Nobuhiro Moteki

Laboratory experiments and theoretical calculations were made to characterize the performance of a Single Particle Soot Photometer (SP2) manufactured by Droplet Measurement Technologies (DMT), which was designed to measure the mass and the mixing state of individual black carbon (BC) or elemental carbon (EC) particles, based on the laser-induced incandescence (LII) technique. In this study, graphite was used as a surrogate of EC. Graphite particles with mass equivalent diameters of 110–200 nm we

We used a single-particle soot photometer (SP2) to measure the mass of individual black carbon (BC) particles down to ∼ 0.5 fg by means of laser-induced incandescence with an intra-cavity, continuous-wave laser. The incandescence of nine different types of BC samples was investigated to provide a physical basis for choosing appropriate BC materials for SP2 calibration. We estimated the vaporization temperatures of these BC samples from the spectral dependence of incandescence at the limit of the

We report the evolution of the mixing state of black carbon (BC) particles in urban plumes measured by an airborne single particle soot photometer. The aircraft observations were conducted over the ocean near the coast of Japan in March 2004. The number fraction of coated BC particles with a core diameter of 180 nm increased from 0.35 to 0.63 within 12 hours (h), namely 2.3% h −1 , after being emitted from the Nagoya urban area in Japan. BC particles with a core diameter of 250 nm increased at t

Size distributions of black carbon (BC) measured by aircraft over East Asia in spring 2009 were highly correlated with BC transport efficiency in air parcels uplifted from the planetary boundary layer to the free troposphere. The average single‐particle BC mass decreased with decreasing transport efficiency, which suggests that aerosols containing larger BC mass were removed more efficiently. This is the first successful observation of the size‐dependent wet removal of aerosols, qualitatively co

Combustion-induced carbonaceous aerosols, particularly black carbon (BC) and brown carbon (BrC), have been largely considered as the only significant anthropogenic contributors to shortwave atmospheric heating. Natural iron oxide (FeO_x) has been recognized as an important contributor, but the potential contribution of anthropogenic FeO_x is unknown. In this study, we quantify the abundance of FeO_x over East Asia through aircraft measurements using a modified singl

Abstract Black carbon (BC) aerosols, which are strong contributors to positive radiative forcing, are found in the atmosphere as bare BC or as internal mixtures of BC with non‐BC compounds (mixed BC‐containing particles). Mixed BC‐containing particles can be broadly classified into two morphological types: bare BC on the surface of non‐BC particles (attached type) or BC embedded within or coated by non‐BC compounds (coated type). For the same amount of mixed non‐BC compounds, enhancements of the

Copyright © 2016 American Association for Aerosol Research

Abstract Quantitative simulation of an aerosol’s lifecycle by regional-scale and global-scale atmospheric models is mandatory for unbiased analysis and prediction of aerosol radiative forcing and climate change. Globally, aerosol deposition is dominated by the rainout process, which is mostly triggered by activation of aerosols to liquid droplets in supersaturated domains of precipitating clouds. However, the actual environmental supersaturation value that aerosols experience in precipitating cl

Abstract Anthropogenic iron oxide (FeO x ) aerosols can affect atmospheric radiation, marine biogeochemistry, and human health. However, due to lack of observational data, their atmospheric abundance and emission flux are not well understood. In this study, we observed size‐resolved concentrations of FeO x (170–2100 nm) and black carbon (BC, 70–850 nm) aerosols at a remote site in the East China Sea in March 2016 using a modified single‐particle soot photometer (SP2). Light signals measured by t