New technology and experiment of rocket dropsondes for typhoon observation

Abstract

This study presents a new technique for typhoon observations that is based on dropsondes launched by long-distance rockets instead of research aircraft. This technology was developed by Shanghai Typhoon Institute of China Meteorological Administration in collaboration with China Aerospace Science and Industry Corporation in the past three years. On October 3, 2015, this meteorological rocket was successfully launched for the first time into an offshore strong typhoon (Mujigae, 2015) located east of Hainan Island. Four dropsondes were subsequently deployed within 6 min by the rocket when it flew into the inner core of Mujigae from the launching city, Wanning in Hainan Province that was located 200 km away from the storm. Real-time data from the dropsondes were sent back to the observation station on the ground. The detailed profiles of wind, temperature and humidity were obtained, showing high quality according to comparisons with the near collocated GPS radio-sondes data. These dropsonde profiles captured some fine-scale wind structure in the Typhoon Mujigae with may be related to large eddies. This field experiment described in this study implied a potential use of this new dropsondes-deployment technique for future TC research and operation. The success of the field campaign with rocket-carrying dropsondes could provide an effective and direct observation technique for rapid and accurate access to the fine-scale structure of typhoon interior (different areas, but at the same time), and provide a new way to achieve the typhoon targeting sensitivity analysis related to forecasting. Showing the advantages of long-range, high-quality and high-precision, this new technique, when deployed from high altitudes could improve TC model initial condition and provide accurate estimates of storm intensity of offshore typhoons, resulting in improved operational TC track and intensity predictions, as proved by previous studies that used aircraft-deployed dropsondes. Under the support of the Economic and Social Commission for Asia and the Pacific (ESCAP) and World Meteorology Organization (WMO) Typhoon Committee, STI together with HKO organized the Experiment of Typhoon Intensity Change in Coastal Area (EXOTICCA) as an international cooperation project. This project carried out field experiments using rocket-platform sounding detection technology and other new typhoon field detection utilities. In the coming few years, EXOTICCA will also implement observations using man aircraft, unman aircraft, long-distance rockets and GPS sounding in South China Sea. It is believed that the new rocket deployment technology presented in this study when used in future field experiment will improve the track and intensity forecasts of typhoons.