A5033746678- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Spectroscopy and Laser Applications
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- Advanced Chemical Sensor Technologies
- Atmospheric aerosols and clouds
- Catalytic Processes in Materials Science
- Indoor Air Quality and Microbial Exposure
- Catalysis and Oxidation Reactions
- Free Radicals and Antioxidants
- Advanced Chemical Physics Studies
- Odor and Emission Control Technologies
- Isotope Analysis in Ecology
- Plant responses to elevated CO2
- Vehicle emissions and performance
- Water Quality Monitoring and Analysis
- Toxic Organic Pollutants Impact
- Chemical Thermodynamics and Molecular Structure
- Climate variability and models
- Photochemistry and Electron Transfer Studies
- Geophysics and Gravity Measurements
- Laser Design and Applications
- Per- and polyfluoroalkyl substances research
NSF National Center for Atmospheric Research
2015-2024
Atmospheric Chemistry Observations & Modeling
2017-2023
Earth Observing Laboratory
2020
NOAA Earth System Research Laboratory
2011
California State University, Fresno
2004
KU Leuven
1998
University of Colorado Boulder
1988-1996
Cooperative Institute for Research in Environmental Sciences
1988-1996
National Oceanic and Atmospheric Administration
1988-1996
McMaster University
1986-1987
The Model for Ozone and Related chemical Tracers, version 4 (MOZART-4) is an offline global transport model particularly suited studies of the troposphere. updates from its previous MOZART-2 are described, including expansion mechanism to include more detailed hydrocarbon chemistry bulk aerosols. Online calculations a number processes, such as dry deposition, emissions isoprene monoterpenes photolysis frequencies, now included. Results eight-year simulation (2000–2007) presented evaluated....
Abstract. The Fire INventory from NCAR version 1.0 (FINNv1) provides daily, 1 km resolution, global estimates of the trace gas and particle emissions open burning biomass, which includes wildfire, agricultural fires, prescribed does not include biofuel use trash burning. Emission factors used in calculations have been updated with recent data, particularly for non-methane organic compounds (NMOC). resulting annual NMOC emission are as much a factor 5 greater than some prior estimates....
We have developed a global three‐dimensional chemical transport model called Model of Ozone and Related Chemical Tracers (MOZART), version 2. This model, which will be made available to the community, is built on framework National Center for Atmospheric Research (NCAR) Transport Chemistry (MATCH) can easily driven with various meteorological inputs resolutions. In this work, we describe standard configuration in by every 3 hours from middle atmosphere NCAR Community Climate (MACCM3) uses...
Abstract. We discuss and evaluate the representation of atmospheric chemistry in global Community Atmosphere Model (CAM) version 4, component Earth System (CESM). present a variety configurations for tropospheric stratospheric chemistry, wet removal, online offline meteorology. Results from simulations illustrating these are compared with surface, aircraft satellite observations. Major biases include negative bias high-latitude CO distribution, positive upper-tropospheric/lower-stratospheric...
PREFACE LIST OF AUTHORS FREQUENTLY-USED SYMBOLS 1. Atmospheric Chemistry and the Earth's System 1.1 Introduction 1.2 The Earth Further Reading Essay: PART 1: FUNDAMENTALS 2. Dynamics Transport 2,1 2.2 Governing Equations 2.3 Constraints on Motion 2.4 Zonal Means Eddies 2.5 Waves 2.6 Tropospheric Circulation 2.7 Stratospheric 2.8 Stratosphere-Troposphere Exchange Why Understand - And What Is Understanding Anyway? 3. Chemical Photochemical Processes 3.1 3.2 Radiation 3.3 Photophysical 3.4...
The Model for Ozone and Related Chemical Tracers, version 3 (MOZART‐3), which represents the chemical physical processes from troposphere through lower mesosphere, was used to evaluate representation of long‐lived tracers ozone using three different meteorological fields. fields are based on (1) Whole Atmosphere Community Climate Model, 1b (WACCM1b), (2) European Centre Medium‐Range Weather Forecasts (ECMWF) operational analysis, (3) a new reanalysis year 2000 ECMWF called EXP471....
The absorption spectrum of O 2 and ‐O collision pairs were measured over the wavelength range from 330 to 1140 nm using pressures 1 55 atm at 298 K. Absorption cross sections, pressure dependences, band centers, full widths half maximum observed bands centered 343.4, 360.5, 380.2, 446.7, 477.3, 532.2, 577.2, 630.0, 688, 762, 1065.2 are reported. 477.3 also 196 K their temperature dependences characterized.
Abstract The Community Earth System Model version 2 (CESM2) includes a detailed representation of chemistry throughout the atmosphere in Atmosphere with and Whole Climate configurations. These model configurations use for Ozone Related chemical Tracers (MOZART) family mechanisms, covering troposphere, stratosphere, mesosphere, lower thermosphere. new MOZART tropospheric scheme (T1) has number updates over previous (MOZART‐4) CESM, including improvements to oxidation isoprene terpenes,...
