Atmospheric Sciences Commons^™

River Discharge As Affected By Precipitation, Temperature And Soil Characteristics, Susan Kotikot, Kelly Hodgskins

Research Horizons Day Posters

No abstract provided.

Comparing The Model-Simulated Global Warming Signal To Observations Using Empirical Estimates Of Unforced Noise, Patrick T. Brown, Wenhong Li, Eugene C. Cordero, Steven A. Mauget

Faculty Publications, Meteorology and Climate Science

The comparison of observed global mean surface air temperature (GMT) change to the mean change simulated by climate models has received much public and scientific attention. For a given global warming signal produced by a climate model ensemble, there exists an envelope of GMT values representing the range of possible unforced states of the climate system (the Envelope of Unforced Noise; EUN). Typically, the EUN is derived from climate models themselves, but climate models might not accurately simulate the correct characteristics of unforced GMT variability. Here, we simulate a new, empirical, EUN that is based on instrumental and reconstructed surface …

Laboratory Studies On The Production Of Alpha-Pinene-Derived Organic Nitrates And Their Atmospheric Fate, Joel David Rindelaub

Open Access Dissertations

Currently, the formation yields of organic nitrates from the oxidation of biogenic volatile organic compounds, such as α-pinene, is highly uncertain, negatively impacting our knowledge on tropospheric ozone production and the fate of atmospheric NO_x. To lower this uncertainty, we quantified the organic nitrate yield from the OH radical oxidation of α-pinene under high NO_x conditions. The α-pinene- derived nitrates created in chamber experiments readily partitioned to the aerosol phase and underwent particle phase hydrolysis, indicating that these processes are likely a sink for atmospheric NO_x. The hydrolysis of organic nitrates was found to be …

Drougthscape, Spring 2015, Kelly Smith

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

Contents

Director’s column.

South Plains ranch workshops 3

First quarter drought summary

First quarter impacts summary

Gary’s favorite pond, D1-4

NDMC’s Haigh leads U2U pubs

SW Montana watersheds convene

Wind River monitors drought

Morocco’s new drought index

Northeast Brazil drought monitoring

EU’s drought initiative

U.S. Drought Monitor Forum

How Colorado tourism coped in 2012

Impact Of Biogenic Volatile Organic Compounds On Peroxyacetyl Nitrate Production In The Southeast United States, Christopher John Groff

Open Access Theses

Our atmosphere is arguably the fundamental entity that has made life on Earth possible. Knowledge of the delicate nature of our atmosphere continues to spread as "green" initiatives promote awareness of human influence on the environment. However, many climate scientists fear that unless immediate mitigation occurs, the reversal of human impact on our planet will be impossible, leading to unknown consequence. Perturbations to natural processes are likely to cause drastic change to the planet as we know it and ultimately result in significant health issues. It is important to push the boundaries of our understanding of atmospheric processes with intent …

Studies Of The Interaction Of Biogenic Volatile Organic Compounds And Nox In Forest Environments, Kevin M. Mcavey

Open Access Dissertations

Ozone is a pollutant that causes crop damage, adverse health effects, and is a contributor to global climate change. Ozone concentrations are predicted to rise over the next half-century along with global temperature. Ozone production is controlled by the chemistry between biogenic volatile organic compounds and NO_x (NO + NO₂), and therefore, a greater understanding of NO_x + BVOC chemistry along with their sources and sinks is needed. One large uncertainty in understanding NO_x + BVOC chemistry is the production of organic nitrates (RONO₂), which act as a radical termination step in the …

Spectroscopic Characterization And Photochemistry Of Nitrogen-Containing Molecules Relevant To Titan's Atmosphere, Deepali N. Mehta-Hurt

Open Access Dissertations

Titan's atmospheric chemistry has been the source of intrigue since the planetary body's discovery. Though there is a growing understanding of the atmospheric chemistry of small molecules on Titan, much less is known about larger molecule formation, and particularly about nitrile chemistry. This dissertation characterizes nitrile/isonitrile intermediates that are postulated to be important in Titan's atmosphere, adding to the necessary foundation for understanding Titan's atmospheric chemistry. The vibronic spectroscopy of para-diisocyanobenzene (pDIB, C≡N-Ph-N≡C) has been characterized as a first step towards photochemical studies that can test the transformation of the isonitrile group to other nitrogen-based functionalities.p …

Comparing Different Methods For Estimating Total Open Heliospheric Magnetic Flux, Samantha J. Wallace

