Active vegetation fires in south‐eastern (SE) Europe resulted in a notable increase in the number concentration of aerosols and cloud condensation nuclei (CCN) particles at two high latitude ...locations—the SMEAR IV station in Kuopio, Finland, and the Zeppelin Observatory in Svalbard, high Arctic. During the fire episode aerosol hygroscopicity κ slightly increased at SMEAR IV and at the Zeppelin Observatory κ decreased. Despite increased κ in high CCN conditions at SMEAR IV, the aerosol activation diameter increased due to the decreased supersaturation with an increase in aerosol loading. In addition, at SMEAR IV during the fire episode, in situ measured cloud droplet number concentration (CDNC) increased by a factor of ∼7 as compared to non‐fire periods which was in good agreement with the satellite observations (MODIS, Terra). Results from this study show the importance of SE European fires for cloud properties and radiative forcing in high latitudes.
Plain Language Summary
Wildfires are large sources of aerosol particles and affect human health and climate. Aerosols from fires are transported long distances in the atmosphere and affect the aerosol and cloud properties at places far from the actual sources. In this study, we measured the long‐range transported (LRT) fire air masses from south‐eastern (SE) Europe at a northern European and a high Arctic site. LRT fire emissions from SE Europe increase the aerosol number and mass loading in Finland and even in the high Arctic. Results show that the effect of fire emissions on aerosol hygroscopicity depends on the properties of both the LRT fires and the background aerosols at a given location. The cloud properties analysis in eastern Finland shows that despite high hygroscopicity and increased CCN activity, the aerosol activation diameter for clouds increased during the fire episode. This is due to the depletion of available water vapor in clouds due to the increased aerosol loading. Satellite observations show an increase in cloud droplet number concentration during the fire episode confirming the effect of LRT fires on cloud properties in eastern Finland. This study can improve the understanding of the effect of LRT fires on aerosol and cloud properties at remote locations.
Key Points
Vegetation fires from southern Europe enhance aerosol and cloud condensation nuclei concentrations in northern Europe and the high Arctic
A contrary trend in aerosol hygroscopicity is observed at these two locations during a strong fire episode as compared to non‐fire periods
Cloud droplet number concentrations in liquid clouds show strong response to fire aerosol both in in situ and satellite observations
The Puijo aerosol-cloud observation station is a unique measurement site for its location in the mixed region between the boreal forestland and the municipality of Kuopio, Finland. A measurement ...campaign was carried out at the station during fall 2010. An Aerodyne high-resolution time-of-flight aerosol mass spectrometer (HR-Tof-AMS) was deployed to characterize the atmospheric submicron aerosols. Positive matrix factorization (PMF) was applied to the unified high-resolution mass spectra organic species with NO+ and NO2+ ions to discover the intrinsic relationships between the organic and inorganic species and their daily cycles. On average, the submicron aerosols in this study were dominated by organic and sulfate species, composing 48.2 and 28.7% of total observed aerosol mass, respectively, with smaller contributions from ammonium (9.3%), nitrate (4.9%), chloride (0.8%) and BC (8.1%). The sources of these species included the primary emissions originating from the city area, secondary formation from both natural and anthropogenic emissions and regional transport. The PMF analysis succeeded in separating the mixed organic and inorganic spectra into three distinct organic and one inorganic factors. For organic factors, the semi-volatile oxygenated organic aerosol (SVOOA) and low-volatility oxygenated OA (LVOOA) accounted for 54.8 and 36.3% of total organic masses, respectively, while the hydrocarbon-like organic aerosol (HOA) accounted for 8.9% of total organics, with its main source from urban emissions. The inorganic factor is identified as NH4NO3, comprising 6.9% of the fitted aerosol mass by PMF. Based on the PMF results, the nitrate species were separated into organic and inorganic components, with the organic nitrates contributing one-third of the total nitrate mass. The results highlight both anthropogenic and biogenic emissions as important atmospheric aerosol sources in a forest-urban mixed region.
This collection of studies tested aspects of Cortina’s theory of selective incivility as a “modern” manifestation of sexism and racism in the workplace and also tested an extension of that theory to ...ageism. Survey data came from employees in three organizations: a city government (N = 369), a law enforcement agency (N = 653), and the U.S. military (N = 15,497). According to analyses of simple mediation, target gender and race (but not age) affected vulnerability to uncivil treatment on the job, which in turn predicted intent to leave that job. Evidence of moderated mediation also emerged, with target gender and race interacting to predict uncivil experiences, such that women of color reported the worst treatment. The article concludes with implications for interventions to promote civility and nondiscrimination in organizations.
