Atmospheric Sciences Commons^™

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

High Plains Regional Climate Center: Staff 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 …

A Recent Systematic Increase In Vapor Pressure Deficit Over Tropical South America, Armineh Barkhordarian, Bahareh Saatchi, Ali Behrangi, Paul C. Loikith, Carlos R. Mechoso

Geography Faculty Publications and Presentations

We show a recent increasing trend in Vapor Pressure Deficit (VPD) over tropical South America in dry months with values well beyond the range of trends due to natural variability of the climate system defined in both the undisturbed Preindustrial climate and the climate over 850–1850 perturbed with natural external forcing. This trend is systematic in the southeast Amazon but driven by episodic droughts (2005, 2010, 2015) in the northwest, with the highest recoded VPD since 1979 for the 2015 drought. The univariant detection analysis shows that the observed increase in VPD cannot be explained by greenhouse-gas-induced (GHG) radiative warming …

Classification Of Aerosol Population Type And Cloud Condensation Nuclei Properties In A Coastal California Littoral Environment Using An Unsupervised Cluster Model, Samuel A. Atwood, Sonia M. Kreidenweis, Paul J. Demott, Markus D. Petters, Gavin Cornwell, Andrew C. Martin, Kathryn A. Moore

Geography Faculty Publications and Presentations

Aerosol particle and cloud condensation nuclei (CCN) measurements from a littoral location on the northern coast of California at Bodega Bay Marine Laboratory (BML) are presented for approximately six weeks of observations during the boreal winter–spring as part of the CalWater-2015 field campaign. The nature and variability of surface (marine boundary layer, MBL) aerosol populations were evaluated by classifying observations into periods of similar aerosol and meteorological characteristics using an unsupervised cluster model to derive distinct littoral aerosol population types and link them to source regions. Such classifications support efforts to understand the impact of changing aerosol properties on precipitation …

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. …

Dust Storms And The Dispersal Of Aquatic Invertebrates In The Chihuahuan Desert Ecoregion, Jose Rivas Jr.

Open Access Theses & Dissertations

The Chihuahuan Desert surrounding El Paso, Texas is one of the most intense sources of dust in the Western Hemisphere. Within this vast desert are ephemeral wetlands with micrometazoan propagules contained within their sediment egg banks. Dispersal of aquatic microinvertebrates between habitats is vital for the success of their populations. Passive dispersal of the propagules provides an escape mechanism from unfavorable conditions. Upon desiccation of these habitats, windstorms can potentially transport propagules mixed within entrained sediments across regional scales. To study this process, I collected falling sediment from 91 windstorms, with 59 samples collected at the University of Texas at …

Extratropical Precursors To The Onset Of Madden-Julian Oscillation Deep Convection Over The Western Indian Ocean, Jennifer Anne Gahtan

Legacy Theses & Dissertations (2009 - 2024)

Madden-Julian Oscillation (MJO) deep convection often initially forms over the western Indian Ocean and is frequently preceded by upper tropospheric circulation precursors. These precursors include subtropical cyclonic Rossby gyres near eastern Africa and Southwest Asia, coherent extratropically circumnavigating Rossby wave trains extending back across the Atlantic, and tropically circumnavigating easterlies. Easterly acceleration associated with the circulation precursors may help to reduce large-scale subsidence over the tropical Indian Ocean prior to convective onset; when intraseasonal easterly acceleration reaches the western extent of a region of intraseasonal upper level westerlies, it produces upper-tropospheric divergence, providing a forcing for upward motion.

Extreme Typhoon Rainfall Of Taiwan, Alexa Henny

Legacy Theses & Dissertations (2009 - 2024)

Taiwan has experienced large increases in extreme rainfall (ER, defined as top 1% by daily total) over the past 60 years. Using 1 km gridded daily rainfall data provided by the Taiwan Climate Change Projection and Adaptation Information Platform (TCCIP), we analyze Taiwan’s rainfall means and trends seasonally and as a function of intensity. ER accounts for about 17% of rainfall in Taiwan, but across much of the island, the 1960-2015 ER trend exceeds the non-extreme rainfall (NR) trend. Most ER occurs during the months of May – October, when warm, southwesterly monsoon flow and frequent typhoons lead to high …

