Using wildfire tracer molecules to investigate the role of eolian dust and aerosols on pedogenesis and watershed chemistry in the Colorado Front Range

This data release compiles concentrations of biomass-burning biomarkers, including the monosaccharide anhydride levoglucosan and its stereoisomers mannosan and galactosan, measured in water samples collected during the summer of 2018 in the Green Lakes Valley (GLV) watershed of the Colorado Front Range (Table_1_Site_Locations.csv and Table_2_Constituents_Analyzed.csv). Sampling sites are shown as green triangles in the topographical map of the GLV watershed (Topographical_Map_Green_Lakes_Valley_watershed_NIWOT_LTER.jpg). The GLV watershed is part of the Niwot Ridge Long-Term Ecological Research network and is located approximately 35 kilometers west of Boulder, Colorado, on the eastern side of the Continental Divide. The east-facing watershed contains six permanent lakes and reservoirs that supply water to the City of Boulder. Water samples were collected from the 8-hectare lobate Rock Glacier 5 (RG5) and from 16 talus-slope and block-field sites located between Green Lake 4 and RG5 (Aerial_view_of_Rock_Glacier_5_near_GL5.jpg and Soil_patches_of_Rock_Glacier_5_near_GL5.jpg). Sampling locations included stream water, lake water, groundwater, snowmelt, springs, and seeps flowing below and around RG5 adjacent to Green Lake 5. Five sampling campaigns were conducted in 2018: once in late July, three times in August, and once in early September. The sampling occurred during a year characterized by extensive wildfire activity in Colorado, providing an opportunity to evaluate evidence of wildfire-derived biomass-burning inputs to alpine waters. The data presented in this release provide wildfire biomarker concentrations measured (Table_3_Wildfire_Biomarkers_Data.csv) and utilized in a companion manuscript investigating the role of eolian dust and aerosol inputs in alpine ecosystems. Quality assurance samples included duplicate environmental samples, procedural blanks, and continuing calibration verification measurements (Table_4_Quality_Assurance.csv). Levoglucosan, mannosan, and galactosan are wildfire biomarkers associated with the combustion of plant biomass which can be transported through smoke plumes into the atmosphere and later deposited in remote alpine environments. Their detection in meltwater and other water samples provides evidence of atmospheric deposition of biomass-burning products within the GLV watershed. Together, the biomarker observations and other geochemical evidence demonstrate that atmospheric inputs, including wildfire-derived material, contribute to alpine soil generation and watershed chemistry in addition to local bedrock weathering and cryospheric processes. The dataset provides a record of biomass-burning biomarkers in alpine waters collected during the 2018 wildfire season and supports evaluation of atmospheric wildfire deposition and its contribution to alpine watershed processes.