http://lod.bco-dmo.org/id/dataset/986798 eng; USA utf8 dataset Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact 2025-10-13 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) Dissolved organic matter, water quality, water isotopes, and discharge measurements of the Tapajós River, Brazil from 2016-2023 2026-01-20 publication 2026-01-20 revision Woods Hole Oceanographic Institution (WHOI BCO-DMO) 2026-02-04 publication https://doi.org/10.26008/1912/bco-dmo.986798.1 Martin R. Kurek Florida State University EOAS principalInvestigator Robert G. M. Spencer Florida State University EOAS principalInvestigator Robert Max Holmes Woodwell Climate Research Center principalInvestigator Amy M. McKenna Florida State University - National High Magnetic Field Lab principalInvestigator José Mauro Moura Federal University of Western Pará principalInvestigator Rafael Muniz Federal University of Western Pará principalInvestigator Bernhard Peucker-Ehrenbrink Woods Hole Oceanographic Institution principalInvestigator Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. publisher Cite this dataset as: Kurek, M. R., Muniz, R., Moura, J. M., Peucker-Ehrenbrink, B., Holmes, R. M., McKenna, A. M., Spencer, R. G. M. (2026) Dissolved organic matter, water quality, water isotopes, and discharge measurements of the Tapajós River, Brazil from 2016-2023. Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 1) Version Date 2026-01-20 [if applicable, indicate subset used]. doi:10.26008/1912/bco-dmo.986798.1 [access date] Methods and Sampling: &lt;p&gt;Water samples were collected near‐monthly from the Tapajós River upstream of Itaituba&amp;nbsp;Brazil&amp;nbsp;(-4.3375,-56.06953).&amp;nbsp;Three water samples (1 L) were collected at 0.5 m depth from the river across the channel in equal spacing and combined into a 4 L acid‐washed carboy to make a composite sample. The water was filtered through a 0.45 μm capsule filter with a peristaltic pump into acid‐rinsed high‐density polyethylene (HDPE) bottles. Filtered samples were kept cold during transport and immediately frozen upon transfer to the laboratory and kept in the dark until analysis. Samples for water isotope analysis were collected in 30 mL HDPE bottles that were filled to capacity, free of air, and stored in a dark, cool place prior to analysis.&lt;/p&gt; Funding provided by NSF Division of Ocean Sciences (NSF OCE) Award Number: OCE-2333961 Award URL: https://www.nsf.gov/awardsearch/show-award?AWD_ID=2333961 completed Martin R. Kurek Florida State University EOAS m.kurek@colostate.edu pointOfContact Robert G. M. Spencer Florida State University EOAS 850-645-0955 Earth, Ocean & Atmospheric Science 303 Oceanography Building Tallahassee FL 32306 USA rgspencer@magnet.fsu pointOfContact Robert Max Holmes Woodwell Climate Research Center rmholmes@woodwellclimate.org pointOfContact Amy M. McKenna Florida State University - National High Magnetic Field Lab mckenna@magnet.fsu.edu pointOfContact José Mauro Moura Federal University of Western Pará jmaurosm@gmail.com pointOfContact Rafael Muniz Federal University of Western Pará rafaelmuniz.cc@gmail.com pointOfContact Bernhard Peucker-Ehrenbrink Woods Hole Oceanographic Institution bpeucker@whoi.edu pointOfContact asNeeded Dataset Version: 1 Unknown Sample_Name Date Date_ISO lat_dd lon_dd Discharge_on_sampling_day Mean_monthly_discharge Mean_daily_air_temp Daily_precipitation Mean_monthly_air_temp Monthly_precipitation DOC FI a350 S275_to_295 S350_to_400 SUVA254 perc_CHO perc_CHON perc_CHOS perc_CHONS perc_CA perc_PPh low_OC_HUP_perc high_OC_HUP_perc high_OC_Ali_perc low_OC_Ali_perc Assigned_formulae RMS_Error Mass H_to_C O_to_C N_to_C_x1000 S_to_C_x1000 AImod DBE DBE_C NOSC perc_IOS Water_temp SpC O2sat O2 pH FDOM C1 C2 C3 C4 C5 d2H d18O D_excess Horiba Scientific Aqualog (Horiba Ltd., Kyoto, Japan) dual‐isotope Cavity Ringdown Spectroscopy (CRDS, 2130i/2140i, Picarro Inc., USA) theme None, User defined sample identification date latitude longitude No BCO-DMO term air temperature precipitation rate dissolved organic Carbon mass water temperature at measurement depth specific conductance O2 saturation dissolved Oxygen pH fDOM d2H oxygen 16 to oxygen 18 ratio featureType