Atmospheric Sciences Commons^™

Resolving Ionospheric E-Region Modeling Challenges: The Solar Photon Flux Dependence, Joseph B. Jensen, Jan J. Sojka, Michael David, Kent Tobiska, Robert W. Schunk, Tom Woods, Frank Eparvier

Browse All Undergraduate research

The EVE instrument of the NASA Solar Dynamics Observatory (SDO) provides for the first time EUV and XUV measurements of the solar irradiance that adequately define the major source of ionization of the atmosphere. In our study we modeled the E-region of the ionosphere and analyzed how it is affected by the solar irradiance data obtained by EVE and contrast this with the S2000 Solar Irradiance model, used previously. The ionosphere has two major layers, the E-layer at 100 km, and the F-layer at 300 km. The difference in solar irradiances are small except at some wavelength bands, it is …

Resolving Ionospheric E-Region Modeling Challenges: The Solar Photon Flux Dependence, Joseph B. Jensen, Jan J. Sojka, Michael David, Kent Tobiska, Robert W. Schunk, Tom Woods, Frank Eparvier

Student Showcase

No abstract provided.

Design, Development, And In-Flight Testing Of A Pointer/Tracker For In-Flight Experiments To Measure Aero-Optical Effects Over A Scaled Turret, Matthew J. Krizo, Salvatore J. Cusumano, Steven T. Fiorino, Ryan Heap, Victor Velten, Joshua Brown, Richard J. Bartell

Faculty Publications

We address the design, development, and testing of a pointer/tracker as a probe beam for the purpose of making high-speed, aero-optical measurements of the flow over a scaled beam director turret. The tracker uses retro-reflection of the probe beam off of a Reflexite annulus surrounding the turret. The constraints of the design required a near-total-commercial off the shelf system that could be quickly installed and removed in a rented aircraft. Baseline measurements of environmental vibrations are used to predict pointing performance; mitigation of line-of-sight jitter on the probe beam is achieved through passive isolation and the design of relay optics. …

The Production Of Organic Nitrates In Portland Oregon And The Columbia River Gorge, Holly Ann Neill

Dissertations and Theses

This work studied the production of aerosol-phase organic nitrates in both Portland and the Columbia River Gorge (CRG). Ozone and NO_x species were investigated for correlation with organic nitrate aerosol, as they function as precursors to the production of organic nitrates. These ambient gas-phase measurements were collected in the same locations as high-volume (Hi-Vol) filters samples, in an urban and rural gorge setting to investigate correlations at the origin of the pollution plume and downwind. A novel Soxhlet extraction method for Hi-Vol filters was developed based on literature and EPA standard methods. Analysis for nitrate production was done by …

Ionospheric Induced Scintillation: A Space Weather Enigma, Jan Josef Sojka

All Physics Faculty Publications

The effect of scintillation on radio signals whose propagation path involves the Earth’s ionosphere is analogous to the allies of World War II receiving radio messages that had passed through the Enigma machine. In both these cases, man-made information has been encrypted and transmitted via radio. The two encryption methods are shown in Figure 1. The right panel shows a World War II Enigma machine used extensively by German U-boats to convey encrypted messages transmitted by radio [Perera, 2010]. The left panel gives an extreme example of a mapping of ionospheric irregularities at 3 m, which creates very severe scintillation …

Droughtscape, Spring 2013, National Drought Mitigation Center

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

Contents

Director’s report

First quarter climate summary and outlook

Impacts: Crop indemnities set records in 2012; water conflicts escalating

International meeting recommends countries have drought policies

NDMC plays key role in international drought policy meeting

EDEN and VOAD guide helps build community drought capacity

Svoboda, other experts and policymakers focus on food and water security

New Mexico ranching workshop set for May 29 in Socorro

Ranch planning updates: archived webinars, new publications

Tune in to the US Drought Monitor Forum, April 16-18

Archived webinar looks at using drought simulations in planning

CoCoRaHS WxTalk on drought

Evaluation Of A Wind-Wave System For Ensemble Tropical Cyclone Wave Forecasting. Part I: Winds, Steven M. Lazarus, Samuel T. Wilson, Michael E. Splitt, Gary A. Zarillo

