Classification of Precipitation Types Using Fall Velocity–Diameter Relationships from 2D-Video Distrometer Measurements

• Published in: Advances in atmospheric sciences Vol. 32; no. 9; pp. 1277 - 1290
• Main Authors: Lee, Jeong-Eun, Jung, Sung-Hwa, Park, Hong-Mok, Kwon, Soohyun, Lin, Pay-Liam, Lee, GyuWon
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.09.2015; Springer Nature B.V; Center for Atmospheric Remote Sensing,Kyungpook National University,Korea%Center for Atmospheric Remote Sensing,Kyungpook National University,Korea%Department of Atmospheric Sciences,NCU,Taipei; Department of Astronomy and Atmospheric Sciences,Research and Training Team for Future Creative Astrophysicists and Cosmologists,Kyungpook National University,Korea%Department of Astronomy and Atmospheric Sciences,Research and Training Team for Future Creative Astrophysicists and Cosmologists,Kyungpook National University,Korea
• Subjects: Algorithms; Atmospheric Sciences; Classification; Earth and Environmental Science; Earth Sciences; Geophysics/Geodesy; Meteorology; Precipitation; Snow; Studies; 人工分类; 分类算法; 水凝物; 测量速度; 直径; 视频; 降水类型; South Korea; Korea, Rep; snowflake types; wet snow; hydrometeor type classification; fall velocity-diameter; 2DVD
• ISSN: 0256-1530; 1861-9533
• DOI: 10.1007/s00376-015-4234-4

Fall velocity–diameter relationships for four different snowflake types（dendrite,plate,needle,and graupel） were investigated in northeastern South Korea,and a new algorithm for classifying hydrometeors is proposed for distrometric measurements based on the new relationships.Falling ice crystals（approximately 40 000 particles） were measured with a two-dimensional video disdrometer（2DVD） during a winter experiment from 15 January to 9 April 2010.The fall velocity–diameter relationships were derived for the four types of snowflakes based on manual classification by experts using snow photos and 2DVD measurements：the coefficients（exponents） for different snowflake types were 0.82（0.24） for dendrite,0.74（0.35） for plate,1.03（0.71） for needle,and 1.30（0.94） for graupel,respectively.These new relationships established in the present study（PS） were compared with those from two previous studies.Hydrometeor types were classified with the derived fall velocity–diameter relationships,and the classification algorithm was evaluated using 3 × 3 contingency tables for one rain–snow transition event and three snowfall events.The algorithm showed good performance for the transition event：the critical success indices（CSIs） were 0.89,0.61 and 0.71 for snow,wet-snow and rain,respectively.For snow events,the algorithm performance for dendrite and plate（CSIs = 1.0 and 1.0,respectively） was better than for needle and graupel（CSIs = 0.67 and 0.50,respectively）.