Chemistry Commons^™

Chemical Synthesis And Biological Application Of Sensitive Rna, Alexander T. Apostle

Dissertations, Master's Theses and Master's Reports

In the field of epigenetics - the dynamic collection of chemical modifications that overlay DNA/RNA - there is increasing interest in the potential for therapeutic and research-based utilization of the epitranscriptomics: those epigenetic modifications specific to RNA. Epitranscriptomics can give us a new approach to understanding and treating RNA viruses, like SARS-CoV-2. Given viruses are often found modified by human epitranscriptomic machinery, understanding how these modifications can modulate virulence is of high interest. We have shown that the N1-methyladensoine modification causes RNA synthesis termination in the SARS-CoV-2 replication complex, and thus may explain the differences in symptoms observed in individuals. …

Whole Genome Crispr-Cas9 Screens Identify Genes Contributing To Viral Entry And Phagocytosis, Md Saddam Hossain

Electronic Theses and Dissertations

CRISPR/Cas9 is a revolutionary technique for genome editing where Cas9 nucleases can be targeted to specific genomic sites by single-guide RNAs (sgRNAs) containing roughly 20-nucleotide sequences that are complementary to the target region. Double strand breaks created by Cas9 are repaired through non-homologous end-joining (NHEJ) in most cells, resulting in insertions and deletions leading to frame shift mutations in coding regions. Thus, the CRISPR-Cas9 system can be exploited for systematic evaluation of gene function relationships by whole genome screening. We also developed a CRISPR whole‐genome screen and counter‐screen strategy based on a pseudoviral platform that allowed identification of genes specific …

Analysis Of Toxic Chemical Agents And Therapeutics For Toxic Inhaled Agents’ Exposure, Khadija Bilkis

Electronic Theses and Dissertations

When inhaled, toxic inhalation agents (TIAs) such as cyanide (CN), ammonia and sulfur compounds (e.g. methanethiol (MeSH)) can be fatal. Many TIAs cause cellular hypoxia, cytotoxic anoxia, apnea, respiratory failure, neurodegenerative disorder, circulatory collapse, seizures, and potential death by blocking mitochondrial cytochrome c oxidase. All TIA’s have the potential to be employed as chemical warfare agents, terrorist weapons, or dangerous occupational gases. Although many TIAs are potential threats, there are minimal FDA-approved treatments for these substances useful in a mass-casualty situation. Recently, cobinamide (Cbi) has come to light as a potential antidote for MeSH poisoning. However, methods for analyzing MeSH …

Enhancement Of Antitumor Effects Of Berberine Chloride With A Copper(Ii) Complex Against Human Triple Negative Breast Cancer: In Vitro Studies, Duaa R. Alajroush, Brittney F. Anderson, Janae A. Bruce, Christian I. Lartey, Dazonte A. Mathurin, Sean T. Washington, Tanaya S. Washington, Sidy Diawara, Sakariyau A. Waheed, Kaylin L. Thomas, Stephen J. Beebe, Alvin A. Holder

Chemistry & Biochemistry Faculty Publications

In this study, the copper(II) complex [Cu(chromoneTSC)Cl₂]•0.5H₂O•0.0625C₂H₅OH (where chromoneTSC = (E)-N-Ethyl-2-((4-oxo-4H-chromen-3-yl)methylene)-hydrazinecarbothioamide) was synthesized and characterized; then used to carry out in vitro studies in combination with berberine chloride (BBC). The ligand and complex were characterized by elemental analysis, FTIR and NMR (¹H and ¹³C) spectroscopy, and conductivity measurements. The cytotoxic effect was analyzed by using the CCK-8 viability assay in cancer MDA-MB-231 VIM RFP and non-cancer MCF-10A cell lines. The IC₅₀ values for the complex and BBC were 21.2 ± 1.6 and 48.3 ± 2.4 μM, respectively at 24 h incubation, while the IC₅₀ value of the combination treatment …

Advanced General Chemistry, Alexandra E. Strom

Open Educational Resources: Textbooks

Textbook adapted for CHM 118 at Smith College:

This course is for students with a very strong background in chemistry. The elementary theories of stoichiometry, atomic structure, bonding, structure, energetics and reactions are quickly reviewed. The major portions of the course involve a detailed analysis of atomic theory and bonding from an orbital concept, an examination of the concepts behind thermodynamic arguments in chemical systems, and an investigation of chemical reactions and kinetics. The laboratory deals with synthesis, physical properties and kinetics.

