2020年10月至2021年2月上旬,受拉尼娜事件和大气环流异常的共同影响,我国江南南部、华南大部及西南的云南等地降水量较常年同期明显偏少,2020年11月上旬气象干旱开始露头并迅速发展,出现了较为严重的秋冬连旱.此次干旱过程影响范围广、干旱日数多、强度强,造成江南、华南及西南的云南等地湖库蓄水大幅减少,森林火险气象等级偏高.2021年2月8—11日,我国南方地区出现明显降水,江南、华南气象干旱解除,但西南的云南等地干旱仍然持续.从气候特征、干旱演变过程入手,分析了此次干旱过程的特点及气候成因,以期为从事气候影响评价和服务的科研人员提供相关信息,同时也为防旱抗旱工作提供参考依据.

Offshore wind energy development and utilization plays an important role in haze governance and fulfilling the reduction commitments in advance. The reserve estimation of offshore wind resource in China is abundant enough to meet the basic needs from the exploitation of wind power. Recently, more and more attention is paid to the accurate estimation of the offshore extreme winds, which impose an important effect on the wind turbine designs and operations. Different from the abundant study of the typhoon extreme winds, because of lack of the effective methods, it shows a significant deficiency in the study of offshore extreme winds over the mid-high latitude, which is also the key area for the exploitation of wind power. Therefore, based on numerical modeling and spectrum analysis, the paper developed a practical, reliable and robust method for 50-years extreme wind estimation that can be applied for other mid-latitude offshore area in China. Taking into account the complex climatic characteristics of China's mid-latitude offshore area affected by high latitude cold winter wind and tropical cyclone, the 50-yr return wind speeds at 100m over Jiangsu offshore area were estimated by this new method. It was shown that (1) affected by the strong cold winter winds, the 50-yr return wind speed in the northern part of Jiangsu offshore area exceeded 40 m/s; (2) the 50-yr return wind speeds of 40 m/s, or even 44m/s near Xiangshui and Rudong was related to the limited typhoon activities; and (3) the 50-yr return wind speeds over the central Jiangsu offshore area were generally lower than 35 m/s. This study may not only provide a scientific basis of the design and operation of offshore engineering, such as offshore wind farms in the future, but also contribute to future understanding of the extreme climate events in China and the development of atmospheric boundary layer theory as well (This abstract has been published in Acta Meteorologica Sinica, 2019, 77(5): 938-948. doi:10.11671/qxxb2019.054).