Upgraded Alo Rayleigh Lidar System And Its Improved Gravity Wave Measurements,
2012
Utah State University
Upgraded Alo Rayleigh Lidar System And Its Improved Gravity Wave Measurements, Leda Sox, Vincent B. Wickwar, Joshua P. Herron, Marcus J. Bingham
Graduate Student Posters
The Rayleigh-Scatter lidar system at the Atmospheric Lidar Observatory (ALO) on the Utah State campus is currently going through a series of upgrades to significantly improve its observational abilities. A specific objective of these upgrades is to expand the altitude range over which backscattered photons can be collected. A second objective is to increase the sensitivity of the instrument to be able to analyze the raw data at finer temporal and/or spatial resolutions. By measuring relative densities, the system will be able to produce absolute temperatures and relative density perturbations, which illustrate gravity wave structures. Gravity wave studies will significantly …
Estimating Annual Precipitation For The Colorado River Basin Using Oceanic-Atmospheric Oscillations,
2012
University of Nevada, Las Vegas
Estimating Annual Precipitation For The Colorado River Basin Using Oceanic-Atmospheric Oscillations, Ajay Kalra, Sajjad Ahmad
Civil and Environmental Engineering and Construction Faculty Research
Estimating long-lead time precipitation under the stress of increased climatic variability is a challenging task in the field of hydrology. A modified Support Vector Machine (SVM) based framework is proposed to estimate annual precipitation using oceanic-atmospheric oscillations. Oceanic-atmospheric oscillations, consisting of Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation (AMO), and El Niño–Southern Oscillation (ENSO) for a period of 1900–2008, are used to generate annual precipitation estimates with a 1 year lead time. The SVM model is applied to 17 climate divisions encompassing the Colorado River Basin in the western United States. The overall results revealed that …
Implementation Of Branch-Point-Tolerant Wavefront Reconstructor For Strong Turbulence Compensation,
2012
Air Force Institute of Technology
Implementation Of Branch-Point-Tolerant Wavefront Reconstructor For Strong Turbulence Compensation, Michael J. Steinbock
Theses and Dissertations
Branch points arise in optical transmissions due to strong atmospheric turbulence, long propagation paths, or a combination of both. Unfortunately, these conditions are very often present in desired operational scenarios for laser weapon systems, optical communication, and covert imaging, which suffer greatly when traditional adaptive optics systems either cannot sense branch points or implement non-optimal methods for sensing and correcting branch points. Previous research by Pellizzari presented a thorough analysis of various novel branch point tolerant reconstructors in the absence of noise. In this research a realistic model of the Air Force Institute of Technology's adaptive optics system is developed …
Ionospheric Plasma Transport And Loss In Auroral Downward Current Regions,
2012
Embry-Riddle Aeronautical University
Ionospheric Plasma Transport And Loss In Auroral Downward Current Regions, M. Zettergren, J. L. Semeter
Publications
A detailed study of the effects of auroral current systems on thermal ionospheric plasma transport and loss is conducted using a new ionospheric model. The mathematical formulation of the model is a variation on the 5‐moment approximation which describes the temporal evolution of density, drift, and temperature for five different ion species in two spatial dimensions. The fluid system is closed through a 2‐D electrostatic treatment of the auroral currents. This model is used to examine the interplay between ion heating, perpendicular transport, molecular ion generation, and type‐1 ion upflows in a self‐consistent way for the first time. Simulations confirm …
Century-Scale Responses Of Ecosystem Carbon Storage And Flux To Multiple Environmental Changes In The Southern United States,
2012
Auburn University Main Campus
Century-Scale Responses Of Ecosystem Carbon Storage And Flux To Multiple Environmental Changes In The Southern United States, Hanqin Tian, Guangsheng Chen, Chi Zang, Mingliang Liu, Ge Sun, Arthur Chappelka, Wei Ren, Xiaofeng Xu, Chaoqun Lu, Shufen Pan, Hua Chen, Dafeng Hui, Steven Mcnulty, Graeme Lockaby, Eric Vance
Chaoqun (Crystal) Lu
Terrestrial ecosystems in the southern United States (SUS) have experienced a complex set of changes in climate, atmospheric CO2 concentration, tropospheric ozone (O3), nitrogen (N) deposition, and land-use and land-cover change (LULCC) during the past century. Although each of these factors has received attention for its alterations on ecosystem carbon (C) dynamics, their combined effects and relative contributions are still not well understood. By using the Dynamic Land Ecosystem Model (DLEM) in combination with spatially explicit, long-term historical data series on multiple environmental factors, we examined the century-scale responses of ecosystem C storage and flux to multiple environmental changes in …