BCO-DMO Standard Parameters Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Horiba Aqualog spectrofluorometer Picarro L2130-I deltaD/delta18O Isotopic Water Analyzer Shimadzu TOC-L Analyzer YSI Professional Plus Multi-Parameter Probe instrument BCO-DMO Standard Instruments otherRestrictions otherRestrictions Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use. RAPID: El Nino Event Impacts on Organic Matter Export and Composition in the Amazon River https://osprey.bco-dmo.org/project/935522 RAPID: El Nino Event Impacts on Organic Matter Export and Composition in the Amazon River <p><em>NSF Award Abstract:</em><br /> The Amazon River is one of the largest sources of freshwater and carbon to the ocean. Thus, understanding the factors that influence freshwater delivery from the Amazon River is important for understanding the carbon cycle of the Amazon River and the receiving Atlantic Ocean. El Niño–Southern Oscillation (ENSO) is a periodic event that causes changes in winds and sea surface temperature over the tropical eastern Pacific Ocean and affects climate in the tropics and subtropics. The National Weather Service predicts that El Niño conditions are likely to form across the Pacific during Summer 2023. These conditions are expected to last through February 2024. This event is expected to impact precipitation and air temperatures in the Amazon Basin and freshwater delivery from the Amazon River. This project aims to study the amount and chemical composition of dissolved organic carbon delivered from the Amazon River to the Atlantic Ocean during the 2023-2024 El Niño event. Scientists involved in this project plan to collect samples from late Summer 2023 through late Summer 2024. The study will identify conditions before, during and after this event. This unique set of samples will enable the team of scientists to study how ENSO influences the delivery of organic carbon to the coastal ocean.<br /> This project provides support for an early career researcher and promotes international cooperation and inclusivity between researchers from the United States of America and researchers in Brazil who are directly impacted by the changing Amazon River.</p> <p>This project examines how El Niño Southern Oscillation (ENSO) anomalies impact the export of dissolved organic carbon (DOC) and composition of dissolved organic matter (DOM) from the Amazon River to the Atlantic Ocean. Based on recent studies, it has been hypothesized that the upcoming 2023 El Niño event will reduce the annual DOC flux and proportion of exported terrestrial DOM from the Amazon River compared to non-ENSO and La Niña years. This hypothesis will be examined by linking established state-of-the-art optical and molecular-level characterization techniques (e.g., Fourier-transform ion cyclotron resonance mass spectrometry; FT-ICR MS) with DOC flux calculations over the course of an El Niño year. Analyzing both bulk DOC fluxes and the molecular-level composition will reveal how the quantity and quality of DOM export will change monthly in response to reduced precipitation and higher temperature across the Amazon Basin and headwaters. DOC fluxes as well as detailed characterizations (FT-ICR MS, optical, fluorescence analysis) of DOM sampled from the furthest downstream Amazon River gauging station at Óbidos (Brazil) will be directly compared to results obtained from the 2011-2012 La Niña year and the following 2012-2013 hydrologically normal year to determine how global climate anomalies impact the DOC export to marine systems and to create a framework for future predictions. Data obtained from this proposed study will lay the foundations for larger studies investigating how ENSO cycles impact discharge and carbon export from other major tropical-subtropical rivers and ultimately, how ENSO cycles impact global land-ocean carbon export.</p> <p>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.