Spiral Wave Teleportation And Multiplex Network Synchronization In Light Sensitive Belousov-Zhabotinsky Systems, Shannyn Alicia Tyler

Graduate Theses, Dissertations, and Problem Reports (ETD)

We experimentally and computationally investigate dynamical behaviors in excitable and oscillatory media using light sensitive Belousov-Zhabotinsky (BZ) systems. These systems are not in a state of thermodynamic equilibrium, and have been proven to show various interesting phenomena including spatiotemporal patterns, self-organization, and chaos. We utilize the BZ reaction, a nonlinear chemical reaction, known for its relaxation-type oscillations, to explore the dynamics of these systems.

We examine spiral wave teleportation in an excitable media as an effective alternate defibrillation method. Spiral waves have emerged as a key phenomenon associated with the initiation and persistence of cardiac arrhythmias. Using a light sensitive …

Processing, Stability, And High-Temperature Properties Of Doped Lacro3-Based Refractory Ceramics And Composites For Harsh Environments Sensing Applications, Javier A. Mena

Graduate Theses, Dissertations, and Problem Reports (ETD)

In order to test and monitor the operational stability and conditions of various energy, transportation, and manufacturing systems and their components, accurate sensors capable of operating at temperatures over 1000 °C in various environments for long durations are required. In addition, many of these harsh environmental systems do not permit sensors to be directly inserted into the environment, so the sensors need to be embedded into the surrounding support or thermal protective materials. Some technological and industrial applications that require the use of harsh environment conditions sensing include nuclear and chemical reactors, jet engines, heavyduty gas turbines, rotating bearings in …

A Portable, Digital Nucleic Acid Amplification Test For Use At The Point Of Care, Bethany J. Fike

Graduate Theses, Dissertations, and Problem Reports (ETD)

Nucleic acid tests are key tools for the detection and diagnosis of many diseases. In many cases, the amplification of nucleic acids is required to reach a detectable level. Although nucleic acid tests have great success, there is a need to make nucleic acid amplification tests more accessible to a point-of-care (POC) setting for diagnosis, prognosis, and monitoring of infectious diseases. Traditionally, these tests are performed through bulk Polymerase Chain Reaction (PCR) and are monitored in real time with a change in fluorescence intensity. With these bulk testing methods, only a qualitative or semi-quantitative result is possible. For more exact …

Scattering Of Larger Molecules – Part 1: General Discussion, Dmitri Babikov

Chemistry Faculty Research and Publications

No abstract provided.

A Facile Auto-Combustion Pathway For Creating Mn- And Fe-Doped Tio2 Nanostructures And Their Photocatalytic Activity, Gharieb Meselhy

Dentistry

Using a combination of two fuels, an auto-combustion method was used to synthesize pure TiO2 and doped TiO2 with different concentrations of iron(III) (Fe) and manganese(II) (Mn) (1, 3, 5, and 7 mol%). The as-prepared materials were characterized using different techniques, including thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). The XRD results showed that both pure TiO2 and all doped TiO2 samples had the anatase phase, indicating the crystalline nature of all the as-prepared nanomaterials. Crystal violet decolorization under UV irradiation was used to …

A New Approach For Discriminating Spatially Acquired Sers Spectra Using Antiretroviral Drug Emtricitabine As A Test Sample, Jana Hrncirova, Marguerite R. Butler, Meredith R. Clark, Gustavo F. Doncel, John B. Cooper

Chemistry & Biochemistry Faculty Publications

In this study, an antiretroviral drug emtricitabine (also known as FTC or Emtriva) was detected and quantified down to 40 ng/ml by using surface-enhanced Raman spectroscopy (SERS). Its aqueous standards were tested with two types of silver nanoparticles (colloidal and dendritic) using a specially developed aluminum well plate. The SERS spectra were acquired using a Raman scanning device with 30-mu m spatial resolution. The spectral data were analyzed using a new approach for the discrimination of the spatially acquired spectra based on the Quality index (Qi). After the Qi is calculated, the spectral data are sorted based on the Qi. …

Type-B Energetic Processes: Introduction And Invitation To Special Issue Of Energies, James Weifu Lee, Daniel P. Sheehan

