2019年全球重点区域内陆水体有色可溶性有机物

有色可溶性有机物（CDOM），又称为黄色物质，是DOM中能强烈吸收紫外辐射和蓝光的那部分物质，能显著影响水下光场及水体中碳氮磷等生源要素的生物地球化学循环。CDOM主要由腐殖酸、富里酸和芳烃聚合物等物质组成的可溶性有机混合物，有效监测CDOM浓度对于评价水生环境DOM的相关水平和空间分布具有重要意义。有色可溶性有机物测量一般采用Shimadzu UV-Vis 2550 紫外可见分光光度计及配套5 cm 比色皿测定CDOM 吸光度，测量波长范围为200~800 nm，间隔为1 nm，采用当天超纯水Milli-Q 水为空白参比。通过即有公式换算得到吸收系数。由于CDOM 组成异常复杂，目前国内外广泛采用a(254)以表征水样中CDOM。本数据集是基于Sentinel2A/B传感器数据和支持向量回归算法生产的全球重点区域季度水体有色可溶性有机物产品。包含区域：京津冀、长三角、珠三角、斯里兰卡、印第安纳。

Colored Dissolved Organic Matter (CDOM), also referred to as yellow substance, is the fraction of Dissolved Organic Matter (DOM) that strongly absorbs ultraviolet radiation and blue light. It significantly impacts the underwater light field and the biogeochemical cycles of biogenic elements including carbon, nitrogen, and phosphorus in aquatic environments. CDOM is a soluble organic mixture primarily composed of humic acids, fulvic acids, aromatic polymers, and other similar substances. Effective monitoring of CDOM concentration is crucial for assessing the relevant levels and spatial distribution of DOM in aquatic habitats. For CDOM measurement, a Shimadzu UV-Vis 2550 ultraviolet-visible spectrophotometer paired with a matched 5 cm cuvette is typically employed to determine CDOM absorbance. The measurement wavelength ranges from 200 to 800 nm with a 1 nm interval, and Milli-Q ultrapure water collected on the same day is used as the blank reference. The absorption coefficient is calculated via established formulas. Due to the highly complex composition of CDOM, a(254) is currently widely adopted worldwide to characterize CDOM in water samples. This dataset is a global quarterly aquatic colored dissolved organic matter product for key regions, generated using Sentinel-2A/B sensor data and support vector regression (SVR) algorithm. The covered regions include the Beijing-Tianjin-Hebei Region, Yangtze River Delta, Pearl River Delta, Sri Lanka, and Indiana.