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Abstract. Agricultural emissions, including those from concentrated animal feeding operations (CAFOs) for beef and dairy cattle, make up a large portion of the United States' total greenhouse gas (GHG) emissions. However, many CAFOs reside in areas where methane (CH4) from oil and natural gas (ONG) complicates the quantification of CAFO emissions. Traditional approaches to quantify emissions in such regions often relied on inventory subtraction of other known sources. We compare the results of two approaches to attribute the CAFO CH4 emission rate from the total CH4 emission rate derived from an aircraft mass balance technique. These methods make use of the mixing ratio data of CH4, ethane (C2H6), and ammonia (NH3) that were collected simultaneously in-flight downwind of CAFOs in northeastern Colorado. The first approach, the subtraction method (SM), is similar to inventory subtraction, except the amount to be removed is derived from the observed C2H6 to CH4 ratio rather than an inventory estimate. The results from this approach showed high uncertainty, primarily due to how error propagates through subtraction. Alternatively, multivariate regression (MVR) can be used to estimate CAFO CH4 emissions using the NH3 emission rate and an NH3 to CH4 ratio. These results showed significantly less uncertainty. We identified criteria to determine the best attribution method; these criteria can support attribution in other regions. The final emission estimates for the CAFOs presented here were 13 ± 3 g of CH4 per head per hour and 13 ± 2 g of NH3 per head per hour. These estimates are higher than the inventory of the US Environmental Protection Agency (EPA) and previous studies highlighting the need for more measurements of CH4 and NH3 emission rates. 

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. 

Abstract An abundance of literature has examined barriers to women’s equitable representation in science, technology, engineering, and math (STEM) fields, with many studies demonstrating that STEM fields are not perceived to afford communal goals, a key component of women’s interest in future careers. Using Goal Congruity Theory as a framework, we tested the longitudinal impact of perceptions of STEM career goal affordances, personal communal and agentic goal endorsements, and their congruity on persistence in science from the second through fourth years of college among women in STEM majors in the United States. We found that women’s intent to persist in science were highest in the fall of their second year, that persistence intentions exhibited a sharp decline, and eventually leveled off by their fourth year of college. This pattern was moderated by perceptions of agentic affordances in STEM, such that women who believe that STEM careers afford the opportunity for achievement and individualism experienced smaller declines. We found that higher perceptions of communal goal affordances in STEM consistently predicted higher persistence intentions indicating women may benefit from perceptions that STEM affords communal goals. Finally, we found women with higher agentic affordances in STEM also had greater intentions to persist, and this relationship was stronger for women with higher agentic goals. We conclude that because STEM fields are stereotyped as affording agentic goals, women who identify interest in a STEM major during their first years of college may be drawn to these fields for this reason and may benefit from perceptions that STEM affords agentic goals. 

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 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.