USER GUIDES

A user guide is available for the MEGAN3.1 modeling system

CODE

Code available for the three MEGAN3.1 components include preprocessor (FORTRAN code), emission factor processor (Python code), and emission calculator (FORTRAN code).

INPUT VARIABLES: The following data need to be processed to obtain values for your model domain

1. LANDCOVER (Required)

• Leaf Area Index of vegetation covered surfaces: LAIv (US, North America and Global data)
• Growth forms: crops, grass, shrub, total tree, needleleaf tree fraction, tropical tree fraction (Global data sets with ~1km resolution)
• Ecotype: Global dataset with detailed ecotype information for the USA (based on LANDFIRE data) and a relatively coarse ecotype information outside of the USA: ecotype

2. Soil nitrogen emission module inputs

• Soil NO model inputs (Global)

3. Stress response algorithm inputs (Optional- used only if you want to include stress responses)

• Isoprene Drought Activity Factor, gammaSM (global, years 2005 to 2014):

These are netcdf format files with monthly values of gammaSM on a global 0.5 degree grid. They were calculated using the approach described by Jiang et al. Atmos Environ , 2018 https://doi.org/10.1016/j.atmosenv.2018.01.026 and can be input into MEGAN3.

• W126 ozone index (US)

EMISSION CALCULATOR TEST CASES (Example input/output data for some specific model domains)

• Southern US (12 km grid) inputs: Note that this is a 1.2 Gb file
• Southern US (12 km grid) outputs: Note that this is a 0.4 Gb file
• North America (36 km grid) inputs: Note that this is a 0.6 Gb file