Reproduction Of Twentieth Century Intradecadal To Multidecadal Surface Temperature Variability In Radiatively Forced Coupled Climate Models,
2012
San Jose State University
Reproduction Of Twentieth Century Intradecadal To Multidecadal Surface Temperature Variability In Radiatively Forced Coupled Climate Models, Patrick T. Brown, Eugene C. Cordero, Steven A. Mauget
Faculty Publications, Meteorology and Climate Science
[1] Coupled Model Intercomparison Project 3 simulations that included time-varying radiative forcings were ranked according to their ability to consistently reproduce twentieth century intradecadal to multidecadal (IMD) surface temperature variability at the 5° by 5° spatial scale. IMD variability was identified using the running Mann-Whitney Z method. Model rankings were given context by comparing the IMD variability in preindustrial control runs to observations and by contrasting the IMD variability among the ensemble members within each model. These experiments confirmed that the inclusion of time-varying external forcings brought simulations into closer agreement with observations. Additionally, they illustrated that the magnitude of …
Reproduction Of Twentieth Century Intradecadal To Multidecadal Surface Temperature Variability In Radiatively Forced Coupled Climate Models,
2012
San Jose State University
Reproduction Of Twentieth Century Intradecadal To Multidecadal Surface Temperature Variability In Radiatively Forced Coupled Climate Models, Patrick T. Brown, Eugene C. Cordero, Steven A. Mauget
Eugene C. Cordero
[1] Coupled Model Intercomparison Project 3 simulations that included time-varying radiative forcings were ranked according to their ability to consistently reproduce twentieth century intradecadal to multidecadal (IMD) surface temperature variability at the 5° by 5° spatial scale. IMD variability was identified using the running Mann-Whitney Z method. Model rankings were given context by comparing the IMD variability in preindustrial control runs to observations and by contrasting the IMD variability among the ensemble members within each model. These experiments confirmed that the inclusion of time-varying external forcings brought simulations into closer agreement with observations. Additionally, they illustrated that the magnitude of …
Assessment Of Gravity Wave Momentum Flux Measurement Capabilities By Meteor Radars Having Different Transmitter Power And Antenna Configurations,
2012
Colorado Research Associates Division, Northwest Research Associates
Assessment Of Gravity Wave Momentum Flux Measurement Capabilities By Meteor Radars Having Different Transmitter Power And Antenna Configurations, D. C. Fritts, D. Janches, W. K. Hocking, Michael J. Taylor
All Physics Faculty Publications
Measurement capabilities of five meteor radars are assessed and compared to determine how well radars having different transmitted power and antenna configurations perform in defining mean winds, tidal amplitudes, and gravity wave (GW) momentum fluxes. The five radars include two new-generation meteor radars on Tierra del Fuego, Argentina (53.8°S) and on King George Island in the Antarctic (62.1°S) and conventional meteor radars at Socorro, New Mexico (34.1°N, 106.9°W), Bear Lake Observatory, Utah (∼41.9°N, 111.4°W), and Yellowknife, Canada (62.5°N, 114.3°W). Our assessment employs observed meteor distributions for June of 2009, 2010, or 2011 for each radar and a set of seven …
Results From An Extremely Sensitive Rayleigh-Scatter Lidar,
2012
Utah State University
Results From An Extremely Sensitive Rayleigh-Scatter Lidar, Leda Sox, Vincent B. Wickwar
Leda Sox
Rayleigh-Scatter lidar systems effectively use remote sensing techniques to continuously measure atmospheric regions, such as the mesosphere (45-100km) where in situ measurements are rarely possible. The Rayleigh lidar located at the Atmospheric Lidar Observatory (ALO) on the Utah State campus is currently undergoing upgrades to make it the most sensitive of its kind. Here, the important components of these upgrades and how they will effect the study of a particular atmospheric phenomena, atmospheric gravity waves, will be discussed. We will also summarize what has been done to the system during this year to bring us to the threshold of initial …
Comparison Of Saber Oh Measurements To Rocket Photometry Data,
2012
Utah State University
Comparison Of Saber Oh Measurements To Rocket Photometry Data, Jordan Rozum, Gene A. Ware, Doran J. Baker
Browse All Undergraduate research
