The Operational Mesogamma-Scale Analysis and Forecast System of the U.S. Army Test and Evaluation Command. Part IV: The White Sands Missile Range Auto-Nowcast System

2008 ◽  
Vol 47 (4) ◽  
pp. 1123-1139 ◽  
Author(s):  
Thomas R. Saxen ◽  
Cynthia K. Mueller ◽  
Thomas T. Warner ◽  
Matthias Steiner ◽  
Edward E. Ellison ◽  
...  
Keyword(s):  
Weather Conditions ◽  
Thunderstorm Activity ◽  
Weather System ◽  
Freezing Level ◽  
Test And Evaluation ◽  
Cloud To Ground Lightning ◽  
Strong Winds ◽  
Convective Cells ◽  
White Sands ◽  
The U.S

Abstract During the summer months at the U.S. Army Test and Evaluation Command’s (ATEC) White Sands Missile Range (WSMR), forecasting thunderstorm activity is one of the primary duties of the range forecasters. The safety of personnel working on the range and the protection of expensive test equipment depend critically on the quality of forecasts of thunderstorms and associated hazards, including cloud-to-ground lightning, hail, strong winds, heavy rainfall, flash flooding, and tornadoes. The National Center for Atmospheric Research (NCAR) Auto-Nowcast (ANC) system is one of the key forecast tools in the ATEC Four-Dimensional Weather System (4DWX) at WSMR, where its purpose is to aid WSMR meteorologists in their mission of very short term thunderstorm forecasting. Besides monitoring the weather activity throughout the region and warning personnel of potentially hazardous thunderstorms, forecasters play a key role in assisting with the day-to-day planning of test operations on the range by providing guidance with regard to weather conditions favorable to testing. Moreover, based on climatological information about the local weather conditions, forecasters advise their range customers about scheduling tests at WSMR months in advance. This paper reviews the NCAR ANC system, provides examples of the ANC system’s use in thunderstorm forecasting, and describes climatological analyses of WSMR summertime thunderstorm activity relevant for long-range planning of tests. The climatological analysis illustrates that radar-detected convective cells with reflectivity of ≥35 dBZ at WSMR are 1) short lived, with 76% having lifetimes of less than 30 min; 2) small, with 67% occupying areas of less than 25 km2; 3) slow moving, with 79% exhibiting speeds of less than 4 m s−1; 4) moderately intense, with 80% showing reflectivities in excess of 40 dBZ; and 5) deep, with 80% of the storms reaching far enough above the freezing level to be capable of generating lightning.

The Operational Mesogamma-Scale Analysis and Forecast System of the U.S. Army Test and Evaluation Command. Part I: Overview of the Modeling System, the Forecast Products, and How the Products Are Used

2008 ◽  
Vol 47 (4) ◽  
pp. 1077-1092 ◽  
Author(s):  
Yubao Liu ◽  
Thomas T. Warner ◽  
James F. Bowers ◽  
Laurie P. Carson ◽  
Fei Chen ◽  
...  
Keyword(s):  
Weather System ◽  
Test And Evaluation ◽  
Resolution Model ◽  
Forecasting System ◽  
High Resolution Model ◽  
And Performance ◽  
The Many ◽  
Effective Use ◽  
And Training ◽  
The U.S

Abstract Given the rapid increase in the use of operational mesoscale models to satisfy different specialized needs, it is important for the community to share ideas and solutions for meeting the many associated challenges that encompass science, technology, education, and training. As a contribution toward this objective, this paper begins a series that reports on the characteristics and performance of an operational mesogamma-scale weather analysis and forecasting system that has been developed for use by the U.S. Army Test and Evaluation Command. During the more than five years that this four-dimensional weather system has been in use at seven U.S. Army test ranges, valuable experience has been gained about the production and effective use of high-resolution model products for satisfying a variety of needs. This paper serves as a foundation for the rest of the papers in the series by describing the operational requirements for the system, the data assimilation and forecasting system characteristics, and the forecaster training that is required for the finescale products to be used effectively.