Aeronautics Faculty Publications

A computationally efficient method of producing tropical cyclone (TC) wind analyses is developed and tested, using a hindcast methodology, for 12 Gulf of Mexico storms. The analyses are created by blending synthetic data, generated from a simple parametric model constructed using extended best-track data and climatology, with a first-guess field obtained from the NCEP-NCAR North American Regional Reanalysis (NARR). Tests are performed whereby parameters in the wind analysis and vortex model are varied in an attempt to best represent the TC wind fields. A comparison between nonlinear and climatological estimates of the TC size parameter indicates that the former yields …

Bottled Sky, Ioannis Michalou(Di)S

The Transdisciplinary STEAM+ Journal

Cloud-hunter Ioannis ΜICHALOU(di)S, lies in wait of air streams, grapping pieces of sky, shaping them, molding them, and baptizing them as ‘aerosculptures’. MICHALOU(di)S is the first visual artist worldwide to use art and science in a unique way. His latest Art-Science achievement is ‘Bottled Sky’. He states:

“In October 2001, while I was trying to create a cubic nephele, in the Visual Arts Research Centre of Massachusetts Institute of Technology (MIT), I came upon the silica aerogel for the first time... It is a space technology material, intangible -consisting of 99.9% air and 0.1% glass - which has been recently …

On The Lack Of Stratospheric Dynamical Variability In Low‐Top Versions Of The Cmip5 Models, Andrew J. Charlton-Perez, Mark P. Baldwin, Thomas Birner, Robert X. Black, Amy H. Butler, Natalia Calvo, Nicholas A. Davis, Edwin P. Gerber, Nathan Gillett, Steven Hardiman, Junsu Kim, Kirsten Krüger, Yun-Young Lee, Elisa Manzini, Brent A. Mcdaniel, Lorenzo Polvani, Thomas Reichler, Tiffany A. Shaw, Michael Sigmond, Seok-Woo Son, Matthew Toohey, Laura Wilcox, Shigeo Yoden, Bo Christiansen, François Lott, Drew Shindell, Seiji Yukimoto, Shingo Watanabe

Faculty Articles

We describe the main differences in simulations of stratospheric climate and variability by models within the fifth Coupled Model Intercomparison Project (CMIP5) that have a model top above the stratopause and relatively fine stratospheric vertical resolution (high-top), and those that have a model top below the stratopause (low-top). Although the simulation of mean stratospheric climate by the two model ensembles is similar, the low-top model ensemble has very weak stratospheric variability on daily and interannual time scales. The frequency of major sudden stratospheric warming events is strongly underestimated by the low-top models with less than half the frequency of events …

Bulk Partitioning The Growing Season Net Ecosystem Exchange Of Co2 In Siberian Tundra Reveals The Seasonality Of Its Carbon Sequestration Strength, Benjamin R. K. Runkle, T. Sachs, C. Wille, E.-M. Pfeiffer, L. Kutzbach

Biological and Agricultural Engineering Faculty Publications and Presentations

This paper evaluates the relative contribution of light and temperature on net ecosystem CO2 uptake during the 2006 growing season in a polygonal tundra ecosystem in the Lena River Delta in Northern Siberia (72°22´ N, 126°30´ E). The occurrence and frequency of warm periods may be an important determinant of the magnitude of the ecosystem's carbon sink function, as they drive temperature-induced changes in respiration. Hot spells during the early portion of the growing season, when the photosynthetic apparatus of vascular plants is not fully developed, are shown to be more influential in creating positive mid-day surface-to-atmosphere net ecosystem CO2 …

Coordinated Investigation Of Summer Time Mid-Latitude Descending E Layer (Es) Perturbations Using Na Lidar, Ionosonde, And Meteor Wind Radar Observations Over Logan, Utah (41.7°N, 111.8°W), Tao Yuan, Chad Fish, Jan Josef Sojka, D. Rice