Abstract. New pathways to form secondary organic aerosol (SOA) have been postulated recently. Glyoxal, the smallest dicarbonyl, is one of proposed precursors. It has both anthropogenic and biogenic sources, readily partitions into aqueous phase cloud droplets deliquesced particles where it undergoes reversible irreversible chemistry. In this work we extend regional scale chemistry transport model WRF-Chem include detailed gas-phase glyoxal formation as well a state-of-the-science module...
Abstract. Multiple trace-gas instruments were deployed during the fourth Fire Lab at Missoula Experiment (FLAME-4), including first application of proton-transfer-reaction time-of-flight mass spectrometry (PTR-TOFMS) and comprehensive two-dimensional gas chromatography–time-of-flight (GC × GC-TOFMS) for laboratory biomass burning (BB) measurements. Open-path Fourier transform infrared spectroscopy (OP-FTIR) was also deployed, as well whole-air sampling (WAS) with one-dimensional...
The reactions of ozone with alkenes have been shown recently to lead the direct production OH radicals. Organic peroxy radicals (RO 2 ) probably accompany OH. In this paper, we draw attention potential importance these in primary HO x (HO = OH, and RO various regions boundary layer. anthropogenic are be most important source many urban settings during day evening, a significant at night. majority comes from trace quantities internal double bonds. Reaction O 3 isoprene terpenes can an...
The reaction between HO2 and RO2 radicals represents an important chemical sink for HOx in the atmosphere. On basis of a few product yield studies, these reactions are believed to form hydroperoxides almost exclusively (R8a), although several different channels may be thermodynamically accessible (R8a−d): + → ROOH O2 (R8a); ROH O3 (R8b); RO OH (R8c); R'CHO H2O (R8d). Branching ratios R8 were measured three organic peroxy radicals: ethyl (C2H5O2), acetyl (CH3C(O)O2), acetonyl (CH3C(O)CH2O2)...
We present a study of the sensitivity isoprene emission calculations in global chemistry transport model (CTM) to input land cover characteristics and analyze impacts changes on tropospheric budgets atmospheric key species. The CTM Model for Ozone Related Chemical Species, version 4 (MOZART‐4) includes online calculation emissions based Emissions Gases Aerosols from Nature (MEGAN), which is driven by three different parameter inputs. also included tagging scheme CTM, keeps track production...
In association with Tropospheric Ozone Production about the Spring Equinox (TOPSE) measurement campaign a regional episodic chemical transport model is used to study seasonal mechanisms of pollutants from their Northern Hemisphere emission regions into remainder troposphere. The simulates strong cycle for CO and hydrocarbons that agrees well TOPSE measurements. this we use isentropic perspective analyze during different seasons regions. Simulations diagnostic tracers are conducted quantify...
Abstract. We have integrated observations of tropospheric ozone, very short-lived (VSL) halocarbons and reactive iodine bromine species from a wide variety tropical data sources with the global CAM-Chem chemistry-climate model offline radiative transfer calculations to compute contribution halogen chemistry ozone loss associated impact in marine troposphere. The inclusion leads an annually averaged depletion around 10% (~2.5 Dobson units) column, largest effects middle upper This contributes...
Abstract. The Fire INventory from NCAR version 1.0 (FINNv1) provides daily, 1 km resolution, global estimates of the trace gas and particle emissions open burning biomass, which includes wildfire, agricultural fires, prescribed does not include biofuel use trash burning. Emission factors used in calculations have been updated with recent data, particularly for non-methane organic compounds (NMOC). resulting annual NMOC emission are as much a factor 5 greater than some prior estimates....
Abstract. Two proton-transfer-reaction mass spectrometry systems were deployed at the Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics and Nitrogen-Southern Rocky Mountain 2008 field campaign (BEACHON-SRM08; July to September, 2008) Manitou Forest Observatory in a ponderosa pine woodland near Woodland Park, Colorado USA. The two PTR-MS simultaneously measured BVOC emissions ambient distributions their oxidation products. Here, we present spectral analysis wide...
The formulations of tropospheric gas-phase chemistry ("mechanisms") used in the regional-scale chemistry-transport models participating Air Quality Modelling Evaluation International Initiative (AQMEII) Phase 2 are intercompared by means box model studies. Simulations were conducted under idealized meteorological conditions, and results representative mean boundary layer concentrations. Three sets conditions – winter, spring/autumn summer to capture annual variability, similar 3-D...
Laboratory studies of atmospheric chemistry characterize the nature atmospherically relevant processes down to molecular level, providing fundamental information used assess how human activities drive environmental phenomena such as climate change, urban air pollution, ecosystem health, indoor quality, and stratospheric ozone depletion. have a central role in addressing incomplete knowledge chemistry. This article highlights evolving science needs for this community emphasizes our is far...