scholarly journals Distinct aerosol effects on cloud-to-ground lightning in the plateau and basin regions of Sichuan, Southwest China

2020 ◽  
Vol 20 (21) ◽  
pp. 13379-13397
Author(s):  
Pengguo Zhao ◽  
Zhanqing Li ◽  
Hui Xiao ◽  
Fang Wu ◽  
Youtong Zheng ◽  
...  
Keyword(s):  
Cloud Droplet ◽  
Lightning Activity ◽  
Freezing Process ◽  
Plateau Region ◽  
Freezing Level ◽  
Aerosol Loading ◽  
Cloud To Ground Lightning ◽  
Basin Region ◽  
Total Column ◽  
Cg Lightning

Abstract. The joint effects of aerosol, thermodynamic, and cloud-related factors on cloud-to-ground lightning in Sichuan were investigated by a comprehensive analysis of ground-based measurements made from 2005 to 2017 in combination with reanalysis data. Data include aerosol optical depth, cloud-to-ground (CG) lightning density, convective available potential energy (CAPE), mid-level relative humidity, lower- to mid-tropospheric vertical wind shear, cloud-base height, total column liquid water (TCLW), and total column ice water (TCIW). Results show that CG lightning density and aerosols are positively correlated in the plateau region and negatively correlated in the basin region. Sulfate aerosols are found to be more strongly associated with lightning than total aerosols, so this study focuses on the role of sulfate aerosols in lightning activity. In the plateau region, the lower aerosol concentration stimulates lightning activity through microphysical effects. Increasing the aerosol loading decreases the cloud droplet size, reducing the cloud droplet collision–coalescence efficiency and inhibiting the warm-rain process. More small cloud droplets are transported above the freezing level to participate in the freezing process, forming more ice particles and releasing more latent heat during the freezing process. Thus, an increase in the aerosol loading increases CAPE, TCLW, and TCIW, stimulating CG lightning in the plateau region. In the basin region, by contrast, the higher concentration of aerosols inhibits lightning activity through the radiative effect. An increase in the aerosol loading reduces the amount of solar radiation reaching the ground, thereby lowering the CAPE. The intensity of convection decreases, resulting in less supercooled water being transported to the freezing level and fewer ice particles forming, thereby increasing the total liquid water content. Thus, an increase in the aerosol loading suppresses the intensity of convective activity and CG lightning in the basin region.

Detecting Multiple Ground Contacts in Cloud-to-Ground Lightning Flashes

2009 ◽  
Vol 26 (11) ◽  
pp. 2392-2402 ◽  
Author(s):  
Christina A. Stall ◽  
Kenneth L. Cummins ◽  
E. Philip Krider ◽  
John A. Cramer
Keyword(s):  
Standard Deviation ◽  
Rise Time ◽  
Random Errors ◽  
Peak Current ◽  
Video Recordings ◽  
Lightning Detection ◽  
Cloud To Ground Lightning ◽  
The U.S ◽  
Good Agreement ◽  
Cg Lightning

Abstract Video recordings of cloud-to-ground (CG) lightning flashes have been analyzed in conjunction with correlated stroke reports from the U.S. National Lightning Detection Network (NLDN) to determine whether the NLDN is capable of identifying the different ground contacts in CG flashes. For 39 negative CG flashes that were recorded on video near Tucson, Arizona, the NLDN-based horizontal distances between the first stroke and the 62 subsequent strokes remaining in a preexisting channel had a mean and standard deviation of 0.9 ± 0.8 km and a median of 0.7 km. The horizontal distances between the first stroke and the 59 new ground contacts (NGCs) had a mean and standard deviation of 2.3 ± 1.7 km and a median of 2.1 km. These results are in good agreement with prior measurements of the random errors in NLDN positions in southern Arizona as well as video- and thunder-based measurements of the distances between all ground contacts in Florida. In cases where the distances between ground contacts are small and obscured by random errors in the NLDN locations, measurements of the stroke rise time, estimated peak current, and stroke order can be utilized to enhance the ability of the NLDN to identify strokes that produce new ground terminations.

