Atmospheric Sciences Commons^™

Ultralow Frequency Electrodynamics Of Magnetosphere-Ionosphere Interactions Near The Plasmapause During Substorms, Anatoly V. Streltsov, Evgeny V. Mishin

Publications

Ultra low frequency (ULF) electromagnetic waves have been regularly observed by the CRRES, Cluster, and Van Allen Probes satellites near the plasmapause during substorms. Frequently, the small-scale waves are detected together with a large-scale quasi-stationary electric field collocating with mesoscale plasma flows penetrating into the plasmasphere. These observations suggest that the plasmapause plays an important role in the conversion of the kinetic energy of energetic particles moving toward the Earth from the reconnection site in the magnetotail into a large-scale electric field. The field penetrates along the magnetic field into the ionosphere and generates small-scale, shear Alfvén waves and field-aligned …

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

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.

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

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, …

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 …

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

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

Michigan Tech Publications

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 …}

Developing A Probabilistic Heavy-Rainfall Guidance Forecast Model For Great Lakes Cities, Cory Kevin Rothstein

Theses and Dissertations

A method for predicting the probability of exceeding specific warm-season (April-October) 0-24 hour precipitation thresholds is developed based upon daily maximums of meteorological parameters. North American Regional Reanalysis and Daily Unified Precipitation data from 2002-2017 were used to gather meteorological data for the Milwaukee and Chicago County Warning Areas. Individual artificial neural networks and multiple logistic regressions were conducted for daily rainfall thresholds above 0.5'', 1'', 1.5'' and 2'' to determine the probability of threshold exceedances for each County Warning Area. The most important parameters were 1000-500 hPa specific humidity, vertical velocities at various levels, high cloud cover, precipitable water …

An Investigation Of The Conditional Practical Predictability Of The 31 May 2013 Heavy-Rain-Producing Mesoscale Convective System, Aidan Kuroski

Theses and Dissertations

On 31 May 2013, strong thunderstorms initiated in west-central Oklahoma with one of the storms eventually creating a very strong tornado near El Reno, OK. The storms then grew upscale into a quasi-stationary mesoscale convective system that produced prolonged heavy rainfall that led to severe flooding across parts of Oklahoma, including the Oklahoma City metropolitan area. A 50-member ensemble of short range (0-24 h) forecasts was conducting using a set of initial conditions generated via cycled data assimilation to quantify event predictability and identify forecast sensitivities, primarily with CI and initial upscale growth. Both a composite and ensemble sensitivity analysis …

Using Advanced Post-Processing Methods With The Hrrr-Tle To Improve The Prediction Of Cold Season Precipitation Type, Timothy Thielke

Theses and Dissertations

In this study we explore advanced statistical methods with the operational High-Resolution Rapid Refresh Model (HRRR) Time-Lagged Ensemble (TLE) to improve the prediction of cold season precipitation type. TLEs are a computationally efficient method to provide a slightly improved probabilistic forecast as the differences between model runs are an approximation of initial condition uncertainty. We apply evolutionary programming, weight-decay bias correction, and Bayesian Model Combination with fifteen HRRR forecast variables that potentially relate to precipitation type for station locations in the contiguous United States that are along and to the east of 100 W longitude to obtain probabilistic precipitation type …

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. …

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) …

Effect Of Aerosol Distributions On Precipitation Patterns Needed For A Rapid Ice Age, Steven M. Gollmer

Proceedings of the International Conference on Creationism

Introduced in the Genesis Flood by Whitcomb and Morris (1961) and fleshed out by Oard (1979) a model for an ice age in the wake of the Genesis flood was used to explain the evidence of glaciation in Canada and the United States without resorting to eons of time. It was proposed that this rapid ice age was the consequence of post flood warm oceans, barren land and volcanic aerosols. The impact of warm oceans was simulated by Vardiman (1998) and Gollmer (2013) using climate models. Although warm oceans increase precipitation in the Arctic, global surface temperatures become unbearably hot …

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

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- 2018 Summer, National Drought Mitigation Center

Droughtscape, Quarterly Newsletter of NDMC, 2007-

Contents

From the director.......................... 2

Drought expands and intensifies ............ 3

Dry down fuels fires ..................... 5

Tweeting #drought18.................... 7

MOISST and NSMN..................... 8

Caribbean planning progress .............. 9

Drought observer network study........... 10

MENA teams report progress ............. 12

NDMC global outreach............... 13

Climate hub workshop................ 15

On the horizon ........................... 16