Atmospheric Sciences Commons^™

Ionospheric Signatures Of Gravity Waves Produced By The 2004 Sumatra And 2011 Tohoku Tsunamis: A Modeling Study, Michael P. Hickey, Yonghui Yu, Wenqing Wang

Publications

Ionospheric fluctuations inferred from observations of total electron content have previously been attributed to tsunamis and have confirmed the strong coupling between Earth’s ocean and ionosphere via atmospheric gravity waves (AGWs). To further advance our understanding of this wave coupling process we employ a linear full-wave model and a nonlinear time-dependent model to examine the ionospheric response to the AGW perturbations induced by the 2004 Sumatra and the 2011 Tohoku tsunamis. In the 2004 case, our modeling analyses reveal that one component of the propagating AGWs becomes dynamically unstable in the E-region ionosphere at a range exceeding 2000 km in …

A Laboratory Facility To Study Gas-Aerosol-Cloud Interactions In A Turbulent Environment: The Π Chamber, K. Chang, J. Bench, M. Brege, Will Cantrell, K. Chandrakar, David Ciochetto, Claudio Mazzoleni, Lynn Mazzoleni, Dennis Niedermeier, R. A. Shaw

Department of Physics Publications

A detailed understanding of interactions of aerosols, cloud droplets/ice crystals, and trace gases within the atmosphere is of prime importance for an accurate understanding of Earth’s weather and climate. One aspect that remains especially vexing is that clouds are ubiquitously turbulent, and therefore thermodynamic and compositional variables, such as water vapor supersaturation, fluctuate in space and time. With these problems in mind, a multiphase, turbulent reaction chamber—called the Π chamber because of the internal volume of 3.14 m³ with the cylindrical insert installed—has been developed. It is capable of pressures ranging from 1,000 to –60 hPa and can sustain …

Umphlett Qci Dec 2016, Natalie A. Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Drought Conditions

Large Fires Impact Region

Heavy Rains Bring Flooding to Montana

Isolated Impacts to Agriculture

3-Month Precipitation and Temperature Outlooks

Soil Moisture Conditions

Infrasound Propagation In Terrestrial Planetary Atmospheres, Lynsey B. Schroeder

Doctoral Dissertations and Master's Theses

Acoustic waves in the infrasonic frequency range, that is below 10 Hertz, have been observed to propagate to high altitudes in Earth's atmosphere. These waves have many sources, both natural and artificial, such as seismic events, convective storm systems, and nuclear explosions. Here, we seek to better understand the characteristics of atmospheric infrasound- below 0.1 Hz in particular- so as to improve the ability to detect their presence and sources. It is well-known that ambient attributes of an atmosphere, such as temperature, density, and composition, directly affect the propagation and growth of waves, and therefore it is likely that these …

The Cloud-Radiative Forcing Of The U.S. Landfalling Atmospheric Rivers, Qianwen Luo

Open Access Dissertations

Atmospheric rivers (ARs) are narrow channels in the atmosphere that transport an enormous amount of moisture from the tropics to the higher latitudes. Streaks of highly reflective clouds are observed along with the ARs in satellite imagery. These clouds both influence the moisture transport of ARs, as well as modify the Earth-Atmospheric energy budget through pathways such as cloud-radiative forcing (CRF). This dissertation studies the CRF of the U.S. Landfalling ARs in weather and climate scales. Three crucial questions are addressed. First, how do clouds produced by the ARs modulate the moisture and heat balance of the Earth-Atmospheric system? Even …

Unraveling The Fingerprints Of Nox Using Stable Isotopes: Implications For Nox Source Partitioning And Oxidation Chemistry, Wendell William Walters

Open Access Dissertations

The nitrogen (N) and oxygen (O) stable isotope composition (δ15N & δ18O) of nitrogen oxides (NOx )may be a useful tool for constraining NOx emission sources as well as for understanding the atmospheric oxidation pathways responsible for its removal if various NOx sources and sink processes exhibit characteristic isotopic compositions (“fingerprints”). However, this requires (1) an accurate and complete inventory of δ15N(NOx) values from major emission sources, (2) an assessment of the kinetic and equilibrium isotope effects that can impact δ15N and δ18O values of NOx, (3) and test these assumptions by conducting accurate in situ δ15N and δ18O measurements …

On The Propagation Of Atmospheric Gravity Waves In A Non-Uniform Wind Field: Introducing A Modified Acoustic-Gravity Wave Equation, Ahmad Talaei

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Atmospheric gravity waves play fundamental roles in a broad-range of dynamical processes extending throughout the Earth’s neutral atmosphere and ionosphere. In this paper, we present a modified form for the acoustic-gravity wave equation and its dispersion relationships for a compressible and non-stationary atmosphere in hydrostatic balance. Importantly, the solutions have been achieved without the use of the well-known Boussinesq approximation which have been used extensively in previous studies.