Detection And Attribution Of Wind Energy Changes In The Contiguous United States, North Atlantic Ocean And European Sector In The Twentieth Century, Shengzhe Chen

Legacy Theses & Dissertations (2009 - 2024)

Wind power is playing a greater role as an alternative energy resource to fossil fuels. The prediction skills for hourly and daily forecasts of hub-height (80 – 100 m) wind power are increasingly reliable. However, regarding historical trends in wind energy availability (an important variable for determining wind farm capacity factors), little is known about the interannual and decadal variability of the hub-height wind speed. With climate change uncertainty now incorporated into wind energy resource assessment, insight into the relative contribution from the internal variability of the climate system versus the external forcing is presently lacking. Here, Empirical Orthogonal Function …

Convection-Permitting Ensemble Forecasts Of The 10-12 December 2013 Lake-Effect Snow Event: : Sensitivity To Microphysical, Planetary Boundary Layer, And Surface Layer Parameterizations, William Massey Bartolini

Legacy Theses & Dissertations (2009 - 2024)

Lake-effect snow (LeS) presents a substantial forecast challenge for convection-permitting models, due in part to uncertainties in the parameterization of microphysical (MP) and planetary boundary layer / surface layer (PBL/SL) processes. Here we focus on understanding these uncertainties for a LeS event that occurred during 10–12 December 2013 during the Ontario Winter Lake-effect Systems (OWLeS) field campaign. Throughout this event, long-lake-axis-parallel snowbands persisted downwind of the eastern shore of Lake Ontario, leading to snowfall accumulations as high as 105 cm (liquid precipitation equivalent of 64.5 mm) on the Tug Hill Plateau.

Design And Implementation Of The New York State Mesonet Flux Tower Network, Jason Michael Covert

Legacy Theses & Dissertations (2009 - 2024)

The New York State Mesonet (NYSM) was established in 2014 to provide high-quality real-time meteorological data for weather monitoring and forecasting, emergency management, and research aimed at improving numerical weather prediction. The mainstay of the network consists of 126 surface weather stations located throughout New York State with an average spacing of 30 km. In 2017, 17 of the sites (“flux” sites) were equipped with additional (permanent) instrumentation to measure short and long-wave radiation components, soil heat flux, and turbulent fluxes of momentum, sensible and latent heat, and carbon dioxide (CO2). The mesoscale resolution of the 17-site NYSM Flux Tower …

Precipitation Characteristics And Their Dependence On Data Resolution And Model Physics, Di Chen

Legacy Theses & Dissertations (2009 - 2024)

To fully characterize precipitation, one often needs not only the accumulative amount (A), but also its frequency (F), intensity (I) and duration (D). These characteristics have large impacts on Earth’s hydrologic cycle. Aiming for a comprehensive understanding, this dissertation investigates precipitation characteristics and their dependence on data resolution and model physics using observational datasets and comprehensive global climate models (GCMs).

An Examination Of North Pacific Jet Regimes Conducive To Landfalling Atmospheric Rivers Along The West Coast Of North America, Eli Jacob Turasky

Legacy Theses & Dissertations (2009 - 2024)

Every year, the west coast of North America experiences significant economic damage and societal disruption due to the extreme precipitation associated with landfalling atmospheric rivers (ARs). ARs not only may produce significant economic and societal impacts, but also may contribute disproportionately to precipitation anomaly statistics along the west coast of the North America. The purpose of this study is to investigate: 1) the average state and evolution of the NPJ prior to AR landfall for selected categories of landfalling ARs; and 2) the dynamical processes applicable to the aforementioned categories of landfalling ARs that are linked to NPJ variability in …

Remote Sensing Of Planetary Boundary Layer Height And Particulate Matter 2.5 In New York State Mesonet Network, Bhupal Shrestha

Legacy Theses & Dissertations (2009 - 2024)

Abstract:

The Role Of The Subtropical Jet In Severe Dry Season Caribbean Rainstorms, Marshall D. Pfahler

Legacy Theses & Dissertations (2009 - 2024)

