Rapidly evolving ultrafine and fine mode biomass smoke physical properties: Comparing laboratory and field results

Combining field and laboratory results, we present biomass smoke physical properties. We report sub-0.56 µm diameter (Dp) particle sizing (fast mobility particle sizer, FMPS) plus light absorption and scattering at 870nm (photoacoustic extinctiometer). For Dp\u3c200 \u3enm, the FMPS characterized sizing within ±20% compared to standards. As compared to the traditional scanning mobility particle sizer, the FMPS responded most accurately to single-mode polydispersions with mean Dp\u3c200 \u3enm, which characterized the smoke sampled here. Smoke was measured from laboratory fresh emissions (seconds to hours old), the High Park Fire (hours to\u3c1 \u3eday), and from regional biomass burning (several days). During a High Park Fire episode, light extinction rapidly reached a maximum of σep = 569 ± 21Mm-1 (10 min) with aerosol single scattering albedo peaking at ω= 0.955 ± 0.004. Concurrently, number concentration and size peaked with maximum Dp = 126nm and a unimodal distribution with σg = 1.5. Long-range transported smoke was substantially diluted (Ntot factor of 7 lower) and shifted larger (maximum Dp = 143) and wider (σg = 2.2). We compared ambient data to laboratory burns with representative western U.S. forest fuels (coniferous species Ponderosa pine and Alaska black spruce). Smoldering pine produced an aerosol dominated by larger, more strongly light scattering particles (Dp\u3e100 nm), while flaming combustion produced very high number concentrations of smaller (Dp ~ 50 nm) absorbing particles. Due to smoldering and particle growth processes, Dp approached 100nm within 3 h after emission. Increased particle cross-sectional area and Mie scattering efficiency shifted the relative importance of light absorption (flaming maximum) and light scattering (smoldering maximum), increasing ω over time. Measurements showed a consistent picture of smoke properties from emission to aging

Ship-based measurements of ice nuclei concentrations over the Arctic, Atlantic, Pacific and Southern oceans

Ambient concentrations of ice-forming particles measured during ship expeditions are collected and summarised with the aim of determining the spatial distribution and variability in ice nuclei in oceanic regions. The presented data from literature and previously unpublished data from over 23 months of ship-based measurements stretch from the Arctic to the Southern Ocean and include a circumnavigation of Antarctica. In comparison to continental observations, ship-based measurements of ambient ice nuclei show 1 to 2 orders of magnitude lower mean concentrations. To quantify the geographical variability in oceanic areas, the concentration range of potential ice nuclei in different climate zones is analysed by meridionally dividing the expedition tracks into tropical, temperate and polar climate zones. We find that concentrations of ice nuclei in these meridional zones follow temperature spectra with similar slopes but vary in absolute concentration. Typically, the frequency with which specific concentrations of ice nuclei are observed at a certain temperature follows a log-normal distribution. A consequence of the log-normal distribution is that the mean concentration is higher than the most frequently measured concentration. Finally, the potential contribution of ship exhaust to the measured ice nuclei concentration on board research vessels is analysed as function of temperature. We find a sharp onset of the influence at approximately 36 C but none at warmer temperatures that could bias ship-based measurements. © Author(s) 2020. This work is distributed under the Creative Commons Attribution 4.0 License

Ice nucleating particle measurements of relevance to cloud properties in Polar Regions

第6回極域科学シンポジウム[OM] 極域気水圏11月16日（月）　統計数理研究所 セミナー室2（D304

Genetic correlation between amyotrophic lateral sclerosis and schizophrenia

A. Palotie on työryhmän Schizophrenia Working Grp Psychiat jäsen.We have previously shown higher-than-expected rates of schizophrenia in relatives of patients with amyotrophic lateral sclerosis (ALS), suggesting an aetiological relationship between the diseases. Here, we investigate the genetic relationship between ALS and schizophrenia using genome-wide association study data from over 100,000 unique individuals. Using linkage disequilibrium score regression, we estimate the genetic correlation between ALS and schizophrenia to be 14.3% (7.05-21.6; P = 1 x 10(-4)) with schizophrenia polygenic risk scores explaining up to 0.12% of the variance in ALS (P = 8.4 x 10(-7)). A modest increase in comorbidity of ALS and schizophrenia is expected given these findings (odds ratio 1.08-1.26) but this would require very large studies to observe epidemiologically. We identify five potential novel ALS-associated loci using conditional false discovery rate analysis. It is likely that shared neurobiological mechanisms between these two disorders will engender novel hypotheses in future preclinical and clinical studies.Peer reviewe