Chemistry & Biochemistry Faculty Publications

[First paragraph] Currently, there is substantial scientific evidence for the existence of Type-B energetic processes on Earth, such as the naturally occurring transmembrane-electrostatically localized protons (TELP) thermotrophic properties in life [1]. A number of groundbreaking human-made Type-B energetic processes, including (but not limited to) “asymmetric function-gated isothermal electricity production” [2], “epicatalysis generating a temperature difference between catalysis-asymmetric filaments” [3], “artificially made asymmetric membrane concentration cell” [4,5], “Fu’s experiment on heat–electric conversion using surface electron emission under a static magnetic field” [6], and the “dynamic processes in superconductors indicating Type-B energetic process” [7,8,9] have been invented and/or experimentally demonstrated. The innovative …

Trends In Atmospheric Composition Between 2004-2023 Using Version 5 Ace-Fts Data, Matthew Schmidt, Peter Bernath, Chris Boone, Michael Lecours, Johnathan Steffen

Chemistry & Biochemistry Faculty Publications

The Atmospheric Chemistry Experiment (ACE) is a satellite mission that has been in orbit since 2003. The primary instrument on ACE is a Fourier transform spectrometer (FTS) that records infrared atmospheric transmittance spectra in the limb geometry using the Sun as a light source. Version 5 of ACE-FTS data processing contains improved volume mixing ratio (VMR) profiles for 46 molecules and 24 isotopologues, including HFC-32 (CH₂F₂) and HOCl as new routine data products. VMR trends for each of the 46 molecules are reported for regions of atmospheric interest. Specifically, the longevity of the ACE mission has …

Stabilization Of Pfas-Contaminated Soil With Sewage Sludge- And Wood-Based Biochar Sorbents, Erlend Sørmo, Clara Benedikte Mader Lade, Julie Zhang, Alexandros G. Asimakopoulos, Geir Wold Åsli, Michel Hubert, Aleksandar I. Goranov, Hans Peter H. Arp, Gerard Cornelissen

Chemistry & Biochemistry Faculty Publications

Sustainable and effective remediation technologies for the treatment of soil contaminated with per- and polyfluoroalkyl substances (PFAS) are greatly needed. This study investigated the effects of waste-based biochars on the leaching of PFAS from a sandy soil with a low total organic carbon content (TOC) of 0.57 ± 0.04% impacted by PFAS from aqueous film forming foam (AFFF) dispersed at a former fire-fighting facility. Six different biochars (pyrolyzed at 700–900°C) were tested, made from clean wood chips (CWC), waste timber (WT), activated waste timber (aWT), two digested sewage sludges (DSS-1 and DSS-2) and de-watered raw sewage sludge (DWSS). Up-flow column …

Green Oxidation Of Aromatic Hydrazide Derivatives Using An Oxoammonium Salt, Nidheesh Phadnis, Jessica A. Molen, Shannon M. Stephens, Shayne M. Weierbach, Kyle M. Lambert, John A. Milligan

Chemistry & Biochemistry Faculty Publications

Aromatic diazenes are often prepared by oxidation of the corresponding hydrazides using stoichiometric quantities of nonrecyclable oxidants. We developed a convenient alternative protocol for the oxidation of aromatic hydrazides using Bobbitt's salt (1), a metal-free, recyclable, and commercially available oxoammonium reagent. A variety of aryl hydrazides were oxidized within 75 min at room temperature using the developed protocol. Computational insight suggests that this oxidation occurs by a polar hydride transfer mechanism.

Unraveling Sources Of Cyanate In The Marine Environment: Insights From Cyanate Distributions And Production During The Photochemical Degradation Of Dissolved Organic Matter, Rui Wang, Jihua Liu, Yongle Xu, Li Liu, Kenneth Mopper

Chemistry & Biochemistry Faculty Publications

Cyanate is a nitrogen and energy source for diverse marine microorganisms, playing important roles in the nitrogen cycle. Despite the extensive research on cyanate utilization, the sources of this nitrogen compound remain largely enigmatic. To unravel the sources of cyanate, distributions and production of cyanate during photochemical degradation of natural dissolved organic matter (DOM) were investigated across various environments, including freshwater, estuarine, coastal areas in Florida, and the continental and slope regions of the North American mid-Atlantic Ocean (NATL). Cyanate production was also examined during the photochemical degradation of exudates from a typical strain of Synechococcus, an important phytoplankton …

