cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.6075/j0dn437m
title: Data From: Reactions of N<sub>2</sub>O<sub>5</sub> with Salty and Surfactant-Coated Glycerol: Interfacial Conversion of Br<sup>–</sup> to Br<sub>2</sub> Mediated by Alkylammonium Cations. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: Publication abstract: Gas−liquid scattering and product-yield experiments are used to investigate reactions of N<sub>2</sub>O<sub>5</sub> with glycerol containing Br<sup>-</sup> and surfactant ions. N<sub>2</sub>O<sub>5</sub> oxidizes Br<sup>-</sup> to Br<sub>2</sub> for every solution tested: 2.7 M NaBr, 0.03 M tetrahexylammonium bromide (THABr), 0.03MTHABr + 0.5MNaBr, 0.03MTHABr + 0.5MNaCl, 0.03MTHABr + 0.01 M sodium dodecyl sulfate (SDS), and 0.01 M cetyltrimethylammonium bromide (CTABr). N<sub>2</sub>O<sub>5</sub> also reacts with glycerol itself to produce mono- and dinitroglycerin. Surface tension measurements indicate that 0.03 M THABr and 2.7 M NaBr have similar interfacial Br<sup>-</sup> concentrations, though their bulk Br<sup>-</sup> concentrations differ by 90-fold. We find that twice as much Br<sub>2</sub> is produced in the presence of THA+, implying that the conversion of Br<sup>-</sup> to Br<sub>2</sub> is initiated at the interface, perhaps mediated by the charged, hydrophobic pocket within the surface THA<sup>+</sup> cation. The addition of 0.5 M NaBr, 0.5 M NaCl, or 0.01 M SDS to 0.03 M THABr lowers the Br<sub>2</sub> production rate by 23%, 63%, and 67% of the THABr value, respectively. When CTA<sup>+</sup> is substituted for THA<sup>+</sup>,Br<sub>2</sub> production drops to 12% of the THABr value. The generation of Br<sub>2</sub> under such different conditions implies that trace amounts of surface-active alkylammonium ions can catalyze interfacial N<sub>2</sub>O<sub>5</sub> reactions, even when salts and other surfactants are present.
DOI: 10.6075/j04j0f85
title: Data from: Absorption Spectra and Electronic Structure of Gallic Acid in Water at Different pH: Experimental Data and Theoretical Cluster Models. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: Publication abstract: Gallic acid (GA) has been characterized in terms of its optical properties in aqueous solutions at varying pH in experiments and in theoretical calculations by analyzing protonated and deprotonated forms of GA. This work is a part of a series of studies of the optical properties of different carboxylic acids in aqueous media. The experimental electronic spectra of GA exhibits two strong well-separated absorption peaks (B- and C-bands), which agrees with previous studies. However, in the current study, an additional well-defined low-energy shoulder band (A-band) in the optical spectra of GA was identified. It is likely that the A-band occurs for other carboxylic acids in solution, but because it can overlap with B-band, it is difficult to discern. The theoretical calculations based on density functional theory were used to simulate optical absorption spectra of GA in water at different pH to prove the existence of this newly founded shoulder band and to describe and characterize full experimental optical spectra of GA. Different cluster models were tested: (i) all water molecules are coordinated near the carboxy-group, and (ii) additional water molecules near the hydroxy-groups of the phenyl ring were included. In this study, we found that both the polarizable continuum model (dielectric property of medium) and neighboring water molecules (hydrogen-bonding) play significant roles in the optical spectrum. Results showed, that only extended cluster-model with water molecules near carboxy- and hydroxy-groups together with polarizable continuum model allowed to fully reproduce the experimental data and captured all three absorption bands (A, B and C). Oscillator strengths of absorption bands were obtained from the experimental data and compared with theoretical results. Additionally, our work provides a detailed interpretation of pH effects observed in the experimental absorption spectra.