Doctoral Dissertations and Master's Theses

There are extended periods over the solar cycle where significant discrepancies occur between the observed open magnetic flux (i.e., those based on spacecraft observations) and that determined from coronal models. One explanation for the source of these discrepancies is the magnetic fields in CMEs, which have yet to magnetically disconnect from the Sun. These “closed” flux sources can be included in open flux estimates, because open and closed magnetic field lines are not easily distinguished in spacecraft data. Another possibility is that a portion of the open flux measured by in situ spacecraft originates from the time-dependent evolution of solar …

Utilizing Four Dimensional Lightning And Dual-Polarization Radar To Develop Lightning Initiation Forecast Guidance, Andrew J. Travis

Theses and Dissertations

Lightning initiation is a major forecast challenge faced by Air Force's 45th Weather Squadron (45 WS), which provides weather support to Cape Canaveral Air Force Station and Kennedy Space Center (KSC). Prior studies by Thurmond (2014) and Woodard (2011) have shown that dual-polarization (DP) radar can be used to identify the presence of hydrometeors indicative of cloud charging, leading to improved lightning initiation forecasts. The 45 WS currently employs empirical lightning initiation forecast rules which state that in-cloud lightning is likely when radar reflectivity meets or exceeds 37.0 dBZ above the -10°C height. This study examined 249 convective cells from …

A Study Of Thunderstorm Microphysical Properties And Lightning Flash Counts Associated With Terrestrial Gamma-Ray Flashes, D. E. Barnes, M. E. Splitt, J. R. Dwyer, S. Lazarus, D. M. Smith, H. K. Rassoul

Aerospace, Physics, and Space Science Faculty Publications

The terrestrial gamma ray flash (TGF) is an emission of highly energetic radiation produced by or at least in close association with lightning. Previous investigations attempted to isolate the production mechanisms and production altitude(s) of TGFs as well as macrophysical characteristics, while thunderstorm microphysical characteristics were largely ignored. This investigation into thunderstorms and their hydrometeor and flash characteristics utilize temporal and spatial coincident satellite passes between the Reuven Ramaty High Energy Solar Spectroscopic Imager and the Tropical Rainfall Measuring Mission to determine the bulk (or footprint) microphysical properties of two types of study events, the thunderstorm complexes which are associated …

Umphlett Qci March 2015, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Mountain Snowpack

Agriculture

Recreation and Tourism

Forestry

Drought Impacts Continue

3-Month Precipitation and Temperature Outlooks

U.S. Seasonal Drought Outlook

Comparison Between Observed And Model-Simulated Atmospheric Circulationpatterns Associated With Extreme Temperature Days Over North Americausing Cmip5 Historical Simulations, Paul C. Loikith, Anthony J. Broccoli

Geography Faculty Publications and Presentations

Circulation patterns associated with extreme temperature days over North America, as simulated by a suite of climate models, are compared with those obtained from observations. The authors analyze 17 coupled atmosphere–ocean general circulation models contributing to the fifth phase of the Coupled Model Intercomparison Project. Circulation patterns are defined as composites of anomalies in sea level pressure and 500-hPa geopotential height concurrent with days in the tails of temperature distribution. Several metrics used to systematically describe circulation patterns associated with extreme temperature days are applied to both the observed and model-simulated data. Additionally, self-organizing maps are employed as a means …

Efficient General Computational Method For Estimation Of Standard Atmosphere Parameters, Nihad E. Daidzic Ph.D., Sc.D.

International Journal of Aviation, Aeronautics, and Aerospace

Knowledge of standard air temperature, pressure, density, speed of sound, and viscosity as a function of altitude is essential information in aircraft design, performance testing, pressure altimeter calibration, and several other aeronautical engineering and aviation science applications. A new efficient computational method for rapid calculations of standard atmospheric parameters up to 86 orthometric km is presented. Additionally, mass and weight of each standard atmospheric layer were calculated using a numerical integration method. The sum of all fractional masses and weights represents the total mass and weight of Earth’s atmosphere. The results obtained here agree well with measurements and models of …

Comparing Flow-Through And Static Ice Cave Models For Shoshone Ice Cave, Kaj E. Williams, Christopher Mckay

International Journal of Speleology

In this paper we suggest a new ice cave type: the “flow-through” ice cave. In a flow-through ice cave external winds blow into the cave and wet cave walls chill the incoming air to the wet-bulb temperature, thereby achieving extra cooling of the cave air. We have investigated an ice cave in Idaho, located in a lava tube that is reported to have airflow through porous wet end-walls and could therefore be a flow-through cave. We have instrumented the site and collected data for one year. In order to determine the actual ice cave type present at Shoshone, we have …

