Meteorology Commons^™

Unmanned Aircraft Systems For Precision Meteorology: An Analysis Of Gnss Position Measurement Error And Embedded Sensor Development, Karla S. Ladino

Theses and Dissertations--Biosystems and Agricultural Engineering

The overarching objective of this research was to enhance our comprehension of the three-dimensional precision of meteorological measurements obtained using small unmanned aircraft systems (UAS). Two complimentary experiments were conducted to achieve this objective.

The first experiment entailed the development and implementation of a system to determine the global navigation satellite system (GNSS) position accuracy on a UAS platform. This system was utilized to assess the static and dynamic accuracy of L1 and L1/L2 GNSS receivers in real-time kinematic (RTK) and non-RTK fix modes. Adjusted two-sample t-tests revealed significant differences in horizontal and vertical error between RTK and non-RTK receivers …

Impacts Of 1.5 °C And 2 °C Global Warming On Net Primary Productivity And Carbon Balance In China’S Terrestrial Ecosystems, Li Yu, Fengxue Gu, Mei Huang, Bo Tao, Man Hao, Zhaosheng Wang

Plant and Soil Sciences Faculty Publications

Assessing potential impacts of 1.5 °C and 2 °C global warming and identifying the risks of further 0.5 °C warming are crucial for climate adaptation and disaster risk management. Four earth system models in the Coupled Model Intercomparison Project Phase 5 (CMIP5) and a process-based ecosystem model are used in this study to assess the impacts and potential risks of the two warming targets on the carbon cycle of China’s terrestrial ecosystems. Results show that warming generally stimulates the increase of net primary productivity (NPP) and net ecosystem productivity (NEP) under both representative concentration pathway (RCP) 4.5 and RCP8.5 scenarios. …

Soil Carbon Dynamics And Greenhouse Gas Emissions In Conservation Tillage Systems At Multiple Scales, Yawen Huang

Theses and Dissertations--Plant and Soil Sciences

Conservation tillage practices like no-tillage and reduced tillage have been widely implemented worldwide, with expectations they would provide multiple benefits (e.g., yield enhancement and soil carbon sequestration) for food security and climate adaptation and mitigation. However, the adoption of conservation tillage faces both opportunities and challenges. A knowledge gap still exists regarding the effects of conservation tillage on the carbon cycle in agroecosystems. This dissertation reflects a comprehensive evaluation of conservation tillage at multiple scales using an integrated systems approach, a combination of data synthesis, the agriculture ecosystem model, and field observations and measurements. I first conducted a meta-analysis to …

Climate Change Impacts On Winter Wheat Yield In Northern China, Xiu Geng, Fang Wang, Wei Ren, Zhixin Hao

Plant and Soil Sciences Faculty Publications

Exploring the impacts of climate change on agriculture is one of important topics with respect to climate change. We quantitatively examined the impacts of climate change on winter wheat yield in Northern China using the Cobb–Douglas production function. Utilizing time-series data of agricultural production and meteorological observations from 1981 to 2016, the impacts of climatic factors on wheat production were assessed. It was found that the contribution of climatic factors to winter wheat yield per unit area (WYPA) was 0.762–1.921% in absolute terms. Growing season average temperature (GSAT) had a negative impact on WYPA for the period of 1981–2016. A …

Intercomparison Of Small Unmanned Aircraft System (Suas) Measurements For Atmospheric Science During The Lapse-Rate Campaign, Lindsay Barbieri, Stephan T. Kral, Sean C. C. Bailey, Amy E. Frazier, Jamey D. Jacob, Joachim Reuder, David Brus, Phillip B. Chilson, Christopher Crick, Carrick Detweiler, Abhiram Doddi, Jack Elston, Hosein Foroutan, Javier González-Rocha, Brian R. Greene, Marcelo I. Guzman, Adam L. Houston, Ashraful Islam, Osku Kemppinen, Dale Lawrence, Elizabeth A. Pillar-Little, Shane D. Ross, Michael P. Sama, David G. Schmale Iii, Travis J. Schuyler, Ajay Shankar, Suzanne W. Smith, Sean Waugh, Cory Dixon, Steve Borenstein, Gijs De Boer

Chemistry Faculty Publications

Small unmanned aircraft systems (sUAS) are rapidly transforming atmospheric research. With the advancement of the development and application of these systems, improving knowledge of best practices for accurate measurement is critical for achieving scientific goals. We present results from an intercomparison of atmospheric measurement data from the Lower Atmospheric Process Studies at Elevation—a Remotely piloted Aircraft Team Experiment (LAPSE-RATE) field campaign. We evaluate a total of 38 individual sUAS with 23 unique sensor and platform configurations using a meteorological tower for reference measurements. We assess precision, bias, and time response of sUAS measurements of temperature, humidity, pressure, wind speed, and …