DOI: 10.6075/j02807s1
title: Data from: Enrichment of Saccharides at Air-Water Interface: A Quantitative Comparison of Sea Surface Microlayer and Foam. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: Organic matter accumulates at the ocean surface. Herein, we provide the first quantitative assessment of the enrichment of dissolved saccharides in persistent whitecap foam and compare this enrichment to the sea surface microlayer (SSML) during a nine day mesocosm experiment involving a phytoplankton bloom. Free monosaccharides were quantified directly, total saccharides were determined following mild acid hydrolysis, and the oligo/polysaccharide component was determined as the difference between total and free monosaccharides. Total saccharides contributed a significant fraction of dissolved organic carbon (DOC), accounting for 13% of DOC in seawater, 27% in SSML and 31% in foam. Median enrichment factors (EF), calculated as the ratio of the concentrations of saccharides relative to sodium in SSML or foam to that of seawater, ranged from 1.7-6.4 in SSML and 2.1-12.1 in foam. Based on median EFs, xylitol, mannitol, glucose, galactose, mannose, xylose, fucose, rhamnose and ribose were more enriched in foam than SSML. The greatest EFs for saccharides coincided with high chlorophyll levels, indicating increasing ocean surface enrichment of saccharides during phytoplankton blooms. Higher enrichments of organic matter in sea foam over the SSML indicate that surface active organic compounds become increasingly enriched on persistent bubble film surfaces. These findings help to explain how marine organic matter becomes highly enriched in sea spray aerosol that is generated by bursting bubbles at the ocean surface. Here we provide the first quantitative enrichment of saccharides on bubble film surfaces where SSA is generated. We observed higher saccharide enrichment in persistent foam compared to SSML, which suggests that maturation of bubbles at the air-water interface contribute to enrichment of organic matter at the ocean surface and ultimately in SSA. Structure-related saccharides, particularly those with HMW, are selectively enriched at the ocean surface. Because of the size of high molecular weight structure-related saccharides, they are unlikely to be transferred to sub-micrometer sized particles, and are more likely to be in super-micron SSA. The quantitative results obtained from this study support the theoretical concept of free monosaccharide enrichment in ocean surface and field observations of saccharide enrichment in SSA.
DOI: 10.6075/j09s1r6b
title: Data from: The effects of atmospheric heterogeneous aging on nascent sea spray aerosols physicochemical properties. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: The effects of atmospherically relevant heterogenous aging on ambient nascent sea spray aerosols (nSSA) physicochemical properties, such as morphology, composition, phase state, water uptake and their size-dependent particle-to-particle variability remained poorly understood. Thus, current study investigates these physicochemical properties, by focusing on heterogeneously aged SSA (hetSSA, size range of 0.1−0.6 μm) generated during a mesocosm study. The hetSSA were generated by exposing nSSA to OH radicals with 4-5 days of atmospheric time-equivalent aging. Filter-based thermal optical analysis, atomic force microscopy (AFM), and AFM photothermal infrared spectroscopy (AFM-PTIR) were utilized. Results collected on hetSSA physicochemical properties were compared with nSSA, collected during the same study. Filter-based measurements
DOI: 10.6075/j0668bh8
title: Data from: Direct on-line mass spectrometry measurements of ice nucleating particles at a California coastal site. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: This item contains the data used in the paper "Direct on-line mass spectrometry measurements of ice nucleating particles at a California coastal site." Data was collected at Bodega Bay (-123.1 W, 38.3 N, alt 15 m) from Feb 12-20, 2015.
description: Data was processed and analyzed in Matlab 2016b. ATOFMS data was processed using the Matlab software toolkit FATES.
