scholarly journals A Confirmatory Snowfall Enhancement Project in the Snowy Mountains of Australia. Part I: Project Design and Response Variables

2011 ◽  
Vol 50 (7) ◽  
pp. 1432-1447 ◽  
Author(s):  
Michael J. Manton ◽  
Loredana Warren ◽  
Suzanne L. Kenyon ◽  
Andrew D. Peace ◽  
Shane P. Bilish ◽  
...  
Keyword(s):  
Supercooled Liquid ◽  
Field Studies ◽  
Control Area ◽  
Target Area ◽  
Fixed Target ◽  
Southeastern Australia ◽  
Seeding Material ◽  
Static Seeding ◽  
A Site ◽  
Precipitation Enhancement

AbstractThe Snowy Precipitation Enhancement Research Project (SPERP) was undertaken from May 2005 to June 2009 in the Snowy Mountains of southeastern Australia with the aim of enhancing snowfall in westerly flows associated with winter cold fronts. Building on earlier field studies in the region, SPERP was developed as a confirmatory experiment of glaciogenic static seeding using a silver-chloroiodide material dispersed from ground-based generators. Seeding of 5-h experimental units (EUs) was randomized with a seeding ratio of 2:1. A total of 107 EUs were undertaken at suitable times, based on surface and upper-air observations. Indium (III) oxide was released during all EUs for comparison of indium and silver concentrations in snow in seeded and unseeded EUs to test the targeting of seeding material. A network of gauges was deployed at 44 sites across the region to detect whether precipitation was enhanced in a fixed target area of 832 km2, using observations from a fixed control area to estimate the natural precipitation in the target. Additional measurements included integrated supercooled liquid water at a site in the target area and upper-air data from a site upwind of the target.

scholarly journals Static Mode Seeding of Summer Cumuli—A Review

1986 ◽  
Vol 43 ◽  
pp. 7-24 ◽  
Author(s):  
Bernard A. Silverman
Keyword(s):  
Field Studies ◽  
Static Mode ◽  
Convective Clouds ◽  
Cumulus Congestus ◽  
Past Experimental Work ◽  
Static Seeding ◽  
Glaciogenic Seeding ◽  
Physical Reasons ◽  
Future Work ◽  
Precipitation Enhancement

Abstract A review of the state of knowledge of the physics of the static mode seeding hypothesis for convective clouds is presented. The central thesis of the review is that the results of past experimental work are diverse but valid and that credibility of the science depends on understanding the physical reasons for the diverse results. Areas of uncertainty and conflicts in evidence associated with the statement of physical hypothesis, the concept of seedability, the seeding operation, and the chain of physical events following seeding are highlighted to identify what issues need to be resolved to further progress in precipitation enhancement research and application. It is concluded that the only aspect of static seeding that meets scientific standards of cause-and-effect relationships and repeatability is that glaciogenic seeding agents can produce distinct “seeding signatures” in clouds. However, the reviewer argues that a body of inferential physical evidence has been amassed that provides a better understanding of which clouds are seedable (susceptible to precipitation enhancement by artificial seeding) and which are not, even though the tools for recognizing and properly treating them are imperfect. In particular, the inferred evidence appears to support the claims of physical plausibility for the positive statistical results of the Israeli experiments. It is suggested that future work continue to be designed for physical understanding and evaluation through comprehensive field studies and numerical modeling. Duplicating the Israeli experiments in another location should receive high priority but, in general, future experiments should move upscale from cumulus congestus to convective complexes. In doing so, a new, more complex physical hypothesis that accounts for cloud–environment and microphysical–dynamical interactions and their response to seeding will have to be developed.

scholarly journals A Confirmatory Snowfall Enhancement Project in the Snowy Mountains of Australia. Part II: Primary and Associated Analyses

2011 ◽  
Vol 50 (7) ◽  
pp. 1448-1458 ◽  
Author(s):  
Michael J. Manton ◽  
Loredana Warren
Keyword(s):  
Secondary Analysis ◽  
Maximum Level ◽  
Cloud Microphysics ◽  
Target Area ◽  
Primary Target ◽  
Primary Analysis ◽  
Significance Level ◽  
Southeastern Australia ◽  
Secondary Analyses ◽  
Seeding Material

