Unusual phenomenon of freezing rain in Perm krai

Simulation of the variations of the temperature of droplets in freezing precipitation

“…When modeling the process of variation of the droplet temperature it was assumed that the initial temperature of droplets was equal to 5.4°C. It corresponds to the observed situation of intensive formation of droplets in the lower part of the cloud in the area of "the warm nose" at the height of about 1000 m over Perm at 12:00 UTC on December 14, 2010 [4].…”

“…Freezing pre cip i ta tion is ob served in win ter and tran si tion sea sons at mid dle and high lat i tudes as well as in moun tain ar eas at lower latitudes; it re sults in neg a tive con se quences for pop u la tion, power engineering, motor, rail way, and air trans port [2][3][4][10][11][12][13][14]. In [14], the idea is con sid ered of the cli mate char ac ter is tics and mech a nisms of freez ing pre cip i ta tion as well as the meth ods of its fore cast ing.…”

“…Af ter that the drop lets cool in the cold air ad join ing the Earth sur face, are of ten cov ered with the ice crust, and take the form of ice balls of ten con tain ing un frozen wa ter in side. When fall ing to the Earth sur face or ob jects, balls break, drop lets flow out, freeze at neg a tive tem per a ture and form glaze [2][3][4]14]. Such mech a nism is re alized in the cases of the most in ten sive and dan ger ous freez ing rain.…”

“…The au thors of the pres ent pa per pro posed in [4] the as sess ment of the pro cess of trans for ma tion of falling drop lets into ice as a re sult of crys tal li za tion of super cooled wa ter not tak ing ac count of the pe cu liar i ties of phase tran si tion on the wa ter-ice in ter face and of the prop a ga tion of the front of crys tal li za tion from the sur face of the drop let to its in ter nal lay ers. The ex am ple is the syn op tic con di tions ob served in the Perm krai on De cem ber 14, 2010 char ac ter ized by freez ing rain at the pres ence of tem per a ture in ver sion in the atmo spheric bound ary layer.…”

Application of the Lagrangian stochastic dispersion model for urban air pollution simulation

“…The considered Lagrangian stochastic dispersion model was applied to simulation of pollutant emission from highaltitude point sources (two adjacent pipes of a thermal power plant) located in the city of Tomsk, Western Siberia, Russia. The question of the influence of subsidence inversion 6 on air pollution at the surface layer of the atmosphere was investigated. The problem arises because the descending air fluxes press pollutants to the ground, which are being emitted by industrial plants.…”