[M-IS16] 火山噴煙・積乱雲のモデリングと観測

[MIS16-P07] Characteristics of polarimetric radar parameters of dry volcanic ash clouds

*Yura Kim¹、Masayuki Maki¹、Masato Iguchi²、Dong-In Lee³ (1.Research and Education Center for Natural Hazards, Kagoshima University, Korimoto, Kagoshima, Japan、2.Sakurajima Volcano Research Center/DPRI, Kyoto University, Sakurajima, Kagoshima, Japan、3.Department of Atmospheric Sciences, Pukyong National University, Namgu, Busan, Republic of Korea)

キーワード：polarimetric radar parameters, volcanic ash, statistical analysis

We analyzed statistically the polarimetric radar data of 9 Sakurajima volcanic eruption clouds in 2013. All eruption clouds have a height exceeding 3000m. According to the results, Z_H has positively skewed distributions (Skewness of 1.6; mean Z_H of 9.77 dBZ and median of 7.4 dBZ), Z_DR has normal distributions (Skewness of 0.02; mean Z_DR of 1.58 dB and median of 1.6 dB), K_DP has positively skewed distributions (Skewness of 7.12; mean K_DP of 0.03 deg/km and median of 0.0 deg/km), and ρ_hv has negatively skewed distributions (Skewness of -1.02; mean ρ_hv of 0.77 and median of 0.8). Depending on time after the eruption, the average Z_H decreased from 22.3 dBZ to 6.75 dBZ while the average Z_DR and ρ_hv tended to increase from 1.24 dB to 1.67 dB, and from 0.47 to 0.83, respectively.