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Articles 61 - 90 of 99

Full-Text Articles in Meteorology

A Neural Network Solution To Predicting Wind Speed At Cape Canaveral’S Atlas Launch Pad, Kenneth P. Cloys Mar 2000

A Neural Network Solution To Predicting Wind Speed At Cape Canaveral’S Atlas Launch Pad, Kenneth P. Cloys

Theses and Dissertations

This thesis demonstrates the potential for using time-delay neural networks to provide Launch Weather Officers (LWOs) at 45th Weather Squadron (45 WS) with advance warning of wintertime (November-March) peak wind speeds at the Atlas launch pad. The 45 WS provides weather support to the United States space program at Cape Canaveral Air Station, NASA's Kennedy Space Center, and Patrick Air Force Base. Due to the complex wintertime environment produced by the effects of friction and instability, 45 WS LWOs consider wintertime launch pad winds their toughest forecast challenge. Neural networks were developed, trained, and tested using observations of wintertime peak …


Data Warehouse Techniques To Support Global On-Demand Weather Forecast Metrics, Meriellen C. Joga Mar 2000

Data Warehouse Techniques To Support Global On-Demand Weather Forecast Metrics, Meriellen C. Joga

Theses and Dissertations

Air Force pilots and other operators make crucial mission planning decisions based on weather forecasts; therefore, the ability to forecast the weather accurately is a critical issue to Air Force Weather (AFW) and its customers. The goal of this research is to provide Air Force Weather with a methodology to automate statistical data analysis for the purpose of providing on-demand metrics. A data warehousing methodology is developed and applied to the weather metrics problem in order to present an option that will facilitate on-demand metrics. On-line analytical processing (OLAP) and data mining solutions are also discussed.


Mixed Layer Height Estimates – A Statistical Analysis Of Algorithm Performance, Lisa C. Shoemaker Mar 2000

Mixed Layer Height Estimates – A Statistical Analysis Of Algorithm Performance, Lisa C. Shoemaker

Theses and Dissertations

The Air Force Technical Applications Center (AFTAC) conducts dispersion transport modeling as part of their mission support for the United States Atomic Energy Detection System. Part of that modeling effort requires knowledge of the height of the mixed layer in the lower atmosphere to determine the vertical extent through which particulates can be distributed. The mixed layer can be estimated by analyzing atmospheric profiles of parameters obtained from observations (e.g., upper air soundings) or atmospheric models. Six mixed layer algorithms were evaluated: Gradient Richardson Number (RICH), Potential Temperature (POTEMP), Potential Instability Mixing Depth (PIMIX), and three variations of the PIMIX …


Extensible Markup Language As A Weather Tool, Michael J. Calidonna Mar 2000

Extensible Markup Language As A Weather Tool, Michael J. Calidonna

Theses and Dissertations

This thesis is a proof of concept work that will extend the Core Mapping Application Program Interface (CMAPI) components to include weather data. The CMAPI project is headed by Air Force Research Lab (AFRL)/Information Directorate Information Handling Branch (IFEB) at Rome labs in Rome, New York. This work extends the CMAPI project in two distinct areas. The first goal is to figure out how to overlay and display weather data on a dynamically linked Internet platform. This was accomplished by incorporating existing data from the Air Force Weather Agency (AFWA) into the CMAPI program in a static environment. The other …


Use Of Climatology To Predict Maximum Wind Speeds At The Kennedy Space Center And Cape Canaveral Air Station, Lisa K. Coleman Mar 2000

Use Of Climatology To Predict Maximum Wind Speeds At The Kennedy Space Center And Cape Canaveral Air Station, Lisa K. Coleman

Theses and Dissertations

This thesis uses statistical analysis to forecast the probability of meeting or exceeding the maximum allowable wind speeds for each of the launch pads at the Kennedy Space Center (KSC) and Cape Canaveral Air Station (CCAS). Wind data were collected from the Weather Information Network Display System (WINDS), a collection of 47 meteorological towers located throughout KSC and CCAS, over a period of five winters. A Fortran program was written to calculate conditional probabilities of meeting or exceeding a given threshold speed during eight consecutive one-hour periods, using the current wind direction and peak wind speed as inputs. Forecast probabilities …