Guidelines for the use of flow cytometry and cell sorting in immunological studies (third edition)

The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer‐reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state‐of‐the‐art handbook for basic and clinical researchers.DFG, 389687267, Kompartimentalisierung, Aufrechterhaltung und Reaktivierung humaner Gedächtnis-T-Lymphozyten aus Knochenmark und peripherem BlutDFG, 80750187, SFB 841: Leberentzündungen: Infektion, Immunregulation und KonsequenzenEC/H2020/800924/EU/International Cancer Research Fellowships - 2/iCARE-2DFG, 252623821, Die Rolle von follikulären T-Helferzellen in T-Helferzell-Differenzierung, Funktion und PlastizitätDFG, 390873048, EXC 2151: ImmunoSensation2 - the immune sensory syste

Characteristics of atmospheric ice nucleating particles associated with biomass burning in the US: prescribed burns and wildfires

2013 Fall.Includes bibliographical references.Insufficient knowledge regarding the sources and number concentrations of atmospheric ice nucleating particles (INP) leads to large uncertainties in understanding the interaction of aerosols with cloud processes, such as cloud life time and precipitation rates. An increasingly important source of aerosol in the United States is biomass burning, particularly in the form of prescribed burns and wildfires in the southeastern and western U.S., respectively. Prior field and laboratory observations have suggested that biomass burning can be a source of INP. However, emissions from biomass burning are complex, varying with combustion efficiency, fuel type, plume age and dilution. Thus, this potentially important source of INP is poorly characterized. This study utilizes measurements of INP from a diverse set of biomass burning events to better understand INP associated with biomass burning in the U.S. Prescribed burns in Georgia and Colorado, two Colorado wildfires and two laboratory burns were monitored for INP number concentrations (nINP) using the Colorado State University continuous-flow diffusion chamber (CFDC) to activate INP in the condensation/immersion freezing nucleation mode. Additional measurements included total particle number concentrations, number concentrations of particles with diameters larger than 500 nm, aerosol mass concentrations, carbon monoxide concentrations and chemically-speciated bulk aerosol filter samples. Additionally, activated INP were collected onto TEM grids downstream of the CFDC, isolating INP for single particle chemical and morphological analyses. These fires varied by fuel type, including wiregrass, longleaf pine and ponderosa pine, and also varied by combustion efficiency, ranging from highly flaming to a mixture of flaming and smoldering. Additionally, plume histories were different between the fires including aged plumes from the wildfires and freshly emitted smoke from the prescribed and laboratory burns. The relationship between nINP and total particle number concentrations, evident within prescribed burning plumes, was degraded within aged smoke plumes from the wildfires, limiting the utility of this relationship for comparing laboratory and field data. Larger particles, represented by n500nm, are less vulnerable to plume processing and have previously been evaluated for their relation to nINP. Our measurements indicated that for a given n500nm, nINP associated with the wildfires were nearly an order of magnitude higher than nINP found in prescribed fire emissions. That is, nINP represented a much larger fraction of n500nm in wildfires as compared with prescribed fires. Further, an existing parameterization for "global" nINP that relates INP abundance to n500nm largely under-predicted and over-predicted nINP emitted from wildfires and prescribed burns, respectively. Reasons for the differences between INP characteristics in these emissions were explored, including variations in combustion efficiency, fuel type, transport time and environmental conditions. Combustion efficiency and fuel type were eliminated as controlling factors by comparing samples with contrasting combustion efficiencies and fuel types. Transport time was eliminated because the expected impact would be to reduce n500nm, thus resulting in the opposite effect from the observed change. Bulk aerosol chemical composition analyses support the potential role of elevated soil dust particle concentrations during the fires, contributing to the population of INP, but the bulk analyses do not target INP composition directly. Predictions from the Naval Aerosol Analysis and Prediction System model further indicate elevated dust mass concentrations during the wildfire periods, suggesting impact of mineral dust from long-range transport (LRT). It is hypothesized that both hardwood burning and soil lofting are responsible for the elevated production of INP in the Colorado wildfires in addition to LRT of mineral dust. The chemical compositions of INP were probed directly via TEM imaging. Single particle analyses of residual INP showed that they comprised various C-containing particle types, but with a higher abundance of mineral and metal oxide containing INP in emissions from flaming phase combustion. Fractal soot was found as an INP type comprising up to 60% of collected INP in young smoke emissions from the Georgia prescribed burns. In a series of laboratory combustion experiments, the use of a new instrumental set up, pairing the CFDC with a single particle soot photometer, revealed up to a 60% decrease in active INP after the removal of refractory black carbon from smoke aerosol emitted from a highly flaming burn of wiregrass, supporting that soot particles serve as INP in fire emissions. The presence of soil minerals was clearly evident in TEM images of samples taken during the wildfires in addition to tarballs, carbon balls most commonly associated with aged smoke plumes. These results demonstrate that the ice nucleating particles observed in the wildfires were influenced by other factors not represented in the smoke emitted from the laboratory or prescribed burns. Finally, an INP parameterization was developed based on the temperature dependent relationship between nINP and n500nm, following methods used by previous studies. This parameterization is likely only representative of the Hewlett and High Park wildfires due to the apparent impact of non-biomass-burning aerosol. However, all wildfires are typically associated with vigorous localized convection and arid soils, required for the lofting of the soils and dusts similar to these wildfires. It will be useful to compare future wildfires in various regions to the proposed parameterization

