Atmospheric Sciences Commons^™

Next-Generation Air Force Weather Metrics Via Bayes Cost Analysis, Brandon M. Bailey

Theses and Dissertations

This research proposes a new methodology for U.S. Air Force weather forecast metrics. Military weather forecasters are essentially statistical classifiers. They categorize future conditions into an operationally relevant category based on current data, much like an Artificial Neural Net or Logistic Regression model. There is extensive literature on statistically-based metrics for these types of classifiers. Additionally, in the U.S. Air Force, forecast errors (errors in classification) have quantifiable operational costs and benefits associated with incorrect or correct classification decisions. There is a methodology in the literature, Bayes Cost, which provides a structure for creating statistically rigorous metrics for classification decisions …

Localized Effects Of Hurricane Michael (2018) On Total Electron Content, Joanna E.S. Williams

Theses and Dissertations

Understanding the connection between terrestrial and space environments is an emerging field of study that can significantly improve operational weather forecasting. In particular, it is well known that tropical cyclones (TCs) and thunderstorms can initiate gravity waves that generate fluctuations in the total electron content (TEC) of the ionosphere. These perturbations can deteriorate and delay the transmission of high-frequency (HF) communications, such as emergency services, amateur radio, and aviation. This study investigates changes in TEC according to the number of lightning ashes and the rainfall rates associated with Hurricane Michael (2018). A composite analysis will be performed using the GOES …

Detection Of Reconnection Signatures In Solar Flares, Taylor R. Whitney

Theses and Dissertations

Solar flare forecasting is limited by the current understanding of mechanisms that govern magnetic reconnection, the main physical phenomenon associated with these events. As a result, forecasting relies mainly on climatological correlations to historical events rather than the underlying physics principles. Solar physics models place the neutral point of the reconnection event in the solar corona. Correspondingly, studies of photospheric magnetic fields indicate changes during solar flares -- particularly in relation to the field helicity -- on the solar surface as a result of the associated magnetic reconnection. This study utilizes data from the Solar Dynamics Observatory (SDO) Helioseismic and …

A Design For A Sustained Assessment Of Climate Forcing And Feedbacks Related To Land Use And Land Cover Change, Thomas Loveland, Rezaul Mahmood

High Plains Regional Climate Center: Staff Publications

L and use and land cover change (LULCC) plays an important role in the climate system. Many studies have documented the impacts of LULCC on local, regional, and global climate. The National Climate Assessment Report (Melillo et al. 2014) identifies LULCC as a “cross cutting” issue of future climate change studies. This report, and the previous U.S. Climate Change Science Program strategic plan (2003), noted that land use and land cover (LULC) and its feedback is an important source of uncertainty within the climate system (Melillo et al. 2014). As a result, the report calls for a better understanding of …

Surface Reservoirs Dominate Dynamic Gas-Surface Partitioning Of Many Indoor Air Constituents, Chen Wang, Douglas B. Collins, Caleb Arata, Allen H. Goldstein, James M. Mattila, Delphine K. Farmer, Laura Ampollini, Peter F. Decarlo, Atila Novoselac, Marina E. Vance, William W. Nazaroff, Jonathan P.D. Abbatt

Faculty Journal Articles

Human health is affected by indoor air quality. One distinctive aspect of the indoor environment is its very large surface area that acts as a poorly characterized sink and source of gas-phase chemicals. In this work, air-surface interactions of 19 common indoor air contaminants with diverse properties and sources were monitored in a house using fast-response, on-line mass spectrometric and spectroscopic methods. Enhanced-ventilation experiments demonstrate that most of the contaminants reside in the surface reservoirs and not, as expected, in the gas phase. They participate in rapid air-surface partitioning that is much faster than air exchange. Phase distribution calculations are …

Modeling Of Ionospheric Responses To Atmospheric Acoustic And Gravity Waves Driven By The 2015 Nepal M W 7.8 Gorkha Earthquake, P. A. Inchin, J. B. Snively, M. D. Zettergren, A. Komjathy, O. P. Verkhoglyadova, S. Tulasi Ram

