Global carbon dioxide efflux from rivers enhanced by high nocturnal emissions

Datasets used in the publication "Global carbon dioxide efflux from rivers enhanced by high nocturnal emissions", published in Nature Geoscience (https://www.nature.com/articles/s41561-021-00722-3).

It consists of three files: 
-"all_hourly_flux": file with all data for all sites at hourly resolution
-"all_daily_flux.csv" : file with summarised values for all sites at daily resolution
-"all_site_metadata.csv" : file with metadata for each site.

Author of the repository: Gerard Rocher-Ros.
Contact: [e-mail]

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Units for the file: "all_hourly_flux"
code;label;units
site;Stream Id;none
datetime; time stamp; "YYYY-MM-DD HH:MM:SS"
co2; partial pressure of co2 in water; ppm
kgas; gas transfer velocity of co2; m d-1
q; discharge; L s-1
flux.mol.m2.h; flux of co2 to (+) or from (-) the atmosphere; mol C m-2 h-1

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Units for the file: "all_site_metadata"
code;label;units
site;Stream Id;none
lat;Latitude;degrees
long;Longitude;degrees
elevation;Elevation;m
country;Country;none
biome;Biome;none
canopy;Riparian coverage ;Category
slope;Channel slope;m m-1
q;Discharge;L s-1
temp;Water temperature ;°C
doc;DOC;mg L-1
no3;NO3-;µg L-1
nh4;NH4+;µg L-1
ph;pH ;none
cond;Conductivity;µS cm-1
area;Area;km2
bare;Bare;%
grass;Grass;%
crops;Crops;%
forest;Forest;%
mat;Mean annual temperature (MAT);°C
map;Mean annual precipitation (MAP);mm 
mar;Mean annual radiation (MAR);KJ m-2
tgpp;Total annual gross primary production (GPP);g C m-2
soc;Soil organic carbon content (SOC);g kg-1
pco2.day;pCO2 Day-time;
pco2.night;pCO2 Night-time;
pco2.diff.ppm;Absolute night-day difference pCO2;ppm
pco2.diff.per;Relative night-day difference pCO2;%
fco2.day;CO2 evasion day-time;g C m-2 d-1
fco2.night;CO2 evasion night-time;g C m-2 d-1
fco2.diff.gc;Absolute night-day difference fCO2;g C m-2
fco2.diff.per;Relative night-day difference fCO2;%
nobs.higher.night;Occurences when night > day;%