Research Data

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Open Access
Calwater2 scanning flow CCN measurements at Bodega Bay Marine Laboratory
(Colorado State University. Libraries, 2015) Kreidenweis, Sonia M.; Atwood, Samuel A.; DeMott, Paul J.
Scanning flow CCN measurements were conducted at the Bodega Bay Marine Laboratory (BML) as part of the Calwater2 campaign.
Open Access
Maps of raw and gridded, population-weighted percent of Facebook posters matching search criteria
(Colorado State University. Libraries, 2015) Ford, Bonne; Pierce, Jeffrey R.; Burke, Moira
This dataset was created using de-identified, aggregated % of Facebook posters matching search criteria at a municipality centroid (location determined by IP address) that were gridded and population-weighted.
Open Access
WRF-chem simulated surface PM2.5
(Colorado State University. Libraries, 2015) Ford, Bonne; Lassman, William; Pfister, Gabriele
The simulation was completed for 1 June – 1 October 2015. For this simulation, we used Global Forecast System (GFS) meteorology, biogenic emissions from the Model of Emissions of Gases and Aerosols from Nature (MEGAN), National Emission Inventory 2011 (NEI) anthropogenic emissions, FINN biomass-burning emissions, MOZCART aerosol species and chemistry, and (MOZART) chemical boundaries. Horizontal resolution is 15 km and there are 27 vertical levels. Concentrations are output for each model hour, which we then average to provide daily 24-hour average surface-concentration maps for each US timezone. These files are provided in netcdf format and were generated using IDL code.
Open Access
North Front Range oil and gas air pollution emission and dispersion study
(Colorado State University. Libraries, 2016) Collett, Jeffrey L.; Hecobian, Arsineh; Ham, Jay; Pierce, Jeff; Clements, Andrea; Shonkwiler, Kira; Zhou, Yong; Desyaterik, Yuri; MacDonald, Landan; Wells, Bradley; Hilliard, Noel; Weber, Derek
Improved unconventional oil and natural gas extraction methods have facilitated the development of these resources in several areas, including the northern Front Range of Colorado. Increased activity has spurred questions concerning possible air pollutant emissions. Processes associated with oil and gas extraction have been identified as emitting a variety of air pollutants, but observations of the rates and types of compounds emitted are limited. This is especially true for emissions during completion (hydraulic fracturing and flowback) of new wells, activities which have not been closely examined for emission of atmospheric pollutants, but additional information is also needed for oil and gas production sites which have long operational lifetimes. This study was designed to characterize and quantify emission rates and dispersion of air toxics, ozone precursors, and greenhouse gases from oil and gas operations in the Denver-Julesburg Basin on the northern Front Range of Colorado. Based on a review of critical knowledge gaps and input from a study Technical Advisory Panel, particular focus was placed on quantifying emissions of individual volatile organic compounds (VOCs), methane, and ethane from oil and gas production sites and from hydraulic fracturing ("fracking") and flowback, important steps in the completion of new wells. Four oil and gas production companies were recruited to participate in the study and provided access to field operations for emission measurements. While some prior studies have measured VOC, ethane, or methane concentrations near oil and gas operations, ambient concentrations are strongly dependent not only on emission rates but also on sampling location and meteorological conditions, which greatly affect downwind dispersion and dilution. By characterizing emission rates directly, results from this study can be used to predict downwind concentration fields for any location of interest under a wide range of weather conditions. By using a similar measurement approach, this study was designed to complement a parallel effort examining methane, ethane, and VOC emission rates from drilling and completion of natural gas wells in the Piceance Basin in Garfield County, Colorado. Emission rates were determined using a tracer ratio method (TRM). In this method, the emission rate of a compound of interest (e.g., g s-1 of benzene) is determined as the product of a known tracer emission rate multiplied by the ratio of the background-corrected concentrations of the compound of interest and the tracer. Acetylene was selected as a tracer gas and its controlled release co-located with the main source of emissions on study sites. Real-time methane and acetylene concentrations and three-minute integrated whole air sample canisters for VOC and ethane analysis were collected downwind of the release location. Meteorological data were collected at two heights (3 m and 10 m) near the activity under study. Upwind acetylene, methane, ethane, and VOC concentrations were determined for background correction. The canisters were analyzed for ethane and a large suite of VOCs using gas chromatography with flame ionization detection. The study results provide novel information concerning emissions from oil and natural gas production and completion activities in the northern Front Range of Colorado. Overall, 18 emission experiments were conducted from 2014-2016. Several sets of canisters were collected at different times during each experiment, in addition to upwind background samples. Using the TRM, each canister in the plume provides an independent measure of ethane and VOC emission rates. Ethane and 47 VOCs are reported for each canister, along with real-time methane and acetylene data collected during each experiment. Using the TRM, the emission rates of methane, ethane, and individual VOCs are