Precipitation enhancement by cloud seeding using the shell structured TiO2/NaCl aerosol as revealed by new model for cloud seeding experiments

2018 ◽  
Vol 212 ◽  
pp. 202-212 ◽  
Author(s):  
Miloš Lompar ◽  
Mladjen Ćurić ◽  
Djordje Romanic ◽  
Linda Zou ◽  
Haoran Liang
Keyword(s):  
Cloud Seeding ◽  
New Model ◽  
Precipitation Enhancement

scholarly journals Evaluation of the First Negative Ion-Based Cloud Seeding and Rain Enhancement Trial in China

Water ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 2473
Author(s):  
Wei Zheng ◽  
Hengben Ma ◽  
Ming Zhang ◽  
Fengming Xue ◽  
Kexun Yu ◽  
...  
Keyword(s):  
Effective Means ◽  
Geographic Location ◽  
Monitoring Network ◽  
Negative Ions ◽  
Comparative Trial ◽  
Negative Ion ◽  
Cloud Seeding ◽  
Experimental Area ◽  
Precipitation Variation ◽  
Precipitation Enhancement

Negative ion-based cloud seeding has been shown to be an effective means in the laboratory. China’s first negative ion-based cloud seeding outfield trial was conducted in the northwestern interior. This paper briefly introduces the principle of the ion-based precipitation enhancement, and the trial location is described. The design of the ionization system and meteorological monitoring network are presented. The implementation plan of the outfield trial is explained. In addition, the evaluation of experimental effects is detailed in this paper. We designed various analytical methods to investigate both the overall precipitation variation of the experimental area and the precipitation variation within the experimental area. The overall precipitation of the experimental area was predicted using a neural network, and then the actual precipitation was compared with the predicted precipitation to evaluate the effectiveness of the experiment. The effectiveness of the experiment was also evaluated using historical precipitation data and the result of the randomized comparative trial. This paper also explores the effects of geographic location differences and wind direction differences on the precipitation differences within the trial area. The changes in the number of negative ions and clouds in the sky were also analyzed. From these analyses, we obtained quantitative assessment results. These results could indicate that the outfield trial basically met the expected requirements, which is to increase the rainfall of the trial area by 20%.

scholarly journals Towards precipitation enhancement through cloud seeding in Kenya

2015 ◽  
Vol 3 (1) ◽  
Author(s):  
Joshua Ngaina ◽  
Nzioka Muthama ◽  
Joseph Ininda ◽  
Alfred Opere ◽  
Bethwel Mutai
Keyword(s):  
Time Series ◽  
Trajectory Analysis ◽  
Lake Victoria ◽  
Western Indian Ocean ◽  
Cloud Seeding ◽  
Lake Victoria Basin ◽  
Backward Trajectory ◽  
Mean Sea Level ◽  
Precipitation Enhancement ◽  
Cloud Top Temperature

The study investigated potential of enhancing precipitation through cloud seeding during October-November-December (OND) season. Rainfall, cloud top temperature (CTT), aerosol optical depth (AOD) and wind data were used. Short-Cut Bartlett correlation, composite wind and time series analysis, and HYSPLIT backward trajectory analysis were used to achieve the objectives of study. Precipitation showed decreasing patterns with peaks between pentad 65 and 68. Delineated dry years (18) exceeded wet years (9). Low level winds were predominantly north-easterly during dry years characterized by continental trajectory. AOD values increased in all stations during dry year with aerosol load being higher in areas characterized by depressed rainfall. Pollutants suspended 1000 above mean sea level (AMSL) originated from Arabian and India subcontinent and pollutants suspended below 1000 AMSL were predominantly south easterly during wet years originated from Western Indian Ocean and characterized by maritime trajectory. Mean CTT during dry/wet years were positve over coastal areas while central, Rift-valley and Lake Victoria basin showed negative values, indicating presence of seedable conditions and thus potential cloud seeding to enhance rainfall and alleviate existing water stress.

scholarly journals Review of Advances in Precipitation Enhancement Research

2019 ◽  
Vol 100 (8) ◽  
pp. 1465-1480 ◽  
Author(s):  
Andrea I. Flossmann ◽  
Michael Manton ◽  
Ali Abshaev ◽  
Roelof Bruintjes ◽  
Masataka Murakami ◽  
...  
Keyword(s):  
Convective Cloud ◽  
Cloud Seeding ◽  
Weather Modification ◽  
Catchment Scale ◽  
Cloud Systems ◽  
The Past ◽  
Expert Team ◽  
Orographic Cloud ◽  
Water Catchment ◽  
Precipitation Enhancement