The Caribbean region experiences a bimodal climate with a dry season during November/December–May/June and a wet season encompassing the remainder of the year. Although significant high-impact heavy rainfall events in the Caribbean are typically associated with tropical cyclones (TCs) during the wet season, significant heavy rainfall events can also occur during the Caribbean dry season without contributions from TCs. Dry season Caribbean rainstorms (CRs) can produce infrastructure- and life-threatening conditions through flooding, mudslides, and damaging winds. The most severe dry season CRs can require international aid for vital recovery resources. Severe dry season CRs can produce rainfall totals that substantially …

Variability Of African Easterly Waves, Yuan-Ming Cheng

Legacy Theses & Dissertations (2009 - 2024)

African Easterly Waves (AEWs) are the most important rain modulators in the sub-Saharan Africa and precursors for tropical cyclone genesis in the Atlantic. While most previous studies have focused on the mean structure and dynamics of AEWs, evidence has shown that AEWs can vary substantially in terms of their structure and characteristics. Therefore, the overarching goal of this dissertation is to document the variability of AEWs and understand its causes. The goal is accomplished through two different but complementary approaches: (1) statistical analysis and (2) vorticity tracking.

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 …

Characterization Of Ambient Aerosols And Their Evolution Under Various Atmospheric Conditions In The Northeast U.S, Jie Zhang

Legacy Theses & Dissertations (2009 - 2024)

The University at Albany Atmospheric Sciences Research Center (ASRC) mobile laboratory, which includes a High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS), a Scanning Mobility Particle Sizer (SMPS), and several gas sensors, etc., has been used to characterize atmospheric aerosols and air quality at different locations in the Northeastern US (including urban, forest, and mountain areas) and the aerosol evolutions under a variety of atmospheric conditions (including extreme weather, fog, and cloud, etc.). In this dissertation, I present the findings of the several field measurements using the ASRC mobile lab, focusing on the influences of extreme events (including high O3, heatwave, …

On The Frequency, Structure, And Characteristics Of Tropical Cyclone Diurnal Pulses, Sarah Dunn Ditchek

Legacy Theses & Dissertations (2009 - 2024)

Taking 6-h IR brightness temperature differences, Dunion et al. (2014) found that in major hurricanes, an area of cold cloud tops routinely propagated radially outward from the storm core at around 5–10 m/s over the course of each day. They defined this feature as a “diurnal pulse” and created a 24-h conceptual clock that identified at which radius the coldest cloud tops would be located based on local time (LT). Due to the inherent predictability of these pulses, this dissertation was undertaken to gain a deeper understanding of their frequency, structure, and characteristics.

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 …

The Simulated Impact Of Snow Cover And Soil Moisture On Convective Precipitation Within The Rocky Mountains Under Climate Warming, Brendan Charles Wallace

Legacy Theses & Dissertations (2009 - 2024)

Warm season moist diurnal convection can be particularly sensitive to changes in land surface

A Multiscale Analysis Of The Rainband And Cellular Structure In Hurricanes Harvey And Irma (2017) Using The Ncar Ensemble, Dylan Card

Legacy Theses & Dissertations (2009 - 2024)

Tropical cyclones pose a significant threat to life and property, and exhibit many severe weather hazards as they make landfall, such as storm surge, strong winds, flooding rains, and tornadoes. Tropical cyclone rainbands are associated with nearly all of these hazards, which can extend hundreds of kilometers inland. Thus, understanding tropical cyclone rainband structure, and the individual convective cells of which rainbands are composed, is important to mitigating risk. Several previous studies have documented the overall structure of tropical cyclone rainbands, including the cells of which they are comprised and the environments in which they are embedded. These studies have …

Synergistic Effects Of Midlevel Dry Air And Vertical Wind Shear On Tropical Cyclone Development, Joshua James Alland

Legacy Theses & Dissertations (2009 - 2024)

This dissertation seeks to better understand how midlevel moisture and vertical wind shear (VWS) modulate tropical cyclone (TC) development. The first component of this dissertation simplifies the objective by focusing solely on how midlevel moisture modulates TC development, utilizing an axisymmetric modeling framework. Results show that low-entropy midlevel air affects the upward vertical mass flux in these experiments through subsidence into the subcloud layer, which results in a longer recovery time before deep convection develops. This process, as well as descending motion closer to the inner core, limits the radial width of deep convection, reduces the area of upward motions, …

