Secchi depth (DP1.20252.001)

This data product contains the quality-controlled, native sampling resolution data from NEON's Secchi depth data collection. Secchi measurements indicate water clarity, and secchi depth is used to determine the depth to which light penetrates. This value can also be used to calculate the depth of the euphotic zone in a lake or river, which is especially important for phytoplankton sampling. Secchi data are collected when collecting data for any standard operating procedure that samples the water column in a lake or river (e.g., surface water chemistry and phytoplankton) by lowering a Secchi disk through the water column, and recorded the depth(s) to which it disappears from view. Secchi depth measurements are collected only during ice-free periods, and are collected a minimum of 4 times per year, up to 12+ times per year. For additional details, see the user guide, protocols, and science design listed in the Documentation section in this data product's details webpage.

Latency:
The expected time from data and/or sample collection in the field to data publication is as follows, for each of the data tables (in days) in the downloaded data package. See the Data Product User Guide for more information.

dep_secchi: 30

本数据产品包含经过质量控制的原生采样分辨率数据，源自美国国家生态观测网络（National Ecological Observatory Network，NEON）的赛氏盘深度（Secchi depth）采集项目。赛氏盘测量值用于表征水体透明度，赛氏盘深度可用于确定光线穿透水体的深度。该数值还可用于计算湖泊或河流中的真光层（euphotic zone）深度，这对浮游植物采样工作尤为关键。
赛氏盘数据的采集流程为：在开展湖泊或河流水柱采样的各类标准作业程序（例如地表水化学与浮游植物采样）时，将赛氏盘（Secchi disk）下放至水柱中，记录其从视野中消失的深度。赛氏盘深度测量仅在无冰期开展，年度采集频次不少于4次，最高可达12次以上。如需了解更多细节，请查阅本数据产品详情网页中“文档”板块所列的用户指南、操作规范与科学设计方案。
延迟说明：
野外数据和/或样品采集至数据正式发布的预期耗时（单位：天），对应下载数据包内各数据表如下，详细信息请参阅《数据产品用户指南》。
dep_secchi：30