Jason C. Schroder
A5000438298- Atmospheric chemistry and aerosols
- Air Quality and Health Impacts
- Atmospheric aerosols and clouds
- Atmospheric Ozone and Climate
- Air Quality Monitoring and Forecasting
- Vehicle emissions and performance
- Atmospheric and Environmental Gas Dynamics
- Advanced Aircraft Design and Technologies
- Groundwater and Isotope Geochemistry
- Odor and Emission Control Technologies
- Water Quality and Pollution Assessment
- Water Quality Monitoring and Analysis
- Transboundary Water Resource Management
- Climate Change and Health Impacts
- Air Traffic Management and Optimization
- Water-Energy-Food Nexus Studies
- Gas Dynamics and Kinetic Theory
- Advanced Glycation End Products research
- Rocket and propulsion systems research
- Maritime Transport Emissions and Efficiency
- Industrial Gas Emission Control
- Nuclear Physics and Applications
- Mass Spectrometry Techniques and Applications
- Aeolian processes and effects
- Conservation Techniques and Studies
Colorado Department of Public Health and Environment
2020-2023
University of Colorado Boulder
2015-2023
Cooperative Institute for Research in Environmental Sciences
2015-2023
University of British Columbia
2012-2018
University of Colorado System
2015
Dimethyl sulfide (DMS), emitted from the oceans, is most abundant biological source of sulfur to marine atmosphere. Atmospheric DMS oxidized condensable products that form secondary aerosols affect Earth's radiative balance by scattering solar radiation and serving as cloud condensation nuclei. We report atmospheric discovery a previously unquantified oxidation product, hydroperoxymethyl thioformate (HPMTF, HOOCH2SCHO), identified through global-scale airborne observations demonstrate it be...
Particle pH is a critical but poorly constrained quantity that affects many aerosol processes and properties, including composition, concentrations, toxicity. We assess PM1 as function of geographical location altitude, focusing on the northeastern U.S., based aircraft measurements from Wintertime Investigation Transport, Emissions, Reactivity campaign (1 February to 15 March 2015). water were predicted with ISORROPIA-II thermodynamic model validated by comparing observed partitioning...
Significance Exposure to fine particulate matter is a leading cause of premature deaths and illnesses globally. In the eastern United States, substantial cuts in sulfur dioxide nitrogen oxides emissions have considerably lowered sulfate nitrate concentrations for all seasons except winter. Simulations that reproduce detailed airborne observations wintertime atmospheric chemistry over States indicate formation limited by availability oxidants acidity particles, respectively. These limitations...
Abstract Nocturnal dinitrogen pentoxide (N 2 O 5 ) heterogeneous chemistry impacts regional air quality and the distribution lifetime of tropospheric oxidants. Formed from oxidation nitrogen oxides, N is heterogeneously lost to aerosol with a highly variable reaction probability, γ ), dependent on composition ambient conditions. Reaction products include soluble nitrate (HNO 3 or NO − nitryl chloride (ClNO ). We report first‐ever derivations wintertime aircraft measurements in critically...
Abstract. From 2016 to 2018 a DC-8 aircraft operated by the US National Aeronautics and Space Administration (NASA) made four series of flights, profiling atmosphere from 180 m ∼12 km above sea level (km a.s.l.) Arctic Antarctic over both Pacific Atlantic oceans. This program, Atmospheric Tomography Mission (ATom), sought sample troposphere in representative manner, making measurements atmospheric composition each season. paper describes aerosol microphysical derived quantities obtained...
Abstract. Atmospheric marine aerosol particles impact Earth's albedo and climate. These can be primary or secondary come from a variety of sources, including sea salt, dissolved organic matter, volatile compounds, sulfur-containing compounds. Dimethylsulfide (DMS) emissions contribute greatly to the global biogenic sulfur budget, its oxidation products mass, specifically as sulfuric acid methanesulfonic (MSA). Further, is known nucleating compound, MSA may able participate in nucleation when...
Abstract. Anthropogenic secondary organic aerosol (ASOA), formed from anthropogenic emissions of compounds, constitutes a substantial fraction the mass submicron in populated areas around world and contributes to poor air quality premature mortality. However, precursor sources ASOA are poorly understood, there large uncertainties health benefits that might accrue reducing emissions. We show production 11 urban on three continents is strongly correlated with reactivity specific volatile...
Abstract One year of aerosol particle observations from Alert, Nunavut shows that new formation (NPF) is common during clean periods the summertime Arctic associated with attendant low condensation sinks and presence methane sulfonic acid (MSA), a product atmospheric oxidation dimethyl sulfide (DMS). The time periods, defined using distribution refractory black carbon number concentrations, increase in frequency June through August as anthropogenic influence dwindles. During concentrations...
Nighttime concentration profiles of the nitrate radical (NO 3 ) together with NO 2 and O were observed spectroscopically. Kinetic analysis formation, early morning photolysis , stoichiometric considerations allowed three independent estimates equilibrium constant K eq = [NO ] · ]/[N 5 ]. From those observations an average (2.0±l) × 10 cm −3 (at 10°C) is derived. Maximum concentrations found to be highly variable. Lifetimes for shorter than l min in presence fog indicate a fast reaction N...
Abstract. Organic aerosol (OA) is an important fraction of submicron aerosols. However, it challenging to predict and attribute the specific organic compounds sources that lead observed OA loadings, largely due contributions from secondary production. This especially true for megacities surrounded by numerous regional create background. Here, we utilize in situ gas observations collected on board NASA DC-8 during NASA–NIER KORUS-AQ (Korea–United States Air Quality) campaign investigate...
