ALBERT

Description: This data set is predominantly sourced from the National Water Quality Monitoring Council (https://www.waterqualitydata.us/portal) and contains water quality data for the United States as well as climate and other ancillary data. This data was used to develop a model to explain groundwater dissolved organic carbon concentrations in the manuscript "Changes in global groundwater organic carbon driven by climate change and urbanization". Units for variables are included in the file "Units for Variables". --- National Water Quality Monitoring Council water chemistry data (https://www.waterqualitydata.us/portal) was obtained from: Chapelle, F. H., Bradley, P. M., Journey, C. A., & McMahon, P. B. (2013). Assessing the Relative Bioavailability of DOC in Regional Groundwater Systems. Ground water 51(3), doi:10.1111/j.1745-6584.2012.00987.x. --- Water table depth data obtained from: Fan, Y., Li, H., & Miguez-Macho, G. (2013). Global patterns of groundwater table depth. Science, 339, 940–943, doi:10.1126/science.1229881. --- Climatic data obtained from www.worldclim.org: Hijmans, R. J., Cameron, S. E., Parra, J. L., Jones, P. G., & Jarvis, A. (2005). Very high resolution interpolated climate surfaces for global land areas. International Journal of Climatology, 25, 1965-1978, doi:10.1002/joc.1276. --- Land use data obtained from: Channan, S., Collins, K., & Emanuel, W. R. (2014). Global mosaics of the standard MODIS land cover type data. University of Maryland and the Pacific Northwest National Laboratory, College Park, Maryland, USA. Retrieved from University of Maryland and the Pacific Northwest National Laboratory. - Friedl, M. A., Sulla-Menasche, D., Tan, B., Schneider, A., Ramankutty, N., Sibley, A., & Huang, X. (n.d.). MODIS Collection 5 global land cover: Algorithm refinements and characterization of new datasets, 2001-2012. Collection 5.1 IGBP Land Cover. Boston University, Boston, MA, USA.

Description: Total Suspended Particulate (TSP) aerosol samples were collected daily during the Stratospheric ozone: Halogen Impacts in a Varying Atmosphere (SHIVA) cruise (FS Sonne, SO218) during 16 - 28 November 2011 through the South China and Sulu Seas. The samples were collected by Birgit Quack and Anke Schneider of GEOMAR, Kiel, Germany. The aerosol sampler was situation on the roof of the ship's wheelhouse and collection time for each sample varied between 13.0 and 24.7 hours. Samples were extracted with ultrapure water and the major ions Na+, NH4+, Mg2+, K+, Ca2+, Cl-, NO3-, SO42-, oxalate and Br- were determined by ion chromatography (IC). Total soluble iodine (TSI) was determined by inductively coupled plasma - mass spectrometry (ICP-MS) and iodide (I-) and iodate (IO3-) were determined by IC-ICP-MS. The dataset contains the atmospheric concentrations of all measured soluble major ions (in nmol m-3) and iodine species (in pmol m-3). The data for iodine species are reported in “The influence of collection substrate and extraction method on the speciation of soluble iodine in atmospheric aerosols”, Chan Yodle, Alex R. Baker, in preparation for Analytical and Bioanalytical Chemistry.

Description: The relative abundance of the C32 1,15 long-chain alkyl diol (LCD) is an emerging proxy for the input of riverine aquatic particulate organic carbon (POC) into coastal oceans. This compound has the potential to complement other established proxies reflecting riverine terrestrial POC input and allows for a more nuanced assessment of riverine POC export to coastal seas. The current understanding of this proxy is, however, limited. In this study, we compare different indices for riverine sediment input to coastal marine waters (i.e. C32 1,15-LCD, BIT index and Fe/Ca ratio) in a source-to-sink assessment in the Amazon River drainage system and the northeast South American continental margin, and we test their down-core applicability in a marine gravity core containing late Pleistocene fluvial Amazonian sediments. We show that the relative abundance of the C32 1,15-LCD is highest in water bodies with low flow velocity and low turbidity such as the downstream portion of lowland tributaries and floodplain lakes. Relative C32 1,15-LCD abundance is lowest in Andean white water tributaries where autotrophic productivity is hindered by high turbidity and high flow velocity. We also find that suspended particulate matter from all major tributaries during the extreme 2015 dry season has a similar LCD distribution to that of floodplain lakes. This indicates that the chemical composition of the tributaries is less relevant for the LCD distribution than their physical properties such as flow velocity and turbidity. Results from marine surface sediments offshore the Amazon River estuary show significant positive correlations between all three studied proxies. In contrast, we find that the relative C32 1,15-LCD abundance in the down-core record is anti-correlated to the BIT index and Fe/Ca ratio. While BIT index and Fe/Ca ratio show high (low) values during Heinrich stadials (Dansgaard-Oeschger interstadials), the C32 1,15-LCD proxy shows the opposite signal. BIT values are also higher during Marine Isotope Stage (MIS) 2 than during MIS 3, in contrast to trends in the C32 1,15-LCD proxy. We posit that this pattern arises from a reduction in relative C32 1,15-LCD abundance and total LCD productivity in the Amazon River during MIS 2 when less-humid conditions and lower sea level led to reduced area of floodplains. During Heinrich stadials, Andean sediment input increased and led to higher turbidity that resulted in lower C32 1,15-LCD production. Our study shows that major changes in water discharge, sediment transport and river morphology can lead to discrepancies between the BIT index and the relative abundance of the C32 1,15-LCD. Thus, we suggest that Amazonian aquatic and terrestrial POC pools had contrasting responses to changes related to both climate (e.g. increased Andean precipitation) and river morphology (e.g. steeper along-channel slope due to falling and low stand sea level).