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Full-Text Articles in Physical Sciences and Mathematics

Comparison Between Fluid Simulation With Test Particles And 1 Hybrid Simulation For The Kelvin-Helmholtz Instability, Xuanye Ma, Katariina Nykyri, Brandon L. Burkholder, Rachel C. Rice, Peter A. Delamere, Bishwa Neupane Aug 2019

Comparison Between Fluid Simulation With Test Particles And 1 Hybrid Simulation For The Kelvin-Helmholtz Instability, Xuanye Ma, Katariina Nykyri, Brandon L. Burkholder, Rachel C. Rice, Peter A. Delamere, Bishwa Neupane

Publications

A quantitative investigation of plasma transport rate via the Kelvin‐Helmholtz (KH) instability can improve our understanding of solar‐wind‐magnetosphere coupling processes. Simulation studies provide a broad range of transport rates by using different measurements based on different initial conditions and under different plasma descriptions, which makes cross literature comparison difficult. In this study, the KH instability under similar initial and boundary conditions (i.e., applicable to the Earth's magnetopause environment) is simulated by Hall magnetohydrodynamics with test particles and hybrid simulations. Both simulations give similar particle mixing rates. However, plasma is mainly transported through a few big ...


Thermal Structure Of The Mesopause Region During The Wadis-2 Rocket Campaign, Raimund Wörl, Boris Strelnikov, Timo P. Viehl, Josef Höffner, Pierre-Dominique Pautet, Michael J. Taylor, Yucheng Zhao, Franz-Josef Lübken Jan 2019

Thermal Structure Of The Mesopause Region During The Wadis-2 Rocket Campaign, Raimund Wörl, Boris Strelnikov, Timo P. Viehl, Josef Höffner, Pierre-Dominique Pautet, Michael J. Taylor, Yucheng Zhao, Franz-Josef Lübken

Publications

This paper presents simultaneous temperature measurements by three independent instruments during the WADIS-2 rocket campaign in northern Norway (69 N, 14 E) on 5 March 2015. Vertical profiles were measured in situ with the CONE instrument. Continuous mobile IAP Fe lidar (Fe lidar) measurements during a period of 24 h, as well as horizontally resolved temperature maps by the Utah State University (USU) Advanced Mesospheric Temperature Mapper (AMTM) in the mesopause region, are analysed. Vertical and horizontal temperature profiles by all three instruments are in good agreement. A harmonic analysis of the Fe lidar measurements shows the presence of waves ...


Uas Flight Operations In Complex Terrain: Assessing The Agricultural Impact From Hurricane Maria In The Central Mountainous Region Of Puerto Rico, Kevin A. Adkins Jan 2019

Uas Flight Operations In Complex Terrain: Assessing The Agricultural Impact From Hurricane Maria In The Central Mountainous Region Of Puerto Rico, Kevin A. Adkins

Publications

Hurricane Maria struck Puerto Rico in September 2017 as a Category 4 storm causing major damage to infrastructure, agriculture and natural ecosystems, as well as the loss of many lives. Among the crops hardest hit was coffee, one of the most important crops in Puerto Rico. As a perennial system, coffee takes various production forms along a gradient from high shade/biodiversity coffee farms to low shade coffee monocultures and therefore offers an ideal means for the study of resistance and resilience of an agroecosystem to weather and climate disturbance. During the summer of 2018, 14 impacted farms across the ...