Assessing The Blending Of Numerical Weather Prediction And Satellite-Derived Irradiance, Alexander Kubiniec

Legacy Theses & Dissertations (2009 - 2024)

This thesis discusses the blending of Numerical Weather Prediction (NWP) short wave

Applying Forecast Track And Intensity Diagnostics To High-Impact Northeast Winter Storms, Tomer Burg

Legacy Theses & Dissertations (2009 - 2024)

A conventional forecasting notion is that as lead time decreases, numerical weather prediction models exhibit a leftward (i.e., west) trend in the forecast position of low-pressure systems along the East Coast of the U.S. This left trend, which may turn seemingly weak ocean cyclones into high-impact weather events for the Northeast U.S., is attributed to various potential causes, such as variability in upstream shortwave troughs, or the representation of latent heat release in the NWP models downstream of the trough associated with the incipient cyclone. This study seeks to address whether this rule of thumb holds any significant merit, and …

The Sensitivity Of The December 2014 New York Mixed Precipitation Event To Initial Condition And Microphysics Uncertainty, Meghan Conway

Legacy Theses & Dissertations (2009 - 2024)

The prediction of wintertime precipitation type and amount can be a challenging undertaking, partly due to uncertainties in meteorological parameters such as temperature (horizontal and vertical), moisture, and wind. During Dec. 9-10, 2014, a mixed precipitation event occurred in the upper Hudson River Valley. This storm produced an unexpected heavy mesoscale snowband during rush hour in the Capitol region, after winter weather advisories had been cancelled.

Arctic Sea Ice Predictability And Prediction, Chao-Yuan Yang

Legacy Theses & Dissertations (2009 - 2024)

Arctic sea ice has experienced dramatic changes for the past few decades, which has profound global climatic effects, or feedbacks. The drastic changes and their associated impacts have led to increasing demand for sea ice predictions from a wide scope of stakeholders across seasonal to decadal timescales. Thus, it is important to improve our understanding of sea ice predictability on different timescales and our ability to predict Arctic sea ice.

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

16-Day Free-Traveling Rossby Waves And Their Association With Northern Hemisphere Blocking, Ernesto W. Findlay

Legacy Theses & Dissertations (2009 - 2024)

An analysis of the 16-day free Rossby wave is performed. The behavior of this wave includes a barotropic vertical structure that is independent of local forcing. An Empirical Orthogonal Function (EOF) analysis was performed on 15–30-day filtered geopotential height anomalies to extract the spatial patterns of the wave. Results show that the first two EOFs are in quadrature with each other, representing a westward moving signal with an average period of around 23 days and a phase velocity of. The Principal Components (PCs) from these EOFs were used to construct a 16-day wave index, which was employed as a tool …

Extreme Molecular Diversity In Biomass Burning Atmospheric Organic Aerosol Observed Through Ultrahigh Resolution Mass Spectrometry, Matthew Brege

Dissertations, Master's Theses and Master's Reports

Ambient atmospheric aerosol is ubiquitous in the atmosphere, originating from a variety of natural and man-made sources. These microscopic particles have profound impacts on the global climate system as well as human health. The organic fraction of atmospheric aerosol is an extremely complex mixture which is not yet fully characterized. These unknown organic aerosol species contribute to the uncertainty in the effect of aerosol on climate and uncertainty in overall ambient aerosol toxicity. Light absorbing organic aerosol can interact with incoming solar radiation and contribute to atmospheric heating; however, the source apportionment and overall fate of these absorbing organic aerosol …

Droughtscape, Winter 2019, National Drought Mitigation Center

DroughtScape: Quarterly Newsletter of the National Drought Mitigation Center (2007–2023)

Contents

From the Director

Drought intensified in California and Nevada, eased elsewhere

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

Drought impact summary for 4th quarter 2018

Drought impact summary 2018

Five states began drought plan updates in 2018

New web-based form makes submitting drought observations easier

FEMA risk assessment process tailored for drought

Upcoming events