In 2002, the Sounding of the Atmosphere us- ing Broadband Emission Radiometry (SABER) instru- ment aboard the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite went online and has since been providing radiometric data concern- ing the mesosphere and lower thermosphere/ionosphere (MLTI) region of the atmosphere. Researchers at the Utah State University NASA Space Grant Consortium have been tasked with validating measurements of the hydroxyl airglow volume emission rates (VER) taken by SABER. To this end, we compare SABER measurements of the altitude distribution of hydroxyl airglow to mea- surements taken by photometers aboard rockets launched between 1961 and 1986 …
Atmospheric Circulation Change In The Central Himalayas Indicated By A High-Resolution Ice Core Deuterium Excess Record,
2012
Nanjing University
Atmospheric Circulation Change In The Central Himalayas Indicated By A High-Resolution Ice Core Deuterium Excess Record, Hongxi Pang, Shugui Hou, Susan Kaspari, Paul Mayewski, Douglas Introne, Valérie Masson-Delmotte, Jean Jouzel, Zhenchao Li, Yuanqing He, Sungmin Hong, Dahe Qin
All Faculty Scholarship for the College of the Sciences
Continuous measurements of both δD and δ18O were performed along a 108.8 m ice core recovered from the East Rongbuk Glacier on the northeast saddle of Mt. Qomolangma (Everest) (28.03° N, 86.96° E, 6518 m above sea level) in September 2002. They provide the first high-resolution historical record of deuterium excess (d) in the central Himalayas. In this paper, we focus on d variability from 1951 to 2001 and its relationship with large scale atmospheric circulation. The d record exhibits significant seasonal variations, with low values in summer and high values in winter, reflecting the atmospheric circulation shift between winter …
Gravity Wave Propagation In A Diffusively Separated Gas: Effects On The Total Gas,
2012
Embry-Riddle Aeronautical University
Gravity Wave Propagation In A Diffusively Separated Gas: Effects On The Total Gas, Michael P. Hickey Ph.D., R. L. Walterscheid
Publications
We present a full-wave model that simulates acoustic-gravity wave propagation in a binary-gas mixture of atomic oxygen and molecular nitrogen, including molecular viscosity and thermal conductivity appropriately partitioned between the two gases. Compositional effects include the collisional transfer of heat and momentum by mutual diffusion between the two gases. An important result of compositional effects is that the velocity and temperature summed over species can be significantly different from the results of one-gas models with the same height dependent mean molecular weight (M(z)). We compare the results of our binary-gas model to two one-gas full-wave models: one where M is …
A Study On The Turbulent Characteristics Within The Hurricane Boundary Layer,
2012
The University of Western Ontario
A Study On The Turbulent Characteristics Within The Hurricane Boundary Layer, Sunwei Li
Electronic Thesis and Dissertation Repository
As the medium between the sea surface and the upper atmosphere in a hurricane, the Hurricane Boundary Layer (HBL) plays a key role in the overall dynamics of a tropical cyclone, and therefore turbulence exchanges within the HBL deserve a thorough investi- gation. However, since it is dangerous and difficult to take direct measurements within the HBL, studies of the HBL turbulence processes based on direct observations are rare. Thanks to the newly developed dropwindsonde equipped with a Global Position System (GPS) receiver, it is now possible to measure wind velocities and other meteorological variables with an unprecedented accuracy and …
The Rapid Intensification Of Hurricane Gustav (2008),
2012
University at Albany, State University of New York
The Rapid Intensification Of Hurricane Gustav (2008), Jason H. Keefer
Atmospheric & Environmental Sciences
Hurricane Gustav was one of two major hurricanes that occurred in the Atlantic basin during the 2008 hurricane season. The storm caused more than $6 billion U. S. dollars of damage in Haiti, Jamaica, Cuba, and along the coast of the Gulf of Mexico from 25 August 2008 to 5 September 2008. The greatest amount of damage and highest number of casualties produced by the storm can be attributed to the rapid intensification of the hurricane. Rapid intensification (RI) of a tropical cyclone is defined as an increase in maximum sustained winds by 15.4 m s⁻¹ (30 kts) in a …
An Evaluation Of Cape Tendency In Tornado Outbreaks,
2012
University at Albany, State University of New York
An Evaluation Of Cape Tendency In Tornado Outbreaks, Timothy W. Humphrey, Lance F. Bosart
Atmospheric & Environmental Sciences
Previous studies (e.g., Rasmussen, 2003; Thompson et al., 2003) have examined the impact that instability has on the occurrence of tornadic supercells. However, few studies (e.g., Calas et al., 2000) have examined the impact that the rate of destabilization has on the development of severe convection. Utilizing a CAPE tendency equation derived by Emanuel (1994), this study examines the impact of the rate of atmospheric destabilization on the severity of convection. Comparing six hour analyses of CAPE tendency with observed tornado tracks from the 4-6 May 2007, 5-6 February 2008, and 17 June 2010 tornado outbreaks reveals a potential correlation …