scholarly journals Gemini T-20G-8 XM1 Tank APU

1981 ◽  
Author(s):  
C. Rodgers ◽  
J. Zeno ◽  
E. A. Drury ◽  
A. Karchon
Keyword(s):  
Gas Turbine ◽  
Power Unit ◽  
Weather Conditions ◽  
Cold Weather ◽  
Turbine Engine ◽  
Auxiliary Power Unit ◽  
Auxiliary Power ◽  
Generator Sets ◽  
Main Engine ◽  
The U.S

Auxiliary power is often provided on combat vehicles in the U.S. Army for battery charging, operation of auxiliary vehicle equipment when the main engine is not running, or to provide assistance in starting the main engine in extreme cold weather conditions. The use of a gas turbine for these applications is particularly attractive, due to its small size and lightweight. In November 1978, the U.S. Army Tank-Automotive Research and Development Command, Warren, MI awarded a contract to the Turbomach Division of Solar Turbines International, San Diego, CA, for the development of a 10 kW 28 vdc gas turbine powered auxiliary power unit (APU) for installation in the XM1 main battle tank. This paper describes the general features of the Solar Turbomach T-20G-8 Auxiliary Power Unit, a single-shaft gas turbine driven generator set which has been developed under this contract. This APU is one of the family of Gemini powered APUs and is a derivative of the U.S. Army 10 kW gas turbine engine-driven, 60 and 400 Hz generator sets developed by Solar. The electrical components were newly developed for this particular application. Currently, the APU is in qualification testing both in the laboratory and in the XM1 main battle tank.

Forecasting for a Remote Island: A Class Exercise

2003 ◽  
Vol 84 (6) ◽  
pp. 777-784 ◽  
Author(s):  
Allen J. Riordan
Keyword(s):  
Research Team ◽  
Weather Conditions ◽  
State University ◽  
Current Output ◽  
North Carolina State University ◽  
Wind Speeds ◽  
Wide Range ◽  
Remote Island ◽  
Satellite Meteorology ◽  
Strong Winds

Students enrolled in a satellite meteorology course at North Carolina State University, Raleigh, recently had an unusual opportunity to apply their forecast skills to predict wind and weather conditions for a remote site in the Southern Hemisphere. For about 40 days starting in early February 2001, students used satellite and model guidance to develop forecasts to support a research team stationed on Bouvet Island (54°26′S, 3°24′E). Internet products together with current output from NCEP's Aviation (AVN) model supported the activity. Wind forecasts were of particular interest to the Bouvet team because violent winds often developed unexpectedly and posed a safety hazard. Results were encouraging in that 24-h wind speed forecasts showed reasonable reliability over a wide range of wind speeds. Forecasts for 48 h showed only marginal skill, however. Two critical events were well forecasted—the major February storm with wind speeds of over 120 kt and a brief calm period following several days of strong winds in early March. The latter forecast proved instrumental in recovering the research team.

Echolocation and foraging behaviour in the Hawaiian hoary bat, Lasiurus cinereus semotus

1984 ◽  
Vol 62 (11) ◽  
pp. 2113-2120 ◽  
Author(s):  
Jacqueline J. Belwood ◽  
James H. Fullard
Keyword(s):  
Prey Availability ◽  
Weather Conditions ◽  
Peak Frequency ◽  
Social Signals ◽  
Lasiurus Cinereus ◽  
Social Signal ◽  
Term Basis ◽  
Strong Winds ◽  
High Degree ◽  
Lasiurus Cinereus Semotus

Free-flying individual Lasiurus cinereus semotus were observed as they foraged near incandescent lights on the island of Kauai, Hawaii. Two types of vocalizations were recorded from the bats: an echolocation–hunting signal with peak frequency of 27.8 kHz and an agonistic social signal, emitted while the bats were in aggressive pursuit of one another, with a peak frequency of 9.6 kHz. The tendency to vocalize agonistically increased with increased numbers of bats in the foraging area and increased as the density of insects available to the hunting bats decreased. Our observations suggest that the bats may gather echolocation information from their social signals. The bats at the site foraged under most weather conditions, including fog, moderate rain, strong winds, and temperatures as low as 13 °C. Groups of up to eight animals were common, although bats hunted in airspaces that were vigorously defended against other individuals. Small flies and small moths (< 10 mm body length) were the most common insects available as prey, but larger moths (16–20 mm) made up the bulk of the bats' diet. Moths larger than 20 mm were available but not fed on by the bats. This unique study site provides a rare opportunity to compare both prey availability to prey consumption in a population of bats. Our results suggest that this bat, at least on a short-term basis, exhibits a high degree of selectivity in its foraging, a behaviour similar to the mainland subspecies.