An Intelligent User Interface To Support Air Force Weather Product Generation And Automated Metrics, Darryl N. Leon Mar 2000

An Intelligent User Interface To Support Air Force Weather Product Generation And Automated Metrics, Darryl N. Leon

Theses and Dissertations

Air Force pilots require dependable weather reports so they may avoid unsafe flying conditions. In order to better gauge the accuracy of its weather products, Air Force Weather has established the requirement for an Air Force-wide automated weather metrics program. Under the guidelines for this program, forecasts will automatically be compared to observed weather to determine their accuracy. Statistics will be collected in the hopes of determining forecast error trends that can be corrected through education and training. In order for the statistical data produced by such a program to draw reliable conclusions about forecast accuracy, however, the correct format …


An Analysis In Cloud-To-Ground Lightning Over Land Versus Water, Elizabeth A. Boll Mar 2000

An Analysis In Cloud-To-Ground Lightning Over Land Versus Water, Elizabeth A. Boll

Theses and Dissertations

Understanding lightning characteristics over land and water is vital to achieving optimal safety and success in Air Force missions. Lightning safety rules are often based on experience rather than a scientific understanding of lightning. Examining lightning characteristics over water and land will assist in a better understanding of lightning and provide answers that can protect human lives and property. Water and land have different compositions and surface conductivity values. A lightning stroke is detected through a change in the electro-magnetic field at the surface. The change in surface conductivity values from land to water can affect the detection of a …


Techniques For Forecasting The Cessation Of Lightning At Cape Canaveral Air Station And The Kennedy Space Center, Michael W. Holmes Mar 2000

Techniques For Forecasting The Cessation Of Lightning At Cape Canaveral Air Station And The Kennedy Space Center, Michael W. Holmes

Theses and Dissertations

The focus of this research effort is directed toward identifying new methods of forecasting the cessation of lightning along the Central Atlantic Coast of Florida. Cloud-to-ground lightning flashes place Air Force (AF) personnel and assets at risk almost daily at this location. Providing a more accurate method of forecasting the cessation of lightning would allow for safer and more efficient execution of AF operations. A data set consisting of 40 thunderstorm cases was identified within a 90 nautical miles (nmi) region surrounding the Melbourne, Florida WSR-88D (KMLB) site. Each case falls between the months of May and September and the …


Determining The Horizontal Distance Distribution Of Cloud-To-Ground Lightning, Tamara L. Parsons Mar 2000

Determining The Horizontal Distance Distribution Of Cloud-To-Ground Lightning, Tamara L. Parsons

Theses and Dissertations

This research effort attempted to quantify what constitutes a safe distance when lightning is present. The method used in this research project groups lightning flashes into clusters using spatial and temporal constraints. However, not all flashes meet the time and distance criteria for clustering and remained outside of tile grouped flashes and as such are identified as isolated flashes. These isolated flashes are outliers in the data set, but are precisely the flashes that prove most dangerous. For this reason not only were the distances between each flash and cluster center studied, but also the distances between each isolated flash …


Timing Of Thunderstorm Occurrence For Cape Canaveral, Florida, Thomas G. Renwick Mar 2000

Timing Of Thunderstorm Occurrence For Cape Canaveral, Florida, Thomas G. Renwick

Theses and Dissertations

This research is concerned with improving an existing algorithm to accurately forecast thunderstorm starting times for Cape Canaveral, Florida. This was accomplished by investigating different linear regression techniques than those used in the existing algorithm. The result is three new thunderstorm start time algorithms. The forecast start times of these new algorithms were then compared to actual thunderstorm start times to determine which method produced the most accurate results. The average thunderstorm starting time was also calculated from the data. This time was also compared to actual thunderstorm starting time. Upon examination of the various start times produced, it was …


A Study Of Morning Radiation Fog Formation, Jimmie L. Trigg Jr. Mar 2000

A Study Of Morning Radiation Fog Formation, Jimmie L. Trigg Jr.

