Atmospheric Sciences Commons^™

Measurement And Modeling Of The Multiwavelength Optical Properties Of Uncoated Flame-Generated Soot, Sara D. Forestieri, Taylor M. Helgestad, Andrew T. Lambe, Lindsay Renbaum-Wolff, Paulo Massoli, Eben S. Cross, Claudio Mazzoleni, Et. Al.

Michigan Tech Publications, Part 1

Optical properties of flame-generated black carbon (BC) containing soot particles were quantified at multiple wavelengths for particles produced using two different flames: a methane diffusion flame and an ethylene premixed flame. Measurements were made for (i) nascent soot particles, (ii) thermally denuded nascent particles, and (iii) particles that were coated and then thermally denuded, leading to the collapse of the initially lacy, fractal-like morphology. The measured mass absorption coefficients (MACs) depended on soot maturity and generation but were similar between flames for similar conditions. For mature soot, here corresponding to particles with volume-equivalent diameters >∼160 nm, the MAC and absorption …

Biology Researcher Publishes Study On Saving Marine Organisms From Ocean Acidification, Noell Saunders

News Items

No abstract provided.

Observation Of A Link Between Energy Dissipation Rate And Oscillation Frequency Of The Large-Scale Circulation In Dry And Moist Rayleigh-Bénard Turbulence, Dennis Niedermeier, Kelken Chang, Will Cantrell, Kamal Kant Chandrakar, David Ciochetto, Raymond Shaw

Department of Physics Publications

In this study both the small- and large-scale flow properties of turbulent Rayleigh-Bénard convection are investigated. Experiments are carried out using the Π chamber (aspect ratio Γ=2) for Rayleigh number range Ra∼10⁸–10⁹ and Prandtl number Pr≈0.7. Furthermore, experiments are run for dry and wet conditions, i.e., top and bottom surfaces of the chamber are dry and wet, respectively. For wet conditions we further distinguish between conditions with and without the presence of sodium chloride aerosol particles which, if supersaturated conditions are achieved, lead to cloud droplet formation. We therefore refer to these conditions as moist and cloudy, …

Hampton Roads Housing Prices Drop 5 Percent Following A Severe Weather Event, Says University Research, Betsy Hnath

News Items

No abstract provided.

On The Short-Term Variability Of Turbulence And Temperature In The Winter Mesosphere, Gerald A. Lehmacher, Miguel F. Larsen, Richard L. Collins, Aroh Barjatya, Boris Strelnikov

Publications

Four mesosphere–lower thermosphere temperature and turbulence profiles were obtained in situ within ∼30 min and over an area of about 100 by 100 km during a sounding rocket experiment conducted on 26 January 2015 at Poker Flat Research Range in Alaska. In this paper we examine the spatial and temporal variability of mesospheric turbulence in relationship to the static stability of the background atmosphere. Using active payload attitude control, neutral density fluctuations, a tracer for turbulence, were observed with very little interference from the payload spin motion, and with high precision (%) at sub-meter resolution. The large-scale vertical temperature structure …

Activity Pattern Of School/University Tenants And Their Family Members In Metro Manila – Philippines, Simonas Kecorius, Everlyn Gale Tamayo, Maria Cecilia Galvez, Leizel Madueño, Grace Betito, Mylene Gonzaga-Cayetano, Edgar Vallar, Alfred Wiedensohler

Physics Faculty Publications

Existing studies that focus on personal exposure to or the deposition dose of particulate pollution in developing regions are limited. Hence, in this study, as a first step, we present results on how people spend their daily time in Metro Manila, Philippines. This information is critical to assessing personal exposure to and the deposition dose of particulate pollutants. We found that people spend less time at home on workdays than weekends (52% versus 70%), the fraction of time spent at work/school increases with age until retirement, adult males spend less time at home than females (18% versus 28%), and people …

Identification And Characterization Of An Anomaly In Two-Dimensional Video Disdrometer Data, Michael L. Larsen, Michael Schönhuber

Michigan Tech Publications, Part 1

The two-dimensional video distrometer (2DVD) is a well known ground based point-monitoring precipitation gauge, often used as a ground truth instrument to validate radar or satellite rainfall retrieval algorithms. This instrument records a number of variables for each detected hydrometeor, including the detected position within the sample area of the instrument. Careful analyses of real 2DVD data reveal an artifact—there are time periods where hydrometeor detections within parts of the sample area are artificially enhanced or diminished. Here, we (i) illustrate this anomaly with an exemplary 2DVD data set, (ii) describe the origin of this anomaly, (iii) develop and present …

Fourier Transform Spectroscopy Of The C³Δ-X³Δ Transition Of Tio In Support Of Exoplanet Spectroscopy, James N. Hodges, Peter Bernath

