scholarly journals Charged Particle (Negative Ion)-Based Cloud Seeding and Rain Enhancement Trial Design and Implementation

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1644
Author(s):  
Wei Zheng ◽  
Fengming Xue ◽  
Ming Zhang ◽  
Qiqi Wu ◽  
Zhou Yang ◽  
...  
Keyword(s):  
Large Scale ◽  
Evaluation Method ◽  
Water Shortage ◽  
Northwest China ◽  
Negative Ion ◽  
Cloud Seeding ◽  
Weather Modification ◽  
Solid Carbon Dioxide ◽  
Design And Implementation ◽  
Hygroscopic Salts

China has been suffering from water shortage for a long time. Weather modification and rainfall enhancement via cloud seeding has been proved to be effective to alleviate the problem. Current cloud seeding methods mostly rely on solid carbon dioxide and chemicals such as silver iodide and hygroscopic salts, which may have negative impacts on the environment and are expensive to operate. Lab experiments have proved the efficiency of ion-based cloud seeding compared with traditional methods. Moreover, it is also more environmentally friendly and more economical to operate at a large scale. Thus, it is necessary to carry out a field experiment to further investigate the characteristics and feasibility of the method. This paper provides the design and implementation of the ion-based cloud seeding and rain enhancement trial currently running in Northwest China. It introduces the basic principle of the trial and the devices developed for it, as well as the installation of the bases and the evaluation method design for the trial.

scholarly journals Deliberate enhancement of rainfall using desert plantations

2019 ◽  
Vol 116 (38) ◽  
pp. 18841-18847 ◽  
Author(s):  
Oliver Branch ◽  
Volker Wulfmeyer
Keyword(s):  
Climate Change Mitigation ◽  
Arid Regions ◽  
Large Scale ◽  
Regional Climate ◽  
Regional Scale ◽  
Climate Impacts ◽  
Decision Makers ◽  
Cloud Seeding ◽  
Weather Modification ◽  
Change Mitigation

Large-scale afforestation is increasingly being considered as a negative emissions method for sequestering large quantities of atmospheric CO2. At the same time, regional weather modification methods, like cloud seeding, are being used to counteract increasing water scarcity in arid regions. Large-scale sustainable desert agroforestry plantations can contribute to climate change mitigation and can also be used to modify regional climate, particularly rainfall. Climate impacts from plantations need to be well understood before considering implementation. Typically, impact studies are attempted at continental or global scales and use coarse-resolution models, which suffer from severe systematic errors. This is highly problematic because decision makers should only countenance geoengineering schemes like global afforestation if impacts are understood on the regional scale. We posit the necessity of using high-resolution regional models with sophisticated representations of land–atmosphere feedback and vegetation. This approach allows for studying desert plantations and the process chain leading to climate modification. We demonstrate that large-scale plantations enhance regional clouds and rainfall and derive an index for predicting plantation impacts. Thus, desert plantations represent a unique environmental solution via predictable regional weather modification and carbon storage.

scholarly journals the Yuba City flood: a case study of weather modification litigation*

1968 ◽  
Vol 49 (7) ◽  
pp. 690-714 ◽  
Author(s):  
Dean E. Mann
Keyword(s):  
Large Scale ◽  
River System ◽  
Tropical Storm ◽  
The State ◽  
Cloud Seeding ◽  
Weather Modification ◽  
Electric Company ◽  
Property Owners ◽  
Severe Flooding

In December 1955 a severe tropical storm caused severe flooding throughout Northern California with damage exceeding $200,000,000. One area suffering large-scale flooding was at Yuba City, at the confluence of the Feather and Yuba Rivers. The levees broke and consequent damage was in the magnitude of $65 million. Property-owners sought recompense through suits brought in the Superior Court of Sutter County against the State of California, Pacific Gas and Electric Company (PG&E), and North American Weather Consultants (NAWC). PG&E, through its contracting agent, NAWC, had undertaken cloud seeding operations in three places in the high Sierras, one of which was in the Lake Almanor water-shed in the Feather River system. NAWC had interrupted seeding activities in that area three days before the levees broke at Yuba City. Plaintiffs charged that PG&E and NAWC were negligent in the operation of their generators, had contributed to the total quantity of water produced by the watershed and therefore were legally liable, and that cloud seeding was ultra-hazardous activity so that those engaged in such activities were strictly liable for damages. The suit was begun in 1958 and concluded in 1964. Trial before a judge only began in October 1963 and a decision was rendered in April 1964. The judge ruled that neither PG&E nor NAWC was liable. In accordance with an agreement among the parties no appeal was taken. Plaintiffs were successful, however, against the State, basing their claim for damages on the doctrine of inverse condemnation which holds that the State must recompense for damages incurred in the lawful exercise of its powers—in this case, the construction of levees. The litigation raises important questions of public policy with regard to weather modification and these are considered in the light of this case.

