The Applications of Feng Yun 4 A Satellite Products for Weather Monitoring over the Asian Regions

The applications of Feng Yun 4 A satellite products for weather monitoring over the Asian regions

CHAN Ying-wa and So Chi-kuen

Hong Kong Observatory

134A Nathan Road, Tsim Sha Tsui, Kowloon, Hong Kong, China

Tel:+852 2926 3074, Fax: +852 2311 9448, Email: ywchan@hko.gov.hk

The Hong Kong Observatory installed a Feng Yun 4A (FY4A) satellite data ground reception system at its King’s Park Meteorological Station in 2018 for enhancing its weather monitoring and forecasting services. The experimental FY4A satellite is equipped with various instruments, including the Advanced Geosynchronous Radiation Imager (AGRI) and Lightning Mapping Imager (LMI). The former instrument has 14 spectral bands in the range of 0.47mm to 13.5mm to enable provision of satellite imageries covering both the eastern and western regions of Asia. The latter instrument contains 400x600 pixel planar charge-coupled device (CCD) array camera to measure the total lightning over the Asian regions round-the-clock.

The FY4A’s visible, infrared and water vapour imageries improved HKO’s weather monitoring capability over the western Asian regions. For instances, the imageries enabled close watch of tropical cyclone Mekunu that affected the southern coast of the Arabian peninsula on 25-27 May 2018 and the evolution of deep convection associated with the northward advancement of the southwest monsoon over the Indian subcontinent in 2018. The imageries also provided great opportunity to study the potential influence of the Madden-Julian Oscillation (MJO) wave on the change of convection over the Indian Ocean. The FY4A’s LMI data provided a broad view of the potential lightning activities arising from severe convection that occurred over China, Indo-China, northern part of the South China Sea and northern India which would be useful for aviation applications and monitoring of rainstorm developments.

Both qualitative and quantitative comparison of the lightning locations and lightning frequency based on FY4A’s LMI data, global lightning data from a service provider and cloud-to-cloud and cloud-to-ground lightning detected by HKO’s Lightning Location Information System (LLIS) was conducted using several thunderstorm and rainstorm cases that occurred over southern China and the northern part of the South China Sea in the summer months of 2018. The HKO’s radar mosaic imageries were used as a cross reference to counter-check the validity of the lightning locations. Preliminary analysis showed that LMI data were generally consistent with global lightning data and LLIS information. However, LMI data seemed to underestimate the lightning occurrences in some occasions and more systematic comparison would be required.

This paper presents HKO’s work in establishing the FY4A satellite data reception system and the experiences gained in using FY4A data. Future plan of further development and utilization of FY4A products in operational weather monitoring is also described.