calculated and reported. Methane, ethane, and propane were the most abundant constituents in measured emissions. Generally, higher rates of VOC, ethane, and methane emissions were observed during flowback operations, although a wide range of emissions was observed for each type of activity studied. Methane emission rates were examined as a percentage of produced natural gas at the diverse array of production sites included in the experiment. These included large and small sites (between 1 and 18 horizontal and/or vertical wells) with a variety of different separation schemes. A positive relationship was observed with gas production rate; median and mean methane emissions measured across all production sites were 0.23% and 0.37%, respectively, with the 95th percentile of emissions at 1.03%. The emission rates and field observations were used to conduct air dispersion simulations (using EPA's AERMOD model) to: (1) evaluate AERMOD's accuracy in predicting observed, near-field dispersion of ethane and VOCs in the Colorado Front Range and (2) predict concentration fields, as a function of emission rate, for dispersion of benzene under a range of local meteorological conditions at a site with terrain similar to that observed in the Front Range of Colorado. While not perfectly designed for prediction of the short-term concentration fields measured in this study, AERMOD did a reasonable job predicting the observed extent of dispersion across several field experiments. Moreover, emission rate ranges determined by activity type in this study can be used in a wide range of future simulations with AERMOD or other models to simulate downwind concentration fields relevant to understanding potential local health and air quality impacts associated with oil and gas well completion and production activities on the northern Front Range.
Open Access
Characterizing emissions from natural gas drilling and well completion operations in Garfield County, CO
(Colorado State University. Libraries, 2016) Collett, Jeffrey; Hecobian, Arsineh; Ham, Jay; Pierce, Jeff; Clements, Andrea; Shonkwiler, Kira; Zhou, Yong; Desyaterik, Yuri; MacDonald, Landan; Wells, Bradley; Hilliard, Noel
This study was designed to characterize and quantify emission rates and dispersion of air toxics, ozone precursors, and greenhouse gases from unconventional natural gas well development activities in Garfield County, CO, located on top of a geological formation known as the Piceance Basin. Particular focus was placed on quantifying emissions of individual volatile organic compounds (VOCs) and methane during well drilling, hydraulic fracturing ("fracking"), and flowback. While some prior studies have measured VOC or methane concentrations near well development operations, ambient concentrations are strongly dependent not only on emission rates but also on sampling location and meteorological conditions, which greatly affect downwind dispersion and dilution. By characterizing emission rates directly, results from this study can be used to predict downwind concentration fields for any location of interest under a wide range of weather conditions. Emission rates were determined using a tracer ratio method (TRM). In this method, the rate of emission of a compound of interest (e.g., g s-1 of benzene) is determined as the product of a known tracer emission rate multiplied by the ratio of the background-corrected concentrations of the compound of interest and the tracer. Acetylene was selected as a tracer gas and its controlled release co-located with the main source of emissions on studied well pads. Real-time methane and acetylene concentrations and three minute integrated whole air sample canisters for VOC analysis were collected downwind of the release location. Meteorological data were collected at two heights (3 m and 10 m) near the well pad. Upwind acetylene, methane, and VOC concentrations were determined for background correction. The canisters were analyzed for a large suite of VOCs using gas chromatography with flame ionization detection. The study results provide novel information concerning emissions from natural gas drilling and completion activities in Garfield County, CO and are some of the first measurements of this type in any U.S. basin. Overall, 21 emission experiments were conducted from 2013-2015. Several sets of 2 to 5 canisters were collected at different times during each experiment, in addition to an upwind background sample per experiment. Using the TRM, each canister in the plume provides an independent measure of VOC emission rates. 28-48 VOCs are reported for each canister, along with real-time methane and acetylene data collected during each experiment. Using the TRM the emission rates of methane and individual VOCs are calculated and reported.The emission rates and field observations were used to conduct air dispersion (using the EPA's AERMOD model) simulations to: (1) evaluate AERMOD's accuracy in predicting observed, near-field dispersion of VOCs in Garfield County, CO and (2) predict concentration fields, as a function of emission rate, for dispersion of a hypothetical compound under a range of local meteorological conditions at a site with terrain similar to that observed in Garfield County. While not perfectly designed for prediction of the short-term concentration fields measured in the study, AERMOD did a reasonable job predicting the observed extent of dispersion across several field experiments. Moreover, emission rate ranges determined by activity type in this study can be used in a wide range of future simulations with AERMOD or other models to simulate downwind concentration fields relevant to understanding potential local health and air quality impacts associated with well development activities in Garfield County.
