建立我国数值预报同化诊断系统的行动方案顶层设计

Top-Level Design of Action Plan for Developing CEMC Numerical Weather Prediction Data Assimilation Diagnosis System

数值预报系统已经发展成非常复杂的系统,对如此复杂的系统进行有效和协调的诊断是必要的。数值预报诊断是“基于问题、归于理解和终于协作”来解决问题而推动数值预报系统的进展。诊断一直是欧洲中期天气预报中心(ECMWF)研究和开发的一个活跃领域。面向ECMWF发展“从此处向何处去”,一个诊断战略是必不可少的。诊断是面向数值预报系统的所有环节及其组成部分。同化是数值预报的一个主要组成部件,而且它是上接观测、下连预报的一个综采工作面,因此它的诊断范围是巨大的。本文面向CMA四维变分同化系统,思考国际上先进气象业务中心的相关工作,在理解清楚“哪些是基本的”和“客观上必须做的”基础上,以程序流的全过程和业务研发的内在逻辑进行我国同化诊断系统的顶层设计,形成其总体架构,包括同化系统的“输入信息”“执行过程”“输出结果”“参数优化”和“新种类观测资料准入”的诊断,旨在初步形成一套日常例行的同化诊断能力。最后,面向工作的现实状况,提出开启这项工作的主要优先任务和开端性思考,特别是突出了它的前端基础任务和支撑性条件:通用、共用、特别是高度灵活性的同化诊断必备数据库建设;还思考了形成诊断工作固有属性的客观共识和按照它的实际样子,开启和推动中国气象局数值预报同化诊断系统研发基于“问题导向、科学理解和团结协作”的高质量发展。

Numerical weather prediction has evolved into a very complex system,hence effective and coordinated diagnosis of such a complex system has become a necessity.Complying with the principle of“based on the problem,understand the problem and then coordinate for the problem”,diagnosis for numerical weather prediction aims to solve problems and then to promote the development of numerical weather prediction system.Diagnosis has always been an active area of research and development at the European Centre for Medium-Range Weather Forecasts(ECMWF).A diagnostic strategy is essential for ECMWF to face“Where to go from here”.Diagnosis involves all aspects and components of the numerical weather prediction system.Data assimilation is an integral component of numerical weather prediction.It is the“coal-face”where forecasting model and observations“collide”and therefore the scope of diagnosis for data assimilation is immense.Centering on CMA four-dimensional variational assimilation system,this paper investigates the diagnosis work of advanced meteorological centers in the world,and then presents the top-level design of CEMC’s data assimilation diagnosis system in face of its fundamental and necessary components.Based on the program flow of the assimilation system and the internal logic of developing an operational assimilation system,its architecture includes diagnostics of input information,optimization process,output result,pre-specified parameters and access to new types of observation data,so as to initially form the assimilation diagnosis ability on a regular routine basis.Finally,the author puts forward the main priority tasks and initial thinking to start this action plan,especially highlighting its front-end basis and supporting conditions,e.g.generalized,shared and highly flexible database.The paper also discusses the requirement for a consensus on this work based on problem-oriented onset,scientific understanding and collaboration.