</p> ENSO impact on Amazon River DOC and DOM largerWorkCitation project eng; USA oceans -56.06953 -56.06953 -4.3375 -4.3375 2016-01-28 2023-11-30 Amazon River basin 0 BCO-DMO catalogue of parameters from Dissolved organic matter, water quality, water isotopes, and discharge measurements of the Tapajós River, Brazil from 2016-2023 Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact http://lod.bco-dmo.org/id/dataset-parameter/992592.rdf Name: Sample_Name Units: unitless Description: <p>Discrete sample name</p> http://lod.bco-dmo.org/id/dataset-parameter/992593.rdf Name: Date Units: unitless Description: <p>Sampling date</p> http://lod.bco-dmo.org/id/dataset-parameter/992594.rdf Name: Date_ISO Units: unitless Description: <p>Sampling date in ISO 8601 format</p> http://lod.bco-dmo.org/id/dataset-parameter/992595.rdf Name: lat_dd Units: decimal degrees Description: <p>Sampling site latitude</p> http://lod.bco-dmo.org/id/dataset-parameter/992597.rdf Name: lon_dd Units: decimal degrees Description: <p>Sampling site longitude</p> http://lod.bco-dmo.org/id/dataset-parameter/992598.rdf Name: Discharge_on_sampling_day Units: cubic meters per second (m3 s-1) Description: <p>River discharge on sampling day</p> http://lod.bco-dmo.org/id/dataset-parameter/992599.rdf Name: Mean_monthly_discharge Units: cubic meters per second (m3 s-1) Description: <p>Mean monthly river discharge</p> http://lod.bco-dmo.org/id/dataset-parameter/992600.rdf Name: Mean_daily_air_temp Units: degrees Celsius (degC) Description: <p>Mean daily air temperature</p> http://lod.bco-dmo.org/id/dataset-parameter/992601.rdf Name: Daily_precipitation Units: millimeters (mm) Description: <p>Daily precipitation</p> http://lod.bco-dmo.org/id/dataset-parameter/992602.rdf Name: Mean_monthly_air_temp Units: degrees Celsius (degC) Description: <p>Mean monthly air temperature</p> http://lod.bco-dmo.org/id/dataset-parameter/992603.rdf Name: Monthly_precipitation Units: millimeters (mm) Description: <p>Monthly total precipitation</p> http://lod.bco-dmo.org/id/dataset-parameter/992604.rdf Name: DOC Units: milligrams per liter (mg L-1) Description: <p>Dissolved Organic Carbon concentration</p> http://lod.bco-dmo.org/id/dataset-parameter/992605.rdf Name: FI Units: unitless Description: <p>Fluorescence Index</p> http://lod.bco-dmo.org/id/dataset-parameter/992606.rdf Name: a350 Units: per meter (m-1) Description: <p>Naperian absorbance at 350 nm (m-1, Naperian)</p> http://lod.bco-dmo.org/id/dataset-parameter/992607.rdf Name: S275_to_295 Units: per nanometer (nm-1) Description: <p>Spectral slope from 275-295 nm</p> http://lod.bco-dmo.org/id/dataset-parameter/992608.rdf Name: S350_to_400 Units: per nanometer (nm-1) Description: <p>Spectral slope from 350-400 nm</p> http://lod.bco-dmo.org/id/dataset-parameter/992609.rdf Name: SUVA254 Units: liters per milligram carbon per meter (L mg C-1 m-1) Description: <p>Specific UV absorbance at 254 nm (L mg C-1 m-1)</p> http://lod.bco-dmo.org/id/dataset-parameter/992610.rdf Name: perc_CHO Units: percent (%) Description: <p>Percent CHO-containing molecular formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992611.rdf Name: perc_CHON Units: percent (%) Description: <p>Percent CHOn-containing molecular formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992612.rdf Name: perc_CHOS Units: percent (%) Description: <p>Percent CHOS-containing molecular formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992613.rdf Name: perc_CHONS Units: percent (%) Description: <p>Percent CHONS-containing molecular formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992614.rdf Name: perc_CA Units: percent (%) Description: <p>Percent condensed aromatic molecular formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992615.rdf Name: perc_PPh Units: percent (%) Description: <p>Percent polyphenolic molecular formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992616.rdf Name: low_OC_HUP_perc Units: percent (%) Description: <p>Percent highly unsaturated and phenolic (low O/C) molecular formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992617.rdf Name: high_OC_HUP_perc Units: percent (%) Description: <p>Percent highly unsaturated and phenolic (high O/C) molecular formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992618.rdf Name: high_OC_Ali_perc Units: percent (%) Description: <p>Percent aliphatic (high O/C) molecular formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992619.rdf Name: low_OC_Ali_perc Units: percent (%) Description: <p>Percent