北半球温带气旋客观研究方法及模拟和预估的研究进展
A Review of the Research on Objective Method and Simulation and Projection of Extratropical Cyclone over the Northern Hemisphere
中文摘要：
温带气旋是影响中高纬度地区大范围天气气候变化的重要天气系统之一，研究其气候特征、活动规律和变化趋势对改进天气预报和理解全球气候变化具有重要意义。从主要温带气旋的识别方法、当前气候时期温带气旋的变化、气候情景下未来温带气旋变化的预估以及不确定性分析等4个方面，全面回顾了北半球温带气旋的研究进展：（1）20世纪80年代后，基于再分析数据和大气环流模式（GCM）的发展，温带气旋研究从主观分析开始向客观识别方法发展；（2）再分析和模式数据均显示北半球存在两个温带气旋主活动中心和两个次活动中心，主活动中心分别位于北太平洋和北大西洋地区，次活动中心分别位于地中海和蒙古地区；（3）在人类活动影响的气候变化情景下，大多数模式模拟得到北半球大部分地区温带气旋数目将减少，个别地区的温带气旋数目将增加；（4）由于不同研究中对阈值、物理量和大气层的选取存在差异，这使得对当前气候时期和GCM模拟研究中的温带气旋及其变化和趋势问题还存在许多不确定性。因此，目前亟待解决的问题是对于温带气旋的不同研究方法和研究结果做更多具体的比较分析，从而给出对温带气旋更深入的认识。
中文关键词：
温带气旋，客观判定和追踪方法，温带气旋的气候态特征和变化，气候情景
KeyWords：
extratropical cyclones, objective detecting and tracking method, climatologies and variations of extratropical cyclones, climate scenario
Abstract：
Extratropical cyclone is one of the important synoptic systems which affect climate/weather variability over a wide area of mid- and high latitudes, and it is meaningful to research its climatic characteristics, activity patterns, and variation tendency. A comprehensive review of research progress of extratropical cyclones over the Northern Hemisphere from four aspects, involving identification methods, changes during present climate period, changes estimated under the future climate scenarios, and uncertainty analysis of extratropical cyclones, is discussed: (1) In view of the development of reanalysis data and GCM, the research method of extratropical cyclones shifts from subjective analysis to objective identification; (2) There are two main activity centers and two subordinate activity centers displayed by reanalysis and model data, with the main activity center located in the North Pacific and North Atlantic region, and the subordinate activity center located in Mediterranean and Mongolian regions; (3) Under the influence of climate change scenarios by human activities, extratropical cyclones will diminish in most parts of the Northern Hemisphere, and increase in individual districts; (4) Different thresholds, different physical quantities, and considerations of different atmospheric vertical levels add to a picture which can be combined to get an uncertainty view of cyclones, their variability, and trends, in the real world and in GCM studies. Hence, the urgent need for an in-depth understanding of cyclones is more specific intercomparison studies which can demonstrate the differences between the approaches and their results.