We utilize the complete set of governing equations for a compressible atmosphere with non-uniform airflows to determine an equation for vertical velocity of possible atmospheric waves. This intricate wave equation is simplified …

Analysis Of Aerosol Absorption Properties And Transport Over North Africa And The Middle East Using Aeronet Data, Ashraf Farahat, Hesham El-Askary, Peter Adetokunbo, Abu-Tharr Fuad

Mathematics, Physics, and Computer Science Faculty Articles and Research

In this paper particle categorization and absorption properties were discussed to understand transport mechanisms at different geographic locations and possible radiative impacts on climate. The long-term Aerosol Robotic Network (AERONET) data set (1999–2015) is used to estimate aerosol optical depth (AOD), single scattering albedo (SSA), and the absorption Ångström exponent (abs) at eight locations in North Africa and the Middle East. Average variation in SSA is calculated at four wavelengths (440, 675, 870, and 1020 nm), and the relationship between aerosol absorption and physical properties is used to infer dominant aerosol types at different locations. It was found that seasonality …

The Magnitude Of The Snow-Sourced Reactive Nitrogen Flux To The Boundary Layer In The Uintah Basin, Maria Zakto, Joseph Erbland, Joel Savarino, Lei Geng, Lauren Easley, Andrew Schauer, Timothy Bates, Patricia K. Quinn, Bonnie Light, David Morison, Hans D. Osthoff, Seth Lyman, William Neff, Bin Yuan, Becky Alexander

USU Uintah Basin Faculty Publications

Reactive nitrogen (N_r = NO, NO₂, HONO) and volatile organic carbon emissions from oil and gas extraction activities play a major role in wintertime ground-level ozone exceedance events of up to 140 ppb in the Uintah Basin in eastern Utah. Such events occur only when the ground is snow covered, due to the impacts of snow on the stability and depth of the boundary layer and ultraviolet actinic flux at the surface. Recycling of reactive nitrogen from the photolysis of snow nitrate has been observed in polar and midlatitude snow, but snow-sourced reactive nitrogen fluxes in mid-latitude …

Observation And Modeling Of Gravity Wave Propagation Through Reflection And Critical Layers Above Andes Lidar Observatory At Cerro Pachón, Chile, Bing Cao, Christopher J. Heale, Yafang Guo, Alan Z. Liu, Jonathan B. Snively

Publications

A complex gravity wave event was observed from 04:30 to 08:10 UTC on 16 January 2015 by a narrow-band sodium lidar and an all-sky airglow imager located at Andes Lidar Observatory (ALO) in Cerro Pachón (30.25∘S, 70.73∘W), Chile. The gravity wave packet had a period of 18–35 min and a horizontal wavelength of about 40–50 km. Strong enhancements of the vertical wind perturbation, exceeding10 m s−1, were found at ∼90 km and ∼103 km, consistent with nearly evanescent wave behavior near a reflection layer. A reduction in vertical wavelength was found as the phase speed approached the background wind speed …

Automated Calibration Of Atmospheric Oxidized Mercury Measurements, Seth Lyman, Colleen Jones, Trevor O'Neil, Tanner Allen, Matthieu Miller, Mae Sexauer Gustin, Ashley M. Pierce, Winston Luke, Xinrong Ren, Paul Kelley

USU Uintah Basin Faculty Publications

The atmosphere is an important reservoir for mercury pollution, and understanding of oxidation processes is essential to elucidating the fate of atmospheric mercury. Several recent studies have shown that a low bias exists in a widely applied method for atmospheric oxidized mercury measurements. We developed an automated, permeation tube-based calibrator for elemental and oxidized mercury, and we integrated this calibrator with atmospheric mercury instrumentation (Tekran 2537/1130/1135 speciation systems) in Reno, Nevada and at Mauna Loa Observatory, Hawaii, U.S.A. While the calibrator has limitations, it was able to routinely inject stable amounts of HgCl2 and HgBr2 into atmospheric mercury measurement systems …

Version 1.3 Aim Sofie Measured Methane (Ch4): Validation And Seasonal Climatology, P. P. Rong, J. M. Russell Iii, B. T. Marshall, D. E. Siskind, M. E. Hervig, L. L. Gordley, P. F. Bernath, K. A. Walker

Chemistry & Biochemistry Faculty Publications

The V1.3 methane (CH₄) measured by the Aeronomy of Ice in the Mesosphere (AIM) Solar Occultation for Ice Experiment (SOFIE) instrument is validated in the vertical range of ~25–70 km. The random error for SOFIE CH₄ is ~0.1–1% up to ~50 km and degrades to ~9% at ∼ 70 km. The systematic error remains at ~4% throughout the stratosphere and lower mesosphere. Comparisons with CH₄ data taken by the SCISAT Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS) and the Envisat Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) show an agreement within ~15% in the altitude range ~30–60 …

Spatial Continuous Biomass Burning Emission Inventory: Application To Wrf-Chem Model Over The Northern Sub-Saharan African Region, Yun Yue

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

Fire, as a significant global source of trace gases and aerosol particles, plays an important role in perturbations of the chemical and physical properties of the atmosphere. Fire products from Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on polar-orbiting satellites Terra and Aqua are largely used in several emission inventories. However, the MODIS fire products have inherent limitations due to the following reasons: (a) they cannot detect fires underneath clouds; (b) the fire detection sensitivity decreases at the edge of MODIS scan where viewing angles and MODIS pixel sizes are bigger than at nadir; and (c) there are gaps between MODIS …

