DOI: 10.5281/zenodo.7052448
title: MOdern River archivEs of Particulate Organic Carbon: MOREPOC

description: Modern River Archives of Particulate Organic Carbon (MOREPOC) version 1.1 is a new, open-access, georeferenced, global database, featuring data on POC in suspended particulate matter (SPM) collected at 233 locations across 121 major river systems. This database includes 3,546 SPM data entries, among which 3,053 with POC content, 3,402 with stable carbon isotope (δ<sup>13</sup>C) values, 2,283 with radiocarbon activity (Δ<sup>14</sup>C) values, 1,936 with total nitrogen content, and 299 with aluminum-to-silicon mass ratios (Al/Si). The MOREPOC database aims at being used by the Earth System community to build comprehensive and quantitative models for the mobilization, alteration, and fate of terrestrial POC. The supply of particulate organic carbon (POC) associated with terrigenous solids transported to the ocean by rivers plays a significant role in the global carbon cycle. To advance our understanding of the source, transport, and fate of fluvial POC from regional to global scales, databases of riverine POC are needed, including elemental and isotope composition data from contrasted river basins in terms of geomorphology, lithology, climate, and anthropogenic pressure. MOREPOC will benefit the scientific community carrying out research on riverine POC sources, transport, and fate, furthermore, helping inform and validate Earth system models to improve the ability to model and understand the global carbon cycle. Existing environmental raster global datasets for climate, geomorphology, lithology, tectonics, hydrology, and land use, also offer promising prospects for the use of MOREPOC for identifying the controls on POC fluxes and composition, in particular using advanced statistical analysis or machine learning techniques. Moreover, MOREPOC enables a better understanding of sources, transport, and fate of fluvial POC combined with some existing ocean sediment databases. Future updates of MOREPOC should include new bulk POC parameters as well as data on molecular fractions, thermal labile fractions, or specific components such as black carbon or fossil carbon, which should, in turn, provide additional insight into the alteration of riverine POC from source to sink, an essential feature of the global carbon cycle. <strong>Data description</strong> The MOREPOC database consists of two parts: 1) the master metadata (MOREPOC_v1.1); 2) the summarization of references and methods (MOREPOC_v1.1_RM). A Readme is provided to better understand all parameters provided in the MOREPOC v1.1 database. MOREPOC_v1.1 includes one table, avaible as Excel spreadsheet (.xslx), comma-limited table (.csv), and GIS shapefile (compiled in .rar) using WGS84 coordinate system. MOREPOC_v1.1.xlsx MOREPOC_v1.1.csv MOREPOC.rar (GIS shapefile) MOREPOC_v1.1_RM only provides one table, avaible as Excel spreadsheet (.xslx), comma-limited table (.csv). MOREPOC_v1.1_RM.xlsx MOREPOC_v1.1_RM.csv The database structure of MOREPOC is listed in Table.1 to understand all provided parameters, more information can be found in the companion manuscript. <strong>Table. 1 Description of the parameters of the MOREPOC v1.1 database.</strong> <strong>Parameter</strong> <strong>Description</strong> <strong>MOREPOC column name</strong> River name Name of the major river basin bas_id Sub river name Name of the sampled river/stream riv_id Country Name of country or places country Continent Name of the continent cont Sampling site/code Expedition sampling ID code Sampling date Time (month/day/year) when the SPM sample was collected time_m/d/y Latitude Decimal latitude using WGS 1984 lat Longitude Decimal longitude using WGS 1984 lon Sampling technique Method of SPM sampling type_spm Size fraction of SPM Reported size fractions analyzed fra_spm SPM concentration (mg/L) The total dry weight of SPM in mg per liter water column conc_spm POC concentration (mg/L) The total dry weight of POC in mg per liter water column conc_poc POC content (%) The total POC content of SPM in wt % per_poc POC content uncertainty (1σ) The analytical uncertainty for POC content (1σ) perc_poc_1sd δ<sup>13</sup>C (‰) δ<sup>13</sup>C values of POC (carbonate removed) in ‰ d13C_poc δ<sup>13</sup>C uncertainty (1σ) The analytical uncertainty for δ<sup>13</sup>C of POC d13C_1sd Δ<sup>14</sup>C (‰) Δ<sup>14</sup>C values of POC (carbonate removed) in ‰ D14C_poc Δ<sup>14</sup>C uncertainty (1σ) The analytical uncertainty for Δ<sup>14</sup>C of POC D14C_1sd Fraction modern (Fm) Fraction modern of POC F14C Radiocarbon ages (year) Radiocarbon ages before present (1950) age_14C TN content (%) The total nitrogen content of SPM in wt % perc_tn C<sub>org</sub>/N mass ratio Mass ratio of POC to TN in SPM cn_ratio Al/Si mass ratio Mass ratio of Al to Si in SPM alsi_ratio Reference Full list of citations of the data source ref Complete reference Complete information for cited references ref_c Measured parameters Summarization of elemental and isotopic carbon parameters measured para_m Calculated parameters Summarization of elemental and isotopic carbon parameters calculated para_c Filter Filter used to obtain SPM filter Acid The acid type used to remove carbonate in SPM acid Carbonate removal method The method used to remove carbonate in SPM m_acid Acid concentration The concentration of adopted acid to remove carbonate in SPM conc_acid carbonate removal temperature The environmental temperature for acid to remove carbonate in SPM temp_acid Carbonate removal duration The reaction time used for acid to remove carbonate in SPM time_acid Note Additional information for carbonate removal process note <strong>Contributing Data</strong> Please contact Yutian Ke at yutianke@caltech.edu or yutian.ke@universite-paris-saclay.fr if you are interested in contributing your published or unpublished data to MOREPOC. <strong>Citation</strong> Ke, Y. T., Calmels, D., Bouchez, J., Cécile, Q.: MOdern River archivEs of Particulate Organic Carbon: MOREPOC, Dataset version 1.1, Zenodo [dataset], https://doi.org/10.5281/zenodo.7052190.