scholarly journals Pyrogenic Transformation of Geosystems of the Western Cibaikalia: Factors, Conditions, Current State

2021 ◽  
Vol 35 ◽  
pp. 3-18
Author(s):  
A. Yu. Bibaeva ◽  
Keyword(s):  
Baikal Region ◽  
Temporal Distribution ◽  
Field Research ◽  
Ground Cover ◽  
Weather Conditions ◽  
Thunderstorm Activity ◽  
Coniferous Forests ◽  
Adverse Weather ◽  
Pyrogenic Transformation ◽  
Mountain Taiga

The factors of pyrogenic impact on the taiga geosystems of the Western Baikal region against the background of the modern transformation of the global atmospheric circula-tion are studied in the paper. The results of world scientific research on modeling climate change and related adverse weather phenomena (prolonged droughts, thunderstorm activity, etc.) are presented. The natural factors contributing to the increase in the pyrogenic transformation of geosystems are described. The study of the spatio-temporal distribution of fires is carried out on the basis of data from remote sensing of the Earth. Information about unfavorable weather conditions and dangerous hydrometeorological phenomena, data on atmospheric phenomena (thunderstorm activity), daily values of air temperature and soil temperature under natural cover at different depths are analyzed in order to factorial analysis of forest fire sources in the study area. The characteristic of the current stage of geosystems is given based on field research conducted in June 2020. It was revealed that catastrophic fires registered in the study area in 1997 and 2015 occurred against the background of minimal thunderstorm activity. At the same time, in the central part of the Western Baikal region thunderstorms were the leading factor in the 2015 fires. Five years after the fire, the restoration of mountain taiga light coniferous forests is characterized by the predominance of the community of Chamaenerion angustifolium (L.) Scop. The successional dynamics of the geosystems of mountain taiga dark coniferous forests is going through the Betula rotundifolia Spach. with Ledum palustre L. and cereal-forb ground cover. Undergrowth of tree species (mainly pine) is rare and uneven about 800–1200 specimens per hectare.

scholarly journals Quality and Yield of Lettuce in an Open-Air Rooftop Hydroponic System

Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2586
Author(s):  
Maha Ezziddine ◽  
Helge Liltved
Keyword(s):  
Leaf Tissue ◽  
Growth Period ◽  
Weather Conditions ◽  
Nutrient Content ◽  
Foliar Analysis ◽  
Fresh Weight ◽  
Hydroponic System ◽  
Nutrient Film Technique ◽  
Lettuce Growth ◽  
Strong Winds

In this study, the yield and growth performance of lettuce in an open-air rooftop hydroponic system were investigated. Lettuce was grown in a closed recirculating nutrient film technique (NFT) unit using a standard nutrient solution (NS). Yield, fresh weight, and nutrient content in the leaf tissue of the harvested lettuce were measured. The results were compared with the results obtained in indoor hydroponic lettuce growth with artificial lightning. Despite strong winds during the growth period, 25% of the total lettuce heads weighed twice the marketable weight; however, 25% of the total lettuce heads were below the marketable weight. A more efficient nutrient uptake was indicated by the lettuces in the rooftop system compared with the uptake in the indoor system. Foliar analysis revealed a higher content of all nutrients in the leaves of rooftop hydroponic lettuce compared with indoor hydroponic lettuce. This study suggests that hydroponic rooftop-grown lettuce can be competitive with their indoor counterparts if the rooftop hydroponic system is protected from extreme weather conditions.

Sign in / Sign up

Export Citation Format

Share Document