Statistical Analysis and Inversion Study on Ice Accretion in Hubei Province

The data collected on the transmission lines of Central China Power Grid from 2009 to 2013 in Hubei Province, the MICAPS meteorological data, the atmospheric soundings, and the NCEP reanalysis data are analyzed to investigate the synoptic situation, the duration of the wire icing, and the inversion layer during the wire icing. Results show that the upper-level circulation during the wire icing process can be divided into three types:Small transverse trough development-oriented type, transverse trough type, and eastward-moving low trough type. The occurrence frequency of each type is 43.8%, 31.2%, and 25%, respectively. Wire icing mainly occurs in January, February, November, and December and the average monthly icing hours in each individual month are 65 h, 42 h, 11 h, and 9 h. The icing processes can be divided into two types:Precipitation icing and foggy icing. A shear of wind direction from north to south could be found in the layer between 900 hPa and 700 hPa when precipitation icing occurs. A far more thick inversion layer could be developed, which is favorable for the maintenance and development of the icing process.