Marine and Terrestrial Organic Ice-Nucleating Particles in Pristine Marine to Continentally Influenced Northeast Atlantic Air Masses

ISSN:0148-0227ISSN:2169-897

Ice nucleation by particles containing long-chain fatty acids of relevance to freezing by sea spray aerosols.

Heterogeneous ice nucleation in the atmosphere regulates cloud properties, such as phase (ice versus liquid) and lifetime. Aerosol particles of marine origin are relevant ice nucleating particle sources when marine aerosol layers are lifted over mountainous terrain and in higher latitude ocean boundary layers, distant from terrestrial aerosol sources. Among many particle compositions associated with ice nucleation by sea spray aerosols are highly saturated fatty acids. Previous studies have not demonstrated their ability to freeze dilute water droplets. This study investigates ice nucleation by monolayers at the surface of supercooled droplets and as crystalline particles at temperatures exceeding the threshold for homogeneous freezing. Results show the poor efficiency of long chain fatty acid (C16, C18) monolayers in templating freezing of pure water droplets and seawater subphase to temperatures of at least -30 °C, consistent with theory. This contrasts with freezing of fatty alcohols (C22 used here) at nearly 20 °C warmer. Evaporation of μL-sized droplets to promote structural compression of a C19 acid monolayer did not favor warmer ice formation of drops. Heterogeneous ice nucleation occurred for nL-sized droplets condensed on 5 to 100 μm crystalline particles of fatty acid (C12 to C20) at a range of temperatures below -28 °C. These experiments suggest that fatty acids nucleate ice at warmer than -36 °C only when the crystalline phase is present. Rough estimates of ice active site densities are consistent with those of marine aerosols, but require knowledge of the proportion of surface area comprised of fatty acids for application

Ice nucleation by particles containing long-chain fatty acids of relevance to freezing by sea spray aerosols.

Heterogeneous ice nucleation in the atmosphere regulates cloud properties, such as phase (ice versus liquid) and lifetime. Aerosol particles of marine origin are relevant ice nucleating particle sources when marine aerosol layers are lifted over mountainous terrain and in higher latitude ocean boundary layers, distant from terrestrial aerosol sources. Among many particle compositions associated with ice nucleation by sea spray aerosols are highly saturated fatty acids. Previous studies have not demonstrated their ability to freeze dilute water droplets. This study investigates ice nucleation by monolayers at the surface of supercooled droplets and as crystalline particles at temperatures exceeding the threshold for homogeneous freezing. Results show the poor efficiency of long chain fatty acid (C16, C18) monolayers in templating freezing of pure water droplets and seawater subphase to temperatures of at least -30 °C, consistent with theory. This contrasts with freezing of fatty alcohols (C22 used here) at nearly 20 °C warmer. Evaporation of μL-sized droplets to promote structural compression of a C19 acid monolayer did not favor warmer ice formation of drops. Heterogeneous ice nucleation occurred for nL-sized droplets condensed on 5 to 100 μm crystalline particles of fatty acid (C12 to C20) at a range of temperatures below -28 °C. These experiments suggest that fatty acids nucleate ice at warmer than -36 °C only when the crystalline phase is present. Rough estimates of ice active site densities are consistent with those of marine aerosols, but require knowledge of the proportion of surface area comprised of fatty acids for application