Atmospheric Sciences Commons^™

Metr 323: Physical Meteorology—A Peer Review Of Teaching Project Benchmark Portfolio, Jun Wang

UNL Faculty Course Portfolios

Hands-on out-door activities are added into a course that is designed to teach students atmospheric physics ranging form solar light transfer to cloud and precipitation formation in the atmosphere. Statistical analysis and anonymous survey are conducted to benchmark the improvement in students' learning. Results show that these hands-on activities increase the student's interest and understanding in the course materials, and also improve the overall students' satisfaction for the course.

Elevated Electron Temperatures Around Twin Sporadic E Layers At Low Latitude: Observations And The Case For A Plausible Link To Currents Parallel To The Geomagnetic Field, A. Barjatya, J. P. St. Maurice, C. M. Swenson

Publications

We present data from nighttime sounding rocket flights in the low latitude E region. The payloads carried a sweeping Langmuir probe, a plasma impedance probe, and electric field probes. A detailed examination of the plasma density, temperature, and electric field measurements show two strong sporadic E (Es) layers with very high electron temperatures (∼1000 K) on each side of the upper layer. The lower layer was consistent with the presence of a strong zonal neutral wind shear. The upper layer was strongly influenced by the presence of a strongly negative vertical electric field, with zonal winds and …

Modeling Visibility In The El Paso Del Norte (Pdn) Region, Richard Medina Calderon

Open Access Theses & Dissertations

Poor visibility is a subject of growing public concern throughout the U.S, and an active area of research. Its societal impacts on air quality, aviation transport and traffic are significant. Aerosols play a fundamental role in the attenuation of solar radiation, and also affect visibility. The scattering and extinction coefficients of aerosol particles in the Paso del Norte Region have been calculated using the T- matrix model in conjunction with a laser particle counter. Inter-comparison of the model's results of the scattering and absorption coefficients against the corresponding data from a Photoacustic extinctiometer instrument (which measures in-situ absorption and scattering …

Multi-Instrument Comparisons Of D-Region Plasma Measurements, M. Friedrich, K. M. Torkar, U. P. Hoppe, T. A. Bekkeng, A. Barjatya, M. Rapp

Publications

The ECOMA (Existence and Charge state Of Meteoric dust grains in the middle Atmosphere) series of sounding rocket flights consisted of nine flights with almost identical payload design and flight characteristics. All flights carried a radio wave propagation experiment together with a variety of plasma probes. Three of these measured electron densities, two ion densities. The rockets were all launched from the Andøya Rocket Range, Norway, in four campaigns between 2006 and 2010. Emphasis is on the final three flights from 2010 where the payloads were equipped with four instruments capable of measuring plasma densities in situ, among them a …

A Modeling Investigation Of Human Exposure To Select Traffic-Related Air Pollutants In The Tampa Area: Spatiotemporal Distributions Of Concentrations, Social Distributions Of Exposures, And Impacts Of Urban Design On Both, Haofei Yu

USF Tampa Graduate Theses and Dissertations

Increasing vehicle dependence in the United States has resulted in substantial emissions of traffic-related air pollutants that contribute to the deterioration of urban air quality. Exposure to urban air pollutants trigger a number of public health concerns, including the potential of inequality of exposures and health effects among population subgroups. To better understand the impact of traffic-related pollutants on air quality, exposure, and exposure inequality, modeling methods that can appropriately characterize the spatiotemporally resolved concentration distributions of traffic-related pollutants need to be improved. These modeling methods can then be used to investigate the impacts of urban design and transportation management …

Cave Ventilation Is Influenced By Variations In The Co2-Dependent Virtual Temperature, Enrique P. Sánchez-Cañete, Penélope Serrano-Ortiz, Francisco Domingo, Andrew S. Kowalski

International Journal of Speleology

Dynamics and drivers of ventilation in caves are of growing interest for different fields of science. Accumulated CO₂ in caves can be exchanged with the atmosphere, modifying the internal CO₂ content, affecting stalagmite growth rates, deteriorating rupestrian paintings or creating new minerals. Current estimates of cave ventilation neglect the role of high CO₂ concentrations in determining air density – approximated via the virtual temperature (T_v) –, affecting buoyancy and therefore the release or storage of CO₂. Here we try to improve knowledge and understanding of cave ventilation through the use of T …

Spatial And Temporal Trends Of Snowfall In Central New York - A Lake Effect Dominated Region, Justin Joseph Hartnett