scholarly journals Large-Scale Precipitation Variability over Northwest China Inferred from Tree Rings

2011 ◽  
Vol 24 (13) ◽  
pp. 3457-3468 ◽  
Author(s):  
Keyan Fang ◽  
Xiaohua Gou ◽  
Fahu Chen ◽  
Edward Cook ◽  
Jinbao Li ◽  
...  
Keyword(s):  
Tree Ring ◽  
Large Scale ◽  
Principal Component ◽  
Northwest China ◽  
Poor Quality ◽  
Contour Method ◽  
Precipitation Reconstruction ◽  
Nw China ◽  
Climate Station ◽  
Instrumental Records

Abstract A preliminary study of a point-by-point spatial precipitation reconstruction for northwestern (NW) China is explored, based on a tree-ring network of 132 chronologies. Precipitation variations during the past ~200–400 yr (the common reconstruction period is from 1802 to 1990) are reconstructed for 26 stations in NW China from a nationwide 160-station dataset. The authors introduce a “search spatial correlation contour” method to locate candidate tree-ring predictors for the reconstruction data of a given climate station. Calibration and verification results indicate that most precipitation reconstruction models are acceptable, except for a few reconstructions (stations Hetian, Hami, Jiuquan, and Wuwei) with degraded quality. Additionally, the authors compare four spatial precipitation factors in the instrumental records and reconstructions derived from a rotated principal component analysis (RPCA). The northern and southern Xinjiang factors from the instrumental and reconstructed data agree well with each other. However, differences in spatial patterns between the instrumentation and reconstruction data are also found for the other two factors, which probably result from the relatively poor quality of a few stations. Major drought events documented in previous studies—for example, from the 1920s through the 1930s for the eastern part of NW China—are reconstructed in this study.

scholarly journals Maternal adherence to micronutrient supplementation before and during pregnancy in Northwest China: a large-scale population-based cross-sectional survey

BMJ Open ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. e028843 ◽  
Author(s):  
Danmeng Liu ◽  
Yue Cheng ◽  
Shaonong Dang ◽  
Duolao Wang ◽  
Yaling Zhao ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Large Scale ◽  
Northwest China ◽  
Population Based ◽  
Shaanxi Province ◽  
Micronutrient Supplementation ◽  
Cross Sectional Survey ◽  
Start Time ◽  
Cross Sectional ◽  
Scale Population

ObjectivesTo report the situation of maternal micronutrient supplementation before and during pregnancy in Northwest China and to examine the rates of and factors related to the adherence to micronutrient supplementation among pregnant women in this region, where dietary micronutrient intake is commonly insufficient.DesignA large-scale population-based cross-sectional survey.SettingTwenty counties and ten districts of Shaanxi Province.ParticipantsA sample of 30 027 women were selected using a stratified multistage random sampling method. A total of 28 678 women were chosen for the final analysis after excluding those who did not provide clear information about nutritional supplementation before and during pregnancy.Main outcome measuresMaternal adherence to micronutrient supplementation (high and low) were the outcomes. They were determined by the start time and duration of use according to Chinese guidelines (for folic acid (FA) supplements) and WHO recommendations (for iron, calcium and multiple-micronutrient (MMN) supplements).ResultsIn total, 83.9% of women took at least one kind of micronutrient supplement before or during pregnancy. FA (67.6%) and calcium (57.5%) were the primarily used micronutrient supplements; few participants used MMN (14.0%) or iron (5.4%). Adherence to supplementation of all micronutrients was low (7.4% for FA, 0.6% for iron, 11.7% for calcium and 2.7% for MMN). Higher educational levels, higher income levels, urban residence and better antenatal care (including pregnancy consultation and a higher frequency of antenatal visits) were associated with high adherence to micronutrient supplementation.ConclusionMaternal micronutrient supplementation before and during pregnancy in Northwest China was way below standards recommended by the Chinese guidelines or WHO. Targeted health education and future nutritional guidelines are suggested to improve this situation, especially in pregnant women with disadvantaged sociodemographic conditions.