AbstractThe Snowy Precipitation Enhancement Research Project (SPERP) was undertaken in winters from May 2005 to June 2009 in the Snowy Mountains region of southeastern Australia. Part I of this paper describes the design and implementation of the project, as well as the characteristics of the key datasets collected during the field phase. The primary analysis in this paper (Part II) shows an unequivocal impact on the targeting of seeding material, with the maximum level of silver in snow samples collected from the primary target area found to be significantly greater in seeded than unseeded experimental units (EUs). A positive but not statistically significant impact on precipitation was found. Further analysis shows that a substantial source of uncertainty in the estimation of the impacts of seeding on precipitation is associated with EUs where the seeding generators operated for relatively few hours. When the analysis is repeated using only EUs with more than 45 generator hours, the increase in precipitation in the primary target area is 14% at the 8% significance level. When applying that analysis to the overall target area, the precipitation increase is 14% at the 3% significance level. A secondary analysis of the ratio of silver to indium in snow supports the hypothesis that seeding material affected the cloud microphysics. Other secondary analyses reveal that seeding had an impact on virtually all of the physical variables examined in a manner consistent with the seeding hypothesis.

Dual-Polarization Radar Data Analysis of the Impact of Ground-Based Glaciogenic Seeding on Winter Orographic Clouds. Part I: Mostly Stratiform Clouds

2015 ◽  
Vol 54 (9) ◽  
pp. 1944-1969 ◽  
Author(s):  
Xiaoqin Jing ◽  
Bart Geerts ◽  
Katja Friedrich ◽  
Binod Pokharel
Keyword(s):  
Radar Data ◽  
Control Area ◽  
Target Area ◽  
Dual Polarization ◽  
Stratiform Clouds ◽  
Orographic Clouds ◽  
Close Range ◽  
Glaciogenic Seeding ◽  
Differential Reflectivity ◽  
The Impact

AbstractThe impact of ground-based glaciogenic seeding on wintertime orographic, mostly stratiform clouds is analyzed by means of data from an X-band dual-polarization radar, the Doppler-on-Wheels (DOW) radar, positioned on a mountain pass. This study focuses on six intensive observation periods (IOPs) during the 2012 AgI Seeding Cloud Impact Investigation (ASCII) project in Wyoming. In all six storms, the bulk upstream Froude number below mountaintop exceeded 1 (suggesting unblocked flow), the clouds were relatively shallow (with bases below freezing), some liquid water was present, and orographic flow conditions were mostly steady. To examine the silver iodide (AgI) seeding effect, three study areas are defined (a control area, a target area upwind of the crest, and a lee target area), and comparisons are made between measurements from a treated period and those from an untreated period. Changes in reflectivity and differential reflectivity observed by the DOW at low levels during seeding are consistent with enhanced snow growth, by vapor diffusion and/or aggregation, for a case study and for the composite analysis of all six IOPs, especially at close range upwind of the mountain crest. These low-level changes may have been affected by natural changes aloft, however, as evident from differences in the evolution of the echo-top height in the control and target areas. Even though precipitation in the target region is strongly correlated with that in the control region, the authors cannot definitively attribute the change to seeding because there is a lack of knowledge about natural variability, nor can the outcome be generalized, because the sample size is small.

Developing Operational and Safety Guidelines for School Sites in Texas

2005 ◽  
Vol 1922 (1) ◽  
pp. 90-97
Author(s):  
Scott A. Cooner
Keyword(s):  
Field Studies ◽  
Advisory Panel ◽  
Department Of Transportation ◽  
School Site ◽  
Texas Department ◽  
District Personnel ◽  
Site Access ◽  
School Sites ◽  
Site Planning ◽  
A Site

The objective of a two-year study was to recommend school site planning guidelines for transportation-related elements such as site selection, general site requirements and design, bus operations, parent drop-off and pickup zones, driveways, turn lanes, signing and marking, parking, and pedestrian and bicycle access. The research team based these guidelines on a comprehensive review of existing guidelines and the results of field studies at school sites in Texas. Examples are provided of good practices and of practices to avoid for three of the more prominent guidelines. The guidelines are focused on transportation design, operations, and safety within school sites—with a particular focus on the parent drop-off and pickup zones. A site plan review checklist based on the 21 consensus guidelines approved by the project advisory panel is provided. Texas Department of Transportation engineers, field crews, architects, and school district personnel can use this checklist to coordinate efforts and improve the safety and efficiency of school site access and traffic flow.

