Large, unique radar echoes in a new, self-enhancing cloud seeding

Fukuta, N.; Wakimizu, Kenji; Nishiyama, Koji; Suzuki, Yôiti; Yoshikoshi, Hisashi

doi:10.1016/s0169-8095(00)00065-x

Cited by 12 publications

(16 citation statements)

References 5 publications

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“…An artificial rainfall technique of liquid carbon dioxide (LCD) was invented by Fukuta (1988), and it was proven successful at Fukuoka on Feb. 2, 1999 as the first effective rainfall production method. Several rainfall investigations confirmed the LCD method's property and efficiency on Feb. 2 and Oct. 27, 1999 (Fukuta et al, 2000;Wakimizu et al, 2002), Feb. 4 and Nov. 7, 2006, Jan. 8 and 17, 2007, Jan. 24, 2009, and other experiment results included (Maki et al, 2011;2012). The experimental results on Feb. 27, 2012 and Mar.…”

Section: Introductionmentioning

confidence: 56%

Artificial rainfall experiment by seeding of liquid carbon dioxide above the Izu Islands of Tokyo on December 15-16 in 2013

Maki

Morita

Suzuki

et al. 2016

J. Agric. Meteorol.

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An artificial rainfall technique of liquid carbon dioxide (LCD) was used in experiments operated on Nii, Miyake and Mikura Islands in the Izu Islands of Tokyo in Japan on December 15-16, 2013. On Dec. 15, rain particles or graupel pellets struck the aircraft front window and virga or rain was observed under a cloud from the aircraft on the east leewardside of the seeded area under the condition of thin cloud of 760 m in depth until 30 minutes. On Dec. 16, rain or graupel struck the aircraft front window at 15 minutes after seeding and virga or rain under the cloud was observed at 37 minutes after the seeding under the condition of a thinner cloud of 610 m in depth. On Dec. 15, rain was recognized along the route of the seeding and a line-type trail of cloud disappeared was visibly recognized with an average width of 2 km. The development and disappearance of clouds were evaluated using satellite images near Mikura Island. On Dec. 16, a cloud developed immediately after the seeding and a line-type cloud running in the NNE-SSW direction was recognized on the satellite image. The cloud developed decreased in scale due to rain and the cloud disappeared was also recognized on a satellite image near Nii Island. On Dec. 15, an analysis showed the existence of following local effects of the seeding; the development of clouds at 700 hPa level higher than the seeding height, the appearance of rain at 850 hPa level around the seeding height, rainfall (virga) and a drastic increase in relative humidity at 925 hPa level lower than the seeding height, and finally the occurrence of artificial rains that were clarified by the upper weather maps based on meso scale model (MSM). The artificial rainfall experiments were succeeded.

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Section: Introductionmentioning

confidence: 56%

Artificial rainfall experiment by seeding of liquid carbon dioxide above the Izu Islands of Tokyo on December 15-16 in 2013

Maki

Morita

Suzuki

et al. 2016

J. Agric. Meteorol.

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“…The LCD at −90℃ instantaneously produces ice crystals with 10 13 particles per 1 gCO 2 (Fukuta, 1988a, b;Fukuta et al, 2000), which collect ambient water vapor and grow to ice crystals or rain particles, thereby producing snow or rain. This procedure exerts its effects through two processes: (1) air masses with these new ice crystals rise because of the release of heat of condensation, and expand in twin cylindrical vortexes as they reach the top of the cloud, and (2) supercooling clouds with ice crystals rise up in humid air masses, reach the top of the cloud and grow vertically and horizontally.…”

Section: Principles Of the Lcd Rainfall Techniquementioning

confidence: 99%

“…However, these methods produce only small amounts of rainfall, and they have environmental and economical problems. A seeding technique using liquid carbon dioxide (LCD), invented by Fukuta (1988a, b), was tested and shown to be effective at Fukuoka on February 2, 1999 and in nu-merous later trials (Fukuta et al, 2000;Wakimizu et al, 2002;Nagata et al, 2005;Nishiyama et al, 2005;Ota et al, 2005;Maki et al, 2008Maki et al, , 2011Maki et al, , 2012.…”

Section: Introductionmentioning

confidence: 99%

Artificial rainfall experiment by seeding liquid carbon dioxide above the Izu Islands of Tokyo on March 14 in 2013