Publications

Near- and far-field ionospheric responses to atmospheric acoustic and gravity waves (AGWs) generated by surface displacements during the 2015 Nepal 7.8 Gorkha earthquake are simulated. Realistic surface displacements driven by the earthquake are calculated in three-dimensional forward seismic waves propagation simulation, based on kinematic slip model. They are used to excite AGWs at ground level in the direct numerical simulation of three-dimensional nonlinear compressible Navier-Stokes equations with neutral atmosphere model, which is coupled with a two-dimensional nonlinear multifluid electrodynamic ionospheric model. The importance of incorporating earthquake rupture kinematics for the simulation of realistic coseismic ionospheric disturbances (CIDs) is demonstrated and …

Air/Sea Transfer Of Highly Soluble Gases Over Coastal Waters, J. G. Porter, Warren J. De Bruyn, S. D. Miller, E. S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The deposition of soluble trace gases to the sea surface is not well studied due to a lack of flux measurements over the ocean. Here we report simultaneous air/sea eddy covariance flux measurements of water vapor, sulfur dioxide (SO₂), and momentum from a coastal North Atlantic pier. Gas transfer velocities were on average about 20% lower for SO₂ than for H₂O. This difference is attributed to the difference in molecular diffusivity between the two molecules (D _{SO 2}/D _{H 2O} = 0.5), in reasonable agreement with bulk parameterizations in air/sea gas …

Analysis Of Concurrent Backscatter Coefficients From In-Situ Cloud Probes And Airborne Lidar, Shawn Wagner, David J. Delene

Datasets

The North Dakota Citation Research Aircraft obtained measurements of anvil cirrus clouds over Florida during the summer of 2015 (CAPE2015). The Citation is fitted to take measurements of atmospheric variables (pressure, temperature, dew point, wind velocity, etc...) as well as cloud particle properties (concentration, size-distribution, water content, etc...). Data (at 1 Hz) is included from four flights occuring on 31 July 2015, 1 August 2015, and 2 August 2015. Cloud properties were measured by the Two-Dimensional Stereo probe (2D-S), the High-Volume Precipitation Spectrometer (HVPS3) probe and the Nevzorov probe. Additionally, particle data from the 2D-S and HVPS3 are combined to …

A 3-Year Sample Of Almost 1,600 Elves Recorded Above South America By The Pierre Auger Cosmic-Ray Observatory, A. Aab, R. Engel, Gregory Snow, Pierre Auger Cosmic-Ray Observatory, 390 Co-Authors

Gregory Snow Publications

Elves are a class of transient luminous events, with a radial extent typically greater than 250 km, that occur in the lower ionosphere above strong electrical storms.We report the observation of 1,598 elves, from 2014 to 2016, recorded with unprecedented time resolution (100 ns) using the fluorescence detector (FD) of the Pierre Auger Cosmic-Ray Observatory. The Auger Observatory is located in the Mendoza province of Argentina with a viewing footprint for elve observations of 3 · 106 km2, reaching areas above the Pacific and Atlantic Oceans, as well as the Córdoba region, which is known for severe convective thunderstorms. Primarily …

Determining Atmospheric Boundary Layer Behavior Over Mountainous Terrain Using Aircraft Vertical Profiles From 2009-2018 Nasa Student Airborne Research Program Data, Dallas Mckinney

Mahurin Honors College Capstone Experience/Thesis Projects

The atmospheric boundary layer (ABL) height separates turbulently mixed air and pollutants emitted at the ground from the free troposphere above and is an important parameter in numerical weather prediction and air pollution dispersion models. Discerning the ABL height over mountainous terrain has historically been difficult because of, for example, complex interactions with upper level winds, venting of humidity and aerosols into the free troposphere, and large spatiotemporal variability. ABL over mountainous terrain (MT) can closely follow the terrain, be flat, or be shallower than surrounding valleys depending on the time of day, synoptic conditions, and effects of the surrounding …

Whitepaper: Understanding Land-Atmosphere Interactions Through Tower-Based Flux And Continuous Atmospheric Boundary Layer Measurements, Manuel Helbig, Tobias Gerken, E Beamesderfer, D D. Baldocchi, T Banerjee, S C. Biraud, N A. Brunsell, S P. Butterworth, W S. Chan, A R. Desai, J D. Fuentes, D Y. Hollinger, N Klijun, M Mauder, K A. Novick, J M. Perkins, C Rey-Sanchez, R L. Scott, B Seyednasrollah, P C. Stoy, R C. Sullivan, J Vilà-Guerau De Arellano, S Wharton, C Yi, A D. Richardson