Aerosol equivalent black carbon (BC
e) was measured at five different background stations in Finland, with the longest data set from Hyytiälä, December 2004–December 2008. Measurements were conducted ...either with an aethalometer or a Multi-Angle Absorption Photometer, MAAP. Measured black carbon concentrations were highest in Virolahti in southeastern Finland, with annual averages ranging from 385 to 460 ng m
−3, followed by Hyytiälä (250–370 ng m
−3), Utö (230–270 ng m
−3), Puijo (225–230 ng m
−3), and Pallastunturi (60–70 ng m
−3) in northern Finland. The BC
e fractions of measured PM
2.5 concentrations were generally between 5 and 10%, with highest fractions at Virolahti close to the Eastern border. At all the stations, the highest concentrations were observed during the spring and the winter, and the lowest concentrations during the summer. The seasonal cycle could generally be attributed to the reaching of long-range-transported black carbon. Additional reasons were increasing domestic wood burning and reduced boundary-layer height during winter, and a more effective vertical mixing during summer. The highest concentrations for each station occurred with southerly winds, and on the basis of trajectory analyses, the source areas of BC
e resided mostly in Central and Eastern Europe. Occasionally the long-range-transported BC
e concentrations were elevated for short periods to fulfill the characteristics of pollution episodes. From these episodes, about 62% were a result of non-fire anthropogenic sources and 36% due to open biomass burning sources. Episodes from the biomass burning sources were most often observed during the spring.
► Long term black carbon measurements reported in and close to the Arctic. ► Trans-boundary transport a major source of black carbon in clean areas. ► Open biomass burning a reason for transported black carbon in Northern Europe.
In the summer 2010 extensive wildfires in the western parts of Russia emitted massive amounts of smoke and aerosols into the atmosphere. These smoke plumes also drifted to Finland over 1000 km away ...from the fires. The smoke plumes were detected in Kuopio (Eastern Finland) with a wide range of instruments on two specific days: July 29 and August 8. The plumes were studied with several spaceborne instruments: MODIS, OMI, AIRS and CALIOP. Furthermore, a ground-based remote sensing instrument (Cimel) was also used in the analysis. Our results show that ground-based and spaceborne instruments were in good agreement on the Aerosol optical depth (AOD
550) values during the episode (July–mid August). The correlation coefficient between MODIS and AERONET measurements done in Kuopio was 0.98 and the mean difference was 0.005 (AERONET AOD being larger). Spaceborne measurements of carbon monoxide provided a clear indicator for biomass burning aerosols. Particle mass (PM
2.5) and AERONET AOD
550 measurements were also in good agreement with a correlation coefficient of 0.87. Single scattering albedo (SSA
675) values derived from AERONET measurements and calculated from in-situ absorption and scattering measurements had similar values close 0.9. On average, the daily in-situ SSA values were 0.02 smaller than the corresponding AERONET values. CALIOP provided vertical profiles of the smoke plumes for the two most polluted days in Kuopio. In July the plume was located close to the surface (mainly below 2 km) while in August the plume had two elevated layers: one between 1 and 2 km and the other between 2.5 and 4 km.
► We studied the 2010 Russian wildfires with remote sensing instruments. ► Ground-based and spaceborne instruments were in good agreement. ► Combined ground-based and spaceborne measurements describe the episode thoroughly.
A 29 m3 Teflon chamber, designed for studies on the aging of combustion aerosols, at the University of Eastern Finland is described and characterized. The chamber is part of a research facility, ...called Ilmari, where small-scale combustion devices, a dynamometer for vehicle exhaust studies, dilution systems, the chamber, and cell and animal exposure devices are located side by side under the same roof. The small surface-to-volume ratio of the chamber enables reasonably long experiment times, with particle wall loss rate constants of 0.088, 0.080, 0.045, and 0.040 h−1 for polydisperse, 50, 100, and 200 nm monodisperse aerosols, respectively. The NO2 photolysis rate can be adjusted from 0 to 0.62 min−1. The irradiance spectrum is centered at either 350 or 365 nm, and the maximum irradiance, produced by up to 160 blacklight lamps, is 29.7 W m−2, which corresponds to the ultraviolet (UV) irradiance in Central Finland at noon on a sunny day in the midsummer. The temperature inside the chamber is uniform and can be kept at 25±1 °C. The chamber is kept in an overpressure with a moving top frame, which reduces sample dilution and entrance of contamination during an experiment. The functionality of the chamber was tested with oxidation experiments of toluene, resulting in secondary organic aerosol (SOA) yields of 12–42%, depending on the initial conditions, such as NOx concentration and UV irradiation. The highest gaseous oxidation product yields of 12.4–19.5% and 5.8–19.5% were detected with ions corresponding to methyl glyoxal (m/z 73.029) and 4-oxo-2-pentenal (m/z 99.044), respectively. Overall, reasonable yields of SOA and gaseous reaction products, comparable to those obtained in other laboratories, were obtained.