DOI: 10.6075/j0pg1q84
title: Data from: Relating Structure and Ice Nucleation of Mixed Surfactant Systems Relevant to Sea Spray Aerosol. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: Publication abstract: Ice nucleating particles (INPs) influence weather and climate by their effect on cloud phase state. Fatty alcohols present within aerosol particles confer a potentially important source of ice nucleation activity to sea spray aerosol produced in oceanic regions. However, their interactions with other aerosol components and the influence on freezing were previously largely unknown. Here we report quantitative measurements of fatty alcohols in model sea spray aerosol and examine the relationships between the composition and structure of the surfactants and subphase in the context of these measurements. Deposited mixtures of surfactants retain the ability to nucleate ice, even in fatty-acid-dominant compositions. Strong refreezing effects are also observed, where previously frozen water-surfactant samples nucleate more efficiently. Structural sources of refreezing behavior are identified as either kinetically trapped film states or 3D solid surfactant particles. Salt effects are especially important for surfactant INPs, where high salt concentrations suppress freezing. A simple water uptake model suggests that surfactant-containing aerosol requires either very low salt content, or kinetic trapping as solid particles to act as INPs in the atmosphere. These types of INP could be identified through comparison of different INP instrument responses.
DOI: 10.6075/j04748d9
title: Data from: Size Dependent Morphology, Phase State, Composition and Water Uptake of Nascent Submicrometer Sea Spray Aerosols During a Phytoplankton Bloom. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: Publication abstract: Sea spray aerosols (SSA) are generated at the ocean-air interface during wave breaking and provide a significant contribution to the climatic-relevant processes via directly by scattering and absorbing solar radiation, and indirectly by activating into cloud condensation nuclei (CCN) or ice nucleating particles (INP). Depending on the generation mechanism on the ocean surface, SSA can exhibit size dependence particle-to-particle variation in physicochemical properties such as the morphology or mixing state, chemical composition, phase states, and water uptake. However, a complete study to correlate the field collected individual submicron SSA particles morphology or mixing state with their corresponding chemical composition, phase state, and water uptake as a function of size, relative humidity (RH), and biological activity in the seawater is not been recorded yet. Herein, the AFM-based imaging and force spectroscopy was used to directly probe the substrate deposited, submicron individual SSA particles morphology, phase state, and water uptake as a function of RH, particle size, as well as the biological activity in water. Five different morphologies of SSA particles were identified over the phytoplankton bloom period. Size dependent phase state measurements revealed the variation of particles phase states as a function of particle size, morphology, as well as the bloom designation day. The water uptake studies showed the different water uptake abilities of the particles depending on the particle morphology and the bloom designation day. Overall, results confirmed that the individual submicron SSA can have a significant difference between the morphologies, phase state, and water uptake depending on the particle size and the biological activity in the seawater.
DOI: 10.6075/j0rb74sb
title: Data from: Amino Acids are Driven to the Interface by Salts and Acidic Environments. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: Publication abstract: Amino acids (AAs), the building blocks of proteins, are enriched by several orders of magnitude in sea spray aerosols compared to ocean waters. This suggests that AAs may reside at the air-water interface and be highly surface active. Using surface tension measurements, infrared reflection-absorption spectroscopy, and molecular dynamics simulations, we show that AAs are surface active and that salts and low pH environments are drivers of surface activity. At typical sea spray salt concentrations and pH values, we determine that the surface coverage of hydrophobic AAs increases by approximately one order of magnitude. Additionally, divalent cations such as Ca2+ and Mg2+ can further increase surface propensity, particularly at neutral pH. Overall, these results indicate that AAs are likely to be found at elevated concentrations at the surface of sea spray aerosols, where they can impact cloud activation properties of the aerosol as well as enhanced peptide formation under certain conditions.
