Radar Echo Observation Dataset for Analyzing the Liquid Carbon Dioxide Role in Canal Formation in a Thick Cloud

KIKURO Tomine1MASAKI Shimada1KENJI Wakimizu2KOJI Nishiyama2

1 Department of Earth and Ocean Sciences，National Defense Academy，Japan2 Faculty of Agriculture，Kyushu University，Japan

DOI:10.3974/geodb.2016.05.02.V1

Published:Aug. 2016

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Key Words：

heavy snowfall,weather modification,radar echo,liquid carbon dioxide,Japan,Journal of Meteorological Research

Abstract：

It has been well known that thin cloud of about 400 m thick can be disappeared by massive artificial cloud seeding using dry ice or liquid carbon dioxide. We, also, have dissipated many thin clouds by artificial cloud seeding using liquid carbon dioxide. Then dissipating cloud by massive seeding is considered to be effective to mitigate the damage caused by heavy snowfall if thick cloud due to the heavy snowfall can be dissipated as well as thin cloud. So, the purpose of the experiment is to show the massive seeding effect to dissipate a thick cloud. The seeding was carried out using an aircraft on January 14, 2014 in Japan. Results were recorded by two video cameras which were settled to take picture of clouds in front of the aircraft and a radar display in the aircraft, respectively. Precipitation Amount analyzed by Radar-AMeDAS in JMA was used to analyze the results. Atmospheric temperature and environmental pressure were observed using a Pitot tube of the aircraft. Vertical profile of atmospheric temperature was calculated and recorded by a crew manually at the beginning and end of the experiment. 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 on both side of the course. The target cloud was 3 km thick with cloud base of 0.6 km AGL. The results showed that a part of the radar echo observed from onboard beneath the seeding track was weakened to divide the radar echo onboard into two parts 20 minutes after the cloud top and the bottom was 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 using Precipitation Amount analyzed by Radar-AMeDAS in JMA. A picture of the cloud in front of the aircraft showed that the target cloud was torn along the seeding track and we could see the sea surface through the break in the cloud. Canal was formed in the cloud along the seeding track. Clouds and snowfall were left on the both sides of the canal. The results validated that massive artificial cloud seeding could disappear the cloud of 3 km thick and meant that super-cooled liquid cloud particles along the seeding track evaporated to form larger precipitation particles around cloud ice particles generated by dispersed liquid carbon dioxide to fall rapidly. The dataset is archived in .mpg with the data size of 7.74GB total. In order to make it easy to be downloaded, it was compressed into two data file groups. 12 data files are included in the first data file group, 12 data files are included in the second data file group. The data file groups can be downloaded all into same folder, and open the first file (CloudObservedFromTheAircraft.part01.rar or RadarOnBoard.part01.rar), all others will be automaticity open as one dataset. The analysis paper was published in Journal of Meteorological Research, No.4, Vol.29, 2015.

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Data Citation：

KIKURO Tomine, MASAKI Shimada, KENJI Wakimizu, KOJI Nishiyama.Radar Echo Observation Dataset for Analyzing the Liquid Carbon Dioxide Role in Canal Formation in a Thick Cloud[J/DB/OL]. Digital Journal of Global Change Data Repository, 2016. https://doi.org/10.3974/geodb.2016.05.02.V1.

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