Evidence Of Direct Interaction Between Cisplatin And The Caspase-Cleaved Prostate Apoptosis Response-4 Tumor Suppressor, Krishna K. Raut, Samjhana Pandey, Gyanendra Kharel, Steven M. Pascal

Chemistry & Biochemistry Faculty Publications

Prostate apoptosis response-4 (Par-4) tumor suppressor protein has gained attention as a potential therapeutic target owing to its unique ability to selectively induce apoptosis in cancer cells, sensitize them to chemotherapy and radiotherapy, and mitigate drug resistance. It has recently been reported that Par-4 interacts synergistically with cisplatin, a widely used anticancer drug. However, the mechanistic details underlying this relationship remain elusive. In this investigation, we employed an array of biophysical techniques, including circular dichroism spectroscopy, dynamic light scattering, and UV–vis absorption spectroscopy, to characterize the interaction between the active caspase-cleaved Par-4 (cl-Par-4) fragment and cisplatin. Additionally, elemental analysis was …

Reducing The Uncertainty In Estimating Soil Microbial-Derived Carbon Storage, Han Hu, Chao Qian, Ke Xue, Rainer Georg Jörgensen, Marco Keiluweit, Chao Liang, Xuefeng Zhu, Ji Chen, Yishen Sun, Haowei Ni, Jixian Ding, Weigen Huang, Jingdong Mao, Rong-Xi Tan, Jizhong Zhou, Thomas W. Crowther, Zhi-Hua Zhou, Jiabao Zhang, Yuting Liang

Chemistry & Biochemistry Faculty Publications

Soil organic carbon (SOC) is the largest carbon pool in terrestrial ecosystems and plays a crucial role in mitigating climate change and enhancing soil productivity. Microbial-derived carbon (MDC) is the main component of the persistent SOC pool. However, current formulas used to estimate the proportional contribution of MDC are plagued by uncertainties due to limited sample sizes and the neglect of bacterial group composition effects. Here, we compiled the comprehensive global dataset and employed machine learning approaches to refine our quantitative understanding of MDC contributions to total carbon storage. Our efforts resulted in a reduction in the relative standard errors …

Potentially Massive And Global Non-Pyrogenic Production Of Condensed "Black" Carbon Through Biomass Oxidation, Aleksandar I. Goranov, Hongmei Chen, Jianshu Duan, Satish C. B. Myneni, Patrick G. Hatcher

Chemistry & Biochemistry Faculty Publications

With the increased occurrences of wildfires worldwide, there has been an increase in scientific interest surrounding the chemistry of fire-derived "black" carbon (BC). Traditionally, wildfire research has assumed that condensed aromatic carbon (ConAC) is exclusively produced via combustion, and thus, ConAC is equated to BC. However, the lack of correlations between ConAC in soils or rivers and wildfire history suggests that ConAC may be produced non-pyrogenically. Here, we show quantitative evidence that this occurs during the oxidation of biomass with environmentally ubiquitous hydroxyl radicals. Pine wood boards exposed to iron nails and natural weather conditions for 12 years yielded a …

Synthetic Approaches Of Carbohydrate Based Self-Assembling Systems, Guijun Wang, Anji Chen, Pramod Aryal, Jonathan Bietsch

Chemistry & Biochemistry Faculty Publications

Carbohydrate-based self-assembling systems are essential for the formation of advanced biocompatible materials via a bottom-up approach. The self-assembling of sugar-based small molecules has applications encompassing many research fields and has been studied extensively. In this focused review, we will discuss the synthetic approaches for carbohydrate-based self-assembling (SA) systems, the mechanisms of the assembly, as well as the main properties and applications. This review will mainly cover recent publications in the last four years from January 2020 to December 2023. We will essentially focus on small molecule self-assembly, excluding polymer-based systems, which include various derivatives of monosaccharides, disaccharides, and oligosaccharides. Glycolipids, …

Assessing The Spatiotemporal Variability Of Dissolved Organic Matter Fluorescence Composition In The Lake George, Ny Watershed, Aleksandar I. Goranov, Mark W. Swinton, David A. Winkler, Jeremy L. Farrell, Sandra A. Nierzwicki-Bauer, Sasha Wagner

