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Aerosol absorption of visible light has an important impact on global radiative forcing. Wildfires are one of the major sources of light-absorbing aerosol, but there remains significant uncertainty about the magnitude, wavelength dependence and bleaching of absorption from biomass burning aerosol. We collected and analyzed data from 21 Western United States wildfire smoke plumes during the 2018 WE-CAN airborne measurement campaign to determine the contribution of black carbon (BC), brown carbon (BrC), and lensing to the aerosol mass absorption cross-section (MAC). MACBC, MAC of organics (MACBrC+lensing), and the MAC of water-soluble BrC (MACws_BrC660) are calculated using Photoacoustic Absorption Spectrometer, Single Particle Soot Photometer and Particle-into-Liquid Sampler measurements. MACBC660 does not change significantly with physical age, organic aerosol (OA) concentration, oxygen to carbon ratio (O:C), gas-phase toluene:benzene ratio, modified combustion efficiency (MCE), altitude, or temperature, and has a relatively stable average value of 10.9 ± 2.1 m2 g-1. On average, 54 % of non-BC absorption (23 % total absorption) at 660 nm is from water-soluble BrC. MACws_BrC660 is 0.06 ± 0.04 m2 g-1 while MACBrC+lensing is 0.11 ± 0.06 m2 g-1 at 660 nm, increasing to 0.59 ± 0.19 m2 g-1 at 405 nm. MACBrC+lensing is constant with physical age and MCE, but increases slightly with increasing O:C or decreasing toluene:benzene, while total absorption (normalized to CO) slightly decreases with increasing O:C or decreasing toluene:benzene due to decreasing OA. No evidence of BrC bleaching is observed. Comparison to commonly used parameterizations, modeling studies, and the FIREX-AQ observations suggest model overestimation of absorption is likely due to incorrect BrC refractive indices. Quantification of significant brown carbon in the red wavelengths and the stability of MACBC, the observation of minimal bleaching, and the observation of changes in OA with O:C and toluene:benzene markers all serve as important constraints on aerosol absorption in regional and global climate models. [ABSTRACT FROM AUTHOR]

Aerosol absorption of visible light has an important impact on global radiative forcing. Wildfires are one of the major sources of light-absorbing aerosol, but there remains significant uncertainty about the magnitude, wavelength dependence and bleaching of absorption from biomass burning aerosol. We collected and analyzed data from 21 Western United States wildfire smoke plumes during the 2018 WE-CAN airborne measurement campaign to determine the contribution of black carbon (BC), brown carbon (BrC), and lensing to the aerosol mass absorption cross-section (MAC). MACBC, MAC of organics (MACBrC+lensing), and the MAC of water-soluble BrC (MACws_BrC660) are calculated using Photoacoustic Absorption Spectrometer, Single Particle Soot Photometer and Particle-into-Liquid Sampler measurements. MACBC660 does not change significantly with physical age, organic aerosol (OA) concentration, oxygen to carbon ratio (O:C), gas-phase toluene:benzene ratio, modified combustion efficiency (MCE), altitude, or temperature, and has a relatively stable average value of 10.9 ± 2.1 m² g-1. On average, 54% of non-BC absorption (23% total absorption) at 660 nm is from water-soluble BrC. MACws_BrC660 is 0.06 ± 0.04 m² g-1 while MACBrC+lensing is 0.11 ± 0.06 m² g-1 at 660 nm, increasing to 0.59 ± 0.19 m² g-1 at 405 nm. MACBrC+lensing is constant with physical age and MCE, but increases slightly with increasing O:C or decreasing toluene:benzene, while total absorption (normalized to CO) slightly decreases with increasing O:C or decreasing toluene:benzene due to decreasing OA. No evidence of BrC bleaching is observed. Comparison to commonly used parameterizations, modeling studies, and the FIREX-AQ observations suggest model overestimation of absorption is likely due to incorrect BrC refractive indices. Quantification of significant brown carbon in the red wavelengths and the stability of MACBC, the observation of minimal bleaching, and the observation of changes in OA with O:C and toluene:benzene markers all serve as important constraints on aerosol absorption in regional and global climate models. [ABSTRACT FROM AUTHOR]

During the Ice in Clouds Experiment-Layer Clouds (ICE-L), aged biomass-burning particles were identified within two orographic wave cloud regions over Wyoming using single-particle mass spectrometry and electron microscopy. Using a suite of instrumentation, particle chemistry was characterized in tandem with cloud microphysics. The aged biomass-burning particles comprised -30%-40% by number of the 0.1-1.0-[micro]m clear-air particles and were composed of potassium, organic carbon, elemental carbon, and sulfate. Aerosol mass spectrometry measurements suggested these cloud-processed particles were predominantly sulfate by mass. The first cloud region sampled was characterized by primarily homogeneously nucleated ice particles formed at temperatures near -40[degrees]C. The second cloud period was characterized by high cloud droplet concentrations (~150-300 [cm.sup.-3]) and lower heterogeneously nucleated ice concentrations (7-18 [L.sup.-1]) at cloud temperatures of -24[degrees] to -25[degrees]C. As expected for the observed particle chemistry and dynamics of the observed wave clouds, few significant differences were observed between the clear-air particles and cloud residues. However, suggestive of a possible heterogeneous nucleation mechanism within the first cloud region, ice residues showed enrichments in the number fractions of soot and mass fractions of black carbon, measured by a single-particle mass spectrometer and a single-particle soot photometer, respectively. In addition, enrichment of biomass-burning particles internally mixed with oxalic acid in both the homogeneously nucleated ice and cloud droplets compared to clear air suggests either preferential activation as cloud condensation nuclei or aqueous phase cloud processing. DOI: 10.1175/2010JAS3330.1

