Archived Extended Spring Indices Average and Anomaly Products (1981-2010 climate normal)

The Extended Spring Indices are mathematical models that predict the "start of spring" (timing of leaf out or bloom for species active in early spring) at a particular location. The USA National Phenology Network (USA-NPN) hosts a suite of gridded Extended Spring Indices products. In 2022, the USA NPN updated all long-term average and anomaly products in this suite to use the more recent climate normal period (1991-2020).<br>This record contains the archived layers that use the prior normal (1981-2010). The data consists of geotiff rasters with leaf out and bloom dates. The "average" files give leaf and bloom dates as day of year, averaged for the period 1981-2010. The "anomaly" files show for each year 1981-2021, the difference between that year's leaf out or bloom date and the long term average. <br>The products using updated normals can be accessed here: Extended Spring Indices, Continental United States, 1981 - Current Year<br><br><i>For inquiries regarding the contents of this dataset, please contact the Corresponding Author listed in the README.txt file. Administrative inquiries (e.g., removal requests, trouble downloading, etc.) can be directed to [e-mail]</i>

扩展春季指数（Extended Spring Indices）是一类用于预测特定地点“春季起始时间”（即早春活跃物种的展叶或开花时间）的数学模型。美国国家物候网络（USA National Phenology Network, USA-NPN）维护并发布了一套网格化的扩展春季指数产品集。2022年，USA-NPN将该产品集中所有长期平均与距平类产品更新为采用最新的气候基准期（1991-2020年）。
本数据集包含使用旧基准期（1981-2010年）的归档图层。数据采用GeoTIFF格式栅格存储，涵盖展叶与开花日期相关数据。其中“平均”文件以年积日形式给出1981-2010年时段的平均展叶与开花日期；“距平”文件则展示了1981-2021年各年份的展叶或开花日期与长期平均值的差值。
使用更新后基准期的产品可通过以下链接获取：扩展春季指数，美国本土，1981年-当前年份。

有关本数据集内容的咨询，请联系README.txt文件中列出的通讯作者。行政类问询（例如数据移除请求、下载故障等）可发送至[e-mail]