Recent Progress In Mesospheric Gravity Wave Studies Using Nigthglow Imaging System, Michael J. Taylor, William R. Pendleton Jr., Pierre-Dominique Pautet, Yucheng Zhao, Chris Olsen, Hema Karnam Surendra Babu, Amauri F. Medeiros, Hisao Takahashi

Publications

A variety of optical remote sensing techniques have now revealed a rich spectrum of wave activity in the upper atmosphere. Many of these perturbations, with periodicities ranging from ~ 5 min to many hours and horizontal scales of a few tens of km to several thousands km, are due to freely propagating atmospheric gravity waves and forced tidal oscillations. Passive optical observations of the spatial and temporal characteristics of these waves in the mesosphere and lower thermosphere (MLT) region ( ~ 80-100 km) are facilitated by several naturally occurring, vertically distinct nightglow layers. This paper describes the use of state-of-the-art …

Surface Temperature Probability Distributions In The Narccap Hindcast Experiment: Evaluation Methodology, Metrics, And Results, Paul C. Loikith, Duane E. Waliser, Huikyo Lee, Jinwon Kim, J. David Neelin, Benjamin R. Lintner, Seth Mcginnis, Chris A. Mattmann, Linda O. Mears

Geography Faculty Publications and Presentations

Methodology is developed and applied to evaluate the characteristics of daily surface temperature distributions in a six-member regional climate model (RCM) hindcast experiment conducted as part of the North American Regional Climate Change Assessment Program (NARCCAP). A surface temperature dataset combining gridded station observations and reanalysis is employed as the primary reference. Temperature biases are documented across the distribution, focusing on the median and tails. Temperature variance is generally higher in the RCMs than reference, while skewness is reasonably simulated in winter over the entire domain and over the western United States and Canada in summer. Substantial differences in skewness …

Coordinated Investigation Of Mid-Latitude Upper Mesospheric Temperature Inversion Layers And The Associated Gravity Wave Forcing By Na Lidar And Advanced Mesospheric Temperature Mapper At Logan, Utah (42°N), Tao Yuan, Pierre-Dominique Pautet, Yucheng Zhao, Xuguang Cai, Neal R. Criddle, Michael J. Taylor, William R. Pendleton Jr.

Publications

Mesospheric inversion layers (MIL) are well studied in the literature but their relationship to the dynamic feature associated with the breaking of atmospheric waves in the mesosphere/lower thermosphere (MLT) region are not well understood. Two strong MIL events (ΔT ~30 K) were observed above 90 km during a 6 day full diurnal cycle Na lidar campaign conducted from 6 August to 13 August Logan, Utah (42°N, 112°W). Colocated Advanced Mesospheric Temperature Mapper observations provided key information on concurrent gravity wave (GW) events and their characteristics during the nighttime observations. The study found both MILs were well correlated with the development …

Simulating Ice Core 10be On The Glacial–Interglacial Timescale, C Elsasser, D Wagenbach, I Levin, A Stanzick, Mark J. Christl, A Wallner, S Kipfstuhl, I K. Seietstad, H Wershofen, Jack E. Dibb

Earth Sciences

¹⁰Be ice core measurements are an important tool for paleoclimate research, e.g., allowing for the reconstruction of past solar activity or changes in the geomagnetic dipole field. However, especially on multi-millennial timescales, the share of production and climate-induced variations of respective ¹⁰Be ice core records is still up for debate. Here we present the first quantitative climatological model of the ¹⁰Be ice concentration up to the glacial–interglacial timescale. The model approach is composed of (i) a coarse resolution global atmospheric transport model and (ii) a local ¹⁰Be air–firn transfer model. Extensive global-scale observational data of short-lived …

Productivity, Absorbed Photosynthetically Active Radiation, And Light Use Efficiency In Crops: Implications For Remote Sensing Of Crop Primary Production, Anatoly A. Gitelson, Yi Peng, Timothy J. Arkebauer, Andrew E. Suyker

School of Natural Resources: Faculty Publications

Vegetation productivity metrics such as gross primary production (GPP) at the canopy scale are greatly affected by the efficiency of using absorbed radiation for photosynthesis, or light use efficiency (LUE). Thus, close investigation of the relationships between canopy GPP and photosynthetically active radiation absorbed by vegetation is the basis for quantification of LUE. We used multiyear observations over irrigated and rainfed contrasting C3 (soybean) and C4 (maize) crops having different physiology, leaf structure, and canopy architecture to establish the relationships between canopy GPP and radiation absorbed by vegetation and quantify LUE. Although multiple LUE definitions are reported in the literature, …

