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Atmospheric Sciences

2019

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Articles 31 - 45 of 45

Full-Text Articles in Meteorology

Conducting A Drought-Specific Thira (Threat And Hazard Identification And Risk Assessment): A Powerful Tool For Integrating All-Hazard Mitigation And Drought Planning Efforts To Increase Drought Mitigation Quality, Elliot Wickham, Deborah J. Bathke, Tarik Abdel-Monem, Tonya K. Bernadt, Denise Bulling, Lisa M. Pytlikzillig, Crystal J. Stiles, Nicole Wall Jan 2019

Conducting A Drought-Specific Thira (Threat And Hazard Identification And Risk Assessment): A Powerful Tool For Integrating All-Hazard Mitigation And Drought Planning Efforts To Increase Drought Mitigation Quality, Elliot Wickham, Deborah J. Bathke, Tarik Abdel-Monem, Tonya K. Bernadt, Denise Bulling, Lisa M. Pytlikzillig, Crystal J. Stiles, Nicole Wall

HPRCC Personnel Publications

In the United States, drought is the second costliest natural disaster, which leads to the need for increased drought mitigation efforts over time. However, drought planning has lagged behind other hazard mitigation efforts, which is likely due to the lack of a national drought planning policy. Although the Federal Emergency Management Agency (FEMA) requires all jurisdictions have a hazard mitigation plan (HMP) to receive pre-disaster mitigation funds, drought has only recently been a requirement in HMPs. In 2012, Nebraska witnessed its worse drought in recent history, which exposed the gaps in drought planning effectiveness at all jurisdictional levels. To address …


Wake Vortex Pair Formation As An Analog For Dust Devil And Tornado Genesis, Robert L. Ash Jan 2019

Wake Vortex Pair Formation As An Analog For Dust Devil And Tornado Genesis, Robert L. Ash

Mechanical & Aerospace Engineering Faculty Publications

In 1966, meteorologist R.S. Scorer attempted to explain how large-scale oceanic tropical depressions become hurricanes or typhoons. His model was based on the idea that when these large-scale tropical depression structures begin to rotate, mostly due to Coriolis effects, an annular outer portion of that structure changes suddenly to a potential vortex segment, with the same outer radial limit as the low-pressure structure, but with an inner radius that conserves the overall system angular momentum and kinetic energy. By analogy with the "jump" instability describing sudden buckling of a vertical column, this paper shows that his conjecture merits additional consideration. …


Droughtscape- 2019 Winter, National Drought Mitigation Center Jan 2019

Droughtscape- 2019 Winter, National Drought Mitigation Center

Droughtscape, Quarterly Newsletter of NDMC, 2007-

Contents

From the director.............. 2

Drought intensified in California and Nevada, eased elsewhere............. 3

Year in Review: Drought spread and intensified in the West; record precipitation in the East.............. 5

Drought impact summary for 4th quarter 2018........... 6

Drought impact summary 2018............ 8

Five states began drought plan updates in 2018................. 10

New web-based form makes submitting drought observations easier............ 12

FEMA risk assessment process tailored for drought............... 14

Upcoming events...............14


The Total Solar Eclipse Of 2017: Meteorological Observations From A Statewide Mesonet And Atmospheric Profiling Systems, Rezaul Mahmood, Megan Schargorodski, Eric Rappin, Melissa Griffin, Patrick Collins, Kevin Knupp, Andrew Quilligan, Ryan Wade, Kevin Cary, Stuart Foster Jan 2019

The Total Solar Eclipse Of 2017: Meteorological Observations From A Statewide Mesonet And Atmospheric Profiling Systems, Rezaul Mahmood, Megan Schargorodski, Eric Rappin, Melissa Griffin, Patrick Collins, Kevin Knupp, Andrew Quilligan, Ryan Wade, Kevin Cary, Stuart Foster

HPRCC Personnel Publications

A total solar eclipse traversed 37 the continental United States on August 21, 2017. It 38 was the first such event in 99 years and provided a rare opportunity to observe the atmospheric response from a variety of instrumented observational platforms. This paper discusses the high quality observations collected by the Kentucky Mesonet (www.kymesonet.org), a research-grade meteorological and climatological observation network consisting of 72 stations and measuring air temperature, precipitation, relative humidity, solar radiation, wind speed, and wind direction. The network samples the atmosphere, for most variables, every three seconds and then calculates and records observations every five minutes. During …


Irrigation Impacts On Minimum And Maximum Surface Moist Enthalpy In The Central Great Plains Of The Usa, Tianyi Zhang, Rezaul Mahmood, Xiaomao Lin, Roger A. Pielke Sr. Jan 2019

Irrigation Impacts On Minimum And Maximum Surface Moist Enthalpy In The Central Great Plains Of The Usa, Tianyi Zhang, Rezaul Mahmood, Xiaomao Lin, Roger A. Pielke Sr.