Glyphosate-Resistant Horseweed (Conyza canadensis) Growth, Seed Production, and Interference in Cotton

Weed Science ◽  
2009 ◽  
Vol 57 (3) ◽  
pp. 346-350 ◽  
Author(s):  
Lawrence E. Steckel ◽  
C. Owen Gwathmey
Keyword(s):  
Seed Production ◽  
Yield Loss ◽  
Maximum Yield ◽  
Field Studies ◽  
Lint Yield ◽  
Growth Stages ◽  
Conyza Canadensis ◽  
Cotton Lint ◽  
Cotton Lint Yield ◽  
A Site

Field studies were conducted to examine both density and duration of glyphosate-resistant (GR) horseweed interference in cotton. Two studies, one examining the effect of horseweed density and a second the duration of horseweed interference, were conducted on a site with a natural population of horseweed that were treated with glyphosate at 0.84 kg ae ha−1prior to planting and at the 2nd and 4th cotton node growth stages. GR horseweed density effect on cotton height, maturity, and lint yield was determined at horseweed densities of 0, 5, 10, 15, 20, and 25 plants m−2. Duration of horseweed interference was evaluated when 20 horseweed m−2were allowed to interfere with cotton from emergence to 2nd node, 6th node, 10th node, 12th node, and 1st bloom stage of cotton. The maximum cotton lint yield loss (46%) occurred when horseweed was allowed to compete with cotton from emergence to maturity at the two highest densities (20 and 25 horseweed m−2). When the data were fit to the Cousens model the estimateda(maximum yield loss) andi(yield loss per unit density as density approaches zero) were 53 ± 7.3 and 2.8 ± 0.6 SE, respectively. In both years of the study, horseweed interference from emergence to the 2nd cotton node did not reduce cotton lint yields. In 2006, cotton lint yield loss was 28% compared to 39% in 2005 when horseweed interfered with cotton from emergence until the 6th cotton node. Cotton lint yield loss was 37 and 44% when horseweed competed to the 8th cotton node in 2005 and 2006, respectively. Maximum horseweed seed production was 134,000 to 148,000 seeds m−2.

scholarly journals The Influence of Experimental Pain on Primary Motor Cortex Function: Protocol for a Systematic Review and Meta-analysis

2020 ◽  
Author(s):  
Nahian Chowdhury ◽  
Wei-Ju Chang ◽  
Samantha K Millard ◽  
Patrick Skippen ◽  
Katarzyna Bilska ◽  
...  
Keyword(s):  
Systematic Review ◽  
Motor Cortex ◽  
Primary Motor Cortex ◽  
Meta Analysis ◽  
Experimental Pain ◽  
Control Area ◽  
Separate Analysis ◽  
Target Area ◽  
Eligibility Criteria ◽  
Experimentally Induced

Abstract Introduction: The primary motor cortex (M1) is a key brain region implicated in pain processing. Here, we present a protocol for a review that aims to synthesise and critically appraise the evidence for the effect of experimentalpain on M1 function. Methods/Analysis: A systematic review and meta-analysis will be conducted. Electronic databases will be searched using a predetermined strategy. Studies published before April 2020 that investigate the effects of experimentally induced pain on corticomotor excitability (CME) in healthy individuals will be included if they meet eligibility criteria. Study identification, data extraction andrisk of bias assessment will be conducted by two independent reviewers, with a third reviewer consulted for any disagreements. The primary outcomes will include group level changes in CME and intracortical, transcortical and sensorimotor modulators of CME. A separate analysis using individual data will also be conducted to explore individual differences in CME in response to experimental pain. The meta-analysis will consider the following factors: pain model (transient, tonic, transitional pain), type of painful tissue (cutaneous, musculoskeletal), time points of outcome measures(during or after recovery from pain) and localisation of pain(target area, control area). Discussion: This review will provide a comprehensive understanding of the mechanisms within M1 that mediate experimentally induced pain, both on a group and individual level. Registration Number: The systematic review is registered with the International Prospective Register of Systematic Reviews (#CRD42020173172)

scholarly journals Spatial interpolation and simulation of post-burn duff thickness after prescribed fire

1999 ◽  
Vol 9 (2) ◽  
pp. 137 ◽  
Author(s):  
P. R. Robichaud ◽  
S. M. Miller
Keyword(s):  
Spatial Patterns ◽  
Prescribed Fire ◽  
Field Studies ◽  
Timber Harvesting ◽  
Surface Model ◽  
Total Consumption ◽  
Trend Surface ◽  
Harvesting Techniques ◽  
A Site ◽  
Floor Material

