Kazuo Osada

Deposition of water-insoluble dust was measured in winter snow deposited at Murododaira (2450 m) on the western flank of Mount Tateyama in central Japan. An analysis of temporal variation in atmospheric aerosol concentration, incremental snow height and concentration of dust in the snow cover suggests that wet deposition is the major process in forming thicker dust layers in the snow cover at Mount Tateyama. Dust layers in the snow cover contain Ca-rich materials typically found in Asian dust (K

Abstract. Tethered balloon-borne aerosol measurements were conducted at Syowa Station, Antarctica, during the 46th Japanese Antarctic expedition (2005–2006). Direct aerosol sampling was operated from near the surface to the lower free troposphere (approximately 2500 m) using a balloon-borne aerosol impactor. Individual aerosol particles were analyzed using a scanning electron microscope equipped with an energy dispersive X-ray spectrometer. Seasonal and vertical features of aerosol constituents

Abstract. Recent ground networks and satellite remote-sensing observations have provided useful data related to spatial and vertical distributions of mineral dust particles in the atmosphere. However, measurements of temporal variations and spatial distributions of mineral dust deposition fluxes are limited in terms of their duration, location, and processes of deposition. To ascertain temporal variations and spatial distributions of mineral dust deposition using wet and dry processes, weekly de

Number‐size distribution of atmospheric aerosol particles and O 3 concentration were measured at Murododaira (36.6N, 137.6E, 2450 m above sea level (asl)) on the western flank of Mt. Tateyama in central Japan from January 1999 to November 2002. This study used nighttime data from 2400 to 0500 hours (local time) on the basis of analysis of their diurnal variation to characterize free tropospheric aerosols and O 3 over Japan. The O 3 concentration shows small variability (standard deviation of 4 p

Deposition of water-insoluble dust was measured in winter snow deposited at Murododaira (2450 m) on the western flank of Mount Tateyama in central Japan. An analysis of temporal variation in atmospheric aerosol concentration, incremental snow height and concentration of dust in the snow cover suggests that wet deposition is the major process in forming thicker dust layers in the snow cover at Mount Tateyama. Dust layers in the snow cover contain Ca-rich materials typically found in Asian dust (K

Abstract. Rapid Asian economic development might engender secondary impacts of atmospheric aerosol particles over the western Pacific after conversion of gaseous pollutants such as SO2. To elucidate changes in aerosol concentrations in leeward areas undergoing remarkable industrialization, the number-size distributions of submicrometer (0.3–1.0 μm) aerosols were measured at Murododaira (36.6° N, 137.6° E, 2450 m a.s.l.) on the western flank of Mount Tateyama in central Japan during January 1999–

Abstract. We have measured black carbon (BC) concentrations at Syowa Station, Antarctica, since February 2005. The measured BC concentrations in 2005–2016 were corrected to equivalent BC (EBC) concentrations using Weingartner's method. Seasonal features of EBC concentrations, long-range transport from mid-latitudes to the Antarctic coast, and their origins were characterized. Results show that daily median EBC concentrations were below the detection limit (0.2 ng m−3) to 63.8 ng m−3 at Syowa Sta

Airborne and ground-based aerosol/gas measurements were carried out in Svalbard between mid-March and mid-April 2000. From the viewpoint of vertical features of sea-salt modification in the lower troposphere (1500 m) of the Arctic spring, more than 1000 individual sea-salt particles were analyzed with scanning electron microscopy energy dispersive X-ray spectrometry (SEM-EDX) in the present study. Individual particle analysis suggested a vertical gradient of sea-salt modification in fine sea-sal

Aerosol acidity plays an important role in atmospheric chemistry, but it is difficult to measure directly. To estimate aerosol acidity or in situ pH (pHISF), the forward mode of thermodynamic equilibrium models (Extended Aerosol Inorganic Model IV, E-AIM IV) was applied in this study of data obtained from continuous observations of NH3, HNO3, and ionic constituents of fine particles (<1.9 μm) conducted in Nagoya during 2017–2018. We investigated the seasonal variation of pHISF and the factors af