README -- describes the contents of CH4/v2023-04/ResME

Overview:
===============================================================================

This directory contains methane emissions data from hydroelectris reservoir
surfaces and dams, as estimated with the ResME ([Res]ervoir [M]ethane
[E]missions) model of Delwiche et al. (2022). Emissions estimates for
hydroelecric reservoirs in the GRanD database (Lehner et al., 2011) were
obtained from https://zenodo.org/record/6360747#.ZEgUFezMJLB and converted to
gridded netCDF files in ArcMap.

The emissions here represent an average between oligotrophic, mesotrophic, and
eutrophic systems. From Delwiche et al. (2022):

   Trophic status is a categorization reflecting the amount of biological
   productivity occurring in a water body. Trophic status is reported in the
   literature as oligotrophic (low productivity), mesotrophic (medium
   productivity), or eutrophic (high productiv-ity).... We therefore assume
   annual emissions are the average emissions between oligotrophic, mesotrophic,
   and eutrophic systems. 

The emissions provided here also assume the reservoirs are stratified 12
months of the year year. Delwiche et al. (2022) states found it better to
assume stratification for 5 months out of the year, but since that 5 months
would vary by reservoir we chose to distribute emissions evenly throughout the
year.


Files:
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ResME_Dam_Emissions.0.1x0.1.nc

 -- CH4 emissions downstream of hydroelectric dams

    For all files:
    Resolution  : GENERIC 0.1 x 0.1 grid (3600 x 1800 boxes)
    Units       : kg m-2 s-1
    Timestamps  : 2022
    Compression : Level 1 (e.g. nccopy -d1)
    Chunking    : nccopy -c lon/3600,lat/1800,time/1

ResME_Surface_Emissions.0.1x0.1.nc

 -- CH4 surface ebullitive and diffusive emissions from hydroelectric reservoirs

    For all files:
    Resolution  : GENERIC 0.1 x 0.1 grid (3600 x 1800 boxes)
    Units       : kg m-2 s-1
    Timestamps  : 2022
    Compression : Level 1 (e.g. nccopy -d1)
    Chunking    : nccopy -c lon/3600,lat/1800,time/1


Reference:
===============================================================================

Delwiche, K.B., J.A. Harrison, J.D. Maasakkers, M.P. Sulprizio, J. Worden, D.J. Jacob, and E.M. Sunderland, Estimating drivers and pathways for hydroelectric reservoir methane emissions using a new mechanistic model, J. Geophys. Res. Biogeosciences,127, e2022JG006908, 2022, https://doi.org/10.1029/2022JG006908.