Largescale Precursors To Major Lake Effect Snowstorms Lee Of Lake Erie,
2012
University at Albany, State University of New York
Largescale Precursors To Major Lake Effect Snowstorms Lee Of Lake Erie, Hannah E. Attard, Ross A. Lazear
Atmospheric & Environmental Sciences
Lake‐effect snowstorms are primarily a mesoscale feature; however, major lakeeffect snowstorms are linked closely to their synoptic environment. Thus, a lakeeffect system which lasts for more than 24 h cannot only be explained by the boundary layer; it is also associated with the upper tropospheric flow. This research will address whether major lake‐effect snow events off of Lake Erie can also be associated with large‐scale planetary features several days prior to event onset. The goal is to aid in the forecast process by increasing the accuracy and leadtime of lake‐effect snow forecasts. This study includes 31 cases recorded from the …
Large, Long-Lived Convective Systems Over Subtropical South America And Their Relationships With Atmospheric Teleconnections,
2012
Western Kentucky University
Large, Long-Lived Convective Systems Over Subtropical South America And Their Relationships With Atmospheric Teleconnections, Kyle Mattingly
Mahurin Honors College Capstone Experience/Thesis Projects
This study provides a climatological assessment of persistent elongated convective systems (PECS) over subtropical South America during the austral warm seasons of 1998-2007 and a comparison of PECS frequency and physical characteristics to mesoscale convective complexes (MCCs) in the region. Relationships between the Antarctic Oscillation (AAO) and El Niño – Southern Oscillation (ENSO) teleconnections and large, long-lived convective systems (LLCSs) are explored. An average of 143 PECS and 37 MCCs occurred per warm season. PECS lasted longer on average than MCCs (17 hrs. vs. 14 hrs.) and reached a greater average maximum cloud-shield extent than MCCs (297,300 km2 vs. 256,500 …
Variability Of Black Carbon Deposition To The East Antarctic Plateau, 1800-2000 Ad,
2012
Desert Research Institute
Variability Of Black Carbon Deposition To The East Antarctic Plateau, 1800-2000 Ad, M. M. Bisiaux, R. Edwards, J. R. Mcconnell, M. R. Albert
Dartmouth Scholarship
Refractory black carbon aerosols (rBC) from biomass burning and fossil fuel combustion are deposited to the Antarctic ice sheet and preserve a history of emissions and long-range transport from low- and mid-latitudes. Antarctic ice core rBC records may thus provide information with respect to past combustion aerosol emissions and atmospheric circulation. Here, we present six East Antarctic ice core records of rBC concentrations and fluxes covering the last two centuries with approximately annual resolution (cal. yr. 1800 to 2000). The ice cores were drilled in disparate regions of the high East Antarctic ice sheet, at different elevations and net snow …
An Assessment Of The Relationship Between Air Mass Frequency And Extreme Drought In The Midwest United States,
2012
SUNY College at Oneonta
An Assessment Of The Relationship Between Air Mass Frequency And Extreme Drought In The Midwest United States, Curtis Walker, Erin Potter, Nicholas Esposito, Melissa Godek
The Compass: Earth Science Journal of Sigma Gamma Epsilon
The Midwest of the United States is a region extensively utilized for agriculture and livestock production despite great susceptibility to widespread and persistent drought. While the location and duration of droughts are related to dynamic meteorological factors, pinpointing when and where a drought will commence, how long it will persist, and when the drought will end, remains a challenge. This investigation examines significant Midwest drought events from a synoptic meteorological perspective through an assessment of air mass frequency over the past decade. A synoptic approach is useful since air masses characteristically describe multiple weather and climate parameters at the same …
Observations With The Most Sensitive Rayleigh-Scatter Lidar,
2012
Utah State University
Observations With The Most Sensitive Rayleigh-Scatter Lidar, Leda Sox, Vincent B. Wickwar, Joshua P. Herron, Marcus J. Bingham
Leda Sox
The mesosphere is the most unexplored region of the atmosphere. Its altitude range of 50-85 km lies in between the reaches of data collecting instruments like weather balloons and satellites. For this reason, remote sensing systems, such as lidar, which are able to employ ground-based instruments to make extensive measurements in this difficult to detect region. The Rayleigh-scatter lidar at USU is currently being redeveloped to be the most powerful and sensitive of its kind. This type of lidar exploits light and particle interactions, like those that account for the blue color of the sky, to make relative density and …