HPRCC Personnel Publications

Agricultural activities notably alter weather and climate including near-surface heat content. However, past research primarily focused on dry bulb temperature without considering the role of water vapor (dew point temperature) on surface air heat content. When using dry bulb temperature trends to assess these changes, for example, not including concurrent trends in absolute humidity can lead to errors in the actual rate of warming or cooling. Here we examined minimum and maximum surface moist enthalpy, which can be expressed as “equivalent temperature.” Using hourly climate data in the Central Great Plains (Nebraska and Kansas) from 1990 to 2014, the averages …


Role Of Sea Surface Temperatures In Forcing Circulation Anomalies Driving U.S. Great Plains Pluvial Years, Paul X. Flanagan, Jeffrey B. Basara, Jason C. Furtado, Elinor R. Martin, Xiangming Xiao Jan 2019

Role Of Sea Surface Temperatures In Forcing Circulation Anomalies Driving U.S. Great Plains Pluvial Years, Paul X. Flanagan, Jeffrey B. Basara, Jason C. Furtado, Elinor R. Martin, Xiangming Xiao

HPRCC Personnel Publications

In the U.S. Great Plains (GP), diagnosing precipitation variability is key in developing an understanding of the present and future availability of water in the region. Building on previous work investigating U.S. GP pluvial years, this study usesERAtwentieth century (ERA-20C) reanalysis data to investigate key circulation anomalies driving GP precipitation anomalies during a subset of GP pluvial years (called in this paper Pattern pluvial years). With previous research showing links between tropical Pacific sea surface temperature (SST) anomalies and GP climate variability, this study diagnoses the key circulation anomalies through an analysis of SSTs and their influence on the atmosphere. …


A New Model For Lifting Condensation Levels Estimation, Nihad E. Daidzic Jan 2019

A New Model For Lifting Condensation Levels Estimation, Nihad E. Daidzic

Aviation Department Publications

Knowledge of and the ability to predict lifting condensation levels (LCL) is important ingredient in weather predictions, cloud formation, planetary albedo and Earth’s energy balance. It is also essential topic in aviation safety and flight operations. In this article, we derive a new model of LCL and compare it to some older commonly-used models. This includes also the recently published Romps’ (2017) model. The new model presented here includes dependence, however weak, of the surface atmospheric pressure and the specific humidity on the LCL height and temperature. Such is not the case with widely used models and expressions by Espy …


Spatial And Temporal Analysis Of The 27 April 2011 Tornado Outbreak In Central Alabama, Whitney Flynn, Tanveer Islam Jan 2019

Spatial And Temporal Analysis Of The 27 April 2011 Tornado Outbreak In Central Alabama, Whitney Flynn, Tanveer Islam

Research, Publications & Creative Work

This study investigates the spatial and temporal patterns of the 27 April 2011 tornado outbreak in Central Alabama. Disasters, and vulnerabilities to such events, vary across space and time. The 2011 Super Outbreak was the largest, most costly, and one of the most deadly tornado outbreaks ever recorded in U.S. history. In this study, the results of 29 documented tornado tracks (889 data points total) in Central Alabama reveal findings related to complex topography and its effects on tornado intensity. The temporal pattern s of this particular outbreak are - consistent with other studies’ evidence that suggests a small peak …


An Overview And Evaluation Of Synthetc: A Statistical Model For Extra-Tropical Cyclones, Rafael Uryayev Jan 2019

An Overview And Evaluation Of Synthetc: A Statistical Model For Extra-Tropical Cyclones, Rafael Uryayev

Dissertations and Theses

Extratropical cyclones (ETCs) are the most common weather phenomena affecting the United States, Canada, and Europe. They can pose serious hazards over large swaths of area. In this thesis, a statistical model of ETCs, called SynthETC, is discussed. The model accounts for the for genesis, track path, termination, and intensity of statistically generated ETCs. Genesis is modeled as a Poisson process, whose mean is determined by climate and historical information. Tracks are modeled as a regression-mean determined by climate and historical information plus a stochastic component. Lysis is modeled using logistic regression, with climate states as covariates. Intensity is modeled …