aliphatic (low O/C) molecular formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992620.rdf Name: Assigned_formulae Units: unitless Description: <p>Number of assigned molecular formulae</p> http://lod.bco-dmo.org/id/dataset-parameter/992621.rdf Name: RMS_Error Units: unitless Description: <p>Root mean squared error of assigned molecular formulae</p> http://lod.bco-dmo.org/id/dataset-parameter/992622.rdf Name: Mass Units: daltons (Da) Description: <p>Measured mass</p> http://lod.bco-dmo.org/id/dataset-parameter/992623.rdf Name: H_to_C Units: unitless Description: <p>H atoms/C atoms (abundance weighted average)</p> http://lod.bco-dmo.org/id/dataset-parameter/992624.rdf Name: O_to_C Units: unitless Description: <p>O atoms/C atoms (abundance weighted average)</p> http://lod.bco-dmo.org/id/dataset-parameter/992625.rdf Name: N_to_C_x1000 Units: unitless Description: <p>N atoms/C atoms (abundance weighted average x1000)</p> http://lod.bco-dmo.org/id/dataset-parameter/992626.rdf Name: S_to_C_x1000 Units: unitless Description: <p>S atoms/C atoms (abundance weighted average x1000)</p> http://lod.bco-dmo.org/id/dataset-parameter/992627.rdf Name: AImod Units: unitless Description: <p>Modified aromaticity index (abundance weighted average)</p> http://lod.bco-dmo.org/id/dataset-parameter/992628.rdf Name: DBE Units: unitless Description: <p>Double bond equivalents (abundance weighted average)</p> http://lod.bco-dmo.org/id/dataset-parameter/992629.rdf Name: DBE_C Units: unitless Description: <p>Double bond equivalents/C atoms (abundance weighted average)</p> http://lod.bco-dmo.org/id/dataset-parameter/992630.rdf Name: NOSC Units: unitless Description: <p>Nominal oxidation state of C (abundance weighted average)</p> http://lod.bco-dmo.org/id/dataset-parameter/992631.rdf Name: perc_IOS Units: percent (%) Description: <p>Percent of Island of Stability formulae (% relative abundance)</p> http://lod.bco-dmo.org/id/dataset-parameter/992632.rdf Name: Water_temp Units: degrees Celsius (degC) Description: <p>Water temperature</p> http://lod.bco-dmo.org/id/dataset-parameter/992633.rdf Name: SpC Units: microSiemens per centimeter (uS cm-1) Description: <p>Specific Conductivity</p> http://lod.bco-dmo.org/id/dataset-parameter/992634.rdf Name: O2sat Units: percent (%) Description: <p>Dissolved oxygen (% saturation)</p> http://lod.bco-dmo.org/id/dataset-parameter/992635.rdf Name: O2 Units: milligrams per liter (mg L-1) Description: <p>Dissolved oxygen concentration (mg L-1)</p> http://lod.bco-dmo.org/id/dataset-parameter/992636.rdf Name: pH Units: pH scale Description: <p>pH</p> http://lod.bco-dmo.org/id/dataset-parameter/992637.rdf Name: FDOM Units: relative fluorescence units (RFU) Description: <p>Total fluorescence of identified peak maxima (Relative Fluorescence Units)</p> http://lod.bco-dmo.org/id/dataset-parameter/992638.rdf Name: C1 Units: percent (%) Description: <p>Percentage of fluorescence component 1 from the PARAFAC model</p> http://lod.bco-dmo.org/id/dataset-parameter/992639.rdf Name: C2 Units: percent (%) Description: <p>Percentage of fluorescence component 2 from the PARAFAC model</p> http://lod.bco-dmo.org/id/dataset-parameter/992640.rdf Name: C3 Units: percent (%) Description: <p>Percentage of fluorescence component 3 from the PARAFAC model</p> http://lod.bco-dmo.org/id/dataset-parameter/992641.rdf Name: C4 Units: percent (%) Description: <p>Percentage of fluorescence component 4 from the PARAFAC model</p> http://lod.bco-dmo.org/id/dataset-parameter/992642.rdf Name: C5 Units: percent (%) Description: <p>Percentage of fluorescence component 5 from the PARAFAC model</p> http://lod.bco-dmo.org/id/dataset-parameter/992643.rdf Name: d2H Units: per mil (0/00) Description: <p>d2H (delta2H) of River water</p> http://lod.bco-dmo.org/id/dataset-parameter/992644.rdf Name: d18O Units: per mil (0/00) Description: <p>d18O (delta18O) of River water</p> http://lod.bco-dmo.org/id/dataset-parameter/992645.rdf Name: D_excess Units: per mil (0/00) Description: <p>Deuterium excess of River water</p> GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact https://doi.org/10.26008/1912/bco-dmo.986798.1 download onLine dataset &lt;p&gt;Water samples were collected near‐monthly from the Tapajós River upstream of Itaituba&amp;nbsp;Brazil&amp;nbsp;(-4.3375,-56.06953).