Vortex: A New Rocketexperiment To Studymesoscale Dynamics At The Turbopause, Gerald A. Lehmacher, Jonathan B. Snively, Aroh Barjatya, Miguel F. Larsen, Michael J. Taylor, Franz-Josef Lübken, Jorge L. Chau Jan 2019

Vortex: A New Rocketexperiment To Studymesoscale Dynamics At The Turbopause, Gerald A. Lehmacher, Jonathan B. Snively, Aroh Barjatya, Miguel F. Larsen, Michael J. Taylor, Franz-Josef Lübken, Jorge L. Chau

Publications

The goal of this new investigation is to better understand gravity waves and their interactions as they propagate from the mesosphere into the lower thermosphere, to characterize the mesoscale wind field, and to identify regions of divergence, vorticity, and stratified turbulence. The Vorticity Experiment (VortEx) will comprise two salvoes of each two sounding rockets scheduled to be launched from Andøya Space Center, Norway in February 2022. The rockets will observe horizontally spaced wind profiles, neutral density and temperature profiles, and plasma densities. Additional information about the background conditions and mesoscale dynamics will be obtained by lidars, meteor radars and a ...


Seasonal Propagation Characteristics Of Mstids Observed At High Latitudes Over Central Alaska Using The Poker Flat Incoherent Scatter Radar, Michael R. Negale, Michael J. Taylor, M. J. Nicolls, Sharon L. Vadas, Kim Nielsen, Craig J. Heinselman May 2018

Seasonal Propagation Characteristics Of Mstids Observed At High Latitudes Over Central Alaska Using The Poker Flat Incoherent Scatter Radar, Michael R. Negale, Michael J. Taylor, M. J. Nicolls, Sharon L. Vadas, Kim Nielsen, Craig J. Heinselman

Publications

Near‐continuous electron density measurements obtained over a ∼3 year period, 2010–2013, using the Poker Flat Incoherent Scatter Radar (PFISR) in central Alaska (69°N, 147°W) have been analyzed to quantify the properties of over 650 high‐latitude medium‐scale traveling ionospheric disturbances (MSTIDs). Our analysis focused on the altitude range 100–300 km encompassing the lower ionosphere/thermosphere and yielded first full seasonal day/night distributions of MSTIDs at high northern latitudes with mean values: horizontal wavelength 446 km, horizontal phase speed 187 m/s, and period 41 min. These year‐round measurements fill an important summertime ...


Thermal Removal Of Carbon Dioxide From The Atmosphere: Energy Requirements And Scaling Issues, Ted Von Hippel May 2018

Thermal Removal Of Carbon Dioxide From The Atmosphere: Energy Requirements And Scaling Issues, Ted Von Hippel

Publications

I conduct a systems-level study of direct air capture of CO2 using techniques from thermal physics. This system relies on a combination of an efficient heat exchanger, radiative cooling, and refrigeration, all at industrial scale and operated in environments at low ambient temperatures. While technological developments will be required for such a system to operate efficiently, those developments rest on a long history of refrigeration expertise and technology, and they can be developed and tested at modest scale. I estimate that the energy required to remove CO2 via this approach is comparable to direct air capture by other techniques. The ...


Unexpected Occurrence Of Mesospheric Frontal Gravity Wave Events Over South Pole (90°S), Pierre-Dominique Pautet, Michael J. Taylor, J. B. Snively, Christina Solorio Jan 2018

Unexpected Occurrence Of Mesospheric Frontal Gravity Wave Events Over South Pole (90°S), Pierre-Dominique Pautet, Michael J. Taylor, J. B. Snively, Christina Solorio

Publications

Since 2010, Utah State University has operated an infrared Advanced Mesospheric Temperature Mapper at the Amundsen–Scott South Pole station to investigate the upper atmosphere dynamics and temperature deep within the vortex. A surprising number of “frontal” gravity wave events (86) were recorded in the mesospheric OH(3,1) band intensity and rotational temperature images (typical altitude of ~87 km) during four austral winters (2012–2015). These events are gravity waves (GWs) characterized by a sharp leading wave front followed by a quasi-monochromatic wave train that grows with time. A particular subset of frontal gravity wave events has been identified ...