Chemistry & Biochemistry Faculty Publications

Recent limitations in the TiO line list used in cross-correlation detection schemes have made the detection and quantification of TiO in exoplanetary atmospheres challenging. The quality of the line list appears to degrade at wavelengths shorter than 630 nm. The C³Δ-X³Δ electronic transition has strong rovibronic bands near 500 nm. In an effort to improve the line list, a spectrum of TiO in a furnace at 1950 K is analyzed, and the assigned lines of the C³Δ-X³Δ transition are fit with the N² Hamiltonian in the molecular spectrum fitting software, _{PGOPHER …}

Enhanced Acidity Of Acetic And Pyruvic Acids On The Surface Of Water, Alexis J. Eugene, Elizabeth A. Pillar, Agustín J. Colussi, Marcelo I. Guzman

Chemistry Faculty Publications

Understanding the acid–base behavior of carboxylic acids on aqueous interfaces is a fundamental issue in nature. Surface processes involving carboxylic acids such as acetic and pyruvic acids play roles in (1) the transport of nutrients through cell membranes, (2) the cycling of metabolites relevant to the origin of life, and (3) the photooxidative processing of biogenic and anthropogenic emissions in aerosols and atmospheric waters. Here, we report that 50% of gaseous acetic acid and pyruvic acid molecules transfer a proton to the surface of water at pH 2.8 and 1.8 units lower than their respective acidity constants pK_{a …}

Assessment Of Indoor & Outdoor Black Carbon Emissions Rural Areas Of Indo-Gangetic Plain: Seasonal Characteristics, Source Apportionment And Radiative Forcing, Mohammad Arif, Rajesh Kumar, Ramesh Kumar, Eric Zusman, Ramesh Singh, Akhilesh Gupta

Mathematics, Physics, and Computer Science Faculty Articles and Research

Black Carbon (BC) has been widely recognized as the second largest source of territorial and global climate change as well as a threat to human health. There has been serious concern of BC emission and its impact in Indo-Gangetic Plains (IGP) due to the use of biomass and fossil fuels for cooking, transportation and industrial activities. An attempt has been made to study indoor (Liquefied Petroleum Gas- LPG & Traditional cookstoves users households) and outdoor concentrations; seasonal characteristics; radiative forcing and source of apportionment of BC in three districts (Sitapur, Patna and Murshidabad) of IGP during January to December 2016. …

Impacts Of Anisotropy, Wave Heating, And Neutral Winds On High-Latitude Ionospheric Dynamics, Meghan R. Burleigh

Doctoral Dissertations and Master's Theses

Significant amounts of ionospheric plasma can be transported to high altitudes (ion upflow) in response to a variety of plasma heating and uplifting processes such as DC electric fields and precipitation. Once ions have been lifted to high altitudes, transverse ion acceleration by broadband ELF waves can give the upflowing ions sufficient energy for the mirror force to propel these ions to escape into the magnetosphere (ion outflow). In order to accurately examine the connection between upflow and outflow processes, a new two dimensional, anisotropic fluid model is developed.

The new model, named GEMINI-TIA, is based on a Bi-Maxwellian distribution …

Nonlinear Acoustic Waves Generated By Surface Disturbances And Their Effect On Lower Thermospheric Composition, Benedict Piñeyro

Doctoral Dissertations and Master's Theses

Recent nonlinear atmospheric models have provided important insight into acoustic waves generated by seismic events, which may steepen into shocks or saw-tooth trains while also dissipating strongly in the thermosphere. Although they have yielded results that agree with observations of ionospheric perturbations, dynamical models for the diffusive and stratified lower thermosphere often use single gas approximations with height-dependent physical properties (e.g. mean molecular weight, specific heats) that do not vary with time (fixed composition). This approximation is simpler and less computationally expensive than a true multi-fluid model, yet captures the important physical transition between molecular and atomic gases in the …

Impact Of Data Selection On The Accuracy Of Atmospheric Refractivity Inversions Performed Over Marine Surfaces, Ian Joseph Matsko

Electronic Theses and Dissertations

Within the Earth’s atmosphere there is a planetary boundary layer that extends from the surface to roughly 1 km above the surface. Within this planetary boundary layer exists the marine atmospheric boundary layer, which is a complex turbulent surface layer that extends from the sea surface to roughly 100 m in altitude. The turbulent nature of this layer combined with the interactions across the air-sea interface cause ever changing environmental conditions within it, including atmospheric properties that affect the index of refraction, or atmospheric refractivity. Variations in atmospheric refractivity lead to many types of anomalous propagation phenomena of electromagnetic (EM) …

Mechanisms Of Abrupt Extreme Precipitation Change Over The Northeastern United States, Huanping Huang, Jonathan M. Winter, Erich C. Osterberg

