Introduction to Rapidly Developing Cumulous Area (RDCA) product and its development with Himawari-8

The Japan Meteorological Agency (JMA) began operation with next generation geostationary satellite, Himawari-8 on July 7, 2015. This satellite carries the Advanced Himawari Imager (AHI), whose observation functions significantly improved over that of the predecessor MTSAT-series satellites. AHI acquires multi-spectral imageries very frequently (10 minute full disk imagery and 2.5 minute Japan area imagery). JMA has taken advantage of this rapid refreshed data to provide Rapidly Developing Cumulous Area (RDCA) product, which is similar to Convective initiation (CI) product by GOES-R, particularly for aviation user.

During the MTSAT-era, this product utilized only two bands (one infrared band (10.4 um) and one visible band (0.64 um)) for assessing cloud top surface condition and time difference of cloud top height. Then this product was not operated in the night time because of visible band usage restrictions. Now that AHI enables to leverage a variety of observation bands (six infrared bands and one visible band) for estimating cloud parameter, JMA has updated RDCA product to operate all day in 2016.

RDCA product statistically estimates the strength of cloud development by using simple cloud tracking method. However, the current method reaches the limits to accurately detect RDCA due to miss-cloud tracking and false detection area. Therefore new algorithms, the successive cloud tracking including cloud object and cloud mask for extracting developing cumulous, are developed to overcome these difficulties. JMA aims to further improvement in RDCA product by introducing new methods. The presentation will show the aspect of these algorithms and the difference between new and original methods.