Does Strong Tropospheric Forcing Cause Large-Amplitude Mesospheric Gravity Waves? A Deepwave Case Study, Martina Bramberger, Andreas Dörnbrack, Katrina Bossert, Benedikt Ehard, David C. Fritts, Bernd Kaifler, Christian Mallaun, Andrew Orr, Pierre-Dominique Pautet, Markus Rapp, Michael J. Taylor, Simon Vosper, Bifford P. Williams, Benjamin Witschas Nov 2017

Does Strong Tropospheric Forcing Cause Large-Amplitude Mesospheric Gravity Waves? A Deepwave Case Study, Martina Bramberger, Andreas Dörnbrack, Katrina Bossert, Benedikt Ehard, David C. Fritts, Bernd Kaifler, Christian Mallaun, Andrew Orr, Pierre-Dominique Pautet, Markus Rapp, Michael J. Taylor, Simon Vosper, Bifford P. Williams, Benjamin Witschas

Publications

On 4 July 2014, during the Deep Propagating Gravity Wave Experiment (DEEPWAVE), strong low-level horizontal winds of up to 35 m s−1 over the Southern Alps, New Zealand, caused the excitation of gravity waves having the largest vertical energy fluxes of the whole campaign (38 W m−2). At the same time, large-amplitude mesospheric gravity waves were detected by the Temperature Lidar for Middle Atmospheric Research (TELMA) located at Lauder (45.0°S, 169.7°E), New Zealand. The coincidence of these two events leads to the question of whether the mesospheric gravity waves were generated by the strong ...


The Extratropical Transition Of Tropical Cyclones. Part I: Cyclonic Evolution And Direct Impacts, Clark Evans, Kimberly M. Wood, Sim D. Aberson, Heather M. Archambault, Shawn M. Milrad, Lance F. Bosart, Et Al. Nov 2017

The Extratropical Transition Of Tropical Cyclones. Part I: Cyclonic Evolution And Direct Impacts, Clark Evans, Kimberly M. Wood, Sim D. Aberson, Heather M. Archambault, Shawn M. Milrad, Lance F. Bosart, Et Al.

Publications

Extratropical transition (ET) is the process by which a tropical cyclone, upon encountering a baroclinic environment and reduced sea surface temperature at higher latitudes, transforms into an extratropical cyclone. This process is influenced by, and influences, phenomena from the tropics to the midlatitudes and from the meso- to the planetary scales to extents that vary between individual events. Motivated in part by recent high-impact and/or extensively observed events such as North Atlantic Hurricane Sandy in 2012 and western North Pacific Typhoon Sinlaku in 2008, this review details advances in understanding and predicting ET since the publication of an earlier ...


Ionospheric Gravity Waves Driven By Oceanic Gravity Waves In Resonance: A Modeling Study In Search Of Their Spectra, Michael P. Hickey, Yonghui Yu Sep 2017

Ionospheric Gravity Waves Driven By Oceanic Gravity Waves In Resonance: A Modeling Study In Search Of Their Spectra, Michael P. Hickey, Yonghui Yu

Publications

Ionospheric observations associated with the 2011 Tohoku tsunami have revealed gravity waves having spectral characteristics that depend on their proximity to the epicenter. There is a preponderance of medium-scale waves in the vicinity of the epicenter, a significant bifurcation into short- and long-period waves over the Hawaiian archipelago, and a narrow and rich spectrum of waves over the West Coast and inland of the United States (U.S.). Guided by these previous observations, we consider wave sources as triads of nonlinearly interacting oceanic gravity waves, whose wave parameters satisfy resonant conditions. These waves are simulated using a 2-D nonlinear model ...


