Terrestrial Condition Assessment (TCA) Nitrogen Deposition

Direct Download (Raster Data Gateway) Objective: Evaluate the impact of atmospheric nitrogen deposition on various ecosystem components including lichens, tree species (both growth and mortality), mycorrhizal communities, herbaceous plant species (changes in species richness), and leaching. Data: Deposition data is the 3-year average output from the Total Deposition (TDep) modeling system (https://nadp.slh.wisc.edu/committees/tdep/). TDep uses measurement-model fusion to bias correct modelled estimates (Tdep Program, https://nadp.slh.wisc.edu/committees/tdep/). TDep uses observations of air concentrations from the Clean Air Status and Trends Network (CASTNET) for measurements of dry deposition and observations of precipitation and precipitation chemistry from various National Atmospheric Deposition Program (NADP) networks. These observations are interpolated and used to create seasonal bias surfaces for results generated from CMAQ. Bias-adjusted CMAQ results are then merged with observations to create a set of deposition estimates that better align with measurements than model results alone. The full description of this methodology is available in: Schwede et al., 2014. There is a two year lag between the source data and the TCA Assessment year, so source data 3-year ranges with assessment year in parentheses are: 2016-2018 (2020 assessment), 2017-2019 (2021 assessment), 2018-2020 (2022 assessment), 2019-2021 (2023 assessment), 2020-2022* (2024 assessment). *The data used in the 2024 assessment had a small gap in western North and South Dakota, which was filled with data from the 2019-2021 product due to the small amount of interannual variability in the region. Data Format: Raster data are continuous Units: kg/ha/yr Spatial Resolution: 400m (resampled from 4km) Source data: Total Deposition Science Committee (TDep) Additional Resources: Details on Method Changes and Source Data Versions Overview of the Terrestrial Condition Assessment: TCA Hubsite or Landfire Office Hour Presentation Explore the results of the most recent assessment: TCA Interactive Data Viewer Learn more about the TCA KPI: TCA Dashboard *if you have trouble viewing the Dashboard, please submit a Tableau Viewer Access Request直接下载（栅格数据网关） 研究目标：评估大气氮沉降对各类生态系统组分的影响，涵盖地衣、树木物种（包括生长与死亡率）、菌根群落、草本植物物种（物种丰富度变化）以及淋溶现象。 数据：沉降数据为总沉降（Total Deposition, TDep）模拟系统的3年平均输出（数据来源：https://nadp.slh.wisc.edu/committees/tdep/）。TDep采用测量-模型融合方法对模拟估算值进行偏差校正（TDep项目，https://nadp.slh.wisc.edu/committees/tdep/）。TDep借助清洁空气状况与趋势网络（Clean Air Status and Trends Network, CASTNET）的空气浓度观测数据开展干沉降测量，并利用各类国家大气沉降项目（National Atmospheric Deposition Program, NADP）网络的降水及降水化学观测数据。上述观测数据经插值处理后，用于为CMAQ生成的结果构建季节偏差校正面。随后将经过偏差校正的CMAQ结果与观测数据融合，生成一组相较于单纯模型结果更贴合实测值的沉降估算值。该方法的完整说明可参见：Schwede等，2014年。 源数据与陆地状况评估（Terrestrial Condition Assessment, TCA）评估年份存在两年的时间滞后，因此源数据3年时段与对应评估年份的对应关系如下（评估年份标注于括号内）：2016-2018年（2020年评估）、2017-2019年（2021年评估）、2018-2020年（2022年评估）、2019-2021年（2023年评估）、2020-2022*（2024年评估）。*2024年评估所使用的数据在北达科他州西部与南达科他州西部存在小幅数据空缺，鉴于该区域年际变率较小，我们采用2019-2021年产品的数据进行了填补。 数据格式：栅格数据为连续型数据 单位：千克/公顷/年（kg/ha/yr） 空间分辨率：400米（由4千米分辨率重采样得到） 源数据：总沉降科学委员会（Total Deposition Science Committee, TDep） 补充资源：方法变更与源数据版本详情、陆地状况评估（TCA）枢纽站点或Landfire在线研讨会演示文稿、探索最新评估结果：TCA交互式数据查看器、了解更多关于TCA关键绩效指标（Key Performance Indicator, KPI）的信息：TCA控制面板（Dashboard）。*若无法正常查看控制面板，请提交Tableau查看器访问申请。