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NEON Secchi深度（Secchi depth）数据采集项目中经过质量控制的原生采样分辨率数据。Secchi测量值反映水体透明度，而Secchi深度用于确定光线可穿透的深度。该值还可用于计算湖泊或河流中真光层（euphotic zone）的深度，这对浮游植物采样尤为重要。当执行任何针对湖泊或河流水体柱采样的标准操作流程（如地表水化学分析和浮游植物采样）时，会通过将Secchi盘下放至水体柱中并记录其从视野中消失的深度来采集Secchi数据。Secchi深度测量仅在无冰期进行，每年至少采集4次，最多可达12次以上。更多详情请参见本数据产品详情网页中“文档”部分列出的用户指南、操作协议及科学设计说明。