Using A Balloon-Launched Unmanned Glider To Validate Real-Time Wrf Modeling, Travis J. Schuyler, S. M. Iman Gohari, Gary Pundsack, Donald Berchoff, Marcelo I. Guzman

Chemistry Faculty Publications

The use of small unmanned aerial systems (sUAS) for meteorological measurements has expanded significantly in recent years. SUAS are efficient platforms for collecting data with high resolution in both space and time, providing opportunities for enhanced atmospheric sampling. Furthermore, advances in mesoscale weather research and forecasting (WRF) modeling and graphical processing unit (GPU) computing have enabled high resolution weather modeling. In this manuscript, a balloon-launched unmanned glider, complete with a suite of sensors to measure atmospheric temperature, pressure, and relative humidity, is deployed for validation of real-time weather models. This work demonstrates the usefulness of sUAS for validating and improving …

“It’S Hard To Get Your Head Around Something Like This”: Figurative And Intense Language For Sensegiving During Severe Weather Coverage, Robert W. Prestley

Theses and Dissertations--Communication

During high-impact weather events like Hurricane Harvey, broadcast meteorologists take on the role of sensegiver, as they develop frameworks to help their viewers make sense of the storm. These frameworks are communicated through rhetorical choices evident in the language the meteorologists use to describe the storm’s threat and impact. This study investigates the rhetorical choices of KHOU broadcast meteorologists during Hurricane Harvey in order to make sense of the disaster, using an inductive thematic analysis. The results indicate that the KHOU broadcasters framed Harvey figuratively as an all-encompassing monster and a heat-seeking machine. The meteorologists used emotionally intense language to …

Additional Data Via Autonomous Systems To Supplement Traditional Sparse Sources For Weather Forecasting And Atmospheric Science, Suzanne Weaver Smith

Commonwealth Computational Summit

No abstract provided.

Nonmeteorological Influences On Severe Thunderstorm Warning Issuance: A Geographically Weighted Regression-Based Analysis Of County Warning Area Boundaries, Land Cover, And Demographic Variables, Megan L. White, J. Anthony Stallins

Geography Faculty Publications

Studies have shown that the spatial distribution of severe thunderstorm warnings demonstrates variation beyond what can be attributed to weather and climate alone. Investigating spatial patterns of these variations can provide insight into nonmeteorological factors that might lead forecasters to issue warnings. Geographically weighted regression was performed on a set of demographic and land cover descriptors to ascertain their relationships with National Weather Service (NWS) severe thunderstorm warning polygons issued by 36 NWS forecast offices in the central and southeastern United States from 2008 to 2015. County warning area (CWA) boundaries and cities were predominant sources of variability in warning …

Seasonal Aeration Rates For The Eastern United States Based On Long-Term Weather Patterns, Michael D. Montross, Samuel G. Mcneill, Thomas C. Bridges

Biosystems and Agricultural Engineering Faculty Publications

Most aeration fans are sized to produce a minimum airflow rate of 0.1 m³/min/t (0.1 cfm/bu) in on-farm grain storage structures. At this airflow rate a significant amount of time is required to move a cooling front completely through a bin. The desired grain temperature and prevailing weather conditions will have a significant effect on required fan size. Thirty years of weather data were analyzed for the eastern United States to determine the amount of time available in temperature windows between 0 to 15.C and 0 to 17.C. Contour maps were generated with ArcMap 8.3 for the percentage …

Regional Variation In Temperature Humidity Index For Poultry Housing, Richard S. Gates, Hanzhong Zhang, Donald G. Colliver, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

A building thermal model was used to compute hourly values of temperature humidity index (THI) for a broiler house with and without an evaporative misting system. Hourly summer time weather data for 238 U.S.A. locations covering 30 years were used to develop extreme occurrences of THI. Results were incorporated into a Geographical Information System (GIS) database to create isolines of THI and percentage of hours exceeding a heat stress threshold. Regional variations in misting as a suitable cooling technique are presented in terms of hours reduction in annual heat stress. The technique may be used for assisting in management decisions …

Slack-Water Deposits And The Magnitude And Frequency Of Flash Floods, Eastern Kentucky, Russell G. Shepherd, Lisa K. Bienkowski

KWRRI Research Reports

The potential for predicting flood magnitude and frequency using sediments deposited in backwater areas during flash floods was investigated on the Cumberland Plateau of eastern Kentucky, a region n9torious for flash flooding. Slack-water deposits are abundant in the area at tributary mouths and bedrock channel expansions. They are identifiable on geologic quandrangle maps, and are locally good potential indicators of maximum flood-crest elevations. However, in this humid region, flash floods could not be distinguished from non-flash floods using slack-water sedimentology.

