大气科学的世纪进展与未来展望

AN OVERVIEW OF CENTENARY ADVANCES AND PROSPECTS IN ATMOSPHERIC SCIENCES

今天的大气科学已从20世纪初经验的阐述转变为既有理论基础又有客观定量化的一门数理学科,其发展步伐在近50年来不断加快.文章回顾了近百年来大气科学在探测、数值天气预报和气候研究3方面所取得的主要成就,并对大气科学在21世纪的潜在发展作一展望.大气探测、计算能力和信息输送方面的技术进步无疑是近代和未来大气科学迅速发展的巨大动力.这些技术进步促使数值模式分辨率在不断提高,越来越多的实测和卫星等遥感资料在通过反演和同化进入模式初始条件和全球气象分析场,模式物理过程和参数化逐步趋向现实,从而使全球和区域数值预报水平持续提高.同时对大量观测资料的统计分析和许多气候子系统耦合模式的若干试验,大大提高了对造成气候变化和影响的物理、动力机制的认识;特别是对全球气温变暖,其中人类活动的影响,以及ENSO的发生、发展和消亡的机制和过程的认识.近期数值天气预报则趋向于模式发展的统一、预报时效的增加和对有足够成员且有代表性的集合预报的日益重视.气候研究将致力于减少各物理和化学过程参数化、分辨率等因素在模式中的不确定性,逐步达到跨月、季节直至年代际气候变化的合理预测.可以预言在不久的将来,地球-空间系统各变量的观测和预报将逐步数字化、自动化,人们可提前3～5 d得知灾害性天气发生时间和地点的概率,人工影响天气等学科在21世纪将会有突破.同时,可以看到世界各国共同协作建立地球-空间综合观测系统,发展能'包罗万象'的地球-空间-减灾的统一模式.然后综合利用大量观测和模式资料,及时掌握地球-空间系统中的各尺度变化规律,以确保人类社会的持续发展.

The atmospheric science has been advanced from a subjective “art” to a mathematical and physical science during the past century, with an accelerated pace in the recent 50 years. Major advances in atmospheric measurements, numerical weather prediction and climate research were reviewed and prospects of the atmospheric sciences in the 21st century were speculated. Undoubtedly, the rapid progress in atmospheric sciences in both the past and the future is highly determined by the technical developments in atmospheric measurements and computing power as well as information technology. As a result, the model grid resolution has continued to increase with time; a growing amount of in situ and remote sensing （e. g. , satellite） data, after retrieval and assimilation, has been incorporated into the model initial conditions and the global meteorological analysis; model physical processes and parameterizations have become more realistic, thereby leading to the persistent improvements in the global and regional meteorological predictions. Similarly, the statistic analysis of tremendous observed data and the conduct of many coupled climate-model simulations have considerably advanced our understanding of the dynamical mechanisms by which climate change and its impact occur, particularly for those associated with the global warming, the effects of human activity, and the development of the ENSO-related events. Recently, it appears today that unified regional and global models tend to be developed; model-prediction periods for our daily weather and larger-scale flows will be extended; and more efforts will likely be devoted to ensemble forecasts with sufficient numbers of members to represent uncertainty in both initial conditions and models. Climate research will focus more on minimizing uncertainties in the parameterization of various physical and chemical processes, and in the model grid resolution, in order to reasonably predict the regional to global climate changes at the monthly to intra-seasonal and decadal time scales. It is speculated that in the near future measuring and forecasting various （meteorological or biological） variables in the earth-space system will be gradually digitized and automated; the location and timing of severe weather events may be predicted 3 - 5 days in advance; and some breakthroughs in weather modification could be made in the 21st century. Meanwhile, we may see the coordinated efforts from all the countries that are devoted to the establishment of a comprehensive earth-space-observing system, and the development of a unified, sophisticated earth-space-disaster mitigation modeling system. Then, the observed and modeled data will be used to monitor closely the natural variability of the earth-space system at all spatial scales to ensure the persistent advances in human society.