Characteristics Of Mesospheric Gravity Waves Over Antarctica Observed By Angwin (Antarctic Gravity Wave Instrument Network) Imagers Using 3-D Spectral Analyses, Takashi S. Matsuda, Takuji Nakamura, Mitsumu K. Ejiri, Masaki Tsutsumi, Yoshihiro Tomikawa, Michael J. Taylor, Yucheng Zhao, Pierre-Dominique Pautet, Damian J. Murphy, Tracy Moffat-Griffin Sep 2017

Characteristics Of Mesospheric Gravity Waves Over Antarctica Observed By Angwin (Antarctic Gravity Wave Instrument Network) Imagers Using 3-D Spectral Analyses, Takashi S. Matsuda, Takuji Nakamura, Mitsumu K. Ejiri, Masaki Tsutsumi, Yoshihiro Tomikawa, Michael J. Taylor, Yucheng Zhao, Pierre-Dominique Pautet, Damian J. Murphy, Tracy Moffat-Griffin

Publications

We have obtained horizontal phase velocity distributions of the gravity waves around 90 km from four Antarctic airglow imagers, which belong to an international airglow imager/instrument network known as ANGWIN (Antarctic Gravity Wave Instrument Network). Results from the airglow imagers at Syowa (69°S, 40°E), Halley (76°S, 27°W), Davis (69°S, 78°E), and McMurdo (78°S, 167°E) were compared, using a new statistical analysis method based on 3-D Fourier transform (Matsuda et al., 2014) for the observation period between 7 April and 21 May 2013. Significant day-to-day and site-to-site differences were found. The averaged ...


Mobile Radar As An Undergraduate Education And Research Tool: The Erau C-Breese Field Experience With The Doppler On Wheels, Shawn M. Milrad, Christopher G. Herbster Sep 2017

Mobile Radar As An Undergraduate Education And Research Tool: The Erau C-Breese Field Experience With The Doppler On Wheels, Shawn M. Milrad, Christopher G. Herbster

Publications

Embry-Riddle Aeronautical University Convective-Boundary Research Engaging Educational Student Experiences (ERAU C-BREESE) was an 18-day National Science Foundation (NSF)-funded educational Doppler on Wheels (DOW) deployment through the Center for Severe Weather Research in May 2015. ERAU C-BREESE had three primary areas of focus: meteorological field observations and research, undergraduate experiential learning, and local community outreach. ERAU undergraduate meteorology students had the unique opportunity to forecast for, collect, and analyze field measurements of sea-breeze processes and convection. The scientific objectives of ERAU C-BREESE were to forecast, observe, and analyze central Florida sea-breeze processes and thunderstorms by combining a DOW with more ...


Secondary Gravity Wave Generation Over New Zealand During The Deepwave Campaign, Katrina Bossert, Christopher G. Kruse, Christopher J. Heale, David C. Fritts, Bifford P. Williams, Jonathan B. Snively, Pierre-Dominique Pautet, Michael J. Taylor Aug 2017

Secondary Gravity Wave Generation Over New Zealand During The Deepwave Campaign, Katrina Bossert, Christopher G. Kruse, Christopher J. Heale, David C. Fritts, Bifford P. Williams, Jonathan B. Snively, Pierre-Dominique Pautet, Michael J. Taylor

Publications

Multiple events during the Deep Propagating Gravity Wave Experiment measurement program revealed mountain wave (MW) breaking at multiple altitudes over the Southern Island of New Zealand. These events were measured during several research flights from the National Science Foundation/National Center for Atmospheric Research Gulfstream V aircraft, utilizing a Rayleigh lidar, an Na lidar, and an Advanced Mesospheric Temperature Mapper simultaneously. A flight on 29 June 2014 observed MWs with horizontal wavelengths of ~80–120 km breaking in the stratosphere from ~10 to 50 km altitude. A flight on 13 July 2014 observed a horizontal wavelength of ~200–240 km ...


