A5090768107- Atmospheric chemistry and aerosols
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Atmospheric aerosols and clouds
- Air Quality and Health Impacts
- Ionosphere and magnetosphere dynamics
- Air Quality Monitoring and Forecasting
- Spectroscopy and Laser Applications
- Climate variability and models
- Vehicle emissions and performance
- Advanced Aircraft Design and Technologies
- Solar and Space Plasma Dynamics
- Spaceflight effects on biology
- Ocean Acidification Effects and Responses
- Climate Change and Geoengineering
- Toxic Organic Pollutants Impact
- Spacecraft Design and Technology
- Methane Hydrates and Related Phenomena
- Gas Dynamics and Kinetic Theory
- Spacecraft and Cryogenic Technologies
- Meteorological Phenomena and Simulations
- Space exploration and regulation
- Arctic and Antarctic ice dynamics
- Gamma-ray bursts and supernovae
- Fire effects on ecosystems
NOAA Chemical Sciences Laboratory
2014-2024
Beijing Jishuitan Hospital
2024
Capital Medical University
2024
Peking University
2024
Xi'an University of Architecture and Technology
2024
National Oceanic and Atmospheric Administration
2014-2023
Cooperative Institute for Research in Environmental Sciences
1995-2023
University of Colorado Boulder
1995-2023
Columbia University
2023
NOAA Earth System Research Laboratory
2011-2020
A single‐particle soot photometer (SP2) was flown on a NASA WB‐57F high‐altitude research aircraft in November 2004 from Houston, Texas. The SP2 uses laser‐induced incandescence to detect individual black carbon (BC) particles an air sample the mass range of ∼3–300 fg (∼0.15–0.7 μm volume equivalent diameter). Scattered light is used size remaining non‐BC aerosols ∼0.17–0.7 diameter. We present profiles both aerosol types boundary layer lower stratosphere two midlatitude flights. Results for...
In situ measurements of the mass, mixing state, and optical size individual black‐carbon (BC) particles in fine mode (90–600 nm) have been made fresh emissions from urban biomass burning sources with an airborne single‐particle soot photometer. Contrasts between two are significant consistent. Urban BC tends to smaller sizes, fewer coated particles, thinner coatings, less absorption per unit mass than biomass‐burning BC. This suggests that may a longer lifetime atmosphere different impact on...
Simultaneous in situ measurements of the concentrations OH, HO(2), ClO, BrO, NO, and NO(2) demonstrate predominance odd-hydrogen halogen free-radical catalysis determining rate removal ozone lower stratosphere during May 1993. A single catalytic cycle, which rate-limiting step is reaction HO(2) with ozone, accounted for nearly one-half total O(3) this region atmosphere. Halogen-radical chemistry was responsible approximately one-third photochemical O(3); reactions involving BrO account loss....
Black carbon (BC) is the dominant aerosol absorber of solar radiation in atmosphere and an important component anthropogenic climate forcing. BC's role strongly dependent on its physical state, which can influence way that BC particles may act as ice cloud nuclei, well they interact with radiation. In situ measurements made a single‐particle soot photometer flown NASA high‐altitude research aircraft show mass size individual tropics, their propensity to be found mixed additional materials....
A Single-Particle Soot Photometer (SP2) detects black refractory or elemental carbon (EC) in particles by passing them through an intense laser beam. The light heats EC causing to vaporize the Detection of wavelength-resolved thermal radiation emissions provides quantitative information on mass individual size range 0.2–1 μm diameter. Non-absorbing are sized based amount they scatter from time series scattering signal a non-absorbing particle is Gaussian, because SP2 TEM00 mode. Information...
This analysis provides an up‐to‐date assessment of long‐term (1990–2010) rural ozone trends using all available data in the western (12 sites) and eastern (41 USA. Rather than focus solely on average values or air quality standard violations, we consider full range values, reporting for 5th, 50th 95th percentiles. Domestic precursor emissions decreased strongly during 1990–2010. Accordingly 83%, 66% 20% summertime U.S. sites experienced statistically significant decreases 95th, 5th...
Up in smoke Extensive and intense wildfires the Pacific Northwest of United States 2017 injected large quantities into stratosphere. Yu et al. used satellite observations modeling to characterize history chemistry that smoke. The rose altitudes between 12 23 kilometers within 2 months owing solar heating black carbon. then remained stratosphere for more than 8 months. Photochemical loss organic carbon resulted a lifetime 40% shorter expected. Science , this issue p. 587
Inter-comparison studies of well-characterized fractal soot particles were conducted using the following four instruments: Aerosol Mass Spectrometer-Scanning Mobility Particle Sizer (AMS-SMPS), Single Soot Photometer (SP2), Multi-Angle Absorption (MAAP), and Photoacoustic Spectrometer (PAS). These instruments provided measurements refractory mass incandescent (SP2) optically absorbing (MAAP PAS). The studied in mobility diameter range from 150 nm to 460 generated by controlled flames with...
Abstract. We present an overview of the background, scientific goals, and execution Aerosol, Radiation, Cloud Processes affecting Arctic Climate (ARCPAC) project April 2008. then summarize airborne measurements, made in troposphere Alaskan Arctic, aerosol particle size distributions, composition, optical properties discuss sources transport aerosols. The data were grouped into four categories based on gas-phase composition. First, background contained a relatively diffuse, sulfate-rich...
Significance Nonvolcanic stratospheric aerosols account for 20% of the radiative forcing entire atmospheric aerosol system since 1850. The Asian summer monsoon (ASM) effectively pumps pollutants to upper troposphere and lower stratosphere, leading enhanced formation. Our in situ measurements combined with modeling work show that formed within ASM anticyclone is exported Northern Hemispheric stratosphere. On an annual average basis, we estimate ∼15% Hemisphere column surface area originates...
