Impacts of a newly-developed aerosol climatology on numerical weather prediction using a global atmospheric forecasting model

摘要

New four-dimensional aerosol climatology for global weather forecasting model is developed to take aerosol direct effect into account and its impacts on numerical weather prediction are investigated. The proposed aerosol climatology provides the global distribution of monthly-varying species-wise aerosol optical depths with more realistic aerosol vertical profiles. Including aerosol climatology enhances vertical stratification by surface cooling and atmospheric heating through the lower atmosphere by affecting radiation budget. Weakened vertical mixing and reduced surface fluxes related to aerosol loading result in decreased cloud fraction, particularly in the lower atmosphere. Evaluation of medium-range forecasts using the proposed aerosol climatology shows the overall improvement statistically for large-scale variable with reducing their biases, and the alleviation of systematic biases of overestimated light precipitation over the northern hemisphere.