Estimating emissions from agricultural fires in the North China Plain based on MODIS fire radiative power

Crop-residue burning plays an important role in regional air quality and global climate change. The North China Plain, the largest winter wheat production district in China, experiences extensive crop fires during harvest seasons. Traditional methods to estimate emissions from crop fires depend strongly on burned area, biomass density, combustion efficiency, and emission factor. However, the uncertainty of burned area derived from satellites can be very large because the agricultural fires in China have small sizes and short duration. Using fire radiative power (FRP) to estimate emissions depends on a few numbers of parameters and has been applied in recent researches. In our study, emissions from crop burning in fields in the North China Plain were estimated using MODIS FRP derived from the Terra and Aqua satellites. The time-integrated FRP (i.e., fire radiative energy, FRE) in per fire pixel and fire counts are important factors in the estimation. The estimated results showed that high fire emissions were in 2005-2007 and 2012, while low emissions were in the fire years 2003 and 2004. Our estimated emissions were close to a previous study with an agricultural statistical approach, but significantly higher than emissions derived from the MODIS burned area product and Global Fire Emissions Database, respectively. The emission uncertainties in our study mainly originated from MODIS pixel resolution, emission factors, FRP measurements, and FRP parameterization. (C) 2015 Elsevier Ltd. All rights reserved.