Chemistry & Biochemistry Faculty Publications

Lake George (LG) is a temperate, oligotrophic, medium-sized lake (114 km²) located in northeastern New York State (U.S.). Lakes are highly understudied environments where extensive dissolved organic matter (DOM) processing occurs. With this study we establish the foundation for researching the organic biogeochemistry of the LG watershed, in particular, the numerous tributaries flowing into the lake. Collected were 213 samples from 64 tributaries and 12 lake locations. Some of the tributaries had unique wastewater, agricultural, or wetland influences. We employed fluorescence spectroscopy, a common biogeochemical technique, to characterize the fluorescent DOM (FDOM) component. We developed a parallel factor …

Photoluminescence Switching In Quantum Dots Connected With Carboxylic Acid And Thiocarboxylic Acid End-Group Diarylethene Molecules, Ephraiem S. Sarabamoun, Pramod Aryal, Jonathan M. Bietsch, Maurice Curran, Sugandha Verma, Grayson Johnson, Lucy U. Yoon, Amelia G. Reid, Esther H. R. Tsai, Charles W. Machan, Christopher Paolucci, Guijun Wang, Joshua J. Choi

Chemistry & Biochemistry Faculty Publications

We contrast the switching of photoluminescence (PL) of PbS quantum dots (QDs) cross-linked with photochromic diarylethene molecules with different end groups, 4,4′-(1-cyclopentene-1,2-diyl)bis[5-methyl-2-thiophenecarboxylic acid] (1C) and 4,4′-(1-cyclopentene-1,2-diyl)bis[5-methyl-2-thiophenethiocarboxylic acid] (2T). Our results show that the QDs cross-linked with the carboxylic acid end group molecules (1C) exhibit a greater amount of switching in photoluminescence intensity compared to QDs cross-linked with the thiocarboxylic acid end group (2T). We also demonstrate that regardless of the molecule used, greater switching amounts are observed for smaller quantum dots. Varying these parameters allows for the fabrication of photoswitches with tunable PL change. We relate these observations to the …

Polarizable Amoeba Force Field Predicts Thin And Dense Hydration Layer Around Monosaccharides, Luke A. Newman, Mackenzie G. Patton, Breyanna A. Rodriguez, Ethan W. Summer, Valerie Vaissier Welbourn

Chemistry & Biochemistry Faculty Publications

Polarizable force fields crucially enhance the modeling of macromolecules in polar media. Here, we present new parameters to model six common monosaccharides with the polarizable AMOEBA force field. These parameters yield a thinner, but denser, hydration layer than that previously reported. This denser hydration layer results in eliminating non-physical aggregation of glucose in water-an issue that has plagued molecular dynamics simulations of carbohydrates for decades.

Reducing Short-Chain Pfas Levels In California Water Supplies, Manu Prabandham

Pomona Senior Theses

This thesis proposes twelve specific policies based on precedents set by prior regulation of persistent organic pollutants (such as PCBs), the costs and benefits of short-chain PFAS, technologies available to remove and destroy short-chain PFAS, and the roles and limitations of California’s regulatory institutions. The twelve policies are chosen to be politically and financially feasible, effective at removing short-chain PFAS from water supplies, and equitable towards lower-income and minority Californians, who suffer the most from the consequences of PFAS and other environmental pollutants. The new definitions, education campaigns, studies, taxes, bans, standards, testing, and filtration systems proposed are intended to …

Mechanisms Of Dendritic Shorting In Lithium Metal Batteries With Li7la3zr2o12 Solid Electrolytes, Lukas Karapin-Springorum

Pomona Senior Theses

Energy storage will play a crucial role in efforts to mitigate the effects of climate change caused by greenhouse gas emissions from human activity. Lithium metal batteries using solid electrolytes like Li₇La₃Zr₂O₁₂ have higher energy density than lithium-ion batteries, which may enable a more rapid and complete electrification of transportation. However, lithium metal batteries suffer from undesirable short-circuiting when metallic lithium deposits connect the two electrodes. It has been debated whether these lithium dendrites generally grow directionally from the anode or are generated by the reduction of lithium ions inside the solid electrolyte, …

Using Virus Like Particle Conjugates Of Synthetic Targeting Compounds To Deliver Chemotherapeutic Drugs To Cancer Stem Cells, Austen W. Kerzee

Chemistry Theses

Cancer stem cells are a type of cell that have the properties of both cancer cells and stem cells. They can differentiate into other types of cancer cells, are resistant to conventional chemotherapeutics, and seem to contribute greatly to the metastasis and recurrence of cancer. Due to these properties, eliminating cancer stem cells would be greatly beneficial in the treatment of cancer. While there have been approved therapeutic methods for the removal of a few of the cancer stem cells types, treatment for most types of cancer stem cells are still in the experimental phase and have yet to be …