An Unusual Aerial Photograph Of An Eddy Circulation In Marine Stratocumulus Clouds (Picture Of The Month), Bradley M. Muller, Christopher G. Herbster, Frederick R. Mosher

Publications

An aerial photograph of a cyclonic, von Kármán–like vortex in the marine stratocumulus clouds off the California coast, taken by a commercial pilot near Grover Beach, is presented. It is believed that this is the first photograph of such an eddy, taken from an airplane, to appear in publication.

The eddy occurred with a strong inversion above a shallow marine boundary layer, in the lee of high, inversion-penetrating terrain. Tower and surface wind measurements plotted on satellite imagery demonstrate that the Grover Beach eddy was not just a cloud-level feature, but extended through the marine atmospheric boundary layer (MABL) to …

Use Of Research Aircraft Data To Validate Mesoscale Model Forecasts, Travis Swaggerty, Melanie Wetzel, Dorothea Ivanova

Aviation / Aeronautics / Aerospace International Research Conference

A NSF funded Student Training in Airborne Research and Technology (START) two-week deployment of the University of Wyoming King Air (UWKA) research aircraft was conducted at Embry-Riddle Aeronautical University (ERAU) in Prescott, Arizona during late March and early April 2014. Some of the goals of this program were to build knowledge on airborne atmospheric research for undergraduate students across multiple departments and to collect a valuable set of aircraft data for atmospheric model validation. Data collection for 10 research flights is available for mesoscale model case study validation.

This project utilizes the Weather Research and Forecasting mesoscale model (WRF), version …

Improvement In Pilot Training For Aircraft Icing Conditions, Cody Denver, Melanie A. Wetzel

Aviation / Aeronautics / Aerospace International Research Conference

One of the most dangerous atmospheric hazards in aviation is aircraft icing. Ice can build on aircraft surfaces, causing decreases in thrust and lift while increasing drag and weight. These effects can be detrimental to any aircraft's ability to successfully remain in flight. Improvement in pilot knowledge of and response to icing conditions can be attained through use of specific meteorological forecast products, completion of interactive training modules, and understanding of cloud physical processes gained through the analysis of aircraft measurement case studies. This poster presents a strategy for enhancing the training of professional pilots in meteorological conditions which cause …

Comparing Three Methods For Estimating Ozone Depleting Substance Substitute Greenhouse Gases: Case Study Of The New York City Region, Wallace A. Murray Iii

Theses and Dissertations

This thesis evaluates the United States Environmental Protection Agency (EPA) method for estimating emissions from one source, Ozone Depleting Substances Substitutes (ODS substitutes) by comparing results for the New York City Metropolitan Statistical Area (NYC-MSA) with results from two other methodologies. The EPA’s method utilizes population data and GDP data to estimate and geographically allocate emissions, with little regard for the geographies of industrial activity. The two alternative methods use data for industrial employment and activity to provide results for comparison and perhaps a more accurate accounting and allocation of emissions throughout the NYC-MSA.

Observations Of Fire-Induced Turbulence Regimes During Low-Intensity Wildland Fires In Forested Environments: Implications For Smoke Dispersion, Warren Heilman, Craig Clements, Daisuke Seto, Xindi Bian, Kenneth Clark, Nicholas Skowronski, John Hom

Faculty Publications, Meteorology and Climate Science

Low-intensity wildland fires occurring beneath forest canopies can result in particularly adverse local air-quality conditions. Ambient and fire-induced turbulent circulations play a substantial role in the transport and dispersion of smoke during these fire events. Recent in situ measurements of fire–atmosphere interactions during low-intensity wildland fires have provided new insight into the structure of fire-induced turbulence regimes and how forest overstory vegetation can affect the horizontal and vertical dispersion of smoke. In this paper, we provide a summary of the key turbulence observations made during two low-intensity wildland fire events that occurred in the New Jersey Pine Barrens.