Interactions between aerosols and liquid water clouds were studied during autumns 2010–2011 at a semiurban measurement station on Puijo tower in Kuopio, Finland. Cloud interstitial and total aerosol ...size distributions, particle chemical composition and hygroscopicity and cloud droplet size distribution were measured, with a focus on comparing clean air masses with those affected by local sources. On average, the polluted air contained more particles than the clean air masses, and generally the concentrations decreased during cloud events. Cloud processing was found to take place, especially in the clean air masses, and to a lesser extent in the polluted air. Some, mostly minor, differences in the average particle chemical composition between the air masses were observed. The average size and number concentration of activating particles were quite similar for both air masses, producing average droplet populations with only minor distinctions. As a case study, a long cloud event was analyzed in detail, with a special focus on the emissions from local sources, including a paper mill and a heating plant. This revealed larger variations in particle and cloud properties than the analysis of the whole data set. Clear differences in the total (between 214 and 2200 cm−3) and accumulation mode particle concentrations (between 62 and 169 cm−3) were observed. Particle chemical composition, especially the concentrations of organics (between 0.42 and 1.28 μg m−3) and sulfate (between 0.16 and 4.43 μg m−3), varied considerably. This affected the hygroscopic growth factor: for example, for 100 nm particles the range was from 1.21 to 1.45 at 90% relative humidity. Particularly, large particles, high hygroscopicities and elevated amounts of inorganics were linked with the pollutant plumes. Moreover, the particle hygroscopicity distributions in the polluted air were clearly bimodal, indicating externally mixed aerosol. The variable conditions also had an impact on cloud droplet formation, with the droplet concentration varying between 138 and 240 cm−3 and mean diameter between 9.2 and 12.4 μm.
We introduce a four-year (in 2006–2010) continuous data set of aerosol optical properties at Puijo in Kuopio, Finland. We study the annual and diurnal variation of the aerosol scattering and ...absorption coefficients, hemispheric backscattering fraction, scattering Ångström exponent, and single scattering albedo, whose median values over this period were 7.2 Mm−1 (at 550 nm), 1.0 Mm−1 (at 637 nm), 0.15, 1.93 (between 450 and 550 nm), and 0.85, respectively. The scattering coefficient peaked in the spring and autumn, being 2–4 times those in the summer and winter. An exception was the summer of 2010, when the scattering coefficient was elevated to ~300 Mm−1 by plumes from forest fires in Russia. The absorption coefficient peaked in the winter when soot-containing particles derived from biomass burning were present. The higher relative absorption coefficients resulted in lower single scattering albedo in winter. The optical properties varied also with wind direction and time of the day, indicating the effect of the local pollutant sources and the age of the particles. Peak values in the single scattering albedo were observed when the wind blew from a paper mill and from the sector without local pollutant sources. These observations were linked, respectively, to the sulphate-rich aerosol from the paper mill and the oxygenated organics in the aged aerosol, which both are known to increase the scattering characteristics of aerosols. Decreases in the single scattering albedo in the morning and afternoon, distinct in the summertime, were linked to the increased traffic density at these hours. The scattering and absorption coefficients of residential and long-range transported aerosol (two separate cloud events) were found to be decreased by clouds. The effect was stronger for the scattering than absorption, indicating preferential activation of the more hygroscopic aerosol with higher scattering characteristics.
With one in eight Americans thinking women are too emotional to be in politics (Carnevale et al., 2019), being labeled as emotional during a disagreement may activate stereotypes about a woman's ...irrationality and affect how legitimate people perceive her arguments to be. We experimentally tested the effects of such labels. In Study 1 (N = 86), participants who read a vignette where a woman (versus a man) was told to “calm down” during a disagreement, saw her argument as significantly less legitimate. Perceived emotionality mediated the relation between condition and perceived legitimacy. Study 2 replicated this finding (N = 126) with different vignettes where the character was explicitly labeled as “emotional.” Using video vignettes in Study 3 (N = 251), we failed to replicate the results observed in Studies 1 and 2. We hope practitioners use these studies to increase awareness of how stereotype-laden labels can delegitimize women's arguments, particularly when heard via writing (e.g., via email, text, or instant messaging) rather than when observed. This work may motivate observers to challenge the use of delegitimizing labels, so that women's claims can be judged based on the soundness of their arguments, rather than stereotypes about their ability to think rationally. Additional online materials for this article are available on PWQ's website at http://journals.sagepub.com/doi/suppl/10.1177/03616843221123745
PDF