All Physics Faculty Publications

It is well known that there is a strong correlation between the formation of a descending sporadic E layer (E_s) and the occurrence of large upper atmospheric zonal wind shears, most likely driven by solar thermal tides and/or gravity waves. We present new results of E_sperturbation events captured between 13 and 17 July 2011 (UT days 194–198) as part of a coordinated campaign using a wind/temperature Na lidar at Utah State University [41.7ºN, 111.8°W], and a Canadian Advanced Digital Ionosonde (CADI; Scientific Instrumentation Ltd., Saskatoon, Saskatchewan, Canada) and SkiYMet meteor wind radar, both located at nearby …

Development, Testing, And Deployment Of An Air Sampling Manifold For Spiking Elemental And Oxidized Mercury During The Reno Atmospheric Mercury Intercomparison Experiment (Ramix), B. D. Finley, D. A. Jaffe, K. Call, Seth Lyman, M. Sexauer Gustin, C. Peterson, M. Miller, T. Lyman

USU Uintah Basin Faculty Publications

The Reno Atmospheric Mercury Intercomparison Experiment (RAMIX) was in Reno, NV from August 22, 2011 to September 16, 2011. The goals of the experiment were to compare existing and new methods for measurements of ambient elemental and oxidized Hg, and to test these with quantitative spikes of Hg0, HgBr2, O3 and water vapor. In this paper we describe the design, testing, and deployment of a high flow manifold system designed to deliver ambient air and spiked compounds to multiple instruments simultaneously. The manifold was constructed of 1” OD PFA tubing and heated to 115 °C for the entire active zone. …

Fast Time Resolution Oxidized Mercury Measurements During The Reno Atmospheric Mercury Intercomparison Experiment (Ramix), Jesse L. Ambrose, Seth N. Lyman, Jiaoyan Huang, Mae Sexauer Gustin, Daneil A. Jaffe

USU Uintah Basin Faculty Publications

The Reno Atmospheric Mercury Intercomparison Experiment (RAMIX) was carried out from 22 August to 16 September, 2011 in Reno, NV to evaluate the performance of new and existing methods to measure atmospheric mercury (Hg). Measurements were made using a common sampling manifold to which controlled concentrations of Hg species, including gaseous elemental mercury (GEM) and HgBr2 (a surrogate gaseous oxidized mercury (GOM) compound), and potential interferents were added. We present an analysis of Hg measurements made using the University of Washington’s Detector for Oxidized Hg Species (DOHGS), focusing on tests of GEM and HgBr2 spike recovery, the potential for interference …

Leeside Boundary Layer Confluence And Afternoon Thunderstorms Over Mayaguez, Puerto Rico, Mark Jury, Sen Chiao

Faculty Publications, Meteorology and Climate Science

The midsummer boundary layer (BL) circulation and afternoon thunderstorm convection on the lee side of Puerto Rico is studied using observations and high-resolution models. Satellite infrared data help to identify cases on 5 and 14 June 2010 when midday surface temperatures show a 2°C gradient between land and sea and afternoon cloud-top temperatures <−60°C. Acoustic sounder profiles are analyzed for climatology, wind shear, turbulence, and diurnal cycles in the 40-300-m layer. Weather Research and Forecasting (WRF) model simulations indicate that sea-breeze flow is entrained into convective cells near Mayaguez, Puerto Rico. The simulated BL wind shear is too weak (0.5 × 10−2 s−1) in comparison with the acoustic sounder (2 × 10−2 s−1). Model 900-hPa winds are southeasterly and spread simulated convection too far north in comparison with radar. The pattern of near-surface winds in the island wake triggers afternoon thunderstorms near Mayaguez. A feature of the confluent circulation around Puerto Rico is opposing shear zones on the leeward corners of the island and a sea breeze of 5 m s−1 over the west coast during midday. [ABSTRACT FROM AUTHOR] . Copyright of Journal of Applied Meteorology & Climatology is the property of American Meteorological Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.).