Open Access
Anomalous integrated water vapor transport-based atmospheric river detection algorithm
(Colorado State University. Libraries, 2016) Mundhenk, Bryan D.; Barnes, Elizabeth A.; Maloney, Eric D.
Atmospheric rivers (ARs) are often characterized as transient, plume-like structures of focused tropospheric water vapor and intense low-level winds that contribute substantially to the atmospheric branch of the hydrologic cycle. Here, we provide an abridged version of an AR detection algorithm, written in the Python 2.7 programming language, that was developed to facilitate climatological and dynamical analyses of ARs. This algorithm employs a unique approach of detecting AR-like features from within gridded fields of anomalous integrated water vapor transport. The use of anomalies was found to be efficient and to benefit automated feature detection in large spatial (i.e., North Pacific) and temporal (i.e., sub-daily across all seasons) domains.
Open Access
Data for the article The evolution of biomass-burning aerosol size distributions due to coagulation: dependence on fire and meteorological details and parameterization
(Colorado State University. Libraries, 2016) Pierce, Jeffrey; Sakomoto, Kimiko
This study calculated the evolution of aerosol size distributions in biomass burning plumes and is used the publication Sakamoto et al., 2016. In this repository we include the SAM-TOMAS input and output data that we used to build our emulator and simple fits. We also include the emulator code, which was also included in the supplementary material of our paper.
Open Access
Supporting data for the manuscript "Ice nucleating particle emissions from photochemically-aged diesel and biodiesel exhaust"
(Colorado State University. Libraries, 2016) Schill, Gregory P.; Jathar, Shantanu; Kodros, John K.; Levin, Ezra J. T.; Galang, Abril M.; Friedman, Beth; Link, Michael F.; Farmer, Delphine K.; Pierce, Jeffrey R.; Kreidenweis, Sonia M.; DeMott, Paul J.
Immersion-mode ice-nucleating particle concentrations from an off-road diesel engine were measured with a Continuous Flow Diffusion Chamber (CFDC). Both petrodiesel and biodiesel were used, and the exhaust was aged up to 1.5 photochemically equivalent days. Total aerosol and refractory black carbon concentrations were determined in this study with a Scanning Mobility Particle Sizer (SMPS) and Single Particle Soot Photometer, respectively. The CFDC, SMPS, and SP2 data used in this study can be found in this archive.
Open Access
2010 C2H6 global emission inventory
(Colorado State University. Libraries, 2016) Zitely, Tzompa-Sosa
Recent measurements over the Northern Hemisphere indicate that the long-term decline in the atmospheric burden of ethane (C2H6) has ended, and the abundance increased dramatically between 2010 and 2014. The rise in the abundance of C2H6 has been attributed to oil and natural gas extraction in North America. Existing global C2H6 emission inventories are based on outdated activity maps that do not account for current oil and natural gas exploitation regions. We present an updated global C2H6 emission inventory based on 2010 satellite-derived CH4 fluxes with adjusted C2H6 emissions over the U.S. from the National Emission Inventory (NEI 2011). We contrast our global 2010 C2H6 emission inventory with one developed for 2001. The C2H6 difference between global anthropogenic emissions is subtle (7.9 versus 7.2 Tg yr-1), but the spatial distribution of the emissions is distinct. In the 2010 C2H6 inventory, fossil fuel sources in the Northern Hemisphere represent half of global C2H6 emissions and 95% of global fossil fuel emissions. Over the U.S., un-adjusted NEI 2011 C2H6 emissions produce mixing ratios that are 14-50 % of those observed by aircraft observations (2008-2014). When the NEI 2011 C2H6 emission totals are scaled by a factor of 1.4, the model largely reproduces a regional suite of observations, with the exception of the central U.S., where it continues to under-predict observed mixing ratios in the lower troposphere. We estimate monthly mean contributions of fossil fuel C2H6 emissions to ozone and peroxyacetyl nitrate surface mixing ratios over North America of ~1% and ~8%, respectively.