USF Tampa Graduate Theses and Dissertations

Central New York is located in one of the snowiest regions in the United States, with the city of Syracuse, New York the snowiest metropolis in the nation. Snowfall in the region generally begins in mid-November and lasts until late-March. Snow accumulation occurs from a multitude of conditions: frontal systems, mid-latitude cyclones, Nor'easters, and most notably lake-effect storms. Lake effect snowfall (LES) is a difficult parameter to forecast due to the isolated and highly variable nature of the storm. Consequently, studies have attempted to determine changes in snowfall for lake-effect dominated regions. Annual snowfall patterns are of particular concern as …

First Temperature Observations With The Usu Very Large Rayleigh Lidar: An Examination Of Mesopause Temperatures, Leda Sox, Vincent B. Wickwar, Joshua P. Herron, Marcus J. Bingham, Lance W. Petersen, Matthew T. Emerick

Posters

As the impetus for extended observational measurements throughout the middle atmosphere has increased1 , the limits of previous instrumentation need to be pushed. The Rayleigh lidar group at the Atmospheric Lidar Observatory (ALO) at Utah State University has pushed such limits on existing Rayleigh scatter lidar technology and, through major upgrades to the previous lidar system, has been able to gather temperature measurements in the upper mesosphere and lower thermosphere from approximately 70P109 km. A data campaign with the new system was conducted around the annual temperature minimum, centered on late June 2012, in this region. The temperatures from this …

Multiple Peaks In Saber Mesospheric Oh Emission Altitude Profiles, Jordan Rozum, Gene A. Ware, Doran J. Baker, Martin G. Wlynczak, James M. Russell

Browse All Undergraduate research

No abstract provided.

2000 Year Moisture Source Record From A Central Nevada Speleothem, Paul Pribyl

UNLV Theses, Dissertations, Professional Papers, and Capstones

The goal of this study was to determine the moisture source of winter precipitation in the central Great Basin for the past 2000 years, and to elucidate the role of Pacific Ocean and North American climate variability modes in driving observed droughts of the region around the Medieval Climatic Anomaly (MCA, ~900-1300 CE). Here a high resolution (~2-4 year) precisely dated moisture source reconstruction is presented from the δ18O values of speleothem LC-1 collected from Leviathan Cave in central Nevada, which reveals significant δ18O variability. I attribute the δ18O variability to changes in winter-season moisture circulation over the past 2000 …

Identification And Classification Of Stratospheric Sudden Warming Events, Thomas S. Ehrmann

Doctoral Dissertations and Master's Theses

Analysis of northern hemisphere stratospheric data from 1978-2011 is used to identify and classify Stratospheric Sudden Warming events. A total of 41 events are identified during this 33 year period, resulting in an average occurrence rate of 1.24 events/year. No significant variation in the rate is observed during the period analyzed. The average temperature increase during an SSW event is 12 K and the average duration is 32 days. Each identified event is classified as either a vortex displacement or split event and the ratio of displacement to split events is found to be 0.86.

An Intense Traveling Airglow Front In The Upper Mesosphere–Lower Thermosphere With Characteristics Of A Bore Observed Over Alice Springs, Australia, During A Strong 2 Day Wave Episode, R. L. Walterscheid, J. H. Hecht, L. J. Galinas, Michael P. Hickey Ph.D., I. M. Reid

Publications

The Aerospace Corporation’s Nightglow Imager observed a large step function change in airglow in the form of a traveling front in the OH Meinel (OHM) and O2 atmospheric (O2A) airglow emissions over Alice Springs, Australia, on 2 February 2003. The front exhibited nearly a factor of 2 stepwise increase in the OHM brightness and a stepwise decrease in the O2A brightness. There was significant (~25 K) cooling behind the airglow fronts. The OHM airglow brightness behind the front was among the brightest for Alice Springs that we have measured in 7 years of observations. The event was associated with a …

Climate Change Up Close And Personal: Impacts On Hampton Roads Region, Russell De Young

November 16, 2012: Best Practices for Adapting to Sea Level Rise and Flooding

No abstract provided.

