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Mentorship can be part of the solution to developing a more diverse global scientific workforce, but robust longitudinal evidence is limited. Developmental mentor network theory can advance our understanding of the impact of a wide range of mentors across social contexts by distinguishing between the content of mentorship support (eg career support) and the structural characteristics of an individual's mentor network (eg density of connections among mentors). We tested the influence of mentor network characteristics on longitudinal social integration into the Earth and environmental sciences, as indicated by science identity development (a key indicator of social integration) and graduate‐school applications in STEM (science, technology, engineering, and mathematics)‐related fields of study, based on a sample of 233 undergraduate women at nine universities in the US. Our findings indicated that belonging to close‐knit, larger, and skill‐focused mentorship networks creates a “sticky web” of social connections, providing information and resources that increase retention of college women in the Earth and environmental sciences. 

Phase One of the Transportation and Transformation of Ammonia (TRANS²Am) field campaign took place in northeastern Colorado during the summer of 2021. One of the goals of TRANS²Am was to measure ammonia (NH₃) emissions from cattle feedlots and dairies. Most of these animal husbandry facilities are co‐located within oil and gas development, an important source of methane (CH₄) and ethane (C₂H₆) in the region. Phase One of TRANS²Am included 12 near‐source research flights. We present estimates of NH₃emissions ratios with respect to CH₄(NH₃EmR), with and without correction of CH₄from oil and gas, for 29 feedlots and dairies in the region. The data shows larger emissions ratios than previously reported in the literature with a large range of values (i.e., 0.1–2.6 ppbv ppbv⁻¹). Facilities housing cattle and dairy had a mean (std) of 1.20 (0.63) and 0.29 (0.08) ppbv ppbv⁻¹, respectively. We also found that only 15% of the total ammonia (NH_x) is in the particle phase (i.e., ) near major sources during the warm summertime months. We examined the evolution of NH₃in one plume that was sampled at different distances and altitudes up to 25 km downwind and estimated the NH₃lifetime against deposition and partitioning to the particle phase to be 87–120 min. Finally, we calculated estimates of NH₃emission rates from four optimally sampled facilities. These ranged from 4 to 29 g NH₃ · h⁻¹ · hd⁻¹.

 

Abstract Sexual harassment in field settings brings unique challenges for prevention and response, as field research occurs outside “typical” workplaces, often in remote locations that create additional safety concerns and new team dynamics. We report on a project that has 1) trained field project participants to recognize, report, and confront sexual harassment, and 2) investigated the perceptions, attitudes, and experiences of field researchers regarding sexual harassment. Pre-campaign surveys from four major, multi-institutional, domestic and international field projects indicate that the majority of sexual harassment reported prior to the field campaigns was hostile work environment harassment, and women were more likely to be the recipients, on average reporting 2-3 incidents each. The majority of those disclosing harassment indicated that they coped with past experiences by avoiding their harasser or downplaying incidents. Of the incidences reported (47) in post-campaign surveys of the four field teams, all fell under the category of hostile work environment and included incidents of verbal, visual, and physical harassment. Women’s harassment experiences were perpetrated by men 100% of the time, and the majority of the perpetrators were in more senior positions than the victims. Men’s harassment experiences were perpetrated by a mix of women and men, and the majority came from those at the same position of seniority. Post-project surveys indicate that the training programs (taking place before the field projects) helped participants come away with more positive than negative emotions and perceptions of the training, the leadership, and their overall experiences on the field campaign. 

