Tropical Cyclone Monitoring and Analysis Techniques: A Review

Tropical cyclones(TCs),including tropical depressions and different categories of typhoons,hurricanes,and cyclonic storms,mostly originate over the oceans in the absence of direct observations.Thus,detailed monitoring and analysis of TCs has always been an unsolved problem.In the recent 20 years,great changes have taken place in domestic and foreign TC monitoring techniques,imposing a significant impact on TC operations and research.Some new technologies and products gradually emerge to support operations,with improved monitoring accuracy.In this paper,the progress on TC monitoring and analysis via meteorological satellites,radars,and airplanes in China and the world is reviewed,compared,and summarized,with special focuses on multisatellite fusion observations,in situ aircraft measurements,and some unconventional observation equipment such as rockets,saildrones,and underwater gliders.On this basis,the paper points out future directions for improving TC monitoring and analysis in aid of better TC forecast and early warning.

Impact of Tropical Cyclones over the North Indian Ocean on Weather in China and Related Forecasting Techniques:A Review of Progress

Tropical cyclones(TCs)over the North Indian Ocean(NIO)are closely related to Asian summer monsoon activities and have a great impact on the precipitation in the Tibetan Plateau,southwestern China,and even the middle and lower reaches of the Yangtze River.In this paper,the research progress on the impacting mechanisms of NIO TCs on the weather in China and associated forecasting techniques is synthesized and reviewed,including characteristics of the NIO TC activity,its variability under climate change,related precipitation mechanism,and associated forecasting techniques.On this basis,the limitations and deficiencies in previous research on the physical mechanisms and forecasting techniques of NIO TCs affecting the weather in China are elucidated and the directions for future investigations are discussed.

THE IMPACT OF TROPICAL CYCLONES ON CHINA IN 2016

In 2016, the Northwest Pacific and the South China Sea registered the genesis of 26 tropical cyclones. 8 of them, including NEPARTAK(1601), MIRINAE(1603), NIDA(1604), DIANMU(1608), MERANTI(1614),MEGI(1617), SARIKA(1621) and HAIMA(1622), made landfall over China's coastal areas. The number one TC of 2016, NEPARTAK, was named on July 3. Although no typhoon generated in the first half of this year,which means 4.6 incidences less compared with the same period of a normal year, more tropical cyclones made landfall over China(the historical average in the same period of 1949-2015 is 6.7). And these 8 tropical cyclones had an averaged intensity up to 40.6 m/s, significantly enhanced compared with the multi-year average of 32.8 m/s.The death toll from the 11 tropical cyclones affected China in 2016 is 206. MERANTI was the most destructive one in 2016, which brought up the largest numbers of affected and evacuated population, damaged houses and direct economic losses. In 2016, China Meteorological Administration(CMA) 24-120 h mean official track forecast errors were 66, 127, 213, 292 and 364 km, respectively. The 24 h track forecast error has been kept within 70 km in two consecutive years.

THE IMPACT OF TROPICAL CYCLONES ON CHINA IN 2015

During 2015 typhoon season(1 January to 15 October), the Northwest Pacifi c and the South China Sea had registered 25 tropical cyclone genesis. 6 of them, including KUJIRA(1508), CHAN-HOM(1509), LINFA(1510), SOUDELOR(1513), DUJUAN(1521) and MUJIGAE(1522), made landfall over China's coastal areas. Despite the high level of activity(the historical average in the same period of 1949-2014 is 21.6), fewer tropical cyclones made landfall over China(the historical average is 6.6). However, these 6 tropical cyclones had an averaged intensity up to 41 m/s, signifi cantly enhanced compared with the multi-year average of 32.8 m/s. The death toll from the 8 tropical cyclones affected China in 2015 is 73. SOUDELOR claimed the most affected population, death toll, missing person, emergency aiding population, damaged home, and MUJIGAE claimed the most direct economic loss. China Meteorological Administration(CMA) mean offi cial track forecast errors in 2015 were smaller than the multi-year means at all forecast times.