Overview Of The 2007 And 2008 Campaigns Conducted As Part Of The Greenland Summit Halogen-HoX Experiment (Gshox), J L. Thomas, Jack E. Dibb, J Stutz, R Von Glasow, Steve Brooks, L Gregory Huey, Barry Lefer

Earth Sciences

From 10 May through 17 June 2007 and 6 June through 9 July 2008 intensive sampling campaigns at Summit, Greenland confirmed that active bromine chemistry is occurring in and above the snow pack at the highest part of the Greenland ice sheet (72°36´ N, 38°25´ W and 3.2 km above sea level). Direct measurements found BrO and soluble gas phase Br⁻ mixing ratios in the low pptv range on many days (maxima < 10 pptv). Conversion of up to 200 pg m⁻³ of gaseous elemental mercury (GEM) to reactive gaseous mercury (RGM) and enhanced OH relative to HO₂ plus RO₂ confirm that active bromine chemistry is …

Spectral Absorption Of Biomass Burning Aerosol Determined From Retrieved Single Scattering Albedo During Arctas, C A. Corr, S R. Hall, B E. Anderson, Kirk Ullman, A J. Beyersdorf, Kenn L. Thornhill, Michael J. Cubison, Jose L. Jimenez, Armin Wisthaler, Jack E. Dibb

Earth Sciences

Actinic flux, as well as aerosol chemical and optical properties, were measured aboard the NASA DC-8 aircraft during the ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) mission in Spring and Summer 2008. These measurements were used in a radiative transfer code to retrieve spectral (350-550 nm) aerosol single scattering albedo (SSA) for biomass burning plumes encountered on 17 April and 29 June. Retrieved SSA values were subsequently used to calculate the absorption Angstrom exponent (AAE) over the 350-500 nm range. Both plumes exhibited enhanced spectral absorption with AAE values that exceeded 1 (6.78 ± …

An Analysis Of Deep Convection Initiation Environments, Noah Lock

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Initiation is the part of the convective life cycle which is currently least understood and least well forecast. The inability to properly forecast the timing and/or location of deep convection initiation degrades forecast skill, especially during the warm season. The goals of this research are examine the spatiotemporal distribution of thunderstorm initiation points and to determine which atmospheric parameters (and ultimately processes) are most important for the initiation of thunderstorms. The spatiotemporal distribution of thunderstorm initiation points shows the expected peaks during summer and during the afternoon. The warm season also produces significant concentrations of initiation points near mountains, mainly …

Characteristics Of Tropospheric Ozone Depletion Events In The Arctic Spring: Analysis Of The Arctas, Arcpac, And Arcions Measurements And Satellite Bro Observations, T P. Kurosu, Yuhang Wang, T P. Kurosu, K Chance, A Rozanov, A Richter, S J. Oltmans, A M. Thompson, Jonathan Hair, Marta Fenn, Andrew Weinheimer, Thomas B. Ryerson, S Solberg, L Gregory Huey, J Liao, Jack E. Dibb, J A. Neuman, J Nowak, B Pierce, M Natarajan, J Al-Saadi

Earth Sciences

Arctic ozone depletion events (ODEs) are caused by halogen catalyzed ozone loss. In situ chemistry, advection of ozone-poor air mass, and vertical mixing in the lower troposphere are important factors affecting ODEs. To better characterize the ODEs, we analyze the combined set of surface, ozonesonde, and aircraft in situ measurements of ozone and bromine compounds during the Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS), the Aerosol, Radiation, and Cloud Processes affecting Arctic Climate (ARCPAC), and the Arctic Intensive Ozonesonde Network Study (ARCIONS) experiments (April 2008). Tropospheric BrO columns retrieved from satellite measurements and back …

Electron Loss And Meteoric Dust In The Mesosphere, M. Friedrich, M. Rapp, T. Blix, U. P. Hoppe, K. Torkar, S. Robertson, S. Dickson, Kristina Lynch

Dartmouth Scholarship

No abstract provided.

Droughtscape, Fall 2012, National Drought Mitigation Center

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

Contents

Director’s report

Updated resources

Drought outlook and review

2012 and past droughters

Summer impacts summary

Urban planners and drought

USDM wins CLEAN seal

Meixiu Yu's Chinese SPEI

Ethiopian project

Mexican VegDRI

Drought monitor sculpture

Investigation Of Diode Pumped Alkali Laser Atmospheric Transmission Using Tunable Diode Laser Absorption Spectroscopy, Christopher A. Rice

Theses and Dissertations

A field deployable, tunable diode laser absorption spectroscopy (TDLAS) device fiber coupled to a pair of 12.5" Ritchey-Chretien telescopes was used to study atmospheric propagation for open path lengths of 100 m to 1,000 m to estimate atmospheric transmission at key High Energy Laser (HEL) wavelengths. The potassium (K) version of the Diode Pumped Alkali Laser (DPAL) operates in between two of the sharp oxygen rotational features in the PP and the PQ branches. Initial experiments were performed in the vicinity of molecular oxygen X3Σ-g to b1Σ+g electronic transition lines near the potassium emission line at 770 nm. More than …