DOI: 10.6075/j0r20zw6
title: Data from: Marine Bacteria Affect Saccharide Enrichment in Sea Spray Aerosol during a Phytoplankton Bloom. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: Publication abstract: Saccharides are a large class of organic matter in sea spray aerosol (SSA) that can impact climate-relevant properties of SSA including hygroscopicity. In seawater, saccharides are produced, exuded, and consumed by phytoplankton and bacteria. However, how heterotrophic bacteria (HB) affect the concentrations of saccharides in seawater and ultimately the composition of SSA were not directly measured in previous experiments. Herein, we added HB to a microcosm to examine how they affect the composition and size of saccharides in seawater and SSA during a phytoplankton bloom. Enrichment factors (EF) between seawater and SSA for saccharides were composition and size-dependent, ranging 100-930,000 in submicron SSA and 38-3700 in supermicron SSA. For glucose, EF increased 30-fold in submicron SSA within a day after HB addition, coincident with increased enzyme activity that indicates increased processing of glucose-containing polysaccharides increased their enrichment in SSA. In contrast, a 20-fold increase in arabinose EF in supermicron SSA lagged behind the HB addition and peak enzyme activity by two days, while EFs of xylose in SSA remained relatively consistent. Together, these observations reflect HB impact saccharide EFs based on composition. For two similar phytoplankton blooms, elevated HB increased saccharide EFs in SSA by 10-fold or more; our data show that HB modified the existing saccharide pool that selectively modified the enrichment of saccharides in SSA. Better understanding the chemical, biological, and physical factors that contribute to the large enrichment of saccharides in SSA will advance our ability to predict the roles of SSA in our planet’s climate.
DOI: 10.6075/j0xk8d31
title: Data from: Tandem fluorescence measurements of organic matter and bacteria released in sea spray aerosols. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: Publication abstract: Biological aerosols, typically identified through their fluorescence properties, strongly influence clouds and climate. Sea spray aerosols (SSA) are a major source of biological aerosols, but detection in the atmosphere is challenging due to potential interference from other sources. Here, the fluorescence signature of isolated SSA, produced using laboratory-based aerosol generation methods, was analyzed and compared with two commonly used fluorescence techniques: excitation-emission matrix spectroscopy (EEMS) and the Wideband Integrated Bioaerosol Sensor (WIBS). A range of dynamic biological ocean scenarios were tested to compare EEMS and WIBS analyses of SSA. Both techniques revealed similar trends in SSA fluorescence intensity in response to changes in ocean microbiology, demonstrating the potential to use the WIBS to measure fluorescent aerosols alongside EEMS bulk solution measurements. Together, these instruments revealed a unique fluorescence signature of isolated, nascent SSA and, for the first time, a size segregated emission of fluorescent species in SSA. Additionally, the fluorescence signature of aerosolized marine bacterial isolates was characterized and showed similar fluorescence peaks to those of SSA, suggesting that bacteria are a contributor to SSA fluorescence. Through investigation of isolated SSA, this study provides a reference for future identification of marine biological aerosols in a complex atmosphere.
DOI: 10.6075/j0t1522v
title: Data from: Ejection of dust from the ocean as a potential source of marine ice nucleating particles. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: Abstract: Oceans are, generally, relatively weak sources of ice nucleating particles (INPs). Thus, dust transported from terrestrial regions can dominate atmospheric INP concentrations even in remote marine regions. Studies of ocean-emitted INPs have focused upon sea spray aerosols containing biogenic species. Even though large concentrations of dust are transported over marine regions, resuspended dust has never been explicitly considered as another possible source of ocean-emitted INPs. Current models assume that deposited dust is not re-emitted from surface waters. Our laboratory studies of aerosol particles produced from coastal seawater and synthetic seawater doped with dust show that dust can indeed be ejected from water during bubble bursting. INP concentration measurements show these ejected dust particles retain ice nucleating activity. Doping synthetic seawater to simulate a strong dust deposition event produced INPs active at temperatures colder than -13 ºC and INP concentrations one to two orders of magnitude greater than either lab sea spray or marine boundary layer measurements. The relevance of these laboratory findings is highlighted by single particle composition measurements along the California coast where at least 9% of dust particles were mixed with sea salt. Additionally, global modeling studies show that resuspension of dust from the ocean could exert the most impact over the Southern Ocean, where ocean-emitted INPs are thought to dominate atmospheric INP populations. More work characterizing the factors governing the resuspension of dust particles is required to understand the potential impact upon clouds.
