2022 Organic Matter Research Lab Sacramento, California Vectorized Fluorescence Data

The U.S. Geological Survey (USGS) California Water Science Center (CAWSC) Organic Matter Research Laboratory (OMRL) provides laboratory services and support to regional and national projects in the analysis of organic matter using the latest methods in absorbance and fluorescence spectroscopy. Optical measurements such as absorbance and fluorescence are used to gain insight into dissolved organic matter (DOM) composition, and can also serve as proxies for more expensive and difficult to obtain measurements. These techniques are relatively rapid and inexpensive and allow for the comprehensive tracking of DOM dynamics in aquatic ecosystems ranging from rivers and lakes to estuaries to open marine systems. Laboratory fluorescence measurements collected on the Aqualog can provide validation or verification of field-based instrument fluorescence measurements where the sensor arrays are encompassed by the full Aqualog array (Booth and others, 2023). This approach may be superior to the other correction approaches where interferences are large, especially in cases where the field sensor measurements constitute less than 10% of the fully corrected value. For projects that already collect discrete samples during field sensor maintenance visits, the cost and effort is minimal for the data quality benefit. Data presented here were analyzed by the U.S Geological Survey California Water Science Center Organic Matter Research Lab, Sacramento CA. This release contains vectorized fluorescence data measured on the Aqualog ® fluorometer January-December 2022.