Theses and Dissertations

This research focuses on developing a linear regression formula that forecasters in the Midwest can use to accurately anticipate the formation of radiation fog. This was accomplished in three stages. First a study of the surface and upper air parameters and processes required to develop radiation fog were identified and explored. Next, a linear regression technique was applied to the 23 parameters identified. The top four indicators were then reprocessed and a new linear regression equation was developed. Finally, the new regression equation was compared to an existing fog forecasting technique. The existing forecast technique selected was the 2nd Weather …


Improving Cape Canaveral's Next-Day Thunderstorm Forecasting Using A Meso-Eta Model-Based Index, John C. Crane Mar 1999

Improving Cape Canaveral's Next-Day Thunderstorm Forecasting Using A Meso-Eta Model-Based Index, John C. Crane

Theses and Dissertations

Reliable thunderstorm forecasts are essential to safety and resource protection at Cape Canaveral. Current methods of forecasting day-2 thunderstorms provide little improvement over forecasting by persistence alone and are therefore in need of replacement. This research focused on using the mesoscale eta model to develop an index for improved forecasting of day-2 thunderstorms. Logistic regression techniques were used to regress the occurrence of a thunderstorm at Cape Canaveral against day-2 forecast variables output, or derived, from the mesoscale eta model. Accuracy and bias scores were calculated for the forecasts made by the regression equations, and the forecast results were compared …


A Refinement And Cross-Validation Of The Special Sensor Microwave Imager (Ssm/I) Calibration-Validation (Cv) Brightness Temperature Algorithm, Mark R. Adair Mar 1999

A Refinement And Cross-Validation Of The Special Sensor Microwave Imager (Ssm/I) Calibration-Validation (Cv) Brightness Temperature Algorithm, Mark R. Adair

Theses and Dissertations

The Air Force Weather Agency (AFWA) currently uses an algorithm to calculate surface temperatures from microwave observations taken by the Special Sensor Microwave Imager (SSM/I) aboard the orbiting platforms of the Defense Meteorological Satellite Program (DMSP). This algorithm, called the Calibration-Validation (CV) algorithm, used multiple linear regression to calculate coefficients relating microwave brightness temperatures and land surface temperatures. Because the coefficients in this algorithm do not take into account the identity of the individual satellite, the question arose whether this assumption was valid. This thesis used multiple linear regression, stepwise linear regression, and qualitative regression on 3700 data sets from …


A Validation Study Of Cloud Scene Simulation Model Temporal Performance, Glenn Kerr Mar 1999

A Validation Study Of Cloud Scene Simulation Model Temporal Performance, Glenn Kerr

Theses and Dissertations

Cloud Scene Simulation Model (CSSM) temporal performance was validated by comparing the cloud forcing signatures on observed radiometric time series with those derived from CSSM output for initial conditions similar to that for the observed data. Observed radiometric data was collected by a normal incidence pyraheliometer sensitive to wavelengths in the range .3mm to 3mm. Simulation radiometric time series data was derived by applying the following process to each case study. CSSM cloud liquid water content (CLWC) grids were converted to grids of slant path optical depth values by the Fast Map post processor to the CSSM. A ray tracing …


Predicting Launch Pad Winds At The Kennedy Space Center With A Neural Network Model, Steven J. Storch Mar 1999

Predicting Launch Pad Winds At The Kennedy Space Center With A Neural Network Model, Steven J. Storch

Theses and Dissertations

This thesis uses neural networks to forecast winds at the Kennedy Space Center and the Cape Canaveral Air Station launch pads. Variables are developed from WINDS tower observations, surface and buoy observations, and an upper-air sounding. From these variables, a smaller set of predictive inputs is chosen using a signal-to-noise variable screening method. A neural network is then trained to forecast launch pad winds from the inputs. The network forecasts are compared to persistence, and peak wind predictions are found skillful compared to persistence. An ensemble modeling technique using Toth's and Kalnay's breeding of growing modes method is explored with …


Using The Wsr-88d To Forecast Downburst Winds At Cape Canaveral Air Station And The Kennedy Space Center (Ccas/Ksc), Gerald D. Sullivan Jr. Mar 1999

Using The Wsr-88d To Forecast Downburst Winds At Cape Canaveral Air Station And The Kennedy Space Center (Ccas/Ksc), Gerald D. Sullivan Jr.

