North Temperate Lakes LTER: Color - Trout Lake Area 1989 - current

Color is measured four times per year in the seven northern study lakes (Allequash, Big Muskellunge, Crystal, Sparkling, and Trout lakes, unnamed lakes 27-02 [Crystal Bog] and 12-15 [Trout Bog]) on water samples that are filtered in the field through 0.45 micron capsule filters (0.45 um nuclepore membrane filters before 2015). A spectrophotometer is used to quantify color in the lab as absorbance units, at 1nm intervals between the wavelengths of 200 and 800 nm. All values are in absorbance units and are given as measurements at the path length of the employed cuvette and should be divided by the cuvette length for a comparable value at a pathlength of 1 cm. Sampling Frequency: 4 times annually. Number of sites: 7.

本数据集针对7处北部研究湖泊的水样每年开展4次色度测定，所涉湖泊包括Allequash湖、Big Muskellunge湖、Crystal湖、Sparkling湖、Trout湖，以及未命名湖泊27-02[Crystal Bog]和12-15[Trout Bog]。所有待测水样均在野外通过0.45微米胶囊式滤膜过滤；2015年前采用的过滤介质为0.45μm核孔膜滤膜（nuclepore membrane filters）。实验室中采用分光光度计（spectrophotometer），以200 nm至800 nm波长区间内每1 nm为间隔，以吸光度单位（absorbance units）量化水体色度。所有测量值均以吸光度单位呈现，为所用比色皿光程下的直接测定结果；若需获得光程为1 cm时的可比数值，需将原始测量值除以所用比色皿的实际光程长度。采样频率：每年4次；研究位点数量：7处。