A5114377084- Atmospheric chemistry and aerosols
- Atmospheric aerosols and clouds
- Atmospheric Ozone and Climate
- Atmospheric and Environmental Gas Dynamics
- Air Quality and Health Impacts
- Fire effects on ecosystems
- Air Quality Monitoring and Forecasting
- Vehicle emissions and performance
- Meteorological Phenomena and Simulations
- Climate variability and models
- Mercury impact and mitigation studies
- Aeolian processes and effects
- Remote Sensing and LiDAR Applications
- Wind and Air Flow Studies
- Geography and Environmental Studies
- Cryospheric studies and observations
- Wind Energy Research and Development
- Remote Sensing in Agriculture
- Energy Load and Power Forecasting
- Catalytic Processes in Materials Science
- Fault Detection and Control Systems
- Cyclone Separators and Fluid Dynamics
- Toxic Organic Pollutants Impact
- Environmental and biological studies
- Particle Dynamics in Fluid Flows
Pacific Northwest National Laboratory
2015-2025
Fiji National University
2025
University of Washington
2008-2011
Battelle
2011
Seattle University
2011
Cooperative Institute for Research in Environmental Sciences
2010
Colorado State University
2010
Max Planck Institute for Chemistry
2003-2009
Helmholtz Zentrum München
2009
Center for Environmental Health
2009
Size-resolved cloud condensation nuclei (CCN) spectra measured for various aerosol types at a non-urban site in Germany showed that CCN concentrations are mainly determined by the number size distribution. Distinct variations of activation with particle chemical composition were observed but played secondary role. When temporal variation effects on is neglected, distribution alone explains 84 to 96% concentrations. Understanding particles' ability act as largely controlled rather than...
Abstract. Spectral aerosol light absorption is an important parameter for the assessment of radiation budget atmosphere. Although on-line measurement techniques absorption, such as Aethalometer and Particle Soot Absorption Photometer (PSAP), have been available two decades, they are limited in accuracy spectral resolution because need to deposit on a filter substrate before measurement. Recently, 7-wavelength (λ) became commercially available, which covers visible (VIS) near-infrared (NIR)...
Abstract. The VAMOS1 Ocean-Cloud-Atmosphere-Land Study Regional Experiment (VOCALS-REx) was an international field program designed to make observations of poorly understood but critical components the coupled climate system southeast Pacific. This region is characterized by strong coastal upwelling, coolest SSTs in tropical belt, and home largest subtropical stratocumulus deck on Earth. intensive phase VOCALS-REx took place during October November 2008 constitutes a part broader CLIVAR...
Aerosol indirect effects have remained the largest uncertainty in estimates of radiative forcing past and future climate change. Observational constraints on cloud lifetime are particularly challenging since it is difficult to separate aerosol from meteorological influences. Here we use three global models, including a multi‐scale aerosol‐climate model PNNL‐MMF, show that dependence probability precipitation loading, termed frequency susceptibility ( S pop ), good measure liquid water path...
Abstract The Observations and Modeling of the Green Ocean Amazon 2014–2015 (GoAmazon2014/5) experiment took place around urban region Manaus in central Amazonia across 2 years. pollution plume was used to study susceptibility gases, aerosols, clouds, rainfall human activities a tropical environment. Many aspects air quality, weather, terrestrial ecosystems, climate work differently tropics than more thoroughly studied temperate regions Earth. GoAmazon2014/5, cooperative project Brazil,...
Secondary organic aerosols (SOA) are large contributors to fine-particle loadings and radiative forcing but often represented crudely in global models. We have implemented three new detailed SOA treatments within the Community Atmosphere Model version 5 (CAM5) that allow us compare semivolatile versus nonvolatile (based on some of latest experimental findings) investigate effects gas-phase fragmentation reactions. The also track from biomass burning biofuel, fossil fuel, biogenic sources....
Wildfires are important contributors to atmospheric aerosols and a large source of emissions that impact regional air quality global climate. In this study, the nearfield influences wildfire on ambient aerosol concentration chemical properties in Pacific Northwest region United States were studied using real-time measurements from fixed ground site located Central Oregon at Mt. Bachelor Observatory (∼2700 m a.s.l.) as well near their sources an aircraft. The characteristics biomass burning...
Uncertainty in the representation of biomass burning (BB) aerosol composition and optical properties climate models contributes to a range modeled effects on incoming solar radiation. Depending model, top-of-the-atmosphere BB effect can from cooling warming. By relating absorption relative extinction carbonaceous 12 observational datasets nine state-of-the-art Earth system models/chemical transport models, we identify varying degrees overestimation absorptivity by these models. Modifications...
Biomass burning (BB) emits enormous amounts of aerosol particles and gases into the atmosphere thereby significantly influences regional air quality global climate. A dominant particle type from BB is spherical organic commonly referred to as tarballs. Currently, tarballs can only be identified, using microscopy, their uniquely shapes following impaction onto a grid. Despite abundance potential significance for climate, many unanswered questions related formation, emission inventory, removal...