&amp;nbsp;Three water samples (1 L) were collected at 0.5 m depth from the river across the channel in equal spacing and combined into a 4 L acid‐washed carboy to make a composite sample. The water was filtered through a 0.45 μm capsule filter with a peristaltic pump into acid‐rinsed high‐density polyethylene (HDPE) bottles. Filtered samples were kept cold during transport and immediately frozen upon transfer to the laboratory and kept in the dark until analysis. Samples for water isotope analysis were collected in 30 mL HDPE bottles that were filled to capacity, free of air, and stored in a dark, cool place prior to analysis.&lt;/p&gt; Specified by the Principal Investigator(s) &lt;p&gt;EEMs were corrected for lamp intensity, inner filter effects, and normalized to Raman units. Parallel factor analysis&lt;/p&gt; &lt;p&gt;(PARAFAC) was modeled in MATLAB with the drEEM toolbox for 81 individual EEMs and validated using core consistency diagnostics and splithalf validation , yielding a 5‐component model that explained 99.93% of the variance.&lt;/p&gt; &lt;p&gt;Mass spectral peaks (&amp;gt;6σ root‐mean‐square (RMS) baseline noise) were exported to a peak list and processed using PetroOrg. Molecular formulae were assigned to ions constrained by C4‐75H4‐150O1‐30N0‐4S0‐2 not exceeding 300 ppb error.&amp;nbsp;&lt;/p&gt; &lt;p&gt;Water isotope data post‐processing included amount‐linearity correction for OA‐ICOS data, memory correction and normalization to the VSMOW‐SLAP scale using LIMS for Lasers 2015.&amp;nbsp;&lt;/p&gt; Specified by the Principal Investigator(s) * Sheet 1 of submitted file &quot;Tapajos_ds1_02-12-25.xlsx&quot; was imported into the BCO-DMO data system for this dataset.  Table will appear as Data File: 986798_v1_tapajos_dom.csv (along with other download format options). * Column names adjusted to conform to BCO-DMO naming conventions designed to support broad re-use by a variety of research tools and scripting languages. [Only numbers, letters, and underscores.  Can not start with a number]. Column name dH changed to d2H for clarity as that was how it was described, as d2H (delta2H). * Date converted to ISO 8601 format * Location field contained both latitude and longitude in degrees minutes and seconds (e.g. '&quot;4°20'15.0&quot;S 56°04'10.3&quot;W&quot;') which was converted to separate lat_dd lon_dd columns (also converted to decimal degrees) Specified by BCO-DMO Data Managers asNeeded 7.x-1.1 Biological and Chemical Oceanography Data Management Office (BCO-DMO) Unavailable 508-289-2009 WHOI MS#36 Woods Hole MA 02543 USA info@bco-dmo.org http://www.bco-dmo.org Monday - Friday 8:00am - 5:00pm For questions regarding this resource, please contact BCO-DMO via the email address provided. pointOfContact PI Supplied Instrument Name: PI Supplied Instrument Description:Solid phase extracted water samples were analyzed on a custom‐built hybrid linear ion trap ultra‐high resolution FT‐ICR mass spectrometer equipped with a 21T superconducting solenoid magnet at the National High Magnetic Field Laboratory (Tallahassee, FL). Negatively charged ions from DOM were produced via electrospray ionization (ESI) at a flow rate of 500 nL min-1 via a syringe pump. Typical conditions for ion formation included: emitter voltage, -2.8–3.2 kV; S‐lens RF level, 40%; and heated metal capillary temperature, 350 degrees C. Instrument Name: Fourier Transform Ion Cyclotron Resonance Mass Spectrometer Instrument Short Name:FTICR MS Instrument Description: In Fourier Transform Ion Cyclotron Resonance Mass Spectrometry, the mass-to-charge ratio (m/z) of an ion is experimentally determined by measuring the frequency at which the ion processes in a magnetic field. These frequencies, which are typically in the 100 KHz to MHz regime, can be measured with modern electronics making it possible to determine the mass of an ion to within +/- 0.000005 amu or 5 ppm. Horiba Scientific Aqualog (Horiba Ltd., Kyoto, Japan) Horiba Scientific Aqualog (Horiba Ltd., Kyoto, Japan) PI Supplied Instrument Name: Horiba Scientific Aqualog (Horiba Ltd., Kyoto, Japan) PI Supplied Instrument