The results from the slack-water deposits studied indicate that they offer limited potential for predicting flash floods because 1) intense …

Limiting Swine Stress With Evaporative Cooling In The Southeast, Robert L. Fehr, K. T. Priddy, Samuel G. Mcneill, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

Three-hourly weather data for 7 locations in the Southeast and Central United States were used to evaluate the feasibility of evaporative cooling for reducing swine stress. Stress was defined as a relationship between dry and wet bulb temperatures which exceeded a stress index of 85. This analysis indicates that properly installed evaporative coolers could reduce the number of hours that stress would occur in swine facilities from 89.6 to 96.4% depending on location.

Stochastic Models For Precipitation, Peter Purdue, Z. Govindarajulu

KWRRI Research Reports

In this project a stochastic model, using Semi-Markov Processes, was developed to simulate daily rainfall patterns in Kentucky. This model contains many of the currently used models as special cases and is applicable at any station in Kentucky as well as elsewhere.

For use in Kentucky an 8 state Semi-Markov Process is developed and the parameters of the model are determined from historical rainfall data. The model is tested at 4 different stations in Kentucky and the simulated and actual rainfall processes are found to be in good agreement. Finally some long run probabilities are calculated as well as mean …

Statistical Models For Precipitation, Z. Govindarajulu, Peter Purdue, Frank Cioch

KWRRI Research Reports

The available data consists of daily rainfall for the past 24 years (1948-1972) for Lexington, Louisville and Paducah. However, for Ashland, the data is available for the period of 40 years (1932-1972). The problem is to find an appropriate family of distributions indexed by a suitable number of parameters that fits the maximum daily rainfall. Further, there might be seasonal variations. The following seasons were considered: (i) Dry Convective season: August 1-0ctober 30; (ii) Early Convective season: May 1-July 31; (iii) Late Convective season: November 1- April 30. After extracting the yearly maximums for each of these seasons (see Appendix …

Stochastic Simulation Of Daily Rainfall, David M. Allen, C. T. Haan, Don Linton, Jim Street, David Jordan

KWRRI Research Reports

The design of many water resources projects requires knowledge of possible long-term rainfall patterns. In this project a stochastic model based on a first order Markov chain was developed to simulate daily rainfall at a point. The model is applicable to any point in Kentucky (and other areas with similar rainfall patterns).

The model in its present form is useful in providing rainfall inputs into hydrologic models for designing water supply facilities and other water resources systems. The model uses historical rainfall data to estimate the Markov transitional probabilities. A separate matrix is estimated for each month of the year. …

Laboratory Simulation Of Rainfall Erosivity For Gully Formation Study, T. Y. Kao

KWRRI Research Reports

The objective of this study was to develop a rainfall simulator, which imparts to the laboratory rainfall the more important characteristics of natural rainfall such as intensity, drop spectrum, kinetic energy, and momentum at impact, for using in soil erosion research with better results. In developing this simulator the better features of the basic types of earlier simulators, drip and nozzle, have been incorporated into this single design. The simulator developed in this study consists of a number of individual box modules placed in a rectangular pattern to form a single unit. Each module has a grid of capillary holes …

Part I - Controlling The Soil Moisture Environment Of Transpiring Plants, Part Ii - Prediction Of Leaf Temperature Under Natural Atmospheric Conditions, Charles T. Haan, Billy J. Barfield, Robert Edling

KWRRI Research Reports

Part I

A technique for controlling the soil moisture potential in the root zone of transpiring plants was developed. The method uses the principles of unsaturated flow through a porous media to develop the desired moisture potential. In the case of non-steady state transpiration, the maximum possible fluctuation in the soil moisture potential can be determined by the techniques presented.

Part II

Two implicit leaf temperature prediction equations were derived from the energy balance approach. The equations define sensible and latent heat transfer from a plant population as a two step process:

1. Transfer between the plant leaf and the canopy …

Evaluation Of Runoff Coefficients From Small Natural Drainage Areas, Carlos Fix Miller, L. Douglas James

KWRRI Research Reports

The Kentucky Department of Highways, as do most other agencies which build small drainage structures, estimates flood peaks as the product of a runoff coefficient, a rainfall intensity, and the drainage area, Available procedures were applied to 39 gaged watersheds in and near Kentucky and compared with the results of frequency analysis of historical stream gage records. The methods consistently underestimated the flood peak.

Therefore, a more intensive study (using the Stanford Watershed Model) of the runoff coefficient was undertaken by dividing it into overland flow and streamflow components. A set of curves was developed based on the 50-year event …