scholarly journals Automated Visual Recognizability Evaluation of Traffic Sign Based on 3D LiDAR Point Clouds

2019 ◽  
Vol 11 (12) ◽  
pp. 1453 ◽  
Author(s):  
Shanxin Zhang ◽  
Cheng Wang ◽  
Lili Lin ◽  
Chenglu Wen ◽  
Chenhui Yang ◽  
...  
Keyword(s):  
Traffic Safety ◽  
Laser Scanning ◽  
Large Scale ◽  
Evaluation Method ◽  
Evaluation Model ◽  
Point Clouds ◽  
Traffic Sign ◽  
Traffic Signs ◽  
3D Point Clouds ◽  
Traffic Environment

Maintaining the high visual recognizability of traffic signs for traffic safety is a key matter for road network management. Mobile Laser Scanning (MLS) systems provide efficient way of 3D measurement over large-scale traffic environment. This paper presents a quantitative visual recognizability evaluation method for traffic signs in large-scale traffic environment based on traffic recognition theory and MLS 3D point clouds. We first propose the Visibility Evaluation Model (VEM) to quantitatively describe the visibility of traffic sign from any given viewpoint, then we proposed the concept of visual recognizability field and Traffic Sign Visual Recognizability Evaluation Model (TSVREM) to measure the visual recognizability of a traffic sign. Finally, we present an automatic TSVREM calculation algorithm for MLS 3D point clouds. Experimental results on real MLS 3D point clouds show that the proposed method is feasible and efficient.

scholarly journals Evaluation of the Wyoming Weather Modification Pilot Project (WWMPP) Using Two Approaches: Traditional Statistics and Ensemble Modeling

2018 ◽  
Vol 57 (11) ◽  
pp. 2639-2660 ◽  
Author(s):  
Roy M. Rasmussen ◽  
Sarah A. Tessendorf ◽  
Lulin Xue ◽  
Courtney Weeks ◽  
Kyoko Ikeda ◽  
...  
Keyword(s):  
Null Hypothesis ◽  
Initial Conditions ◽  
Pilot Project ◽  
Physical Experiment ◽  
Annual Precipitation ◽  
Ensemble Modeling ◽  
Cloud Seeding ◽  
Weather Modification ◽  
Mountain Ranges ◽  
The Impact

AbstractThe Wyoming Weather Modification Pilot Project randomized cloud seeding experiment was a crossover statistical experiment conducted over two mountain ranges in eastern Wyoming and lasted for 6 years (2008–13). The goal of the experiment was to determine if cloud seeding of orographic barriers could increase snowfall and snowpack. The experimental design included triply redundant snow gauges deployed in a target–control configuration, covariate snow gauges to account for precipitation variability, and ground-based seeding with silver iodide (AgI). The outcomes of this experiment are evaluated with the statistical–physical experiment design and with ensemble modeling. The root regression ratio (RRR) applied to 118 experimental units provided insufficient statistical evidence (p value of 0.28) to reject the null hypothesis that there was no effect from ground-based cloud seeding. Ensemble modeling estimates of the impact of ground-based seeding provide an alternate evaluation of the 6-yr experiment. The results of the model ensemble approach with and without seeding estimated a mean enhancement of precipitation of 5%, with an inner-quartile range of 3%–7%. Estimating the impact on annual precipitation over these mountain ranges requires results from another study that indicated that approximately 30% of the annual precipitation results from clouds identified as seedable within the seeding experiment. Thus the seeding impact is on the order of 1.5% of the annual precipitation, compared to 1% for the statistical–physical experiment, which was not sufficient to reject the null hypothesis. These results provide an estimate of the impact of ground-based cloud seeding in the Sierra Madre and Medicine Bow Mountains in Wyoming that accounts for uncertainties in both initial conditions and model physics.

Design and implementation of multi-mode routers for large-scale inter-core networks

Integration ◽  
2016 ◽  
Vol 53 ◽  
pp. 1-13 ◽  
Author(s):  
Ning Ma ◽  
Zhuo Zou ◽  
Zhonghai Lu ◽  
Lirong Zheng
Keyword(s):  
Large Scale ◽  
Core Networks ◽  
Design And Implementation ◽  
Multi Mode
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