AbstractThis paper provides a summary of the assessment report of the World Meteorological Organization (WMO) Expert Team on Weather Modification that discusses recent progress on precipitation enhancement research. The progress has been underpinned by advances in our understanding of cloud processes and interactions between clouds and their environment, which, in turn, have been enabled by substantial developments in technical capabilities to both observe and simulate clouds from the microphysical to the mesoscale. We focus on the two cloud types most commonly seeded in the past: winter orographic cloud systems and convective cloud systems. A key issue for cloud seeding is the extension from cloud-scale research to water catchment–scale impacts on precipitation on the ground. Consequently, the requirements for the design, implementation, and evaluation of a catchment-scale precipitation enhancement campaign are discussed. The paper concludes by indicating the most important gaps in our knowledge. Some recommendations regarding the most urgent research topics are given to stimulate further research.

scholarly journals Precipitation Enhancement—A Scientific Challenge

1986 ◽  
Vol 43 ◽  
pp. 1-6 ◽  
Author(s):  
Roscoe R. Braham
Keyword(s):  
Cloud Seeding ◽  
Weather Modification ◽  
Scientific Challenge ◽  
Precipitation Enhancement

Abstract Schaefer's 1946 cloud seeding experiment initiated a quest for weather modification techniques. Progress has been slow; but there are several reasons for believing that useful precipitation augmentation may be possible.

scholarly journals Satellite-Retrieved Microstructure of AgI Seeding Tracks in Supercooled Layer Clouds

2005 ◽  
Vol 44 (6) ◽  
pp. 760-767 ◽  
Author(s):  
Daniel Rosenfeld ◽  
Xing Yu ◽  
Jin Dai
Keyword(s):  
Spatial Relations ◽  
Central China ◽  
Cloud Seeding ◽  
Weather Modification ◽  
Fall Velocity ◽  
Cloud Tops ◽  
Visible Reflectance ◽  
Precipitation Enhancement ◽  
Cloud Top Temperature ◽  
Observation Period

Abstract NOAA Advanced Very High Resolution Radiometer (AVHRR) images revealed conspicuous tracks of glaciated cloud in thick supercooled layer clouds over central China. These tracks were identified as being artificially produced by cloud-seeding operations at the −10°C isotherm, less than 1 km below cloud tops, aimed at precipitation enhancement, by means of AgI acetone generators. The cloud composition was deduced by retrieving the cloud-top effective radius (re) and analyzing its spatial relations with cloud-top temperatures and with the visible reflectance. Cloud-top temperature varied between −13° and −17°C. The glaciation became apparent at cloud tops about 22 min after seeding. The glaciated tops sank and formed a channel in the supercooled layer cloud. The rate of sinking of about 40 cm s−1 is compatible with the fall velocity of ice crystals that are likely to form at these conditions. A thin line of new water clouds formed in the middle of the channel of the seeded track between 38 and 63 min after seeding, probably as a result of rising motions induced by the released latent heat of freezing. These clouds disappeared in the more mature segments of the seeded track, which continued to expand throughout the observation period of more than 80 min. Eventually the seeding tracks started to dissipate by expansion of the ambient cloud tops inward from the sides. Using the brightness temperature difference between 10.8 and 12.0 μm allowed for observation of the seeding signature deep in the clouds, even when it was obscured under thin supercooled layer clouds. This is the third and most detailed report of effects of advertent cloud seeding for precipitation enhancement being detected and analyzed based on satellite observations. It opens new possibilities of using satellites for directing and monitoring weather modification experiments and operations.

The Hitachi Model HS-8 Electron Microscope

1967 ◽  
Vol 25 ◽  
pp. 238-239
Author(s):  
H. Akabori ◽  
K. Nishiwaki ◽  
K. Yoneta
Keyword(s):  
Electron Microscope ◽  
New Model ◽  
Predecessor Model

By improving the predecessor Model HS- 7 electron microscope for the purpose of easier operation, we have recently completed new Model HS-8 electron microscope featuring higher performance and ease of operation.

516: A Simplified Method to Estimate the Absolute Renal Uptake of 99MTC-DMSA: Evaluation with a New Model using the Radioactivity of Nephrectomy Specimens as Reference

2005 ◽  
Vol 173 (4S) ◽  
pp. 140-141
Author(s):  
Mariana Lima ◽  
Celso D. Ramos ◽  
Sérgio Q. Brunetto ◽  
Marcelo Lopes de Lima ◽  
Carla R.M. Sansana ◽  
...  
Keyword(s):  
New Model ◽  
Renal Uptake ◽  
Simplified Method ◽  
The Absolute
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