Abstract. A closed-path quantum-cascade tunable infrared laserdirect absorption spectrometer (QC-TILDAS) was outfitted with an inertialinlet for filter-less separation of particles and several custom-designedcomponents including an aircraft inlet, a vibration isolation mountingplate, and a system for optionally adding active continuous passivation forgas-phase measurements of ammonia (NH3) from a research aircraft. Theinstrument was then deployed on the NSF/NCAR C-130 aircraft during researchflights and test flights associated with the Western wildfire Experiment forCloud chemistry, Aerosol absorption and Nitrogen (WE-CAN) field campaign.The instrument was configured to measure large, rapid gradients in gas-phaseNH3, over a range of altitudes, in smoke (e.g., ash and particles), inthe boundary layer (e.g., during turbulence and turns), in clouds, and in ahot aircraft cabin (e.g., average aircraft cabin temperatures expected toexceed 30 ∘C during summer deployments). Important designgoals were to minimize motion sensitivity, maintain a reasonable detectionlimit, and minimize NH3 “stickiness” on sampling surfaces to maintainfast time response in flight. The observations indicate that adding ahigh-frequency vibration to the laser objective in the QC-TILDAS andmounting the QC-TILDAS on a custom-designed vibration isolation plate weresuccessful in minimizing motion sensitivity of the instrument during flight.Allan variance analyses indicate that the in-flight precision of theinstrument is 60 ppt at 1 Hz corresponding to a 3σ detection limitof 180 ppt. Zero signals span ±200, or 400 pptv total, withcabin pressure and temperature and altitude in flight. The option for activecontinuous passivation of the sample flow path with1H,1H-perfluorooctylamine, a strong perfluorinated base, preventedadsorption of both water and basic species to instrument sampling surfaces.Characterization of the time response in flight and on the ground showedthat adding passivant to a “clean” instrument system had little impact onthe time response. In contrast, passivant addition greatly improved the timeresponse when sampling surfaces became contaminated prior to a test flight.The observations further show that passivant addition can be used tomaintain a rapid response for in situ NH3 measurements over the duration of anairborne field campaign (e.g., ∼2 months) since passivantaddition also helps to prevent future buildup of water and basic species oninstrument sampling surfaces. Therefore, we recommend the use of activecontinuous passivation with closed-path NH3 instruments when rapid(>1 Hz) collection of NH3 is important for the scientificobjective of a field campaign (e.g., sampling from aircraft or anothermobile research platform). Passivant addition can be useful for maintainingoptimum operation and data collection in NH3-rich and humid environments orwhen contamination of sampling surfaces is likely, yet frequent cleaning isnot possible. Passivant addition may not be necessary for fast operation,even in polluted environments, if sampling surfaces can be cleaned when thetime response has degraded. 

Abstract. Anthropogenic secondary organic aerosol (ASOA), formed from anthropogenicemissions of organic compounds, constitutes a substantial fraction of themass of submicron aerosol in populated areas around the world andcontributes to poor air quality and premature mortality. However, theprecursor sources of ASOA are poorly understood, and there are largeuncertainties in the health benefits that might accrue from reducinganthropogenic organic emissions. We show that the production of ASOA in 11urban areas on three continents is strongly correlated with the reactivityof specific anthropogenic volatile organic compounds. The differences inASOA production across different cities can be explained by differences inthe emissions of aromatics and intermediate- and semi-volatile organiccompounds, indicating the importance of controlling these ASOA precursors.With an improved model representation of ASOA driven by the observations,we attribute 340 000 PM2.5-related premature deaths per year to ASOA, which isover an order of magnitude higher than prior studies. A sensitivity casewith a more recently proposed model for attributing mortality to PM2.5(the Global Exposure Mortality Model) results in up to 900 000 deaths. Alimitation of this study is the extrapolation from cities with detailedstudies and regions where detailed emission inventories are available toother regions where uncertainties in emissions are larger. In addition tofurther development of institutional air quality management infrastructure,comprehensive air quality campaigns in the countries in South and CentralAmerica, Africa, South Asia, and the Middle East are needed for furtherprogress in this area. 

We use a 0-D photochemical box model and a 3-D global chemistry-climate model, combined with observations from the NOAA Southeast Nexus (SENEX) aircraft campaign, to understand the sources and sinks of glyoxal over the Southeast United States. Box model simulations suggest a large difference in glyoxal production among three isoprene oxidation mechanisms (AM3ST, AM3B, and MCM v3.3.1). These mechanisms are then implemented into a 3-D global chemistry-climate model. Comparison with field observations shows that the average vertical profile of glyoxal is best reproduced by AM3ST with an effective reactive uptake coefficient γglyx of 2 × 10-3, and AM3B without heterogeneous loss of glyoxal. The two mechanisms lead to 0-0.8 µg m-3 secondary organic aerosol (SOA) from glyoxal in the boundary layer of the Southeast U.S. in summer. We consider this to be the lower limit for the contribution of glyoxal to SOA, as other sources of glyoxal other than isoprene are not included in our model. In addition, we find that AM3B shows better agreement on both formaldehyde and the correlation between glyoxal and formaldehyde (RGF = [GLYX]/[HCHO]), resulting from the suppression of δ-isoprene peroxy radicals (δ-ISOPO2). We also find that MCM v3.3.1 may underestimate glyoxal production from isoprene oxidation, in part due to an underestimated yield from the reaction of IEPOX peroxy radicals (IEPOXOO) with HO2. Our work highlights that the gas-phase production of glyoxal represents a large uncertainty in quantifying its contribution to SOA.