On the Impact of Satellite Data Assimilation on Mineral Dust Predictions

Mineral dust plays a significant role in climate systems, air quality, and human health, making its accurate prediction essential. This study explores the impact of satellite data assimilation (DA) on mineral dust forecasts, with a focus on the first pre-operational DA system at the Barcelona Supercomputing Center (BSC) using VIIRS aerosol optical depth (AOD) observations.

Results from the DA system which employs the MONARCH (Multiscale Online Non-hydrostatic AtmospheRe Chemistry) model for VIIRS AOD assimilation will be presented. MONARCH contributes to the Barcelona Sand and Dust Storm Warning Advisory System (SDS-WAS) and has previously been used to produce a decadal dust reanalysis based on MODIS, showcasing its reliability in modeling and assimilating mineral dust related observations. The new NRT MONARCH DA system produces daily dust analyses and DA initialized forecasts with a 3 days range since October 2024. The presentation will discuss key methodological choices, including ensemble perturbations, with a particular emphasis on meteorological perturbations and their influence on dust assimilation. Evaluation against the operational control simulation, AERONET ground-based observations and other leading dust forecasting systems will provide a comprehensive assessment of forecast accuracy as a function of forecast range and insights about the impact of different DA setups for mineral dust predictions.

Additionally, the impact of offline satellite-estimated dust emissions on forecast quality will be analyzed with MONARCH. These emissions are derived using an ensemble Kalman Smoother applied to multi-year MONARCH simulations and VIIRS observations, providing a robust estimate of dust sources. This work underscores the importance of integrating diverse data sources to enhance dust modeling and prediction capabilities. The findings contribute to the development of more robust operational dust forecasting systems, with implications for climate research, air quality management, and health risk mitigation.