Dartmouth Scholarship

In 1996, the northeastern United States experienced an abrupt increase in extreme precipitation, but the causal mechanisms driving this increase remain poorly understood. We find that 89% of the 1996–2016 increase relative to 1979–1995 is explained by only 273 unique extreme events affecting >5 stations and occurring in the months of February, March, June, July, September, and October. We use daily weather maps to classify the 273 extreme precipitation events by meteorological cause (tropical cyclones, fronts, and extratropical cyclones) and use reanalysis data to determine large‐scale changes in the atmosphere and ocean associated with increased extreme precipitation for each classification. …

Considerations For Atmospheric Measurements With Small Unmanned Aircraft Systems, Jamey D. Jacob, Phillip B. Chilson, Adam L. Houston, Suzanne Weaver Smith

Mechanical Engineering Faculty Publications

This paper discusses results of the CLOUD-MAP (Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics) project dedicated to developing, fielding, and evaluating integrated small unmanned aircraft systems (sUAS) for enhanced atmospheric physics measurements. The project team includes atmospheric scientists, meteorologists, engineers, computer scientists, geographers, and chemists necessary to evaluate the needs and develop the advanced sensing and imaging, robust autonomous navigation, enhanced data communication, and data management capabilities required to use sUAS in atmospheric physics. Annual integrated evaluation of the systems in coordinated field tests are being used to validate sensor performance while integrated into various sUAS platforms. …

The Interactive Stratospheric Aerosol Model Intercomparison Project (Isa-Mip): Motivation And Experimental Design, Claudio Timmreck, Graham W. Mann, Valentina Aquila, Rene Hommel, Lindsay A. Lee, Simon Carn, Et. Al.

Michigan Tech Publications, Part 1

The Stratospheric Sulfur and its Role in Climate (SSiRC) Interactive Stratospheric Aerosol Model Intercomparison Project (ISA-MIP) explores uncertainties in the processes that connect volcanic emission of sulfur gas species and the radiative forcing associated with the resulting enhancement of the stratospheric aerosol layer. The central aim of ISA-MIP is to constrain and improve interactive stratospheric aerosol models and reduce uncertainties in the stratospheric aerosol forcing by comparing results of standardized model experiments with a range of observations. In this paper we present four co-ordinated inter-model experiments designed to investigate key processes which influence the formation and temporal development of stratospheric …

Droughtscape, Summer 2018, National Drought Mitigation Center

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

Contents

From the director

Drought expands and intensifies

Dry down fuels fires

Tweeting #drought18

MOISST and NSMN

Caribbean planning progress

Drought observer network study

MENA teams report progress

NDMC global outreach

Climate hub workshop

On the horizon

Controls On Deuterium Excess Across Asia, John Bershaw

Geology Faculty Publications and Presentations

Deuterium excess (d-excess) is a second-order stable isotope parameter measured in meteoric water to understand both the source of precipitation and the evolution of moisture during transport. However, the interpretation of d-excess patterns in precipitation is often ambiguous, as changes in moisture source and processes during vapor transport both affect d-excess in non-unique ways. This is particularly true in Asia where continental moisture travels a long distance across diverse environments from unique moisture sources before falling as precipitation. Here, I analyzed published d-excess records from meteoric water throughout Asia to better characterize what influences d-excess values. I conclude that, (1) …

Development Of The Nebraska Department Of Transportation Winter Severity Index, Mark R. Anderson, Behzad Esmaeili, Curtis L. Walker, Dylan Steinkruger, Sogand Hasanzadeh, Pouya Gholizadeh, Bac Dao

Nebraska Department of Transportation: Research Reports

Adverse weather conditions are responsible for millions of vehicular crashes, thousands of vehicular deaths and billions of dollars in economic and congestion costs. Many transportation agencies utilize a performance or mobility metric to assess how well they are maintaining road access. This research focuses on the development of a winter severity index for the State of Nebraska (NEWINS). NEWINS is an event-driven index that was derived for the Nebraska Department of Transportation (NDOT) and its districts across the state. The NEWINS framework includes a categorical storm classification framework and climatological aspect to capture atmospheric conditions more accurately across the diverse …

Madden-Julian Oscillation Relationships With Cool Season Cyclogenesis, Daily Precipitation, And Cool Season Severe Weather Frequencies In The Gulf Of Mexico Region, Stephen Paul Caparotta

LSU Doctoral Dissertations

Tropical cyclone variability in the Gulf of Mexico (GoM) has been the focus of a considerable amount of research. Variability on both interannual scales, related to the El Niño-Southern Oscillation (ENSO), and on subseasonal scales, related to the Madden-Julian Oscillation (MJO), is well documented. By contrast, very little research exists on the relationships between the MJO and cool season, non-tropical cyclones in the GoM.