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...
The concentrations of the hydrogen radicals OH and HO2 in middle upper troposphere were measured simultaneously with those NO, O3, CO, H2O, CH4, non-methane hydrocarbons, ultraviolet visible radiation field. data allow a direct examination processes that produce O3 this region atmosphere. Comparison calculations based on their production from water vapor, ozone, methane demonstrate these sources are insufficient to explain observed radical troposphere. photolysis carbonyl peroxide compounds...
Large particles containing nitric acid (HNO3) were observed in the 1999/2000 Arctic winter stratosphere. These situ observations made over a large altitude range (16 to 21 kilometers) and horizontal extent (1800 on several airborne sampling flights during period of weeks. With diameters 10 20 micrometers, these sedimenting have significant potential denitrify lower A microphysical model trihydrate is able simulate growth sedimentation sizes stratosphere, but nucleation process not yet known....
Global satellite observations of ozone and carbon monoxide from the Microwave Limb Sounder (MLS) on EOS Aura spacecraft are discussed with emphasis those in 215–100 hPa region (the upper troposphere lower stratosphere). The precision, resolution accuracy data produced by MLS “version 2.2” processing algorithms quantified. O 3 is estimated at ∼40 ppbv +5% (∼20 +20% 215 hPa) while CO ∼30 +30% for pressures 147 less. Comparisons expectations other show good agreements product, generally...
Refractory black carbon (rBC) aerosol loadings and mass size distributions have been quantified during the HIPPO campaign above remote Pacific from 80N to 67S. Over 100 vertical profiles of rBC loadings, extending ∼0.3 ∼14 km were obtained with a Single‐Particle Soot Photometer (SP2) two‐week period in January 2009. The dataset provides striking, previously unobtainable, pole‐to‐pole snapshot loadings. concentration reveal significant dependences on latitude, while associated highly uniform....
This paper summarizes measured photodissociation quantum yields for acetone in the 290‐320 nm wavelength region pressures and temperatures characteristic of upper troposphere. Calculations combine this laboratory data with trace gas concentrations obtained during NASA NOAA sponsored Stratospheric Tracers Atmospheric Transport (STRAT) field campaign, which measurements OH, HO 2 , odd‐nitrogen, other compounds were collected over Hawaii, west California fall winter 1995/1996. OH within to 5 km...
A single particle soot photometer (SP2) uses an intense laser to heat individual aerosol particles of refractory black carbon (rBC) vaporization, causing them emit detectable amounts thermal radiation that are used quantify rBC mass. This approach is well suited for the detection majority mass loading in ambient atmosphere, which occurs primarily accumulation mode (∼ 1–300 fg-rBC/particle). In addition operator choices about instrument parameters, SP2 number and/or can be limited by physical...
Emission indices of reactive gases and particles were determined from measurements in the exhaust plume a Concorde aircraft cruising at supersonic speeds stratosphere. Values for NO x (sum 2 ) agree well with ground-based estimates. Measurements HO indicate limited role nitric acid plume. The large number submicrometer measured implies efficient conversion fuel sulfur to sulfuric engine or emission. A new fleet similar particle emissions would significantly increase stratospheric aerosol...
Optically thin cirrus near the tropical tropopause regulate humidity of air entering stratosphere, which in turn has a strong influence on Earth’s radiation budget and climate. Recent high-altitude, unmanned aircraft measurements provide evidence for two distinct classes formed region: ( i ) vertically extensive with low ice number concentrations, extinctions, large supersaturations (up to ∼70%) respect ice; ii layers much higher concentrations that effectively deplete vapor excess...
A light-weight, low-cost optical particle spectrometer for measurements of aerosol number concentrations and size distributions has been designed, constructed, demonstrated. The is suitable use on small, unmanned aerial vehicles (UAVs) in balloon sondes. uses a 405 nm diode laser to count individual particles the range 140–3000 nm. compact data system combines custom electronics with single-board commercial computer. Power consumption 7W at 9–15 V. 3D printing technology was used...
Fourteen research flights were conducted in the Pacific Dust Experiment (PACDEX) during April and May 2007 to sample pollution dust outbreaks from east Asia as they traveled across northern Ocean into North America interacted with maritime storms. Significant concentrations of black carbon (BC, consisting soot other light‐absorbing particles measured a photometer 2 instrument) observed both west Asian plumes pollution. BC through much troposphere, but major finding is that percentage these...
Abstract Airborne observations of fluorescent aerosol were made aboard an airship during CloudLab, a series flights that took place in September and October 2013 covered wideband longitude across the continental U.S. between Florida California 28 37 N latitudes. Sampling occurred from near surface to 1000 m above ground. A Wideband Integrated Bioaerosol Sensor (WIBS‐4) measured average concentrations supermicron particles aloft (1 µm 10 µm), revealing number ranging 2.1 ± 0.8 8.7 2.2 × 4 −3...
The effect of anthropogenic black carbon (BC) aerosol on snow is enduring interest due to its consequences for climate forcing. Until now, too little attention has been focused BC's size in snow, an important parameter affecting BC light absorption snow. Here we present first observations this parameter, revealing that can be shifted larger sizes than are typically seen the atmosphere, part processes associated with removal from atmosphere. Mie theory analysis indicates a corresponding...
[1] Black carbon (BC) aerosol loadings were measured during the High-performance Instrumented Airborne Platform for Environmental Research Pole-to-Pole Observations (HIPPO) campaign above remote Pacific from 85°N to 67°S. Over 700 vertical profiles extending near surface max ∼14 km altitude obtained with a single-particle soot photometer between early 2009 and mid-2011. The data provides climatology of BC in regions that reveals gradients concentration reflecting global-scale transport...