Open Access
Manuscript supporting data for The increasing importance of reduced nitrogen deposition in the United States
(Colorado State University. Libraries, 2016) Li, Yi; Schichtel, Bret A.; Walker, John T.; Schwede, Donna B.; Chen, Xi; Lehmann, Christopher M. B.; Puchalski, Melissa A.; Gay, David A.; Collett, Jeffrey
Rapid development of agriculture and fossil fuel combustion greatly increased US reactive nitrogen emissions to the atmosphere in the second half of the 20th century, resulting in excess nitrogen deposition to natural ecosystems. Recent efforts to lower nitrogen oxides emissions have substantially decreased nitrate wet deposition. Levels of wet ammonium deposition, by contrast, have increased in many regions. Together these changes have altered the balance between oxidized and reduced nitrogen deposition. Across most of the United States, wet deposition has transitioned from being nitrate-dominated in the 1980s to ammonium-dominated in recent years. Ammonia has historically not been routinely measured because there are no specific regulatory requirements for its measurement. Recent expansion in ammonia observations, however, along with ongoing measurements of nitric acid and fine particle ammonium and nitrate, permit new insight into the balance of oxidized and reduced nitrogen in the total (wet + dry) US nitrogen deposition budget. Observations from 37 sites reveal that reduced nitrogen contributes, on average, ∼65% of the total inorganic nitrogen deposition budget. Dry deposition of ammonia plays an especially key role in nitrogen deposition, contributing from 19% to 65% in different regions. Future progress toward reducing US nitrogen deposition will be increasingly difficult without a reduction in ammonia emissions.
Open Access
Data for Temporal and spatial variability of ammonia in urban and agricultural regions of northern Colorado, United States
(Colorado State University. Libraries, 2017) Li, Yi; Thompson, Tammy M.; Van Damme, Martin; Chen, Xi; Benedict, Katherine B.; Shao, Yixing; Day, Derek; Boris, Alexandra; Sullivan, Amy P.; Ham, Jay; Whitburn, Simon; Clarisse, Lieven; Coheur, Pierre-François; Collett, Jeffrey
Concentrated agricultural activities and animal feeding operations in the northeastern plains of Colorado represent an important source of atmospheric ammonia (NH3) that contributes to regional fine particle formation and to nitrogen deposition to sensitive ecosystems in Rocky Mountain National Park (RMNP) located ~ 80 km to the west. In order to better understand temporal and spatial differences in NH3 concentrations in this source region, weekly concentrations of NH3 were measured at 14 locations during the summers of 2010 to 2015 using Radiello passive NH3 samplers. Weekly (biweekly in 2015) average NH3 concentrations ranged from 2.66 μg/m3 to 42.7 μg/m3 with the highest concentrations near large concentrated animal feeding operations (CAFOs). The annual summertime mean NH3 concentrations were stable in this region from 2010 to 2015, providing a baseline against which concentration changes associated with future changes in regional NH3 emissions can be assessed. Vertical profiles of NH3 were also measured on the 300 m Boulder Atmospheric Observatory (BAO) tower throughout 2012. The highest NH3 concentration along the vertical profile was always observed at the 10 m height (annual average concentration of 4.63 μg/m3), decreasing toward the surface (4.35 μg/m3) and toward higher altitudes (1.93 μg/m3). Seasonal changes in the steepness of the vertical concentration gradient were observed, with the sharpest gradients in cooler seasons when thermal inversions restricted vertical mixing of surface-based emissions. The NH3 spatial distributions measured using the passive samplers are compared with NH3 columns retrieved by the Infrared Atmospheric Sounding Interferometer (IASI) satellite and concentrations simulated by the Comprehensive Air quality Model with extensions (CAMx), providing insight into the regional performance of each. The satellite comparison adds to a growing body of evidence that IASI column retrievals of NH3 provide very useful insight into regional variability in atmospheric NH3, in this case even in a region with strong local sources and sharp spatial gradients. The CAMx comparison indicates that the model does a reasonable job simulating NH3 concentrations near sources but tends to underpredict concentrations at locations farther downwind. Excess NH3 deposition by the model is hypothesized as a possible explanation for this trend.