DOI: 10.6075/j0zc80s8
title: Data from: Automation and Heat Transfer Characterization of Immersion Mode Spectroscopy for Analysis of Ice Nucleating Particles. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: The heat transfer properties of the SIO-Automated Ice Spectrometer (AIS), an ice nucleation measurement technique, are characterized using a finite-element analysis based heat transfer simulation that was developed using the 3D Design Software SOLIDWORKS. The heat transfer simulation is proposed as a tool that could be used to explain the sources of bias in temperature measurements in ice nucleation particles (INP) measurement techniques, and ultimately explain the observed discrepancies in measured ice nucleation particles (INP) freezing temperatures between different instruments. The simulation results posted here show that a difference of +8.4 °C between the well base temperature and the headspace gas results in an up to 0.6 °C stratification of the aliquot, whereas a difference of +4.2 °C or less results in a thermally homogenous water volume within the error of the thermal probe, ±0.2 °C. The results also show that there is a strong temperature gradient in the immediate vicinity of the aliquot, such that without careful placement of temperature probes, or characterization of heat transfer properties of the water and cooling environment, ice nucleation particles (INP) measurements can be biased toward colder temperatures. Using the modified immersion mode technique, the Automated Ice Spectrometer (AIS) measurements of the standard test dust illite NX are reported and compared against 6 other immersion mode droplet assay techniques featured in (Hiranuma et al., 2015) that used wet suspensions.
DOI: 10.6075/j028065j
title: Data from: Acidity Across the Interface: From the Ocean Surface to Sea Spray Aerosol. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: All code is saved as .mat files and each is written to function as a MATLAB R2019b script, figure, or data source for a script.
description: Publication abstract: Aerosols impact climate, human health and the chemistry of the atmosphere and aerosol pH plays a major role in the physicochemical properties of the aerosol. However, there remains uncertainty as to whether aerosols are acidic, neutral, or basic. In this research, we show that the pH of freshly emitted (nascent) sea spray aerosols is significantly lower than that of sea water (approximately four pH units, with pH being a log scale value) and that smaller aerosol particles below 1 micron in diameter have pH values that are even lower. These measurements of nascent sea spray aerosol pH, performed in a unique ocean-atmosphere facility, provide convincing data to show that acidification occurs "across the interface" within minutes, when aerosols form from ocean surface waters and become airborne. We also show there is a correlation between aerosol acidity and dissolved carbon dioxide but no correlation with marine biology within the seawater. We discuss the mechanisms and contributing factors to this acidity and its implications on atmospheric chemistry.
DOI: 10.6075/j0zs2wpj
title: Data from: Electronic and mechanical anharmonicities in the vibrational spectra of the H-bonded, cryogenically cooled X‾∙HOCl (X=Cl, Br, I) complexes: Characterization of the strong anionic H-bond to an acidic OH group. In Center for Aerosol Impacts on Chemistry of the Environment (CAICE)

description: Publication Abstract: We report vibrational spectra of the H2-tagged, cryogenically cooled X‾∙HOCl (X = Cl, Br and I) ion-molecule complexes and analyze the resulting band patterns with electronic structure calculations and an anharmonic theoretical treatment of nuclear motions on extended potential energy surfaces. The complexes are formed by “ligand exchange” reactions of X‾∙(H2O)n clusters with HOCl molecules at low pressure (~10−2 mbar) in a radio-frequency ion guide. The spectra generally feature many bands in addition to the fundamentals expected at the double harmonic level. These “extra bands” appear in patterns that are similar to those displayed by the X‾∙HOD analogues, where they are assigned to excitations of nominally IR forbidden overtones and combination bands. The interactions driving these features include mechanical and electronic anharmonicities. Particularly intense bands are observed for the v = 0 → 2 transitions of the out-of-plane bending soft modes of the HOCl molecule relative to the ions. These involve displacements that act to break the strong H-bond to the ion, which give rise to large quadratic dependences of the electric dipoles (electronic anharmonicities) that drive the transition moments for the overtone bands. On the other hand, overtone bands arising from the intramolecular OH bending modes of HOCl are traced to mechanical anharmonic coupling with the v = 1 level of the OH stretch (Fermi resonances). These interactions are similar in strength to those reported earlier for the X‾∙HOD complexes.