On Atmospheric Lapse Rates, Nihad E. Daidzic Jan 2019

On Atmospheric Lapse Rates, Nihad E. Daidzic

International Journal of Aviation, Aeronautics, and Aerospace

We have derived and summarized and most important atmospheric temperature lapse rates. ALRs essentially govern vertical atmospheric air stability and creation of some cloud types. The sensitivity analysis of various atmospheric lapse rates and their dependence on actual ideal-gas air properties and gravitational attraction was conducted for the first time to the best of our knowledge. SALR, which has DALR as the upper asymptote, showed steepest decrease at around 9 degrees Celsius then flattening out and apparently approaching another asymptotic solution which has not been investigated as it falls outside of the terrestrial temperature range. ISA lapse rates are adopted …


Adding Value To Numerical Weather Predictions For The Aviation Industry In South Africa., Quinton Jacobs Mr., Willem A. Landman Prof. Jan 2019

Adding Value To Numerical Weather Predictions For The Aviation Industry In South Africa., Quinton Jacobs Mr., Willem A. Landman Prof.

International Journal of Aviation, Aeronautics, and Aerospace

The main objective of this study is to determine whether human forecasters at the main airports of South Africa add value to the raw numerical weather prediction model output when they provide forecast services to the aviation industry. Dataset pairs of weather observations made at these airports and terminal aerodrome forecasts are constructed for three forecast systems: the human forecasters, persistence forecast and the raw output from the 12 km resolution Unified Model administered by the South African Weather Service. These three dataset pairs are independently evaluated by a forecast verification system developed at the South African Weather Service. A …


A New Model For Lifting Condensation Levels Estimation, Nihad E. Daidzic Ph.D., Sc.D. Jan 2019

A New Model For Lifting Condensation Levels Estimation, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

Knowledge of and the ability to predict lifting condensation levels (LCL) is important ingredient in weather predictions, cloud formation, planetary albedo and Earth’s energy balance. It is also essential topic in aviation safety and flight operations. In this article, we derive a new model of LCL and compare it to some older commonly-used models. This includes also the recently published Romps’ (2017) model. The new model presented here includes dependence, however weak, of the surface atmospheric pressure and the specific humidity on the LCL height and temperature. Such is not the case with widely used models and expressions by Espy …


A New York State Mesonet Based Analysis Of Squall Line Cold Pool Strength And Uses For Short Term Forecasting, Daniel William Reese Jan 2019

A New York State Mesonet Based Analysis Of Squall Line Cold Pool Strength And Uses For Short Term Forecasting, Daniel William Reese

Legacy Theses & Dissertations (2009 - 2024)

The recently finished New York State Mesonet (NYSM) has a network of 126 standard surface sites and 17 vertical profiler sites across the state. This high density network allows for a wide range of potential uses in research and operational forecasting. One such use is in the area of severe thunderstorm forecasting, where mesoscale and storm scale features can become highly important. This thesis examines three case studies, events from 2017-2018 that produced long-lived, high impact squall lines which moved across the state. As the squall line’s cold pool has long been recognized to play a critical role in squall …


A Revised Technique For Measuring Vertical Velocity Using Dropsondes, Timothy Connor Nelson Jan 2019

A Revised Technique For Measuring Vertical Velocity Using Dropsondes, Timothy Connor Nelson

Legacy Theses & Dissertations (2009 - 2024)

The earliest iterations of dropsondes in the 1960's obtained vertical velocity by measuring the geometric fall speed of the dropsonde and the true airspeed (TAS) of the dropsonde from a pitot-static. The vertical velocity errors from this methodology were claimed to be ±1 m s-1. Subsequent dropsonde iterations used various forms of the drag force equation to obtain vertical velocity. The accuracy of these drag force-based measurements, however, are also quite large at ±1–2 m s-1. In this dissertation, an attempt is made to improve vertical velocity errors by revisiting and revising the pitot-static-derived TAS methodology on the eXpendable Digital …


Influence Of Upper-Tropospheric Troughs On Tropical Cyclone Intensity Change And Structure : Observational, Reanalysis, And Idealized Numerical Modeling Perspectives, Casey Peirano Jan 2019

Influence Of Upper-Tropospheric Troughs On Tropical Cyclone Intensity Change And Structure : Observational, Reanalysis, And Idealized Numerical Modeling Perspectives, Casey Peirano

Legacy Theses & Dissertations (2009 - 2024)

The interaction between tropical cyclones (TCs) and upper-tropospheric troughs is a