Open Access
Spatial and temporal estimates of population exposure to wildfire smoke during the Washington State 2012 wildfire season using blended model, satellite, and in-situ data: process data and code archive
(Colorado State University. Libraries, 2017) Lassman, William
In the western U.S., smoke from wild and prescribed fires can severely degrade air quality. Due to changes in climate and land-management, wildfires have increased in frequency and severity, and this trend is expected to continue. Consequently, wildfires are expected to become an increasingly important source of air pollutants in the western U.S. Hence, there is a need to develop a quantitative understanding of wildfire-smoke-specific health effects. A necessary step in this process is to determine who was exposed to wildfire smoke, the concentration of the smoke during exposure, and the duration of the exposure. Three different tools have been used in past studies to assess exposure to wildfire smoke: in-situ measurements, satellite-based observations, and chemical-transport model (CTM) simulations. Each of these exposure-estimation tools have associated strengths and weakness. We investigate the utility of blending these tools together to produce estimates of PM2.5 exposure from wildfire smoke during the Washington 2012 fire season. For blending, we use a ridge-regression model and a geographically weighted ridge-regression model. We evaluate the performance of the three individual exposure-estimate techniques and the two blended techniques using leave-one-out cross-validation. We find that predictions based on in-situ monitors are more accurate for this particular fire season than the CTM simulations and satellite-based observations because of the large number of monitors present; therefore, blending provides only marginal improvements above the in-situ observations. However, we show that in hypothetical cases with fewer surface monitors, the two blending techniques can produce substantial improvement over any of the individual tools.
Open Access
Data associated with the manuscript Using TES retrievals to investigate PAN in North American biomass burning plumes
(Colorado State University. Libraries, 2017) Fischer, Emily V.; Zhu, Liye; Payne, Vivienne H; Brey, Steven
Peroxyacyl nitrate (PAN) is a critical atmospheric reservoir for nitrogen oxide radicals, and it plays a lead role in their redistribution in the troposphere. We analyze new Tropospheric Emission Spectrometer (TES) PAN observations over North America during July 2006 to 2009. Using aircraft observations from the Colorado Front Range, we demonstrate that TES can be sensitive to elevated PAN in the boundary layer (~750 hPa) even in the presence of clouds. In situ observations have shown that wildfire emissions can rapidly produce PAN, and PAN decomposition is an important component of ozone production in smoke plumes. We identify smoke-impacted TES PAN retrievals by co-location with NOAA Hazard Mapping System (HMS) smoke plumes. Depending on the year, 15 – 32 % of cases where elevated PAN is identified in TES observations (retrievals with DOF > 0.6) overlap smoke plumes during July. Of all the retrievals attempted in July 2006 to July 2009, the percent associated with smoke is 18%. A case study of smoke transport in July 2007 illustrates that PAN enhancements associated with HMS smoke plumes can be connected to fire complexes, providing evidence that TES is sufficiently sensitive to measure elevated PAN several days downwind of major fires. Using a subset of retrievals with TES 510 hPa carbon monoxide (CO) > 150 ppbv, and multiple estimates of background PAN, we calculate enhancement ratios for tropospheric average PAN relative to CO in smoke-impacted retrievals. Most of the TES-based enhancement ratios fall within the range calculated from in situ measurements.
Open Access
PROGRESS_dataset_YR1
(Colorado State University. Libraries, 2017) Fischer, Emily V.
Women are underrepresented in a number of science, technology, engineering, and mathematics (STEM) disciplines. Limited diversity in the development of the STEM workforce has negative implications for scientific innovation, creativity, and social relevance. The current study reports the first-year results of the PROmoting Geoscience Research, Education, and SuccesS (PROGRESS) program, a novel theory-driven informal mentoring program aimed at supporting first- and second-year female STEM majors. Using a prospective, longitudinal, multi-site (i.e., 7 universities in Colorado/Wyoming Front Range & Carolinas), propensity score matched design, we compare mentoring and persistence outcomes for women in and out of PROGRESS (N = 116). Women in PROGRESS attended an off-site weekend workshop and gained access to a network of volunteer female scientific mentors from on- and off-campus (i.e., university faculty, graduate students, and outside scientific professionals). The results indicate that women in PROGRESS had larger networks of developmental mentoring relationships and were more likely to be mentored by faculty members and peers than matched controls. Mentoring support from a faculty member benefited early-undergraduate women by strengthening their scientific identity and their interest in earth and environmental science career pathways. Further, support from a faculty mentor had a positive indirect impact on women's scientific persistence intentions, through strengthened scientific identity development. These results imply that first- and second- year undergraduate women's mentoring support networks can be enhanced through provision of protégé training and access to more senior women in the sciences willing to provide mentoring support.
