Biogenic Emissions Inventory
Biogenic emissions are estimated using the MEGAN3.0 biogenics emissions model. MEGAN3.0 incorporates a new pre-processor (MEGAN-EFP) for estimating biogenic emission factors based on available landcover and emissions data. The MEGAN3.0 default datasets for plant growth form, ecotype, and emissions are utilized. Leaf Area Index (LAI) for non-urban grid cells is based on the year-specific 8-day 500-m resolution MODIS Terra/Aqua combined product (MCD15A2H). The LAI data is converted to LAIv, which represents the LAI for the vegetated fraction within each grid cell, by dividing the gridded MODIS LAI values by the Maximum Green Vegetation Fraction (MGVF) for each grid cell. The MODIS LAI product does not provide information on LAI in urban regions, so urban LAIv is estimated from the US Forest Service’s Forest Inventory and Analysis (FIA) urban tree plot data, processed through the i-Tree v6 software. Peak summertime urban LAIv for different urban regions is estimated, and this peak value is adjusted for each 8-day MODIS period based on the relative change in non-urban MODIS LAI across the state. Hourly meteorology is provided by WRF model simulations, and stress factor adjustments are not considered.