First Na Lidar Measurements Of Turbulence Heat Flux, Thermal Diffusivity, And Energy Dissipation Rate In The Mesopause Region, Yafang Guo, Alan Z. Liu, Chester S. Gardner Jun 2017

First Na Lidar Measurements Of Turbulence Heat Flux, Thermal Diffusivity, And Energy Dissipation Rate In The Mesopause Region, Yafang Guo, Alan Z. Liu, Chester S. Gardner

Publications

Turbulence is ubiquitous in the mesopause region, where the atmospheric stability is low and wave breaking is frequent. Measuring turbulence is challenging in this region and is traditionally done by rocket soundings and radars. In this work, we show for the first time that the modern Na wind/temperature lidar located at Andes Lidar Observatory in Cerro Pachón, Chile, is able to directly measure the turbulence perturbations in temperature and vertical wind between 85 and 100 km. Using 150 h of lidar observations, we derived the frequency (ω) and vertical wave number (m) spectra for both gravity wave and turbulence ...


Investigation Of The 2013 Alberta Flood From Weather And Climate Perspectives, Bernardo Teufel, G. T. Diro, K. Whan, S. M. Milrad, Et Al. May 2017

Investigation Of The 2013 Alberta Flood From Weather And Climate Perspectives, Bernardo Teufel, G. T. Diro, K. Whan, S. M. Milrad, Et Al.

Publications

During 19–21 June 2013 a heavy precipitation event affected southern Alberta and adjoining regions, leading to severe flood damage in numerous communities and resulting in the costliest natural disaster in Canadian history. This flood was caused by a combination of meteorological and hydrological factors, which are investigated from weather and climate perspectives with the fifth generation Canadian Regional Climate Model. Results show that the contribution of orographic ascent to precipitation was important, exceeding 30% over the foothills of the Rocky Mountains. Another contributing factor was evapotranspiration from the land surface, which is found to have acted as an important ...


Cirrus Cloud Microphysics Over Darwin, Australia, Dorothea Ivanova, Matthew Johnson Apr 2017

Cirrus Cloud Microphysics Over Darwin, Australia, Dorothea Ivanova, Matthew Johnson

Publications

Ice clouds, crucial to the understanding of both short - and long - term climate trends, are poorly represented in global climate models (GCMs). Cirrus clouds, one of the largest uncertainties in the global radiation budget, have been inadequately studied at low latitudes. Parameterizations exist for mid - latitude and tropical cirrus ( Ivanova et al. 2001; McFarquhar et al. 1997). Due to climate sensitivity in the GCM with respect to cloud input, without robust parameterizations of cirrus clouds, the GCM is inaccurate over most output fields, including radiative forcing, temperature, albedo, and heat flux (Yao and Del Genio 1999).

Studies of the microphysical ...


Nonlinear Ionospheric Responses To Large-Amplitude Infrasonic-Acoustic Waves Generated By Undersea Earthquakes, M. D. Zettergren, J. B. Snively, A. Komjathy, O. P. Verkhoglyadova Feb 2017

Nonlinear Ionospheric Responses To Large-Amplitude Infrasonic-Acoustic Waves Generated By Undersea Earthquakes, M. D. Zettergren, J. B. Snively, A. Komjathy, O. P. Verkhoglyadova

Publications

Numerical models of ionospheric coupling with the neutral atmosphere are used to investigate perturbations of plasma density, vertically integrated total electron content (TEC), neutral velocity, and neutral temperature associated with large-amplitude acoustic waves generated by the initial ocean surface displacements from strong undersea earthquakes. A simplified source model for the 2011 Tohoku earthquake is constructed from estimates of initial ocean surface responses to approximate the vertical motions over realistic spatial and temporal scales. Resulting TEC perturbations from modeling case studies appear consistent with observational data, reproducing pronounced TEC depletions which are shown to be a consequence of the impacts of ...