Abstract Most intensive field studies investigating aerosols have been conducted in summer, and thus, wintertime aerosol sources chemistry are comparatively poorly understood. An mass spectrometer was flown on the National Science Foundation/National Center for Atmospheric Research C‐130 during Wintertime INvestigation of Transport, Emissions, Reactivity (WINTER) 2015 campaign northeast United States. The fraction boundary layer submicron that organic (OA) about a factor 2 smaller than 2011...
Abstract Primary marine aerosol (PMA)‐cloud interactions off the coast of California were investigated using observations aerosol, cloud condensation nuclei (CCN), and stratocumulus clouds during Eastern Pacific Emitted Aerosol Cloud Experiment (E‐PEACE) Stratocumulus Observations Los‐Angeles Emissions Derived Aerosol‐Droplets (SOLEDAD) studies. Based on recently reported measurements PMA size distributions, a constrained lognormal‐mode‐fitting procedure was devised to isolate number...
Abstract We examine the distribution and fate of nitrogen oxides (NO x ) in lower troposphere over Northeast United States (NE US) using aircraft observations from Wintertime INvestigation Transport, Emissions, Reactivity (WINTER) campaign February–March 2015, as well GEOS‐Chem chemical transport model concurrent ground‐based observations. find that National Emission Inventory U.S. Environmental Protection Agency is consistent with WINTER total reactive ( T NO y to within 10% on average,...
Abstract. Aerosol intercomparisons are inherently complex as they convolve instrument-dependent detection efficiencies vs. size (which often change with pressure, temperature, or humidity) and variations in the sampled aerosol population, addition to differences chemical principles (e.g., inorganic-only nitrate inorganic plus organic for two instruments). The NASA Atmospheric Tomography Mission (ATom) spanned four separate aircraft deployments which remote marine troposphere from 86∘ S 82∘ N...
Abstract. The spatial distribution and properties of submicron organic aerosol (OA) are among the key sources uncertainty in our understanding effects on climate. Uncertainties particularly large over remote regions free troposphere Southern Ocean, where very few data have been available OA predictions from AeroCom Phase II global models span 2 to 3 orders magnitude, greatly exceeding model spread source regions. (nearly) pole-to-pole vertical non-refractory aerosols was measured with an...
Abstract Although urban NO x lifetimes have been examined extensively during summertime conditions, wintertime chemistry has comparatively less studied. We use measurements of and its oxidation products from the aircraft‐based WINTER (Wintertime INvestigation Transport, Emissions, Reactivity) experiment over northeastern United States February–March 2015 to describe lifetime conditions when days are shorter, actinic flux is reduced, temperatures colder. By analyzing regional outflow East...
Organosulfur compounds are important components of secondary organic aerosols (SOA). While the Aerodyne high-resolution time-of-flight aerosol mass spectrometer (AMS) has been extensively used in studies, response AMS to organosulfur is not well-understood. Here, we investigated fragmentation patterns organosulfurs and inorganic sulfates AMS, developed a method deconvolve total sulfate into origins, applied this both laboratory field measurements. Apportionment results from isoprene...
Abstract The inorganic fraction of fine particles affects numerous physicochemical processes in the atmosphere. However, there is large uncertainty its burden and composition due to limited global measurements. Here, we present observations from eleven different aircraft campaigns around globe investigate how aerosol pH ammonium balance change polluted remote regions, such as over oceans. Both parameters show increasing acidity with remoteness, at all altitudes, decreasing about 3 −1 almost...
Dark chamber experiments were conducted to study the SOA formed from oxidation of α-pinene and Δ-carene under different peroxy radical (RO2) fate regimes: RO2 + NO3, RO2, HO2. mass yields <1 ∼25% strongly dependent on available OA up ∼100 μg m-3. The strong yield dependence is driven by absorptive partitioning not surface area for condensation. Yields NO3 consistently higher, ranging ∼10-50% with some <25 Explicit kinetic modeling including vapor wall losses was enable comparisons across VOC...
Pyrocumulonimbus (pyroCb) are wildfire-generated convective clouds that can inject smoke directly into the stratosphere. PyroCb have been tracked for years, yet their apparent rarity and episodic nature lead to highly uncertain climate impacts. In situ measurements of pyroCb reveal its distinctive exceptionally stable aerosol properties define long-term influence activity on stratospheric budget. Analysis 13 years airborne observations shows responsible 10 25% black carbon organic aerosols...
Abstract We describe the University of Washington airborne high‐resolution time‐of‐flight chemical ionization mass spectrometer (HRToF‐CIMS) and evaluate its performance aboard NCAR‐NSF C‐130 aircraft during recent Wintertime INvestigation Transport, Emissions Reactivity (WINTER) experiment in February–March 2015. New features include (i) a computer‐controlled dynamic pinhole that maintains constant flow‐rate into instrument independent altitude changes to minimize variations response times;...
Abstract Nitryl chloride (ClNO 2 ) plays an important role in the budget and distribution of tropospheric oxidants, halogens, reactive nitrogen species. ClNO is formed from heterogeneous uptake reaction dinitrogen pentoxide (N O 5 on chloride‐containing aerosol, with a production yield, ϕ ), defined as moles produced relative to N lost. The has been increasingly incorporated into 3‐D chemical models where it parameterized based laboratory‐derived kinetics currently accepted aqueous‐phase...
Abstract As part of the WINTER (Wintertime Investigation Transport, Emissions, and Reactivity) campaign, a Particle‐into‐Liquid Sampler with fraction collector was flown aboard National Center for Atmospheric Research C‐130 aircraft. Two‐minute integrated liquid samples containing dissolved fine particulate matter (PM 1 ) species were collected analyzed off‐line smoke marker levoglucosan using high‐performance anion‐exchange chromatography‐pulsed amperometric detection to compare aerosol...