Ice concentrations in orographic wave clouds at temperatures between -24[degrees] and -29[degrees]C were shown to be related to aerosol characteristics in nearby clear air during five research flights over the Rocky Mountains. When clouds with influence from colder temperatures were excluded from the dataset, mean ice nuclei and cloud ice number concentrations were very low, on the order of 1-5 [L.sup.-1]. In this environment, ice number concentrations were found to be significantly correlated with the number concentration of larger particles, those larger than both 0.1- and 0.5-[micro]m diameter. A variety of complementary techniques was used to measure aerosol size distributions and chemical composition. Strong correlations were also observed between ice concentrations and the number concentrations of soot and biomass-burning aerosols. Ice nuclei concentrations directly measured in biomass-burning plumes were the highest detected during the project. Taken together, this evidence indicates a potential role for biomass-burning aerosols in ice formation, particularly in regions with relatively low concentrations of other ice nucleating aerosols. DOI: 10.1175/2010JAS3310.1

Author(s): Peter M. Edwards [1, 2, 8]; Steven S. Brown (corresponding author) [1]; James M. Roberts [1]; Ravan Ahmadov [1, 2]; Robert M. Banta [1]; Joost A. deGouw [1, 2]; [...]

The chemical composition of secondary organic aerosol (SOA) from the photooxidation of isoprene over the full range of N[O.sub.x] conditions is investigated through a series of controlled laboratory chamber experiments. It is learnt that the chemical nature of the resultant SOA is significantly different in the two N[O.sub.x] regimes.

Other Test Method 33A (OTM 33A) is a near-source flux measurement method developed by the Environmental Protection Agency (EPA) primarily used to locate and estimate emission fluxes of methane from oil and gas (O&G) production facilities without requiring site access. A recent nation-wide estimate of methane emissions from O&G production included a large number of flux measurements of upstream O&G facilities made using OTM 33A and concluded the EPA National Emission Inventory underestimates this sector by a factor of ~ 2.1 (Alvarez et al., 2018). The study presented here investigates the accuracy of OTM 33A through a series of test releases performed at the Methane Emissions Technology Evaluation Center (METEC), a facility designed to allow quantified amounts of natural gas to be released from decommissioned O&G equipment to simulate emissions from real facilities (Fig. 1). This study includes test releases from single and multiple points, from equipment locations at different heights, and spanned methane release rates ranging from 0.16 to 2.15 kg h-1. Approximately 95 % of individual measurements (N = 45) fell within ±70 % of the known release rate. A simple linear regression of OTM 33A versus known release rates at the METEC site gives an average slope of 0.96 with 95 % CI (0.66,1.28), suggesting that an ensemble of OTM 33A measurements may have a small but statistically insignificant low bias. [ABSTRACT FROM AUTHOR]

An investigation was carried out concerning the effect of imagery instructions on a simple motor skill accuracy task (putting a golf ball). Male college students (N = 50) were randomly assigned to one of six experimental conditions in a design that allowed the presence or absence of mental rehearsal of the physical movements involved in the task to be completely crossed with the imaginal depiction of task outcome (successful, unsuccessful, or no outcome component). A significant outcome by trials interaction was found on task performance. This finding reflected the degradation of performance in the conditions employing negative outcome imagery rather than any enhancement of performance by positive outcome imagery. Self-efficacy was found to be correlated with performance, but this association seemed to be a by-product of the strong relationships between these variables and performance on the previous trial. Results are discussed in relation to the existing literature, and future research directions are delineated. [ABSTRACT FROM AUTHOR]

Sport psychology services were provided at the 1991 U.S. Olympic Festival. A consultation model was employed that included aspects of the traditional medical model and a more proactive preventive approach. Consultations were delivered using a "professional/clinical" style (i.e., emphasis on expertness, empathy, warmth, and congruence). Two sport psychologists provided 85 formal consultations to more than 300 athletes, coaches, staff members, and others from 16 different sports. Process and outcome evaluations suggested that these services were very well received. Eleven recommendations are provided for delivery of sport psychology services at future Olympic events. [ABSTRACT FROM AUTHOR]

A description is given of the sport psychology services provided to the U.S. Team at the 1988 Summer Olympics in Seoul, South Korea. The service delivery model is described and several examples illustrate the nature of the consultations provided to coaches and athletes. Some 72 formal consultations were held with 40 individuals and teams, and an analysis is given of the types of services requested and the clients who were served. [ABSTRACT FROM AUTHOR]

The U.S. Olympic Committee's Sports Medicine Council decided in 1987, for the first time, to assign a sport psychologist to the medical team of the 1987 U.S. Olympic Festival. This article describes the outcome of providing sport psychology services at the Festival. A brief history is given of the relationship between sport psychology and the U.S. Olympic movement, and the current status of sport psychologists within the Olympic movement is described. An analysis is provided of the types of services requested at the Festival, the referral sources, the major sports served, and several illustrative case examples describing athletes. Two models influenced the delivery of sport psychology services at the Olympic Festival, the medical model and the consultation model, and the advantages and disadvantages of each are discussed. Based upon the Olympic Festival experience, a consultation model may be appropriate for sport psychologists working in such a setting. The paper concludes with some suggestions regarding the training of students in the theory of effective consultation, drawing upon the knowledge base of industrial-organizational and medical psychology. [ABSTRACT FROM AUTHOR]

The article presents a study that gauges the effects of emotive imagery on strength performance in sports. Subjects were asked to imagine angry, fearful, and relaxing images, then told to grip a dynamometer. Results indicate that the relaxation image significantly lowered strength performance while the other two conditions showed no increase.