Theses and Dissertations

The 45 Weather Squadron is tasked with providing several convective wind warnings in support of the U. S. Space Program. The forecasters use a radar-based forecast technique to determine if a thunderstorm has the potential to produce a gust that meets warning criteria. This technique, the Echo Top/Vertically Integrated Liquid Wind Gust Potential (ET/VIL WGP), has not previously been evaluated for use in the Cape Canaveral Air Station and Kennedy Space Center (CCAS/KSC) locale. Additionally, there are two other radar-based forecast techniques that required evaluation for possible inclusion into the 45 WS forecast process. These are the Maximum Reflectivity / …


A Comparison Of Horizontal Cloud-To-Ground Lightning Flash Distance Using Weather Surveillance Radar And The Distance Between Successive Flashes Method, Christopher C. Cox Mar 1999

A Comparison Of Horizontal Cloud-To-Ground Lightning Flash Distance Using Weather Surveillance Radar And The Distance Between Successive Flashes Method, Christopher C. Cox

Theses and Dissertations

On April 29th, 1996 an airman servicing a C-130 aircraft on Huriburt AFB Florida was struck and killed by a lightning flash that traveled an estimated 7 to 10 miles from storms south of the airfield. Ten other workers were injured in the incident. The fatal flash occurred just 8 minutes after the base weather station allowed a lightning advisory to expire. The incident brought to question the adequacy of lightning advisory criteria. Very little research has been done on the horizontal distance that cloud-to-ground lightning flashes occurs from the center of a thunderstorm. This thesis used the WSR-88D method, …


Evaluation Of Barnes' Method And Kriging For Estimating The Low Level Wind Field, Michael W. Engel Mar 1999

Evaluation Of Barnes' Method And Kriging For Estimating The Low Level Wind Field, Michael W. Engel

Theses and Dissertations

This thesis evaluates two different methods of estimating a three dimensional wind field based upon a limited number of irregularly-spaced observations. This work was performed for the 45th Weather Squadron to determine how well the two methods worked and their potential for use in a visualization program. The two methods evaluated were Barnes' method and a method called Kriging, which is commonly used in geostatistics. Both of these estimation techniques were implemented and then evaluated to determine how accurate the estimates were that they created. The methods' accuracies were determined by withholding an observation from the observed wind field data …


An Improved Thunderstorm Forecast Index For Cape Canaveral, Florida, James A. Everitt Mar 1999

An Improved Thunderstorm Forecast Index For Cape Canaveral, Florida, James A. Everitt

Theses and Dissertations

This thesis creates a new algorithm to replace the Neumann-Pfeffer Thunderstorm Index (NPTI). The 45th Weather Squadron at Patrick AFB, Florida, uses the NPTI as an objective means of determining the probability of thunderstorm occurrence at Cape Canaveral. The probability is used for mission planning and resource protection, and increasing the accuracy of NPTI can potentially save billions of dollars for the United States space program. Stratified logistical regressions are performed and probability equations are derived for May through September using upper air data and surface observations for Cape Canaveral. A logistical regression of NPTI was also performed. Variables include …


Forecasting Downdraft Wind Speeds Associated With Airmass Thunderstorms For Peterson Air Force Base, Colorado, Using The Wsr-88d, Travis A. Steen Mar 1999

Forecasting Downdraft Wind Speeds Associated With Airmass Thunderstorms For Peterson Air Force Base, Colorado, Using The Wsr-88d, Travis A. Steen

Theses and Dissertations

During the period Jun-Aug 96, four Air Force installations suffered over $4.8 million in damage from convective winds. During the same summer, Air Force Space Command units issued nearly 65% of their weather warnings for convective winds, making the forecasting of convective winds the most frequent challenge to forecasters. This thesis seeks to assist Air Force forecasters at Peterson Air Force Base (PAFB), Colorado, in forecasting airmass thunderstorm downdraft wind speeds using the Weather Surveillance Radar-1988 Doppler (WSR-88D). To accomplish this purpose, several existing potential downdraft wind speed prediction techniques were evaluated against the observed wind speeds of nineteen airmass …


Survey Of Military Applications For Fourier Transform Infrared (Ftir) Spectroscopy, Robert G. Hauser Feb 1999

Survey Of Military Applications For Fourier Transform Infrared (Ftir) Spectroscopy, Robert G. Hauser

