Researcher's Profile

Global changes in the chemical composition of the atmosphere are making large impacts on the atmospheric environment and climate system. I have made investigations on atmospheric ozone and aerosols for many years. They have great influences on human activities and the climate system, respectively. I made observations of these components by developing advanced measurement techniques and elucidating key physical and chemical processes, through which human activities influence the atmospheric environment. Recent objectives of my studies have been the effects of aerosols on the climate in the Arctic. Many of these studies were conducted in close collaboration with NOAA and NASA.
Aerosols influence the radiation budget of the Earth via the direct effect (by scattering and absorption) and indirect effect (by changing properties of clouds). Inorganic and organic aerosols scatter solar radiation and contribute to atmospheric cooling. Black carbon aerosol (BC) emitted from incomplete combustion of carbon fuels strongly absorbs solar radiation and heats the atmosphere. Aerosols as a whole lead to global cooling. Therefore, reducing aerosols would accelerate global warming, depending on the emissions scenarios of aerosols and GHGs. I succeeded in measuring the distributions aerosols with high accuracy, which contributes to improving the estimates of the aerosol effects on climate by using Earth system models.
If the future reductions of GHGs turns out to be insufficient to mitigate global warming, the possibility of a climate crisis cannot be excluded. To avoid possible cascading impacts in the climate system, NOAA is conducting systematic studies of cooling the Earth by using aerosols, which is called solar radiation management (SRM). I plan to inform people in general of the latest knowledge on climate change science, including SRM, by organizing cooperation between RCAST and NOAA. This will contribute to deepening the understanding of people in general on climate change, which is necessary to minimize risks.