Estimates of Health Impacts and Radiative Forcing in Winter Haze in Eastern China through Constraints of Surface PM Predictions.

The Gridpoint Statistical Interpolation (GSI) Three-Dimensional Variational (3DVAR) data assimilation system is extended to treat the MOSAIC aerosol model in WRF-Chem, and to be capable of assimilating surface PM concentrations. The coupled GSI-WRF-Chem system is applied to reproduce aerosol levels over China during an extremely polluted winter month, January 2013. After assimilating surface PM concentrations, the correlation coefficients between observations and model results averaged over the assimilated sites are improved from 0.