Maki

Morita

Suzuki

et al. 2014

J. Agric. Meteorol.

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Experiments of cloud seeding using liquid carbon dioxide (LCD) were carried out on March 14, 2013 near Miyake Island and Mikura Island in the Izu Islands, Tokyo, Japan. Convective clouds near the islands developed 0.5 to 1 h after the seeding. Artificial convective clouds accompanied by rain stream, i.e., virga, were observed, and rain was seen around the islands. Photos from aircraft and satellite images revealed trails and holes of disappeared clouds about 1 h and 2 h later, respectively. Within 1 h, the amount of precipitation was presumed to be about 0.1 million tons, with the precipitation intensity of 1 mm/h, based on a disappeared area 2 km × 50 km, constituting the first direct effect. Within 2 h, the total amount of precipitation from the disappeared cloud was presumed to be 1.8 million tons, based on a disappeared cloud area of diameter 50 km, constituting the secondary indirect effect. The main objective is whether the experiment of artificial rain is a success or not in a meteorological condition. Other objectives were shown successfully by photos taken of virga and the disappeared cloud, and by a satellite image based on the combination of convective cloud and the air temperature inversion layer. We found that LCD seeding at about 5 g/s within convective clouds near their bases is feasible when the air temperature is below 0℃, i.e., suitable around −5℃. The excellence of LCD seeding technique is supported by the results of this study, and we believe this technique will spread worldwide.

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“…This method assumes that the cloud's neighbors, if far enough away, are not affected by the seeding and can be used for comparison. However, seeding of one element of a cloud ensemble can affect its neighbors by turbulent transport of seeding materials [seeding with dry ice or liquid nitrogen (Fukuta et al 2000) would exclude such transport], while dynamic interactions are also possible.…”

Section: Randomized Experiments (The First Wmo Criterion)mentioning

confidence: 99%

Weather Modification—a Scenario for the Future

List¹

2004

Bulletin of the American Meteorological Society

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The ever-increasing severe economic damage imposed on national and world wide economies by severe weather, the need for sufficient and safe water resources for an increasing world population, and the threat of adverse climate change led to this critical assessment of the state-of-the-art of weather modification (WM) and to a proposal of a road map for the future. Special attention is given to rain enhancement because it is further developed than snowpack augmentation, hail suppression, tornado and hurricane modification, and other weather-related disaster control ideas. The question of what makes a rain enhancement experiment acceptable to the scientific community is answered by the World Meteorological Organization's (WMO) criteria, which address statistical evaluation, the measurement of rain, the understanding of nature's precipitation processes with the underlying physics and dynamics of clouds and cloud systems, and the transferability of experiment design. These criteria are no longer specific enough or satisfactory and will have to be reconsidered. An actual WM experiment also involves a variety of techniques and technologies, aspects that need to be complemented by numerical modeling of clouds and cloud responses to seeding. Modeling also allows assessment of the extra-area effects, that is, detrimental effects of precipitation on adjacent areas. Assimilation models may be giving better estimates of the rain at the ground because they can integrate restricted information from radar and rain gauges with mesoscale meteorological and remote sensing, as well as hydrological, data. However, massive improvements in computer capacity are required to handle these problems. Weather modification has been progressing very slowly in the past because of the enormity of the problem and the fact that the precipitation process is far from being understood. Considering that rain increases are attempted within a range of 10%–20%, the lack of knowledge at corresponding accuracy is particularly evident in the fields of cloud physics, cloud and cloud systems dynamics, weather forecasting, numerical modeling, and measuring technology. Benefits of new intensive studies of precipitation processes will not be limited to WM; they are also vital to improving weather forecasting and climate change modeling. There is one additional aspect of WM; WM can also be used to test newly developed precipitation physics and models by studying if the clouds react to seeding in the predicted manner. This article is a wake-up call to put more intellectual and financial resources into the exploration and modification of the precipitation processes in all their forms. All these points lead to the suggestion of an outline of a national precipitation research and weather modification program.

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Large, unique radar echoes in a new, self-enhancing cloud seeding

Cited by 12 publications

References 5 publications

Artificial rainfall experiment by seeding of liquid carbon dioxide above the Izu Islands of Tokyo on December 15-16 in 2013

Artificial rainfall experiment by seeding of liquid carbon dioxide above the Izu Islands of Tokyo on December 15-16 in 2013

Artificial rainfall experiment by seeding liquid carbon dioxide above the Izu Islands of Tokyo on March 14 in 2013

Weather Modification—a Scenario for the Future

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