Description:UV‐visible absorbance spectra were measured at room temperature in a 1‐cm quartz cuvette with a Horiba Scientific Aqualog (Horiba Ltd., Kyoto, Japan) at wavelengths of 230–800 nm. Excitation‐Emission matrices (EEMs) from fluorescence spectra were measured at room temperature in a 1‐cm quartz cuvette using a Horiba Scientific Aqualog (Horiba Ltd., Kyoto, Japan). EEMs were collected at 250– 500 nm excitation wavelengths and 300–600 nm emission wavelengths with 5 and 2 nm intervals, respectively, at integration times ranging from 3 to 6s. Instrument Name: Horiba Aqualog spectrofluorometer Instrument Short Name:Horiba Aqualog Instrument Description: A benchtop optical spectrometer suitable for measuring coloured dissolved organic matter (CDOM). Outputs include absorbance spectra, fluorescence emission spectra, and fluorescence excitation-emission matrices. This instrument simultaneously measures absorbance spectra and fluorescence Excitation-Emission Matrices. It employs the Absorbance-Transmission Excitation Emission Matrix (A-TEEM) technique to acquire an Excitation Emission Matrix. dual‐isotope Cavity Ringdown Spectroscopy (CRDS, 2130i/2140i, Picarro Inc., USA) dual‐isotope Cavity Ringdown Spectroscopy (CRDS, 2130i/2140i, Picarro Inc., USA) PI Supplied Instrument Name: dual‐isotope Cavity Ringdown Spectroscopy (CRDS, 2130i/2140i, Picarro Inc., USA) PI Supplied Instrument Description:For water samples up to sampling dates of August 2017, analyses were conducted in replicate by Off‐Axis Integrated Cavity Output Spectroscopy (OA‐ICOS, TLWIA 45EP, Los Gatos Inc., USA) with nine injections per sample vial of which five were accepted. The later batch was analyzed, again in replicate, via dual‐isotope Cavity Ringdown Spectroscopy (CRDS, 2130i/2140i, Picarro Inc., USA) with six injections per vial (three accepted). Instrument Name: Picarro L2130-I deltaD/delta18O Isotopic Water Analyzer Instrument Short Name:Picarro L2130-I Instrument Description: A portable analyser designed for laboratories or field based isotope analysis. It uses Cavity Ring-Down Spectroscopy (CRDS) to measure the spectral signature of the molecule of interest. The instrument includes a closed-loop temperature and pressure control. The L2130-i can be used in all aspects of the water cycle: water vapor, liquid water, or water trapped in solids. It has a typical precision of 0.25 per mil for d18O and 1.20 per mil for dD in solid samples. Corresponding typical values for liquid samples are 0.011 per mil for d18O and 0.038 per mil for dD. PI Supplied Instrument Name: PI Supplied Instrument Description:Filtered  water samples were acidified (HCl, pH 2) and DOC concentrations were measured with a Shimadzu TOC‐L CPH high temperature catalytic oxidation total organic carbon analyzer (Shimadzu Corp., Kyoto, Japan). Instrument Name: Shimadzu TOC-L Analyzer Instrument Short Name:Shimadzu TOC-L Instrument Description: A Shimadzu TOC-L Analyzer measures DOC by high temperature combustion method. Developed by Shimadzu, the 680 degree C combustion catalytic oxidation method is now used worldwide. One of its most important features is the capacity to efficiently oxidize hard-to-decompose organic compounds, including insoluble and macromolecular organic compounds. The 680 degree C combustion catalytic oxidation method has been adopted for the TOC-L series. http://www.shimadzu.com/an/toc/lab/toc-l2.html Community Standard Description: http://onto.nerc.ac.uk/CAST/124.html PI Supplied Instrument Name: PI Supplied Instrument Description:In situ water temperature, dissolved oxygen (DO), specific conductivity (SpC), and pH were measured in the center of the river channel at 0.5 m depth with a calibrated YSI Professional Plus multimeter. Instrument Name: YSI Professional Plus Multi-Parameter Probe Instrument Short Name:YSI ProPlus Instrument Description: The YSI Professional Plus handheld multiparameter meter provides for the measurement of a variety of combinations for dissolved oxygen, conductivity, specific conductance, salinity, resistivity, total dissolved solids (TDS), pH, ORP, pH/ORP combination, ammonium (ammonia), nitrate, chloride and temperature. More information from the manufacturer.