Numerical Modeling Of A Multiscale Gravity Wave Event And Its Airglow Signatures Over Mount Cook, New Zealand, During The Deepwave Campaign, C. J. Heale, K. Bossert, J. B. Snively, D. C. Fritts, P. -D. Pautet, M. J. Taylor Jan 2017

Numerical Modeling Of A Multiscale Gravity Wave Event And Its Airglow Signatures Over Mount Cook, New Zealand, During The Deepwave Campaign, C. J. Heale, K. Bossert, J. B. Snively, D. C. Fritts, P. -D. Pautet, M. J. Taylor

Publications

A 2-D nonlinear compressible model is used to simulate a large-amplitude, multiscale mountain wave event over Mount Cook, NZ, observed as part of the Deep Propagating Gravity Wave Experiment (DEEPWAVE) campaign and to investigate its observable signatures in the hydroxyl (OH) layer. The campaign observed the presence of a �x = 200 km mountain wave as part of the 22nd research flight with amplitudes of >20 K in the upper stratosphere that decayed rapidly at airglow heights. Advanced Mesospheric Temperature Mapper (AMTM) showed the presence of small-scale (25–28 km) waves within the warm phase of the large mountain wave. The ...


Wiggle 3d Displays Of Weather Data, Frederick R. Mosher Jan 2017

Wiggle 3d Displays Of Weather Data, Frederick R. Mosher

Publications

Weather is a time varying 3-dimensional phenomena, but the displays of weather data are inherently 2-dimensional. Since weather phenomena at one level can impact the weather at another level, it would be desirable to view weather on a 3D volume type of display. Initially weather displays were on paper and currently weather information is displayed on computer screens. The human mind can interpret 3D volume information in a number of ways. Having two eyes, the brain can detect the parallax differences between the images for the left eye being slightly different from the right eye. Objects that are closer to ...


Anisotropic Fluid Modeling Of Ionospheric Upflow: Effects Of Low‐Altitude Anisotropy And Thermospheric Winds, M. R. Burleigh, M. Zettergren Jan 2017

Anisotropic Fluid Modeling Of Ionospheric Upflow: Effects Of Low‐Altitude Anisotropy And Thermospheric Winds, M. R. Burleigh, M. Zettergren

Publications

A new anisotropic fluid model is developed to describe ionospheric upflow responses to magnetospheric forcing by electric fields and broadband ELF waves at altitudes of 90–2500 km. This model is based on a bi‐Maxwellian ion distribution and solves time‐dependent, nonlinear equations of conservation of mass, momentum, parallel energy, and perpendicular energy for six ion species important to E, F, and topside ionospheric regions. It includes chemical and collisional interactions with the neutral atmosphere, photoionization, and electron impact ionization. This model is used to examine differences between isotropic and anisotropic descriptions of ionospheric upflow driven by DC electric ...


Spatial And Temporal Variability In Mlt Turbulence Inferred From In Situ And Ground-Based Observations During The Wadis-1 Sounding Rocket Campaign, B. Strelnikov, A. Szewczyk, I. Strelnikova, R. Latteck, G. Baumgarten, Aroh Barjatya, Et.Al Jan 2017

Spatial And Temporal Variability In Mlt Turbulence Inferred From In Situ And Ground-Based Observations During The Wadis-1 Sounding Rocket Campaign, B. Strelnikov, A. Szewczyk, I. Strelnikova, R. Latteck, G. Baumgarten, Aroh Barjatya, Et.Al

Publications

In summer 2013 the WADIS-1 sounding rocket campaign was conducted at the Andøya Space Center (ACS) in northern Norway (69° N, 16° E). Among other things, it addressed the question of the variability in mesosphere/lower thermosphere (MLT) turbulence, both in time and space. A unique feature of the WADIS project was multi-point turbulence sounding applying different measurement techniques including rocket-borne ionization gauges, VHF MAARSY radar, and VHF EISCAT radar near Tromsø. This allowed for horizontal variability to be observed in the turbulence field in the MLT at scales from a few to 100 km. We found that the turbulence ...