Libraries

Executive summary

● Target audience: AmeriFlux community, AmeriFlux Science Steering Committee & Department of Energy (DOE) program managers [ARM/ASR (atmosphere), TES (surface), and SBR (subsurface)]

● Problem statement: The atmospheric boundary layer mediates the exchange of energy and matter between the land surface and the free troposphere integrating a range of physical, chemical, and biological processes. However, continuous atmospheric boundary layer observations at AmeriFlux sites are still scarce. How can adding measurements of the atmospheric boundary layer enhance the scientific value of the AmeriFlux network?

● Research opportunities: We highlight four key opportunities to integrate tower-based flux measurements with continuous, …

Multi-Doppler Radar Wind Retrieval Data For Deep Convective Cloud Observed On May 11, 2020, Mariko Oue, Kirk North, Andrea Neumann

SoMAS Research Data

The US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program’s Southern Great Plains (SGP) site includes a heterogeneous distributed scanning Doppler radar network suitable for collecting coordinated Doppler velocity measurements in deep convective clouds. The surrounding National Weather Service (NWS) Next Generation Weather Surveillance Radar 1988 Doppler (NEXRAD WSR-88D) further supplements this network. The multi-Doppler radar reflectivity and velocity measurements are assimilated in a three-dimensional variational (3DVAR) algorithm to retrieve horizontal and vertical air motions in deep convective clouds. The data includes the 3D wind fields retrieved over a large analysis domain (100 km x 100 km) at storm-scale …

Multi-Doppler Radar Wind Retrieval Data For Deep Convective Clouds Observed In The Southern Great Plains On May 11, 2011, Mariko Oue, Kirk North, Andrea Neumann

SoMAS Research Data

The US Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program’s Southern Great Plains (SGP) site includes a heterogeneous distributed scanning Doppler radar network suitable for collecting coordinated Doppler velocity measurements in deep convective clouds. The surrounding National Weather Service (NWS) Next Generation Weather Surveillance Radar 1988 Doppler (NEXRAD WSR-88D) further supplements this network. The multi-Doppler radar reflectivity and velocity measurements are assimilated in a three-dimensional variational (3DVAR) algorithm to retrieve horizontal and vertical air motions in deep convective clouds. The data includes the 3D wind fields retrieved over a large analysis domain (100 km x 100 km) at storm-scale …

A Multi-Platform, In-Situ Kinematic And Microphysical Analysis Of A Parallel Stratiform-Mesoscale-Convective System, Andrea Neumann, Michael Poellet, David J. Delene, Mark Askelson, Kirk North, Mariko Oue

Datasets

The North Dakota Citation Research Aircraft obtained measurements of stratiform precipitation clouds within mesoscale convective systems over Oklahoma during the spring of 2011 (MC3E) in conjunction with a multitude of ground- and airborne-based remote sensing instruments. The Citation was used to take measurements of base atmospheric variables as well as cloud and precipitation properties. Cloud droplet properties were measured by the Cloud Imaging Probe (CIP), Two-Dimensional Cloud probe (2D-C), the High-Volume Precipitation Spectrometer Version 3 (HVPS3) probe, with the spectra from these probes combined to create a single drop size distribution. The Atmospheric Radiation Measurement (ARM) program ran three X-Band …

Volcanic Impact On Stratospheric Chlorine Chemistry And Perchlorate Formation: Evidence From Ice Cores, Joshua Andrew Kennedy

Electronic Theses and Dissertations

Perchlorate, suspected to be chemically formed in both the troposphere and stratosphere, has been recently measured in Arctic snow and ice cores. These comprise both discontinuous snow and ice cores from the Canadian Arctic and a continuous record of perchlorate was compiled from an analysis of Greenland ice cores. While the background perchlorate concentration typically is very low, a few spikes in concentration coinciding with deposition of volcanic sulfate were observed in the Greenland record, suggesting that perchlorate levels in the atmosphere may be impacted by volcanic eruptions. As of yet, no work has been done to investigate the connection …

