The purpose of this experiment is to show that massive cloud seeding is effective in mitigating the damage caused by heavy snowfall. In order to show its effect, we attempted to form a canal in a thick convective clou...The purpose of this experiment is to show that massive cloud seeding is effective in mitigating the damage caused by heavy snowfall. In order to show its effect, we attempted to form a canal in a thick convective cloud by massive seeding, and left the parts that were not influenced by the seeding as a reference to show that the canal was formed by the massive seeding only. The seeding was carried out by using an aircraft. The seeding rate and air speed of the aircraft were 35 g s-1 and 115 m s 1, respectively. The flight course for seeding was selected to be parallel to the wind direction to ensure that the dispersed liquid carbon dioxide did not influence both sides of the course. The results show that a part of the radar echo observed from onboard beneath the seeding track was weakened and divided the radar echo into two parts 20 minutes after the cloud top and the bottom were seeded, and distribution of rainfall rate on the ground from the target cloud was confirmed to be divided into two parts 24 minutes after the seeding. The target cloud was torn along the seeding track, and we could see the sea surface through the break in the cloud. Canal formation occurred in the cloud along the seeding track. Clouds and snowfall were left on both sides of the canal. The results show that supercooled liquid cloud particles along the seeding track evaporated to form larger precipitable particles which grew and fell rapidly.展开更多
An artificial cloud seeding experiment was performed over the Japan Sea in winter to show how massive seeding could be effective to mitigate heavy snowfall damage.The results showed that 20 min after cloud seeding,a p...An artificial cloud seeding experiment was performed over the Japan Sea in winter to show how massive seeding could be effective to mitigate heavy snowfall damage.The results showed that 20 min after cloud seeding,a portion of the radar echo beneath the seeding track was weakened to divide the radar echo into two parts.In order to analyze the results,a numerical simulation was conducted by using the Weather Research and Forecasting model verion 3.5.1.In this simulation,the seeding effects were represented as phenomena capable of changing rain particles by accreting cloud ice and snow to form graupel particles and by changing cloud liquid water to snow particles.The graupel particles fell rapidly,thus temporarily intensifying the rainfall,which subsequently decreased.Therefore,the weakened radar echo in the field experiment is deemed to have been caused by the increase in rapidly falling graupel particles.展开更多
文摘The purpose of this experiment is to show that massive cloud seeding is effective in mitigating the damage caused by heavy snowfall. In order to show its effect, we attempted to form a canal in a thick convective cloud by massive seeding, and left the parts that were not influenced by the seeding as a reference to show that the canal was formed by the massive seeding only. The seeding was carried out by using an aircraft. The seeding rate and air speed of the aircraft were 35 g s-1 and 115 m s 1, respectively. The flight course for seeding was selected to be parallel to the wind direction to ensure that the dispersed liquid carbon dioxide did not influence both sides of the course. The results show that a part of the radar echo observed from onboard beneath the seeding track was weakened and divided the radar echo into two parts 20 minutes after the cloud top and the bottom were seeded, and distribution of rainfall rate on the ground from the target cloud was confirmed to be divided into two parts 24 minutes after the seeding. The target cloud was torn along the seeding track, and we could see the sea surface through the break in the cloud. Canal formation occurred in the cloud along the seeding track. Clouds and snowfall were left on both sides of the canal. The results show that supercooled liquid cloud particles along the seeding track evaporated to form larger precipitable particles which grew and fell rapidly.
文摘An artificial cloud seeding experiment was performed over the Japan Sea in winter to show how massive seeding could be effective to mitigate heavy snowfall damage.The results showed that 20 min after cloud seeding,a portion of the radar echo beneath the seeding track was weakened to divide the radar echo into two parts.In order to analyze the results,a numerical simulation was conducted by using the Weather Research and Forecasting model verion 3.5.1.In this simulation,the seeding effects were represented as phenomena capable of changing rain particles by accreting cloud ice and snow to form graupel particles and by changing cloud liquid water to snow particles.The graupel particles fell rapidly,thus temporarily intensifying the rainfall,which subsequently decreased.Therefore,the weakened radar echo in the field experiment is deemed to have been caused by the increase in rapidly falling graupel particles.