Theses and Dissertations

This paper surveyed four potential military uses for a Fourier Transform Infrared (FTIR) Spectrometer. A physical method to retrieve vertical atmospheric temperature profiles using a least-squares solution on atmospheric radiance observed at the surface in the 4.3-micrometer carbon dioxide absorption band was analyzed. The method was not successful. Weighting functions, calculated from the surface looking up, were a maximum at the surface, so no unique solution for temperature retrieval by height was determined. Observed atmospheric radiance measurements were compared with radiance calculated using the Moderate Resolution Transmittance Code (MODTRAN). Qualitative comparison showed spectral features of observed and calculated radiance plots …


Forecasting Wet Microbursts Associated With Summertime Airmass Thunderstorms Over The Southeastern United States, James B. Mackey Mar 1998

Forecasting Wet Microbursts Associated With Summertime Airmass Thunderstorms Over The Southeastern United States, James B. Mackey

Theses and Dissertations

Microbursts are intense downbursts from thunderstorms that affect an area less than 4 km and have a lifespan less than 10 minutes. Wet microbursts are associated with heavy precipitation and are common in the eastern and southeastern part of the country. The greatest threat from microbursts is to low flying aircraft, where the rapid fluctuations in horizontal and vertical airflow create tremendous shear zones. Microbursts have been determined to be the causal factor behind at least three major aircraft accidents resulting in numerous fatalities. Due to the short lifespan of microbursts, they often strike without warning and pose a serious …


A Validation Study Of The Air Force Weather Agency (Afwa) Jetrax Contrail Forecast Algorithm, Jeffrey D. Shull Mar 1998

A Validation Study Of The Air Force Weather Agency (Afwa) Jetrax Contrail Forecast Algorithm, Jeffrey D. Shull

Theses and Dissertations

Accurate contrail forecasts allow pilots to avoid levels of the atmosphere which are conducive to contrail formation, reducing their likelihood of being visually detected by enemy forces. The primary objective of this thesis is to evaluate the performance of the JETRAX contrail forecast algorithm currently used by the Air Force Weather Agency to support military air operations. A total of 397 ground-based contrail observations were collected at Wright-Patterson Air Force Base on 27 different days. Observations were collected with the aid of air traffic control radar, which greatly facilitated the positive identification of overflying aircraft and provided necessary information such …


A Comparison Of Advect Cloud Model And Fifth-Generation Mesoscale Model Total Fractional Cloud Forecasts, Brian D. Pukall Mar 1998

A Comparison Of Advect Cloud Model And Fifth-Generation Mesoscale Model Total Fractional Cloud Forecasts, Brian D. Pukall

Theses and Dissertations

Total fractional cloudiness (FC) forecasts from the advect cloud (ADVCLD) model and total FC forecasts diagnosed from the relative humidity and total cloud condensate (snow, ice, rain water, and cloud water) fields from the fifth generation mesoscale model (MM5) were statistically and subjectively compared to determine which model produced the better total FC forecasts from August through November 1997 for a forecast window centered on Bosnia. The real time nephanalysis (RTNFPH) model was used to represent the true state of the atmosphere. ADVCLD and MM5 forecasts were also compared against a persistence forecast to provide a minimal skill baseline. The …


Analyzing Horizontal Distances Between Wsr-88d Thunderstorm Centroids And Cloud-To-Ground Lightning Strikes, Steve L. Renner Mar 1998

Analyzing Horizontal Distances Between Wsr-88d Thunderstorm Centroids And Cloud-To-Ground Lightning Strikes, Steve L. Renner

Theses and Dissertations

On April 29, 1996, lightning struck the airfield at Hurlburt Field, FL, killing one Airmen and injuring ten others. This cloud to ground lightning strike hit eight minutes after a lightning advisory was canceled. At the time of the strike, thunderstorms were observed 7 to 10 miles north and south of the airfield. The incident raised questions about Air Force Weather Agency's lightning criteria. Soon after the incident, a Lightning Safety Review Panel was assembled to determine the adequacy of lightning advisories. One of the questions posed to the panel was could an incident like Hurlburt happen again? The review …


Improving Cape Canaveral's Day-2 Thunderstorm Forecasting Using Meso-Eta Numerical Model Output, Christian S. Wohlwend Mar 1998