B(C₆F₅)₃ Co-Catalyst Promotes Unconventional Halide Abstraction From Grubbs I To Enhance Reactivity And Limit Decomposition, Austin W. Medley, Diya Patel, Calvin Utne, Trandon A. Bender

Chemistry & Biochemistry Faculty Publications

Ruthenium based Grubbs metathesis has become a commonplace reaction for synthetic chemists. Development of new generations of catalysts evolving from Grubbs I (GI) have led to greater stability, functional group compatibility, and superior reactivities. However, these advancements lead to increased costs. To this end, we report here how the addition of the commercially available tris(pentafluorophenyl)borane Lewis acid, which has become a common place catalyst in its own right, leads to enhanced reactivity of GI. Moreover, the increased reactivity arises via halide abstraction rather than traditional phosphine dissociation, providing ring-opening metathesis polymerization products that are divergent from those synthesized without the …

Toxicity Of Crude Oil-Derived Polar Unresolved Complex Mixtures To Pacific Herring Embryos: Insights Beyond Polycyclic Aromatic Hydrocarbons, Maxwell L. Harsha, Yanila Salas-Ortiz, Alysha D. Cypher, Ed Osborn, Eduardo Turcios Valle, Jacob L. Gregg, Paul K. Hershberger, Yuri Kurerov, Sarah King, Aleksandar I. Goranov, Patrick G. Hatcher, Anastasia Konefal, T. Erin Cox, Justin B. Greer, James P. Meador, Matthew A. Tarr, Patrick L. Tomco, David C. Podgorski

Chemistry & Biochemistry Faculty Publications

Crude oil toxicity to early life stage fish is commonly attributed to polycyclic aromatic hydrocarbons (PAHs). However, it remains unclear how the polar unresolved complex mixture (UCM), which constitutes the bulk of the water-soluble fraction of crude oil, contributes to crude oil toxicity. Additionally, the role of photomodification-induced toxicity in relation to the polar UCM is not well understood. This study addresses these knowledge gaps by assessing the toxicity of two laboratory generated polar UCMs from Cook Inlet crude oil, representing the readily water-soluble fraction of crude oil and photoproduced hydrocarbon oxidation products (HOPs), to Pacific herring (Clupea pallasii …

The Impact Of Biochar's Physicochemical Properties On Sorption Of Perfluorooctanoic Acid (Pfoa), Karen Ane Skjennum, Katinka M. Krahn, Erlend Sørmo, Raoul Wolf, Aleksandar I. Goranov, Patrick G. Hatcher, Thomas Hartnik, Hans Peter H. Arp, Andrew R. Zimmerman, Yaxin Zhang, Gerard Cornelissen

Chemistry & Biochemistry Faculty Publications

To better characterize properties governing the sorption of per- and polyfluoroalkyl substances (PFAS) to biochar, twenty-three diverse biochars were characterized and evaluated as sorbents for perfluorooctanoic acid (PFOA). Biochars were produced at various temperatures, using two different technologies, and made from sewage sludge, food waste reject, wood wastes, and one reference substrate (wood pellets). The biochars were characterized in terms of surface area, pore volume and pore size distributions, elemental composition, leachable elements, ash content, pH, zeta potential, condensed aromatic carbon (ConAC) content (determined by benzenepolycarboxylic acid (BPCA) markers), and their -OH functional group content (infrared spectroscopy). PFOA sorption isotherms …

Antarctic Polar Stratospheric Cloud Analysis Of Ace-Fts Data From 2005 To 2023, M. Lecours, C. D. Boone, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

We present an analysis of Antarctic polar winters from 2005 to 2023 as observed by the Atmospheric Chemistry Experiment (ACE). The unique broad band infrared spectral features in ACE “residual” spectra are used to classify the spectra of polar aerosols by composition into polar stratospheric clouds (PSCs) and sulfate aerosols. The spectra of PSCs are further classified into nitric acid trihydrate, supercooled ternary solutions, supercooled nitric acid, ice-mix, and mixtures of PSCs. A breakdown of PSC composition is presented for each year. Antarctic winter seasons with unusual compositions are: 2011, in which volcanic ash mixed with PSCs was observed from …