Remote Sensing Of Surface Visibility From Space: A Look At The United States East Coast, Amy L. Kessner

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

While important for the management of air quality, human health and transportation, surface visibility data currently are only available through ground-based measurements, such as the Automated Surface Observing System (ASOS), and therefore lack spatial coverage. In analogy to the recent work of using satellite-based aerosol optical depth (AOD) to derive surface dry aerosol mass concentration at continental-to-global scale for cloud-free conditions, this study evaluates the potential of AOD retrieved from the MODerate Resolution Imaging Spectroradiometer (MODIS) for deriving surface visibility. For this purpose of evaluation, the truncated and discrete visibility data from daily weather reports are not suitable and the …

Effects Of Molecular Structure Of The Oxidation Products Of Reactive Atmospheric Hydrocarbons On The Formation Of Secondary Organic Particulate Matter, Including The Effects Of Water, Negar Niakan

Dissertations and Theses

Organic aerosols have significant effects on human health, air quality and climate. Secondary organic aerosols (SOA) are produced by the oxidation of primary-volatile organic compounds (VOC). For example, α-pinene reacts with oxidants such as hydroxyl radical (OH), ozone (O₃), and nitrate radical (NO₃), accounting for a significant portion of total organic aerosol in the atmosphere. Experimental studies have shown that the oxidation process between α-pinene and ozone has the most significant impact in the formation of SOA (Hoffmann et al., 1997). Most of the models used to predict SOA formation, however, are limited in that they …

Do We Understand What The Mercury Speciation Instruments Are Actually Measuring? Results Of Ramix, Mae Sexauer Gustin, Jiaoyan Huang, Matthieu B. Miller, Christianna Peterson, Daniel A. Jaffe, Jesse Ambrose, Brandon D. Finley, Seth N. Lyman, Kevin Call, Robert Talbotl, Dara Feddersen, Huiting Mao, Steven E. Lindberg

USU Uintah Basin Faculty Publications

From August 22 to September 16, 2012, atmospheric mercury (Hg) was measured from a common manifold in the field during the Reno Atmospheric Mercury Intercomparison eXperiment. Data were collected using Tekran systems, laser induced fluorescence, and evolving new methods. The latter included the University of Washington-Detector for Oxidized Mercury, the University of Houston Mercury instrument, and a filter-based system under development by the University of Nevada-Reno. Good transmission of total Hg was found for the manifold. However, despite application of standard protocols and rigorous quality control, systematic differences in operationally defined forms of Hg were measured by the sampling systems. …

Numerical Investigations Of Convective Initiation In Barbados, Kim Whitehall, Sen Chiao, Margarette Mayers-Als

Faculty Publications, Meteorology and Climate Science

Localized convection in Barbados accounts for hazardous conditions and a significant percentage of the island’s annual rainfall. The feature results in rainfall accumulations exceeding 50 mm in 3 hours or less, over isolated locations. Weather Research and Forecasting model (WRF) simulations are conducted for a rapid convective initiated and heavy precipitation event of 26 August 2008 over Barbados. The simulation results from the 1 km grid resolution domain depict that the shallow topography on the island plays a significant role in enhancing convective activity under weak synoptically disturbed conditions. The model results also demonstrate that the driving forces for the …

Evaluation Of Wrf-Sfire Performance With Field Observations From The Fireflux Experiment, A. Kochanski, M. Jenkins, J. Mandel, J. Beezley, Craig Clements, S. Krueger

Faculty Publications, Meteorology and Climate Science

This study uses in situ measurements collected during the FireFlux field experiment to evaluate and improve the performance of the coupled atmosphere–fire model WRF-SFIRE. The simulation by WRF-SFIRE of the experimental burn shows that WRF-SFIRE is capable of providing realistic head-fire rate of spread and vertical temperature structure of the fire plume, and fire-induced surface flow and vertical velocities within the plume up to 10 m above ground level. The simulation captured the changes in wind speed and direction before, during, and after fire front passage, along with the arrival times of wind speed, temperature, and updraft maxima, at the …

Kinematic Structure Of A Wildland Fire Plume Observed By Doppler Lidar, A. Charland, Craig Clements

Faculty Publications, Meteorology and Climate Science

Wildland fires present a challenging environment to make meteorological measurements. Observations in the vicinity of wildland fires are needed to better understand fire-atmosphere interactions and to provide data for the evaluation of coupled fire-atmosphere models. An observational study was conducted during a low-intensity prescribed fire in an area of complex terrain with grass fuels east of San José, California. A ground-based scanning Doppler lidar acquired radial wind velocities and backscatter intensity in and around the fire plume from multiple horizontal and vertical scans. The development of a convergence zone was consistently observed to exist downwind of the plume and was …