Improving Cape Canaveral's Day-2 Thunderstorm Forecasting Using Meso-Eta Numerical Model Output, Christian S. Wohlwend

Theses and Dissertations

The 45th Weather Squadron (WS) is responsible for the protection of billions of dollars worth of Air Force and NASA equipment from weather hazards. They produce a seven day planning forecast as one tool to support the space launch community. Improving this forecast can potentially save millions of dollars of government funds. This research focuses on the feasibility of improving the day two thunderstorm forecast by applying Meso Eta numerical forecasts to the Neumann-Pfeffer Thunderstorm Index (NPTI). The NPTI is currently used by the 45th WS for same day thunderstorm probability forecasting utilizing the morning radiosonde as input. The perfect …


Calibrated Probabilistic Quantitative Precipitation Forecasts Based On The Mrf Ensemble, Frederick Anthony Eckel Mar 1998

Calibrated Probabilistic Quantitative Precipitation Forecasts Based On The Mrf Ensemble, Frederick Anthony Eckel

Theses and Dissertations

Probabilistic quantitative precipitation forecasts (PQPF) based on the medium range forecast (MRF) ensemble are currently in operational use below their full potential quality (i.e., accuracy and reliability). This unfulfilled potential is due to the MRF ensemble being adversely affected by systematic errors which arise from an imperfect model and less than ideal ensemble initial perturbations. This thesis sought to construct a calibration to account for these systematic errors and thus produce higher quality PQPF. Systematic errors were explored with the use of the verification rank histogram, which tracks the performance of the ensemble. The information in these histograms was then …


Evaluation Of Satellite Microwave Derived Surface Temperature Algorithms For The Period August 1996 To February 1997, Charles H. Harris Mar 1998

Evaluation Of Satellite Microwave Derived Surface Temperature Algorithms For The Period August 1996 To February 1997, Charles H. Harris

Theses and Dissertations

The Air Force Weather Agency (AFWA) has two operational algorithms that derive surface temperatures from microwave observations taken by the Special Sensor Microwave Imager (SSM/I) which rides aboard space platforms of the Defense Meteorological Satellite Program (DMSP). The algorithm called Temperature from Satellite Microwave Imager (TS) is used to analyze global cloud coverage. The second algorithm is fittingly called Calibration and Validation (CV), as it was the algorithm used to calibrate and validate the first SSM/I in 1987. Multiple linear regression defined the algorithms from empirically gathered brightness temperatures and simultaneous surface temperatures. The key questions were how much data …


Nowcasting Thunderstorms At Cape Canaveral, Florida, Using An Improved Neumann-Pfeffer Thunderstorm Index, Cindy L. Howell Mar 1998

Nowcasting Thunderstorms At Cape Canaveral, Florida, Using An Improved Neumann-Pfeffer Thunderstorm Index, Cindy L. Howell

Theses and Dissertations

The Neumann-Pfeffer Thunderstorm Index (NPTI) is used daily by the 45th Weather Squadron during the convective season to estimate the probability of afternoon thunderstorms. The current I , developed by Charles J. Neumann in the 1960s, i based on only 13 years of data taken over 30 years ago. The index was in desperate need of an upgrade. Following the multiple regression techniques outlined by Neumann, this thesis examines whether or not including additional data would improve the performance of the NPTI. After performing the multiple regressions and retuning the regression coefficients, both NPTs were validated using a 2-year independent …


Azimuth And Range Optimization Of The Velocity Azimuth Display (Vad) Algorithm In The Wsr-88d, David L. Craft Mar 1998

Azimuth And Range Optimization Of The Velocity Azimuth Display (Vad) Algorithm In The Wsr-88d, David L. Craft

Theses and Dissertations

The Velocity Azimuth Display (VAD) algorithm occasionally produces inaccurate wind estimates for the VAD Wind Profile (VWP) product of the Weather Surveillance Radar 1988 Doppler (WSR-88D) System. Weather forecasters have observed differences between the radar's wind profiles and wind profiles produced by rawinsondes and vertical wind profilers, when radiation and subsidence inversions in the atmosphere caused the radar beam to super refract. This thesis sought to improve the operational use of the VWP product for the WSR-88D near Denver, CO, by finding the optimal VAD algorithm Azimuth and Range parameter settings to overcome data contamination by hills located at the …