totals

The Climate Resilience Information System (CRIS) provides data and tools for developers of climate services. This layer has projections of VAR in decadal increments from 1950 to 2100 and for three Shared Socioeconomic Pathways (SSPs). The variables included are: Annual total precipitation (inches) Annual highest precipitation total for a single day (inches) Annual highest precipitation total over a 5-day period (inches) Annual highest precipitation total over a 10-day period (inches) Annual total precipitation for all days exceeding the 90th percentile (inches) Annual total precipitation for all days exceeding the 95th percentile (inches) Annual total precipitation for all days exceeding the 99th percentile (inches) Annual number of days with no precipitation (dry days) Annual number of days with precipitation (wet days) Maximum number of consecutive dry days Maximum number of consecutive wet days This layer uses data from the LOCA2 and STAR-ESDM downscaled climate models for the Contiguous United States. Further processing by the NOAA Technical Support Unit at CICS-NC and Esri are explained below. For each time and SSP, there are mean values for the defined respective geography: counties, tribal areas, HUC-8 watersheds. The process for deriving these summaries is available in Understanding CRIS Data. The combination of time and geography is available for a weighted ensemble of 16 climate projections. More details on the models included in the ensemble and the weighting methodologies can be found in CRIS Data Preparation. Other climate variables are available from the CRIS website’s Data Gallery page or can be accessed in the table below. Additional geographies, including Alaska, Hawai’i and Puerto Rico will be made available in the future. Geographies This layer provides projected values for three geographies: county, tribal area, and HUC-8 watersheds. County: based on the U.S. Census TIGER/Line 2022 distribution. Tribal areas: based on the U.S. Census American Indian/Alaska Native/Native Hawaiian Area dataset 2022 distribution. This dataset includes federal- and state-recognized statistical areas. HUC-8 watershed: based on the USGS Washed Boundary Dataset, part of the National Hydrography Database Plus High Resolution. Time Ranges Projected climate threshold values (e.g. Days Over 90°F) were calculated for each year from 2005 to 2100. Additionally, values are available for the modeled history runs from 1951 - 2005. The modeled history and future projections have been merged into a single time series and averaged by decade. Climate Scenarios Climate models use future scenarios of greenhouse gas concentrations and human activities to project overall change. These different scenarios are called the Shared Socioeconomic Pathways (SSPs). Three different SSPs are available here: 2-4.5, 3-7.0, and 5-8.5 (STAR does not have SSP3-7.0). The number before the dash represents a societal behavior scenario. The number after the dash indicates the amount of radiative forcing (watts per meter square) associated with the greenhouse gas concentration scenario in the year 2100 (higher forcing = greater warming). It is unclear which scenario will be the most likely, but SSP 2-4.5 currently aligns with the international targets of the COP-26 agreement. SSP3-7.0 may be the most likely scenario based on current emission trends. SSP5-8.5 acts as a cautionary tale, providing a worst-case scenario if reductions in greenhouse gasses are not undertaken. Data Export Exporting this data into shapefiles, geodatabases, GeoJSON, etc is enabled.气候韧性信息系统（Climate Resilience Information System, CRIS）为气候服务开发者提供数据与工具。本图层提供了1950年至2100年以十年为步长的VAR预估数据，涵盖3种共享社会经济路径（Shared Socioeconomic Pathways, SSPs）。所包含的变量如下： 年总降水量（单位：英寸）、单日最大降水量（单位：英寸）、连续5日最大降水量（单位：英寸）、连续10日最大降水量（单位：英寸）、日降水量超过90百分位的年总降水量（单位：英寸）、日降水量超过95百分位的年总降水量（单位：英寸）、日降水量超过99百分位的年总降水量（单位：英寸）、无降水年天数（干旱日数）、有降水年天数（湿润日数）、最长连续干旱日数、最长连续湿润日数。 本图层使用针对美国本土的LOCA2与STAR-ESDM降尺度气候模型数据，后续由美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）下属CICS-NC技术支持单元与Esri完成进一步处理，具体说明如下。 针对每个时间维度与SSP场景，已针对定义的地理单元计算平均值，涵盖县、部落区域、HUC-8流域。相关汇总值的推导过程可参阅《CRIS数据解读》（Understanding CRIS Data）。 本图层提供的时间与地理单元组合数据，基于16个气候预估结果的加权集合。关于集合中包含的模型及加权方法的更多细节，可参阅《CRIS数据制备》（CRIS Data Preparation）。 其他气候变量可通过CRIS官网的数据图库页面获取，或从下文表格中查阅。未来将新增阿拉斯加、夏威夷及波多黎各等地的地理单元数据。 ### 地理单元 本图层提供三类地理单元的预估数值：县、部落区域及HUC-8流域。 1. 县：基于美国人口普查局TIGER/Line 2022数据集发布版本。 2. 部落区域：基于美国人口普查局2022年发布的《美国印第安人/阿拉斯加原住民/夏威夷原住民区域数据集》，该数据集包含联邦及州认可的统计区域。 3. HUC-8流域：基于美国地质调查局（United States Geological Survey, USGS）水洗边界数据集（Washed Boundary Dataset），该数据集属于国家水文数据库Plus高分辨率版的一部分。 ### 时间范围 本数据集针对2005年至2100年的每年计算了气候阈值预估数值（例如：日最高温超过90°F的天数）。此外，还提供了1951年至2005年的模拟历史运行数据。模拟历史数据与未来预估数据已合并为单一时序序列，并按十年维度取平均值。 ### 气候情景 气候模型通过温室气体浓度与人类活动的未来情景来预估整体气候变化，这类不同的情景即称为共享社会经济路径（Shared Socioeconomic Pathways, SSPs）。本数据集提供3种SSP场景：2-4.5、3-7.0及5-8.5（注：STAR未收录SSP3-7.0）。 横杠前的数字代表社会行为情景，横杠后的数字代表2100年时与温室气体浓度情景相关的辐射强迫强度（单位：瓦每平方米），辐射强迫越高则变暖程度越强。 目前尚无法确定哪种情景最符合实际，但SSP 2-4.5目前与第26届联合国气候变化大会（Conference of the Parties 26, COP26）达成的国际减排目标相符。基于当前排放趋势，SSP3-7.0或为最贴合实际的情景。SSP5-8.5则作为警示情景，展示了若不采取温室气体减排措施将出现的最坏情况。 ### 数据导出 本数据集支持导出为形状文件（shapefiles）、地理数据库（geodatabases）、GeoJSON等格式。