Open Access
Dataset associated with "Observations of ice nucleating particles over Southern Ocean waters"
(Colorado State University. Libraries, 2018) McCluskey, Christina
Aerosol number, surface area, black carbon mass concentrations, Radon-222 concentrations, and Immersion-mode ice nucleating particle (INP) number concentrations were monitored onboard the RV Investigator (voyage IN2016_V02), an Australian Government research platform operated by the Commonwealth Science and Industrial Research Organisation (CSIRO) from 13 March to 15 April in 2016. These data were used to characterize INP composition and abundance present over the Southern Ocean. Measurements were made from the RV Investigator's custom-designed air sampling inlet and a dedicated sampling line for the aerosol concentrator (both located approximately 18.4 m above sea level at the front of the ship), with the exception of the aerosol particles that were collected onto polycarbonate membrane filters in open-faced filter holders that were located approximately 23 m above the ocean surface. Total aerosol surface area and number were determined using a nephelopmeter and a condensation particle counter, respectively. Black carbon concentrations were determined using a multi-angle absorption photometer (MAAP). Radon (222Rn) concentrations were measured using a 700 L dual flow loop two-filter detector (Chambers et al., 2014; Griffiths et al., 2016), built by the Australian Nuclear Science and Technology Organization (ANSTO) and installed as part of the permanent suite of atmospheric instrumentation onboard the RV Investigator. Finally, immersion-mode ice nucleating particles were measured using two methods: the ice spectrometer (IS, offline) and continuous flow diffusion chamber (CFDC, online).
Open Access
Dataset for "Outperforming yet undervalued: undergraduate women in STEM"
(Colorado State University. Libraries, 2018) Bloodhart, Brittany
Gender diversity is critically needed in many science fields, but women continue to encounter beliefs that they lack ability and talent. Undergraduate education is a critical time when peer influence may alter choice of majors and careers for women interested in science. Even in life science courses, where women outnumber men, peer-to-peer interactions could detract from women's success and interest. We find that women are outperforming their male classmates in both physical and life science courses, but men continue to be perceived as equal or better students. This is problematic because it suggests that undergraduate women cannot escape gender-ability stereotypes even when they are more capable than men, and has important implications for the recognition of women's achievements among their peers in undergraduate education.
Open Access
Supporting data for manuscript titled "Marine and terrestrial organic ice nucleating particles in pristine marine to continentally-influenced northeast Atlantic air masses"
(Colorado State University. Libraries, 2018) McCluskey, C. S.; Ovadnevaite, J.; Rinaldi, M.; Atkinson, J.; Belosi, F.; Ceburnis, D.; Marullo, S.; Hill, T. C. J.; Lohmann, U.; Kanji, Z. A.; O’Dowd, C.; Kreidenweis, S. M.; DeMott, P. J.
Open Access
RAMS model simulation output for "Cold pool - land surface interactions in a dry continental environment"
(Colorado State University. Libraries, 2018) Grant, Leah D.; van den Heever, Susan C.
These data represent model output from simulations using the Regional Atmospheric Modeling System (RAMS). These data accompany the manuscript: Grant, L. D., & van den Heever, S. C. (2018): Cold pool - land surface interactions in a dry continental environment. Journal of Advances in Modeling Earth Systems, submitted. The accompanying abstract from this manuscript is as follows: "Cold pools influence convective initiation and organization, dust lofting, and boundary layer properties, but little is known about their interactions with the land surface, particularly in dry continental environments. In this study, cold pool - land surface interactions are investigated using high-resolution idealized simulations of an isolated, transient cold pool evolving in a dry convective boundary layer. Results using a fully interactive land surface demonstrate that sensible heat fluxes are suppressed at the center of the cold pool but enhanced at the edge due to the spatial patterns of land surface cooling and the temperature and wind speed perturbations. This leads to cold pool dissipation from the edge inwards. By comparing the interactive land surface simulation to a simulation with imposed surface fluxes, the land surface feedbacks are shown to reduce the cold pool lifetime, extent, and intensity by up to 50%, which has significant implications for cold pool-induced convective initiation."
