A5020536906- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Advanced Chemical Sensor Technologies
- Mass Spectrometry Techniques and Applications
- Climate variability and models
- Spectroscopy and Laser Applications
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- Indoor Air Quality and Microbial Exposure
- Meat and Animal Product Quality
- Ocean Acidification Effects and Responses
- Ionosphere and magnetosphere dynamics
- Analytical Chemistry and Chromatography
- Odor and Emission Control Technologies
Cooperative Institute for Research in Environmental Sciences
2023-2025
University of Colorado Boulder
2024-2025
University of Miami
2022-2025
NOAA Chemical Sciences Laboratory
2023-2025
National Oceanic and Atmospheric Administration
2023-2024
University of Rhode Island
2017-2019
Radiotelevisione Italiana (Italy)
2015
Deep convection in the Asian summer monsoon is a significant transport process for lifting pollutants from planetary boundary layer to tropopause level. This enables efficient injection into stratosphere of reactive species such as chlorinated very short-lived substances (Cl-VSLSs) that deplete ozone. Past studies convective associated with have focused mostly on south monsoon. Airborne observations reported this work identify East an effective pathway carried record-breaking levels...
Abstract. We apply a high-resolution chemical transport model (GEOS-Chem CTM) with updated treatment of volatile organic compounds (VOCs) and comprehensive suite airborne datasets over North America to (i) characterize the VOC budget (ii) test ability current models capture distribution reactivity atmospheric VOCs this region. Biogenic emissions dominate American in model, accounting for 70 % 95 annually emitted carbon reactivity, respectively. Based on inventories anthropogenic have...
Abstract Rapid growing emissions of dichloromethane (CH 2 Cl ), a chlorinated very‐short‐lived substance (Cl‐VSLS) and an ozone depleting (ODS), has raised concerns as this increase offset part the stratospheric chlorine (Cl) reduction due to decreasing long‐lived ODSs. We have combined simulations two most abundant Cl‐VSLSs, CH chloroform (CHCl 3 ) using NASA GEOS Chemistry Climate Model (GEOSCCM) with Asian Summer Monsoon Chemical CLimate Impact Project aircraft observations examine...
Abstract The Asian Summer Monsoon (ASM) has garnered attention in recent years for its impacts on the composition of upper troposphere and lower stratosphere (UTLS) via deep convection. A observational effort into this mechanism, Chemical CLimate Impact Project (ACCLIP), sampled ASM UTLS over northwestern Pacific region during boreal summer 2022 using two airborne platforms. In work, we integrate Lagrangian trajectory modeling with convective cloud top observations to diagnose transport...
Abstract. A chemical ionization mass spectrometry (CIMS) method utilizing a reagent gas mixture of O2, CO2, and CH3I in N2 is described optimized for quantitative gas-phase measurements hydrogen peroxide (H2O2), methyl (CH3OOH), formic acid (HCOOH), the sum acetic (CH3COOH) hydroxyacetaldehyde (HOCH2CHO; also known as glycolaldehyde). The instrumentation methodology were designed airborne situ field measurements. CIMS quantification acid, used I− cluster formation to produce detect ion...
Abstract Chemistry Climate Models (CCMs) are essential tools for characterizing and predicting the role of atmospheric composition chemistry in Earth's climate system. This study demonstrates use airborne situ observations to diagnose representation chemical transport by CCMs. Process‐based diagnostics using dynamical coordinates presented which minimize spatial temporal sampling differences between measurements CCM grid points. The chosen process is impact Asian summer monsoon (ASM), where...
The Asian Summer Monsoon (ASM) has garnered attention in recent years for its impacts on the composition of upper troposphere and lower stratosphere (UTLS) via deep convection. A observational effort into this mechanism, summer monsoon Chemical CLimate Impact Project (ACCLIP), sampled ASM UTLS over northwestern Pacific during boreal 2022 using two airborne platforms. In work, we integrate Lagrangian trajectory modeling with convective cloud top observations to diagnose transport which...
Abstract. An ion-neutral chemical kinetic model is described and used to simulate the negative ion chemistry occurring within a mixed-reagent ionization mass spectrometer (CIMS). The objective was establishment of theoretical basis understand ambient pressure (variable sample flow reagent carrier gas rates), water vapor, ozone oxides nitrogen effects on cluster sensitivities for hydrogen peroxide (H2O2), methyl (CH3OOH), formic acid (HFo) acetic (HAc). development started with established...