A One Year Landsat 8 Conterminous United States Study Of Cirrus And Non-Cirrus Clouds, Valeriy Kovalskyy, David P. Roy

GSCE Faculty Publications

The first year of available Landsat 8 data over the conterminous United States (CONUS), composed of 11,296 acquisitions sensed over more than 11 thousand million 30 m pixel locations, was analyzed comparing the spatial and temporal incidence of 30 m cloud and cirrus states available in the standard Landsat 8 Level 1 product suite. This comprehensive data analysis revealed that on average over a year of CONUS observations (i) 35.9% were detected with high confidence cloud, with spatio-temporal patterns similar to those observed by previous Landsat 5 and 7 cloud analyses; (ii) 28.2% were high confidence cirrus; (iii) 20.1% were …

Drougthscape, Winter 2015, Kelly Smith

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

Contents

Director’s report

Central U.S. 2012 report

October-December drought summary

2014 drought summary

Caribbean capacity building

Drought impacts in 2014

California timeline 2014

UC Davis ranching workshop

NASA SMAP data

Global drought info system

Community Capitals

Evaluation and assessment

Indicator-impact research

NDMC on YouTube

A Fast Visible Infrared Imaging Radiometer Suite Simulator For Cloudy Atmospheres, Chao Liu, Ping Yang, Steven Platnick, Kerry G. Meyer, Chenxi Wang, Shouguo Ding

Department of Earth and Atmospheric Sciences: Faculty Publications

A fast instrument simulator is developed to simulate the observations made in cloudy atmospheres by the Visible Infrared Imaging Radiometer Suite (VIIRS). The correlated k distribution technique is used to compute the transmissivities associated with absorbing atmospheric gases. The bulk scattering properties of ice clouds are based on the ice model used for the Moderate Resolution Imaging Spectroradiometer Collection 6 ice cloud products, and those ofwater clouds are computedwith the Lorenz-Mie theory. Two fast radiative transfer models based on precomputed ice cloud look-up tables are used for the VIIRS solar and infrared channels. The accuracy and efficiency of the fast …

Dimethylsulfide Gas Transfer Coefficients From Algal Blooms In The Southern Ocean, T. G. Bell, Warren J. De Bruyn, Christa A. Marandino, S. D. Miller, C. S. Law, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Air-sea dimethylsulfide (DMS) fluxes and bulk air-sea gradients were measured over the Southern Ocean in February-March 2012 during the Surface Ocean Aerosol Production (SOAP) study. The cruise encountered three distinct phytoplankton bloom regions, consisting of two blooms with moderate DMS levels, and a high biomass, dinoflagellate-dominated bloom with high seawater DMS levels (> 15 nM). Gas transfer coefficients were considerably scattered at wind speeds above 5 m s(-1). Bin averaging the data resulted in a linear relationship between wind speed and mean gas transfer velocity consistent with that previously observed. However, the wind-speed-binned gas transfer data distribution at all wind …

Studying Air Pollutants Origin And Associated Meteorological Parameters Over Seoul From 2000 To 2009, Sunmin Park, Hesham El-Askary, Ismail Sabbah, Hanbin Kwak, Anup K. Prasad, Woo-Kyun Lee, Menas Kafatos

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We investigate the temporal characteristics of major air pollutants collected from 44 air quality stations over the city of Seoul, Korea, namely, nitrogen dioxide, carbon monoxide, particular matter at 10 microns, and sulfur dioxide (SO2) between 2000 and 2009. The corresponding satellite datasets, namely, aerosol optical depth (AOD_sat), Ångström exponent, and fine mode fraction, collected from moderate resolution imaging spectroradiometer (MODIS) as well as the Aeronet ground aerosol optical depth (AOD_aeronet), have been analyzed. Pollutants’ seasonal effect has been inferred from the precipitation and temperature. The four pollutants under study show varying temporal characteristics with different …

The Gravity Environment Of Zhouqu Debris Flow Of August 2010 And Its Implication For Future Recurrence, Diandong Ren, Lance M. Leslie, Xinyi Shen, Yang Hong, Qingyun Duan, Rezaul Mahmood, Yun Li, Gang Huang, Weidong Guo, Mervyn J. Lynch

High Plains Regional Climate Center: Staff Publications

This study investigates the geological background of the August 7-8, 2010 Zhouqu debris flows in the northwestern Chinese province of Gansu, and possible future occurrence of such hazards in the peri-Tibetan Plateau (TP) regions. Debris flows are a more predictable type of landslide because of its strong correlation with extreme precipitation. However, two factors affecting the frequency and magnitude of debris flows: very fine scale precipitation and degree of fracture of bedrock, both defy direct observations. Annual mean Net Primary production (NPP) is used as a surrogate for regional precipitation with patchiness filtered out, and gravity satellite measured regional mass …