Quantifying Gravity Wave Momentum Fluxes With Mesosphere Temperature Mappers And Correlative Instrumentation, David C. Fritts, Pierre-Dominique Pautet, Katrina Bossert, Michael J. Taylor, Bifford P. Williams, Hiroyuki Iimura, Tao Yuan, Nicholas J. Mitchell, Gunter Stober Dec 2016

Quantifying Gravity Wave Momentum Fluxes With Mesosphere Temperature Mappers And Correlative Instrumentation, David C. Fritts, Pierre-Dominique Pautet, Katrina Bossert, Michael J. Taylor, Bifford P. Williams, Hiroyuki Iimura, Tao Yuan, Nicholas J. Mitchell, Gunter Stober

Publications

An Advanced Mesosphere Temperature Mapper and other instruments at the Arctic Lidar Observatory for Middle Atmosphere Research in Norway (69.3°N) and at Logan and Bear Lake Observatory in Utah (42°N) are used to demonstrate a new method for quantifying gravity wave (GW) pseudo-momentum fluxes accompanying spatially and temporally localized GW packets. The method improves on previous airglow techniques by employing direct characterization of the GW temperature perturbations averaged over the OH airglow layer and correlative wind and temperature measurements to define the intrinsic GW properties with high confidence. These methods are applied to two events, each of ...


Ionospheric Signatures Of Gravity Waves Produced By The 2004 Sumatra And 2011 Tohoku Tsunamis: A Modeling Study, Michael P. Hickey, Yonghui Yu, Wenqing Wang Dec 2016

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 ...


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 Nov 2016

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 ...


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 Sep 2016

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 layer ...


On Safety Assessment Of Novel Approach To Robust Uav Flight Control In Gusty Environments, Vladimir Golubev, Petr Kazarin, William Mackunis, Sherry Borener, Derek Hufty Sep 2016

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 ...


The Deep Propagating Gravity Wave Experiment (Deepwave): An Airborne And Ground-Based Exploration Of Gravity Wave Propagation And Effects From Their Sources Throughout The Lower And Middle Atmosphere, David C. Fritts, Ronald B. Smith, Michael J. Taylor, James D. Doyle, Stephen D. Eckermann, Andreas Dörnbrack, Markus Rapp, Bifford P. Williams, Pierre-Dominique Pautet, Katrina Bossert, Neal R. Criddle, Carolyn A. Reynolds, P. Alex Reineke, Michael Uddstrom, Michael J. Revell, Richard Turner, Bernd Kaifler, Johannes S. Wagner, Tyler Mixa, Christopher G. Kruse, Alison D. Nugent, Campbell D. Watson, Sonja Gisinger, Steven M. Smith, James J. Moore, William O. Brown, Julie A. Haggerty, Alison Rockwell, Gregory J. Stossmeister, Et Al. Et Al. Apr 2016

The Deep Propagating Gravity Wave Experiment (Deepwave): An Airborne And Ground-Based Exploration Of Gravity Wave Propagation And Effects From Their Sources Throughout The Lower And Middle Atmosphere, David C. Fritts, Ronald B. Smith, Michael J. Taylor, James D. Doyle, Stephen D. Eckermann, Andreas Dörnbrack, Markus Rapp, Bifford P. Williams, Pierre-Dominique Pautet, Katrina Bossert, Neal R. Criddle, Carolyn A. Reynolds, P. Alex Reineke, Michael Uddstrom, Michael J. Revell, Richard Turner, Bernd Kaifler, Johannes S. Wagner, Tyler Mixa, Christopher G. Kruse, Alison D. Nugent, Campbell D. Watson, Sonja Gisinger, Steven M. Smith, James J. Moore, William O. Brown, Julie A. Haggerty, Alison Rockwell, Gregory J. Stossmeister, Et Al. Et Al.

Publications

The Deep Propagating Gravity Wave Experiment (DEEPWAVE) was designed to quantify gravity wave (GW) dynamics and effects from orographic and other sources to regions of dissipation at high altitudes. The core DEEPWAVE field phase took place from May through July 2014 using a comprehensive suite of airborne and ground-based instruments providing measurements from Earth’s surface to ∼100 km. Austral winter was chosen to observe deep GW propagation to high altitudes. DEEPWAVE was based on South Island, New Zealand, to provide access to the New Zealand and Tasmanian “hotspots” of GW activity and additional GW sources over the Southern Ocean ...


