Cinrad data quality control and precipitation estimation

Abstract

Cinrad is the acronym describing China's next-generation weather radar that inherits the technology of the US national weather system Nexrad (WSR-88D) through a joint agreement between the two countries. More than 100 Cinrad systems have currently been deployed in China, but challenges exist for their wider application. The data quality assessment and the development of quantitative precipitation estimation for flood risk management will pose a significant challenge as the national system is both commissioned and further developed. This paper is based on an assessment of the data quality of a Cinrad system deployed in southern China and describes aspects of the initial data quality-control procedure. Precipitation was estimated for the Liuxihe River basin using 11 observed storms. The data quality-control procedure presented in this paper has four components, including volume-scan data, missing-data interpolation, abnormal-reflectivity detection and correction and fine-day reflectivity removal. The results indicate that the radar-estimated precipitation is consistent with that measured by conventional rain-gauge networks; also radar estimated precipitation can provide a better representation of the spatial distribution of the precipitation over the whole basin, and thereby has the potential to improve flood forecasting and warning systems. Given the importance of flooding to China, the continued quantitative development of the radar system is of national importance, particularly in terms of the tropical-cyclone-induced flooding prevalent in south China.