This paper describes the chemical, aerosol, and meteorological measurements taken at Mount Bachelor Observatory (MBO), a new mountaintop site in central Oregon, USA (44.0°N, 121.7°W, 2763 m above mean sea level). During initial campaign (28 March to 19 May 2004) we evaluated utility of this location as observe global atmosphere, especially free troposphere (FT). We observed some boundary layer (BL)/upslope flow during daytime, which produced 37–62% higher average water vapor mixing ratio...
Abstract. Estimating the aerosol contribution to global or regional radiative forcing can take advantage of relationship between spectral optical properties and size chemical composition aerosol. Long term measurements from observational networks satellites be used in such studies. Using in-situ mixing state help us constrain limitations estimates. In this study, Absorption Ångström Exponent (AAE) Scattering (SAE) derived 10 operational AERONET sites California are combined for deducing...
In this study we have evaluated the role of wildfires on concentrations fine particle (d < 2.5 µm) organic carbon (OC) and particulate mass (PM2.5) in Western United States for period 1988–2004. To do this, examined relationship between mean summer PM2.5 OC at 39 IMPROVE sites with a database fires developed from federal fire reports. The gridded area burned was used to generate biomass fuel using ecosystem-specific loads. OC, PM2.5, data were five regions: Northern Rocky Mountains (Region...
In the recent years, New Delhi, capital city of India, has ranked among most polluted cities in world regarding its air quality related to submicron Particulate Matter (PM2.5). Using NASA's A-train satellite data (MODIS, OMI, and CALIOP), ground-level PM2.5 measured Delhi (2013–2016), back-trajectory calculations, we show that over is strongly affected by agricultural fires northwestern Indian states Punjab Haryana during post-monsoon season (October November). The mass concentration...
Abstract. The VAMOS Ocean-Cloud-Atmosphere-Land Regional Experiment (VOCALS-REx) was conducted from 15 October to November 2008 in the South East Pacific (SEP) region investigate interactions between land, sea and atmosphere this unique tropical eastern ocean environment improve skill of global regional models representing region. This study synthesises selected aircraft, ship surface site observations VOCALS-REx statistically summarise characterise atmospheric composition variability Marine...
Abstract. Substantial uncertainties still exist in the scientific understanding of possible interactions between urban and natural (biogenic) emissions production transformation atmospheric aerosol resulting impact on climate change. The US Department Energy (DOE) Atmospheric Radiation Measurement (ARM) program's Carbonaceous Aerosol Radiative Effects Study (CARES) carried out June 2010 Central Valley, California, was a comprehensive effort designed to improve this understanding. primary...
Abstract The Second Wind Forecast Improvement Project (WFIP2) is a U.S. Department of Energy (DOE)- and National Oceanic Atmospheric Administration (NOAA)-funded program, with private-sector university partners, which aims to improve the accuracy numerical weather prediction (NWP) model forecasts wind speed in complex terrain for energy applications. A core component WFIP2 was an 18-month field campaign that took place Pacific Northwest between October 2015 March 2017. large suite...
Because forest fires emit substantial NOx and hydrocarbons--known contributors to O3 production--we hypothesize that interannual variation in western U.S. is related the burned area. To evaluate this hypothesis we used a gridded database of summer area (BA) biomass consumed (BC) by between 101-125 degrees W. The fire data were compared with daytime mixing ratios from nine rural Clean Air Status Trends Network (CASTNET) National Park Service (NPS) sites. Large years exhibited widespread...
Estimates of global mean direct climate forcing by absorbing aerosols located above boundary layer clouds are large, uncertain, and almost entirely unconstrained observations. Spaceborne lidar offers a new opportunity for constraints. Here we examine techniques using liquid water as targets, allowing aerosol optical depth Ångström exponent to be deduced directly from effects on light transmission. Two such examined data the Cloud‐Aerosol Lidar Infrared Pathfinder Satellite Observations...
Remote sensing observations of aerosol from surface and satellite instruments are extensively used for atmospheric climate research. From passive sensors, the apparent cloud‐free atmosphere in vicinity clouds often appears to be brighter than further away clouds, leading an increase retrieved optical depth ( τ ). Mechanisms contributing this enhancement or increase, including contamination by undetected hygroscopic growth particles, meteorological conditions, have been debated recent...
The Department of Energy Atmospheric Radiation Measurement (ARM) program is a climate research user facility operating stationary ground sites that provide long-term measurements climate-relevant properties, mobile ground- and ship-based facilities to conduct shorter field campaigns (6–12 months), the ARM Aerial Facility (AAF). airborne observations acquired by AAF enhance surface-based providing high-resolution in situ for process understanding, retrieval-algorithm development, model...
Abstract Ice formation by diesel soot particles was investigated at temperatures ranging from −40 to −50°C. Size‐selected were physically and chemically aged in an environmental chamber, their ice nucleating properties determined using a continuous flow diffusion type nucleation chamber. Bare (freshly formed), hydrated, compacted particles, as well α ‐pinene secondary organic aerosol (SOA)‐coated high relative humidity conditions, showed activity subsaturation conditions with respect water...