Impact Of Upper-Tropospheric Temperature Anomalies And Vertical Wind Shear On Tropical Cyclone Evolution Using An Idealized Version Of The Operational Gfdl Hurricane Model, Robert E. Tuleya, Morris Bender, Thomas R. Knutson, Joseph R. Sirutis, Biju Thomas, Isaac Ginis

CCPO Publications

The GFDL hurricane modeling system, initiated in the 1970s, has progressed from a research tool to an operational system over four decades. This system is still in use today in research and operations, and its evolution will be briefly described. This study used an idealized version of the 2014 GFDL model to test its sensitivity across a wide range of three environmental factors that are often identified as key factors in tropical cyclone (TC) evolution: SST, atmospheric stability (upper-air thermal anomalies), and vertical wind shear (westerly through easterly). A wide range of minimum central pressure intensities resulted (905-980 hPa). The …

Droughtscape, Fall 2016, National Drought Mitigation Center

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

Contents

NDMC welcome two to team

Third quarter drought summary: Drought still spreading

Third quarter drought impacts: It was a hot, dry summer

Drought management framework for Africa approved

MENA region update

US Virgin Islands one step closer to its own drought monitor

Montana looks to improve watershed resilience

Tournament tackles hazards

Web tool will help officials make drought-related decisions

Dry Horizons launches

Measuring Landfill Methane Emissions Using Satellite And Ground Data, Madjid Delkash, Bowen Zhou, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

Landfill methane emissions (LME) vary in short periods depending upon the meteorological and atmospheric conditions. In this paper, coupling the Atmospheric InfraRed Sounder (AIRS) with the tracer dilution method (TDM) is proposed during unmeasured emission days to have a better annual estimation of the LME. Some assumptions were made to develop this proposed model. The atmospheric model Advanced Regional Prediction System (ARPS) was employed to evaluate assumptions made during emission estimation using the proposed technique. Methane emissions of a landfill for 13 days during 2011–2013 were measured by the TDM and filtered to remove unreliable data. Then, the filtered data …

Dynamics Of Orographic Gravity Waves Observed In The Mesosphere Over Auckland Islands During The Deep Propagating Gravity Wave Experiment (Deepwave), Stephen D. Eckermann, Dave Broutman, Jun Ma, James D. Doyle, Pierre-Dominique Pautet, Michael J. Taylor, Katrina Bossert, Bifford P. Williams, David C. Fritts, Ronald B. Smith

Publications

On 14 July 2014 during the Deep Propagating Gravity Wave Experiment (DEEPWAVE), aircraft remote sensing instruments detected large-amplitude gravity wave oscillations within mesospheric airglow and sodium layers at altitudes z ~ 78–83 km downstream of the Auckland Islands, located ~1000 km south of Christchurch, New Zealand. A high-altitude reanalysis and a three-dimensional Fourier gravity wave model are used to investigate the dynamics of this event. At 0700 UTC when the first observations were made, surface flow across the islands’ terrain generated linear three-dimensional wave fields that propagated rapidly to z ~ 78 km, where intense breaking occurred in a narrow …

Breakdown Of Itcz-Like Pv Patterns, Ajay Raghavendra, Thomas A. Guinn

Beyond: Undergraduate Research Journal

The Inter-Tropical Convergence Zone (ITCZ) is a zonal belt of intense convection, responsible for the genesis of over 80% of all tropical cyclones. This region of intense diabatic heating and shear results in a maximum of Ertel's potential vorticity (PV) meeting Rayleigh's necessary condition for barotropic instability. A fundamental issue is understanding the necessary precursor events leading to the breakdown of the ITCZ and subsequent formation of tropical cyclones. Our research examines the non-linear PV dynamics of the breakdown of both finite-length and infinite-length vorticity strips of varying widths and shapes, simulating the ITCZ found near the tropical eastern Pacific …

Umphlett Qci Sept 2016, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Streamflow Conditions

Challenging Season for Bird Breeding

Mixed Impacts to Agriculture this Summer

Unprecedented Fish Kill on Yellowstone River

3-Month Precipitation and Temperature Outlooks

Soil Moisture Conditions

On Safety Assessment Of Novel Approach To Robust Uav Flight Control In Gusty Environments, Vladimir Golubev, Petr Kazarin, William Mackunis, Sherry Borener, Derek Hufty

Publications

In a follow-up to our previous study, the current work examines the gust-induced “cone of uncertainty” in a small unmanned aerial vehicle’s (UAV) flight trajectory addressed in the context of safety assessments of UAV operations. Such analysis is a critical facet of the integration of unmanned aerial systems (UAS) into the National Airspace System (NAS), particularly in terminal airspace. The paper describes a predictive, robust feedback-loop flight control model that is applicable to various classes of UAVs and unsteady flight-path scenarios. The control design presented in this paper extends previous research results by demonstrating asymptotic (zero steady-state error) altitude regulation …