Research theme
1. Long-range transport of air pollutants in Japan
My research interests are:
- Meteorological controls to a spatial and temporal variations of an Asian dust concentration in Japan (mountain-barrierred Asian dust, elevated dust layer, wet deposition, etc.)
- Characteristics of mixing state of anthropogenic pollutants and Asian dust
- Linkage between climate change and long-range transport of pollutants
Figure 1 showed Aqua/MODIS true color image of the massive Asian dust episode in 8 April 2006. In this case, band-shaped Asian dust crossed over mainland Japan (Honshu island) and touched down at the ground level. In-situ measurement for suspended particulate matter (SPM. SPM concentration is nearly equal to PM7) shows extreme high concentration in the central mainland Japan (Fig.2; See Hayasaki et al., 2006, Tenki p.843-844, in Japanese).
Fig. 1. True color image from Aqua/MODIS in 8 April 2006 (30-50N, 118-143E). RGB compisite is constructed by band-1 (620-670 nm; red), band-4 (545-565 nm; green), and band-3 (459-479 nm; blue). A discontinuous line in the image show a differences of observing time (left: 1340JST, right: 1200JST). See Fig. 1 of Hayasaki et al. (2006, Tenki p.843-844, in Japanese).
Fig. 2. Hourly concentration (unit: micro gram / m3) of a suspended particulate matter (SPM) in Japan. Left: 11JST, middle: 14JST, and right: 23JST 8 April 2006.
2. Inter-annual/decadal variations of cold outbreaks, cyclone, and frontal activities in Asia
Cold air outbreaks in Japan were originated from Siberia. A cold air passed over Mongolia, northeastern China, Korea. My research interests are inter-annual or long-term variations of their activities (intensity, frequencies, and their passage route).