A5101443276- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Air Quality and Health Impacts
- Air Quality Monitoring and Forecasting
- Atmospheric and Environmental Gas Dynamics
- Marine and coastal ecosystems
- Atmospheric aerosols and clouds
- Water Quality Monitoring and Analysis
- Spectroscopy and Laser Applications
- Odor and Emission Control Technologies
- Vehicle emissions and performance
- Mercury impact and mitigation studies
- Environmental Chemistry and Analysis
- Isotope Analysis in Ecology
- Plant responses to elevated CO2
- Catalytic Processes in Materials Science
- Groundwater and Isotope Geochemistry
- Chemical and Physical Properties in Aqueous Solutions
- Forest ecology and management
- Oil Spill Detection and Mitigation
- Free Radicals and Antioxidants
- Algal biology and biofuel production
- Cryospheric studies and observations
- Environmental Toxicology and Ecotoxicology
- Aeolian processes and effects
Chongqing Jiulongpo People's Hospital
2024
New York State Department of Health
2012-2023
Wadsworth Center
2014-2023
University at Albany, State University of New York
2012-2023
Albany State University
2008-2022
New York State Department of Environmental Conservation
2004-2009
Indiana University Bloomington
2007
State University of New York
2002
Brookhaven National Laboratory
1991-1997
University of Miami
1990-1991
Photochemical production rates and steady-state concentrations of hydroxyl radicals (⋅OH) were measured in sunlight-irradiated seawater. Values ranged from 110 nanomolar per hour 12 × 10 -18 molar coastal surface water to 1.1 open ocean water. The wavelengths responsible for this are the ultraviolet B region (280 320 nanometers) solar spectrum. Dissolved organic matter (DOM) appears be main source ⋅OH over most oceans, but upwelling areas nitrite nitrate photolysis may also important. DOM...
Low‐molecular‐weight (LMW) carbonyl compounds, e.g. formaldehyde, acetaldehyde, and the α ‐keto acid glyoxylate, were produced in a wide variety of natural waters upon irradiation with sunlight. Production rates linearly related ( r 2 > 0.98) to initial absorbance at 300 nm fluorescence (360/460 nm) all tested. Photochemical production was also loss (photobleaching) during irradiation, irrespective time prior photobleaching history sample. These results attributed absorption light by...
Abstract. Ozone pollution in the Southeast US involves complex chemistry driven by emissions of anthropogenic nitrogen oxide radicals (NOx ≡ NO + NO2) and biogenic isoprene. Model estimates surface ozone concentrations tend to be biased high region this is concern for designing effective emission control strategies meet air quality standards. We use detailed chemical observations from SEAC4RS aircraft campaign August September 2013, interpreted with GEOS-Chem transport model at 0.25° ×...
Breaking waves on the ocean surface produce bubbles that, upon bursting, inject seawater constituents into atmosphere. Nascent aerosols were generated by bubbling zero‐air through flowing within an RH‐controlled chamber deployed at Bermuda and analyzed for major chemical physical characteristics. The composition of feed was representative surrounding ocean. Relative size distributions inorganic aerosol similar to those in ambient air. Ca 2+ significantly enriched relative (median factor =...
Photolysis of nitric acid on the surface has been found recently to be greatly enhanced from that in gas phase. Yet, photolysis particulate nitrate (pNO3) associated with atmospheric aerosols is still relatively unknown. Here, aerosol filter samples were collected both near ground and throughout troposphere board NSF/NACR C-130 aircraft. The rate constants pNO3 determined these by directly monitoring production rates nitrous (HONO) nitrogen dioxide (NO2) under UV light (>290 nm) irradiation....
Photolysis of nitric acid and nitrate (HNO3/nitrate) was investigated on the surfaces natural artificial materials, including plant leaves, metal sheets, construction materials. The were conditioned in outdoor air prior to experiments receive depositions ambient HNO3/nitrate other atmospheric constituents. photolysis rate constant (JHNO3(s)) surface measured based production rates nitrous (HONO) nitrogen oxides (NOx). JHNO3(s) values, from 6.0 × 10–6 s–1 3.7 10–4 s–1, are 1 3 orders...
A variety of short-lived, reactive chemical species (i.e. free radicals and excited state species) are known to be photochemically produced in natural waters. Some these transients may strongly affect biological processes, they have been implicated the degradation organic pollutants compounds aqueous environments. Previous studies demonstrated that highly hydroxyl radical (OH) is formed seawater. However, quantitative importance this key sea has not previously studied because past analytical...
Nitric acid (HNO 3 ) is the dominant end product of NO x (= + 2 oxidation in troposphere, and its dry deposition considered to be a major removal pathway for atmospheric reactive nitrogen. Here we present both field laboratory results demonstrate that HNO deposited on ground vegetation surfaces may undergo effective photolysis form HONO , 1–2 orders magnitude faster than gas phase aqueous phase. With this enhanced rate, significantly impact chemistry overlying boundary layer remote low‐NO...