Modeling Spatiotemporal Variability Of The Bioclimate Envelope Of Homarus Americanus In The Coastal Waters Of Maine And New Hampshire, Kisei Tananka, Yong Chen Feb 2016

Modeling Spatiotemporal Variability Of The Bioclimate Envelope Of Homarus Americanus In The Coastal Waters Of Maine And New Hampshire, Kisei Tananka, Yong Chen

Publications

A bioclimate envelope model was developed to evaluate the potential impacts of climate variability on American lobster (Homarus americanus). Bioclimate envelopes were defined by season-, sex-, and stage- specific Habitat Suitability Indices (HSI) based on (1) bottom temperature, (2) bottom salinity, and (3) depth. The species’ association to each of these three environmental attributes was expressed using Suitability Indices (SIs) calibrated by standardized lobster abundance derived from 14 years of fishery independent survey. A regional ocean model (Finite-Volume Community Ocean Model) was integrated with the HSI to hindcast spatiotemporal variability of bioclimate envelopes for American lobster in coastal waters of ...


Measuring The Seeds Of Ion Outflow: Auroral Sounding Rocket Observations Of Low-Altitude Ion Heating And Circulation, P. A. Fernandes, K. A. Lynch, M. Zettergren, D. L. Hampton, T. A. Bekkeng, Et Al. Feb 2016

Measuring The Seeds Of Ion Outflow: Auroral Sounding Rocket Observations Of Low-Altitude Ion Heating And Circulation, P. A. Fernandes, K. A. Lynch, M. Zettergren, D. L. Hampton, T. A. Bekkeng, Et Al.

Publications

We present an analysis of in situ measurements from the MICA (Magnetosphere-Ionosphere Coupling in the Alfvén Resonator) nightside auroral sounding rocket with comparisons to a multifluid ionospheric model. MICA made observations at altitudes below 325 km of the thermal ion kinetic particle distributions that are the origins of ion outflow. Late flight, in the vicinity of an auroral arc, we observe frictional processes controlling the ion temperature. Upflow of these cold ions is attributed to either the ambipolar field resulting from the heated electrons or possibly to ion-neutral collisions. We measure convection away from the arc (poleward) and downflows of ...


Evidence Of Dispersion And Refraction Of A Spectrally Broad Gravity Wave Packet In The Mesopause Region Observed By The Na Lidar And Mesospheric Temperature Mapper Above Logan, Utah, Tao Yuan, Christopher J. Heale, Jonathan B. Snively, Xuguang Cai, Pierre-Dominique Pautet, C. Fish, Yucheng Zhao, Michael J. Taylor, William R. Pendleton Jr., V. Wickwar, Nicholas John Mitchell Jan 2016

Evidence Of Dispersion And Refraction Of A Spectrally Broad Gravity Wave Packet In The Mesopause Region Observed By The Na Lidar And Mesospheric Temperature Mapper Above Logan, Utah, Tao Yuan, Christopher J. Heale, Jonathan B. Snively, Xuguang Cai, Pierre-Dominique Pautet, C. Fish, Yucheng Zhao, Michael J. Taylor, William R. Pendleton Jr., V. Wickwar, Nicholas John Mitchell

Publications

Gravity wave packets excited by a source of finite duration and size possess a broad frequency and wave number spectrum and thus span a range of temporal and spatial scales. Observing at a single location relatively close to the source, the wave components with higher frequency and larger vertical wavelength dominate at earlier times and at higher altitudes, while the lower frequency components, with shorter vertical wavelength, dominate during the latter part of the propagation. Utilizing observations from the Na lidar at Utah State University and the nearby Mesospheric Temperature Mapper at Bear Lake Observatory (41.9°N, 111.4 ...