Open Access
Dataset associated with "Role modeling is a viable retention strategy for undergraduate women in the geosciences"
(Colorado State University. Libraries, 2018) Hernandez, Paul; Bloodhart, Brittany; Adams, Amanda S.; Barnes, Rebecca T.; Burt, Melissa; Clinton, Sandra M.; Du, Wenyi; Godfrey, Elaine; Henderson, Heather; Pollack, Ilana B.; Fischer, Emily V.
Gender diversity leads to better science; however, a number of STEM disciplines, including many geoscience sub-disciplines show a persistent gender gap. PROmoting Geoscience Research, Education, and SuccesS (PROGRESS) is a theory-driven role modeling and mentoring program aimed at supporting undergraduate women interested in geoscience-related degree and career pathways. This study is unique because it is being conducted in a long-term applied setting, rather than as a laboratory exercise. We compare female STEM majors in PROGRESS to a matched control group (N = 380) using a longitudinal prospective multi-site quasi-experimental design. College women in PROGRESS participated in a mentoring and role modeling weekend workshop with follow-up support, while women in the control group participated in neither the workshop nor the follow-up support. PROGRESS members identified more female STEM career role models than controls (60% vs. 42%, respectively), suggesting that deliberate interventions can develop the networks of undergraduate women. Undergraduate women that participate in PROGRESS have higher rates of persistence in geoscience-related majors (95% vs. 73%), although the rates of switching into a geoscience-related major did not differ across groups. More strikingly, we also find that the persistence of undergraduate women in geoscience-related majors is related to the number of female STEM career role models they identify, as their odds of persisting approximately doubles for each role model they identify. We conclude that our ability to retain undergraduate women in the geosciences will depend, in part, on helping them to identify same-gender career role models. Further, the success of PROGRESS points to steps universities and departments can take to sustain their students' interest and persistence, such as hosting interactive panels with diverse female scientists to promote the attainability and social relevance of geoscience careers.
Open Access
Data behind Figures in "Peroxy acetyl nitrate (PAN) measurements at northern midlatitude mountain sites in April: a constraint on continental source–receptor relationships"
(Colorado State University. Libraries, 2018) Fiore, Arlene M.; Fischer, Emily V.; Milly, George P.; Pandey Deolal, Shubha; Wild, Oliver; Jaffe, Dan; Staehelin, Johannes; Clifton, Olivia E.; Bergmann, Dan; Collins, William; Dentener, Frank; Doherty, Ruth M.; Duncan, Bryan N.; Fischer, Bernd; Gilge, Stefan; Hess, Peter G.; Horowitz, Larry W.; Lupu, Alexandru; MacKenzie, Ian; Park, Rokjin; Ries, Ludwig; Sanderson, Michael G.; Schultz, Martin G.; Shindell, Drew T.; Steinbacher, Martin; Stevenson, David S.; Szopa, Sophie; Zellweger, Christoph; Zeng, Guang
Abundance-based model evaluations with observations provide critical tests for the simulated mean state in models of intercontinental pollution transport, and under certain conditions may also offer constraints on model responses to emission changes. We compile multiyear measurements of peroxy acetyl nitrate (PAN) available from five mountaintop sites and apply them in a proof-of-concept approach that exploits an ensemble of global chemical transport models (HTAP1) to identify an observational "emergent constraint". In April, when the signal from anthropogenic emissions on PAN is strongest, simulated PAN at northern midlatitude mountaintops correlates strongly with PAN source–receptor relationships (the response to 20 % reductions in precursor emissions within northern midlatitude continents; hereafter, SRRs). This finding implies that PAN measurements can provide constraints on PAN SRRs by limiting the SRR range to that spanned by the subset of models simulating PAN within the observed range. In some cases, regional anthropogenic volatile organic compound (AVOC) emissions, tracers of transport from different source regions, and SRRs for ozone also correlate with PAN SRRs. Given the large observed interannual variability in the limited available datasets, establishing strong constraints will require matching meteorology in the models to the PAN measurements. Application of this evaluation approach to the chemistry– climate models used to project changes in atmospheric composition will require routine, long-term mountaintop PAN measurements to discern both the climatological SRR signal and its interannual variability.

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