Both snow manipulation experiments and ambient measurements during the Polar Sunrise Experiment 2000 at Alert (Alert2000) indicate intensive photochemical production of nitrous acid (HONO) in snowpack. This process constitutes a major HONO source for overlying atmospheric boundary layer Arctic springtime, sustained concentrations high enough that upon photolysis they became dominant hydroxyl radical (OH) source. implies much greater role OH radicals polar sunrise chemistry than previously...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTApparent partition coefficients of 15 carbonyl compounds between air and seawater freshwater; implications for air-sea exchangeXianliang Zhou Kenneth MopperCite this: Environ. Sci. Technol. 1990, 24, 12, 1864–1869Publication Date (Print):December 1, 1990Publication History Published online1 May 2002Published inissue 1 December 1990https://pubs.acs.org/doi/10.1021/es00082a013https://doi.org/10.1021/es00082a013research-articleACS PublicationsRequest...
Trace gas measurements pertinent to understanding the transport and photochemical formation of O 3 were made at a surface site in rural Georgia as part Southern Oxidant Study during summer 1991. It was found that there strong correlation between oxidation products NO x : (ppb) = 27 + 11.4 (NO y − (ppb)), r 2 0.78. This fit is similar observed other sites eastern North America indicates nominal background level ppb; values higher than ppb are due production recent past, which varied from near...
Airborne measurements of formaldehyde (FA), glycolaldehyde (GA), glyoxal (GL), methylglyoxal (MG), and pyruvic acid (PD) were made on board instrumented aircraft platforms, the Department Energy G1 National Oceanic Atmospheric Administration P3 (FA only), during 1995 Nashville/Middle Tennessee Ozone Study. FA data determined these two three intercomparison flights agreed to within ∼10%. The mean median (in parentheses) concentrations observed boundary layer (<2000 m) for FA, GA, GL, MG,...
Ambient measurements of HONO and HNO 3 , using a highly sensitive coil scrubbing/HPLC/visible detection technique, were made at rural site in southwestern New York State from 26 June to 14 July 1998, along with concurrent NO x y O various meteorological parameters. The mean (and median) half‐hour concentrations during this period 63 56) pptv 418 339) pptv, respectively. On average, there two concentration peaks, the first around 0200–0300 LT second 0700–0800 LT, minimum about 2000 LT. sum...
Significant production of HONO was observed on glass sample manifold wall surface when exposed to sunlight during the PROPHET 2000 summer measurement intensive. It is hypothesized that artifact produced by photolysis adsorbed nitric acid/nitrate surfaces followed subsequent reaction NO 2 and H O surface. This observation suggests against use an unshielded as a sampling inlet for atmospheric HONO. may also have some implications in interpreting field x data measured using similar manifolds,...
Hydroxyl (OH), hydroperoxy (HO 2 ) radicals, collectively known as HO x , and OH reactivity, were measured during the PMTACS–NY (PM2.5 Technology Assessment Characteristics Study‐New York) summer 2002 intensive at Whiteface Mountain, Wilmington, New York. The measurement results of for 4 weeks are presented. Diurnal cycles show that average noontime maximum mixing ratios about 0.11 pptv (2.6 × 10 6 cm −3 20 . Measured to typically between 40 400, which greater than those obtained in polluted...
Here we present the first HONO vertical profiles in atmospheric boundary layer (BL) and lower free troposphere (FT) over a forested region northern Michigan neighboring Great Lakes, measured from small aircraft summer of 2007. The mixing ratios ranged 4 to 17 pptv FT 8 74 BL. distribution pattern was strongly influenced by air column stability, i.e., strong negative gradients existed stable BL morning hours, whereas relatively uniform unstable well‐mixed afternoons. ground surface major...
Abstract. Hydroxyl (OH) and hydroperoxyl (HO2) radicals are key species driving the oxidation of volatile organic compounds that can lead to production ozone secondary aerosols. Previous measurements these in forest environments with high isoprene, low NOx conditions have shown serious discrepancies modeled concentrations, bringing into question current understanding isoprene chemistry environments. During summers 2008 2009, OH peroxy radical concentrations were measured using a...
Atmospheric concentrations of a series carbonyl compounds known as formaldehyde (FA), acetaldehyde (AC), acetone (AN), glycolaldehyde (GA), glyoxal (GL), methylglyoxal (MG), glyoxylic acid (GD), and pyruvic (PD) were measured at rural site in Georgia summers 1991 1992. The midafternoon median concentrations, parts per billion, determined for 1991–1992 FA, 3.6/3.1; AC, 0.58/0.74; AN, 1.7/1.8; GA, 0.21/0.26; GL, 0.02/0.09; MG, 0.03/0.08; GD, 0.46; PD, 0.11, the latter two 1992 only. All...
HONO, HCHO, and O 3 concentrations were measured at the summit of Whiteface Mountain, New York, during summer 1999. Concentrations in range ≤5–400 pptv with a median 27 mean 46 for ≤30–6170 1260 1340 20–105 ppbv 51 49 . The daily HO x productions from photolysis , HCHO 6.1, 2.8, 1.9 d −1 respectively, contributing 57, 26, 17% to overall radical budget these precursors. Significant diurnal variation average HONO was observed, late morning maximum afternoon/early evening minimum. HNO on...