An Annual Time Series Of Weekly Size-Resolved Aerosol Properties In The Megacity Of Metro Manila, Philippines, Connor Stahl, Melliza Templonuevo Cruz, Paola Angela Bañaga, Grace Betito, Rachel A. Braun, Mojtaba Azadi Aghdam, Maria Obiminda L. Cambaliza, Genevieve Rose Lorenzo, Alexander B. Macdonald, Preciosa Corazon Pabroa, John Robin Yee, James Bernard Simpas, Armin Sorooshian

Physics Faculty Publications

Size-resolved aerosol samples were collected in Metro Manila between July 2018 and October 2019. Two Micro-Orifice Uniform Deposit Impactors (MOUDI) were deployed at Manila Observatory in Quezon City, Metro Manila with samples collected on a weekly basis for water-soluble speciation and mass quantification. Additional sets were collected for gravimetric and black carbon analysis, including during special events such as holidays. The unique aspect of the presented data is a year-long record with weekly frequency of size-resolved aerosol composition in a highly populated megacity where there is a lack of measurements. The data are suitable for research to understand the sources, …

Factors Influencing Rainfall Over The Congo, Ajay Raghavendra

Legacy Theses & Dissertations (2009 - 2024)

The hydrological cycle over tropical rainforests includes some of the most intense thunderstorms and rainfall totals. The energy associated with this convective activity plays an important role in the Earth’s weather and climate system. Therefore, the interannual variability, trends, and future climate projections of the hydrological cycle over tropical rainforests are important topics for research. The Congo rainforest situated over equatorial Africa is the second largest rainforest in the world, and recent studies have documented a >30-year large-scale and long-term drying trend over the Congo since the late-1970s. However, unlike the Amazon rainforest in South America, the Congo rainforest is …

The Impact Of Warm Conveyor Belt Forecast Uncertainty On Downstream Predictability, Jeremy Berman

Legacy Theses & Dissertations (2009 - 2024)

Perturbations to the potential vorticity (PV) waveguide can lead to the downstream radiation of Rossby waves, and in turn high-impact weather events. The PV waveguide is often perturbed in association with cyclogenesis, largely due to the latent heat release within the cyclone’s warm conveyor belt (WCB). Previous studies have hypothesized that forecast uncertainty associated with diabatic heating in WCBs can result in large downstream forecast variability; however these studies have not established a direct connection between the two. This hypothesis is evaluated for six cyclogenesis events characterized by highly amplified flow over the North Atlantic using ensemble model simulations.

Ozone And Reactive Oxidized Nitrogen Chemistry In The Northeast U.S, Matthew Ninneman

Legacy Theses & Dissertations (2009 - 2024)

Ongoing reductions in oxides of nitrogen concentrations ([NOx] = nitric oxide ([NO]) + nitrogen dioxide ([NO2])) throughout the continental United States (U.S.) have important implications for tropospheric ozone (O3) and reactive oxidized nitrogen chemistry (NOy ≈ NOx + nitric acid (HNO3) + particle nitrate (pNO3) + peroxy nitrates (PNs) + alkyl nitrates (ANs)). Specifically, decreasing [NOx] concentrations have likely (1) increased the sensitivity of O3 to the [NOx] level, and (2) affected NOy speciation and partitioning. An understanding of the impacts of continued [NOx] reductions is needed to inform current and future air pollution control strategies, especially since the National …

Global Circulation Variability Associated With Mjo Phase Speed, Alexander Marat Tomoff

Legacy Theses & Dissertations (2009 - 2024)

Differences in the Madden–Julian oscillation (MJO) phase speed help explain some of the variability in the global circulation patterns associated with the MJO. Select mechanisms that identify these distinctive circulation signals are applied to help explain MJO variability associated with different phase speeds. Wavelet filter analysis is first used to compute regression models of the MJO at different phase speeds, isolating the associated patterns in outgoing longwave radiation (OLR), geopotential height, and upper-level wind. Covariance matrices provide a deeper understanding of how the tropical and extratropical patterns compare between two phase speeds at any point in time. Both Fourier and …