MOdern River archivEs of Particulate Organic Carbon: MOREPOC

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 (δ13C) values, 2,283 with radiocarbon activity (Δ14C) 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.

Data description

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_v1.1.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.

Table. 1 Description of the parameters of the MOREPOC v1.1 database.

Parameter
Description
MOREPOC column name

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

δ13C (‰)
δ13C values of POC (carbonate removed) in ‰
d13C_poc

δ13C uncertainty (1σ)
The analytical uncertainty for δ13C of POC
d13C_1sd

Δ14C (‰)
Δ14C values of POC (carbonate removed) in ‰
D14C_poc

Δ14C uncertainty (1σ)
The analytical uncertainty for Δ14C 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

Corg/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

Contributing Data

Please contact Yutian Ke at [e-mail] or  [e-mail] if you are interested in contributing your published or unpublished data to MOREPOC.

Citation

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.7055970.