a r t i c l e i n f o The difference between the top of atmosphere shortwave clear sky (cloud and aerosol free, SWCLR) and aerosol sky radiative fluxes is known as direct radiative effect (DRE) for all aerosols or Direct Climate Forcing (DCF) for anthropogenic aerosols. There are several methods for calculating SWCLR including satellite-based methods and radiative transfer approaches. Since unc...

it is very important to determine the stable nitrogen isotope ratio for the nitrogenous substances in aerosols and the geochemistry behavior of stable nitrate ion isotopes in aerosols in order to elucidate the chemical and physical functions of clouds. hence, aerosol field sampling was conducted in the skies offshore from malibu beach and santa barbara, california, u.s.a. on 16 and 18 july 200...

[1] Waliguan Observatory (WO) is a land-based Global AtmosphereWatch baseline station on the Tibetan Plateau. Size-resolved ionic aerosols (NH4 , Na, K, Ca, Mg, SO4 2 , Cl , NO3 CO3 2 , formate, acetate and oxalate), organic aerosols, black carbon and gaseous HNO3 and SO2 were measured during an intensive fall-winter field experiment. The observational data were analyzed with a focus on the par...

Atmospheric aerosols directly and indirectly affect the radiative balance of the Earth’s atmosphere1. Nanoparticles are a key component of atmospheric aerosols, growing rapidly under ambient conditions2–4. Organic species are thought to lead to the growth of nanoparticles smaller than 20 nm (refs 5, 6), but the identity of these species and the underlying chemical mechanisms remain elusive. Her...

The May spinning top generator was adapted to a modified Henderson tube for producing large aerosol particles (>4 mum) to obtain almost exclusive upper respiratory tract deposition of infectious aerosols in exposed mice. The system was installed in a biological safety cabinet to permit experimentation with pathogens. A novel mechanism utilizing parts from a machinists micrometer and the mechani...

The health effects of aerosol depend on the size distribution and the chemical composition of the particles. Heavy metals of anthropogenic origin are connected to the fine aerosol fraction (PM2.5). The composition and speciation of aerosols can be variable in time, due to the time-dependence of anthropogenic sources as well as meteorological conditions. Synchrotron-radiation total-reflection X-...

Secondary organic aerosols (SOA) forms a major fraction of organic aerosols in the atmosphere. Knowledge of SOA properties that affect their dynamics in the atmosphere is needed for improving climate models. By combining experimental and modeling techniques, we investigated the factors controlling SOA evaporation under different humidity conditions. Our experiments support the conclusion of par...

In the analysis of electromagnetic scattering by distributions of small dielectric particles an approximation to the scattered field can be obtained by representing the electrical interaction of the particles in terms of the dipole moments of the individual particles. The calculation of the moments necessitates the solution of certain static scattering problems, and this becomes numerically dif...

[1] The reaction kinetics of submicron oleic (9-octadecanoic (Z)-) acid aerosols with ozone was studied using a novel aerosol mass spectrometric technique. In the apparatus a flow of size-selected aerosols is introduced into a flow reactor where the particles are exposed to a known density of ozone for a controlled period of time. The aerosol flow is then directed into an aerosol mass spectrome...

In polluted urban environments, background aerosols govern the formation and growth of sub-3 nm particles.