Prescribed fire is used as a site treatment after timber harvesting. These fires result in spatial patterns with some portions consuming all of the forest floor material (duff) and others consuming little. Prior to the burn, spatial sampling of duff thickness and duff water content can be used to generate geostatistical spatial simulations of these characteristics. Results from field studies indicated that spatial patterns of duff characteristics occurred, and they were then modeled by kriging, simulation and a trend-surface modeling techniques. The higher elevations of the study unit burned more severely than the lower portion. This is believed to be due to the heat generated by the fire drying out the upper portions of the units, thus consuming more duff material and thinner pre-burn duff thickness due to ground-based harvesting techniques. Attempts to predict duff consumption and subsequent post-burn duff thickness were successful using a trend-surface model developed for this site and a general duff consumption model. Knowledge of spatial patterns of duff remaining may help land managers adjust prescriptions and alter ignition patterns to reduce areas where total consumption of duff might occur.

A Transformational Approach to Winter Orographic Weather Modification Research: The SNOWIE Project

2019 ◽  
Vol 100 (1) ◽  
pp. 71-92 ◽  
Author(s):  
Sarah A. Tessendorf ◽  
Jeffrey R. French ◽  
Katja Friedrich ◽  
Bart Geerts ◽  
Robert M. Rauber ◽  
...  
Keyword(s):  
Silver Iodide ◽  
Supercooled Liquid ◽  
Cloud Seeding ◽  
Remotely Sensed Data ◽  
Weather Modification ◽  
Before And After ◽  
Orographic Clouds ◽  
Seeding Material ◽  
Airborne Sensors

AbstractThe Seeded and Natural Orographic Wintertime Clouds: The Idaho Experiment (SNOWIE) project aims to study the impacts of cloud seeding on winter orographic clouds. The field campaign took place in Idaho between 7 January and 17 March 2017 and employed a comprehensive suite of instrumentation, including ground-based radars and airborne sensors, to collect in situ and remotely sensed data in and around clouds containing supercooled liquid water before and after seeding with silver iodide aerosol particles. The seeding material was released primarily by an aircraft. It was hypothesized that the dispersal of the seeding material from aircraft would produce zigzag lines of silver iodide as it dispersed downwind. In several cases, unambiguous zigzag lines of reflectivity were detected by radar, and in situ measurements within these lines have been examined to determine the microphysical response of the cloud to seeding. The measurements from SNOWIE aim to address long-standing questions about the efficacy of cloud seeding, starting with documenting the physical chain of events following seeding. The data will also be used to evaluate and improve computer modeling parameterizations, including a new cloud-seeding parameterization designed to further evaluate and quantify the impacts of cloud seeding.

scholarly journals Field Studies Using a Recombinant Mycoinsecticide (Metarhizium anisopliae) Reveal that It Is Rhizosphere Competent

2002 ◽  
Vol 68 (12) ◽  
pp. 6383-6387 ◽  
Author(s):  
Gang Hu ◽  
Raymond J. St. Leger
Keyword(s):  
Metarhizium Anisopliae ◽  
Fluorescent Protein ◽  
Pathogenic Fungi ◽  
Field Studies ◽  
Field Conditions ◽  
Research Station ◽  
Potential Reservoir ◽  
Green Fluorescent ◽  
A Site ◽  
Transgenic Strains

ABSTRACT In the summer of 2000, we released genetically altered insect-pathogenic fungi onto a plot of cabbages at a field site on the Upper Marlboro Research Station, Md. The transformed derivatives of Metarhizium anisopliae ARSEF 1080, designated GPMa and GMa, carried the Aequorea victoria green fluorescent protein (gfp) gene alone (GMa) or with additional protease genes (Pr1) (GPMa). The study (i) confirmed the utility of gfp for monitoring pathogen strains in field populations over time, (ii) demonstrated little dissemination of transgenic strains and produced no evidence of transmission by nontarget insects, (iii) found that recombinant fungi were genetically stable over 1 year under field conditions, and (iv) determined that deployment of the transgenic strains did not depress the culturable indigenous fungal microflora. The major point of the study was to monitor the fate (survivorship) of transformants under field conditions. In nonrhizosphere soil, the amount of GMa decreased from 105 propagules/g at depths of 0 to 2 cm to 103 propagules/g after several months. However, the densities of GMa remained at 105 propagules/g in the inner rhizosphere, demonstrating that rhizospheric soils are a potential reservoir for M. anisopliae. These results place a sharp focus on the biology of the soil/root interphase as a site where plants, insects, and pathogens interact to determine fungal biocontrol efficacy, cycling, and survival. However, the rhizospheric effect was less marked for GPMa, and overall it showed reduced persistence in soils than did GMa.

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