Abstract. We apply a high-resolution chemical transport model (GEOS-Chem CTM) with updated treatment of volatile organic compounds (VOCs) and comprehensive suite airborne datasets over North America to i) characterize the VOC budget, ii) test ability current models capture distribution reactivity atmospheric VOCs, this region. Biogenic emissions dominate American budget in model, accounting for 70 % 95 annually emitted VOC-carbon reactivity, respectively. Based on inventories anthropogenic...
Abstract Aircraft observations of the four chloromethanes: carbon tetrachloride (CCl 4 ), methyl chloride (CH 3 Cl), dichloromethane 2 Cl and chloroform (CHCl collected over North America between 2000 2022, were used to evaluate their vertical distributions temporal trends in atmosphere. We examine profiles, from surface lower stratosphere (LS), these increasingly important contributors ozone‐depleting chlorine both altitude potential temperature space. Airborne chloromethane compared with...
Abstract. A chemical ionization mass spectrometry (CIMS) method utilizing a reagent gas mixture of O2, CO2, and CH3I in N2 is described optimized for quantitative gas-phase measurements hydrogen peroxide (H2O2), methyl (CH3OOH), formic acid (HCOOH), the sum acetic (CH3COOH) hydroxyacetaldehyde (HOCH2CHO; also known as glycolaldehyde). The instrumentation methodology were designed airborne situ field measurements. CIMS quantification acid, used I- cluster formation to produce detect ion...
Notes on mechanism development and adjustment of kinetic rates to resolve pressure humidity trends in -( ), )( -() sensitivities.1.1 Base thermodynamic data for the -- - hydroperoxide system.Formation enthalpy (∆ entropy Gibb's formation energy are published some neutral, ion ion-cluster species involved 2 system.Reaction enthalpy(∆ ) also available reactions this system.These summarized Table A5 A6.The NIST Chemistry WebBook (Bartmess, 2016) was used extensively analysis as it provides...
Abstract. An ion-neutral chemical kinetic model is described and used to simulate the negative-ion chemistry occurring within a mixed-reagent ion ionization mass spectrometer (CIMS). The objective was establishment of theoretical basis understand ambient pressure (variable sample flow reagent carrier gas rates), water vapor, ozone oxides nitrogen effects on ion-cluster sensitivities for hydrogen peroxide (H2O2), methyl (CH3OOH), formic acid (HFo) acetic (HAc). development started with...
<p>One of the scientific objectives Asian Summer Monsoon Chemical & CLimate Impact Project (ACCLIP) project was to sample chemical content air processed in (ASM) ascertain its role UTLS ozone chemistry and re-distributing active species short-lived climate forcers. Whole Air Samplers were used on NSF/NCAR GV NASA WB-57 aircraft collect samples for analysis a range organic compounds, including halogens hydrocarbons. From these we determined vertical distributions...
Airborne research missions were conducted during the summer season over Western Pacific downwind of Asian monsoon (ACCLIP, Summer Monsoon Chemical & CLimate Impact Project, Aug/Sept., 2022) and central N. America (DCOTSS: Dynamics Chemistry Of The Stratosphere, July/Aug., 2021 May/July, 2022).  A major objective both these was to characterize impact convective transport trace gases on regional hemispheric air quality ozone chemistry in UT/LS.  The DCOTSS campaign...
Whole Air Samples (WAS) were collected as part of the Dynamics and Chemistry Summer Stratosphere (DCOTSS) field campaign in Upper Troposphere-Lower (UTLS) region during 2021 2022. Grid-Rad satellite imagery used to identify regions overshooting convection, areas with outflow from targeted by DCOTSS aircraft using trajectory models in-situ measurements. Because a wide range trace gases different atmospheric lifetimes sources are measured, WAS can provide insight into processes that influence...
Although the Montreal Protocol has been successful in reducing emissions of long-lived ozone-depleting substances, certain unregulated, chlorinated very short-lived substances (VSLS, lifetimes < 6 months) are believed to be having an increasing impact on stratospheric ozone depletion. The major sources VSLS anthropogenic. Emissions have reported from both bottom-up estimates and observations recent years, among which dichloromethane (DCM) is most abundant. East Asia identified as...