The MJO influence on cool season (October-March) cyclogenesis in the GoM variability is explored here. Additionally, daily precipitation variability and cool season severe weather variability is examined for areas near and just inland of the GoM. …

Crop Residue Burning In Northern India: Increasing Threat To Greater India, S. Sarkar, Ramesh P. Singh, A. Chauhan

Mathematics, Physics, and Computer Science Faculty Articles and Research

Crop residue burning (CRB) is a recurring problem, during October–November, in the northwestern regions (Punjab, Haryana, and western Uttar Pradesh) of India. The emissions from the CRB source regions spread in all directions through long-range transport mechanisms, depending upon the meteorological conditions. In recent years, numerous studies have been carried out dealing with the impact of CRB on the air quality of Delhi and surrounding areas, especially in the Indo-Gangetic Basin (also referred to as Indo-Gangetic Plain). In this paper, we present detailed analysis using both satellite- and ground-based sources, which show an increasing impact of CRB over the eastern …

Book Review: Fundamentals Of International Aviation, Alan Bender

International Journal of Aviation, Aeronautics, and Aerospace

Not applicable.

Aerosol And Meteorological Parameters Associated With The Intense Dust Event Of 15 April 2015 Over Beijing, China, Sheng Zheng, Ramesh P. Singh

Mathematics, Physics, and Computer Science Faculty Articles and Research

The northeastern parts of China, including Beijing city, the capital of China, were hit by an intense dust storm on 15 April 2015. The present paper discusses aerosol and meteorological parameters associated with this dust storm event. The back trajectory clearly shows that the dust originated from Inner Mongolia, the border of China, and Mongolia regions. Pronounced changes in aerosol and meteorological parameters along the dust track were observed. High aerosol optical depth (AOD) with low Ångström exponent (AE) are characteristics of coarse-mode dominated dust particles in the wavelength range 440–870 nm during the dusty day. During dust storm, dominance …

Odu, City Of Norfolk To Host Neighbors Building Neighborhoods Conference June 23, Noell Saunders

News Items

No abstract provided.

Assessment Of Observational Uncertainty In Extreme Precipitation Over The Continental United States, Emily Anne Slinskey

Dissertations and Theses

An extreme precipitation categorization scheme, developed to temporally and spatially visualize and track the multi-scale variability of extreme precipitation climatology, is introduced over the continental United States and used as the basis for an observational dataset intercomparison. The categorization scheme groups three-day precipitation totals exceeding 100 mm into five precipitation categories, or "P-Cats". To assess observational uncertainty across a range of precipitation measurement approaches, we compare in situ station data from the Global Historical Climatology Network-Daily (GHCN-D), satellite derived data from the Tropical Rainfall Measuring Mission (TRMM), gridded station data from the Parameter-elevation Regression on Independent Slopes Model (PRISM), global …

Umphlett Qci June 2018, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature Anomalies

Precipitation Anomalies

Water Resources

Agriculture

Temperature

Precipitation

Odu, Mit Solve And Rise Co-Host Workshop For Local Entrepreneurs Focused On Coastal Resilience Solutions, Betsy Hnath

News Items

No abstract provided.

Description And Mechanisms Of The Mid-Year Upwelling In The Southern Caribbean Sea From Remote Sensing And Local Data, Digna T. Rueda-Roa, Tal Ezer, Frank E. Muller-Karger

CCPO Publications

The southern Caribbean Sea experiences strong coastal upwelling between December and April due to the seasonal strengthening of the trade winds. A second upwelling was recently detected in the southeastern Caribbean during June-August, when local coastal wind intensities weaken. Using synoptic satellite measurements and in situ data, this mid-year upwelling was characterized in terms of surface and subsurface temperature structures, and its mechanisms were explored. The mid-year upwelling lasts 6-9 weeks with satellite sea surface temperature (SST) ~1-2°C warmer than the primary upwelling. Three possible upwelling mechanisms were analyzed: cross-shore Ekman transport (csET) due to alongshore winds, wind curl (Ekman …

Formation Of Evolved Rocks At Gale Crater By Crystal Fractionation And Implications For Mars Crustal Composition, Arya Udry, Esteban Gazel, Harry Y. Mcsween Jr.

Geoscience Faculty Research

The recent discovery of some ancient evolved rocks in Gale crater by the Curiosity rover has prompted the hypothesis that continental crust formed in early Martian history. Here we present petrological modeling that attempts to explain this lithological diversity by magma fractionation. Using the thermodynamical software MELTS, we model fractional crystallization of different Martian starting compositions that might generate felsic igneous compositions like those analyzed at Gale crater using different variables, such as pressure, oxygen fugacities, and water content. We show that similar chemical and mineralogical compositions observed in Gale crater felsic rocks can readily be obtained through different degrees …

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 gap in existing MSTID measurements revealing predominantly eastward wave propagation during …