Progresses of Weather Modification Technologies and Applications in China from 2008 to 2018

Important progresses of weather modification technologies and application are made from 2008 to 2018 in China due to the strong requirements from drought relief, hail suppression, bioenvironmental protection, and important activities support. Supported by both national and provincial projects, important field experiments and achievements have been made in aspects of aerosols, cloud and fog structure and precipitation formation mechanism. The national weather modification operational model is established and utilized in real-time operation, and it can greatly improve the forecasting ability of properties and evolution of target clouds and plays an important role in designing operational plan. Some key observational instruments and seeding instrumentation relevant to weather modification such as airborne cloud particles measuring system, multi-channel microwave radiometer, X-band polarized Doppler radar, fog monitor, and advanced cloud-seeding rocket are developed and applied, and this achievement greatly improve the surveillance and identification of seeding condition and seeding ability. Advanced weather modification aircraft based on King-Air 350ER and M-60 are refitted and applied to weather modification activities through national and local projects of engineering construction, which largely improve the operational flight height, navigation time and seeding ability. The new weather modification technologies, such as ionization, femtosecond laser and acoustic wave etc., are tested in laboratory experiment. Important progresses are made on the mechanism and numerical simulation of snow formation induced by femtosecond laser.There are still many aspects, such as effectiveness evaluation, the theory and observation in identification of suitable conditions for weather modification operation, needing improvement. The research and application of new theories, technologies and methods relevant to weather modification should be further strengthened. The cloud is the target for weather modification operation, however, the knowledge and treatment of clouds and precipitation in atmospheric community is still semi-quantitative. The non-repeatability of natural clouds and precipitation processes and limitation of current weather modification technologies cause the difficulty of repeatable experiment of weather modification, and many uncertainties for effectiveness evaluation. The present weather prediction primarily depends on numerical models, and the incomplete quantitative treatments of cloud physical processes in these models restrict the accurate prediction of clouds and precipitation, and the application of model results is also challenging. It is critical to improve the observation ability of cloud structure and precipitation formation processes. The current remote sensing technologies in the phase detection of cloud particles and cloud dynamics are very limited and greatly impede the improvement of weather modification.