Atmospheric Physics and Chemistry Group

Motoki Sasakawa

Research Interests

Stable Isotope Geochemistry, Atmospheric Chemistry, Earth Science

Publications

Sasakawa, M., Urumu Tsunogai, Sohiko Kameyama, Fumiko Nakagawa, Yukihiro Nojiri, and Atsushi Tsuda
Carbon isotopic characterization for the origin of excess methane in subsurface seawater.
Journal of Geophysical Research-Ocean, in press

Tsuda, A. et al.
Evidence for the grazing hypothesis: Grazing reduces phytoplankton responses of the HNLC ecosystem to iron enrichment in the western subarctic Pacific (SEEDS II).
Journal of Oceanography, 63, 983-994, 2007

Sasakawa, M., and M. Uematsu
Relative contribution of chemical composition to acidification of sea fog (stratus) over the northern North Pacific and its marginal seas.
Atmospheric Environment, 39, 1357-1362, 2005.

Sasakawa, M., A. Ooki, and M. Uematsu
Aerosol size distribution during sea fog and its scavenge process of chemical substances over the northwestern North Pacific.
Journal of Geophysical Research-Atmospheres, 108 (D3), art. no.-4120, 2003.

Sasakawa, M., and M. Uematsu
Chemical composition of aerosol, sea fog, and rainwater in the marine boundary layer of the northwestern North Pacific and its marginal seas.
Journal of Geophysical Research-Atmospheres, 107 (D24), art. no.-4783, 2002.

Awards

2nd prize poster

The mass independent oxygen isotope anomaly as a tool to study nitrate aerosol formation in the atmosphere
Autumnschool on measurement techniques in atmospheric chemistry, Oberwesel. Germany, (October 2006)

1st prize poster

Carbon isotopic evidence for the origin of excess methane in subsurface seawater.
SOLAS summer school 2005, Corsica. France, (September 2005)

3rd prize oral presentation

Carbon isotopic evidence for the origin of excess methane in subsurface seawater.
SOLAS summer school 2005, Corsica. France, (September 2005)

Curriculum vitae

• 3/2003 Ph. D. in School of Science, the University of Tokyo ; Chemical characteristics and behavior of sea fog over the northern North Pacific
• 4/2003-9/2003 Postdoctoral Fellowship, Ocean Research Institute, the University of Tokyo
• 10/2003-3/2004 Postdoctoral Fellowship, The 21st Century COE program, Hokkaido University
• 4/2004-5/2005 Postdoctoral Fellowship, Japan Society for the Promotion of Science, Hokkaido University
• 6/2005-3/2007 Postdoctoral Fellowship, Japan Society for the Promotion of Science, Utrecht University
• 4/2007-(3/2008) Postdoctoral Fellowship, Utrecht University

Presentations

Fumiko Nakagawa1, Urumu Tsunogai1, Sohiko Kameyama1, Motoki Sasakawa1, Daisuke D. Komatsu1, Junko Yamaguchi1, Shinsuke Kawagucci1, Mitsuo Uematsu2, and Atsushi Tsuda2
1 Graduate School of Science, Hokkaido University, Sapporo, Japan
2 Ocean Research Institute, University of Tokyo, Tokyo, Japan
Stable isotopic studies of trace gases in seawater: Constraints on their production and fate mechanisms
SOLAS (surface ocean - lower atmosphere study) Science 2004, the first open science conference, Halifax, CANADA, Oct, 2004

M. Sasakawa, S. Kawaguchi, F.Nakagawa, T. Gamo, and U. Tsunogai
Graduate School of Science, Hokkaido University, Sapporo, Japan
Oxygen Isotopic Compositions in Aerosols: Tracers For Present And Paleo Atmospheric Photochemistry?
International Symposium, Dawn of a New Natural History - Integration of Geoscience and Biodiversity Studies, Sapporo, Japan, March 5-6, 2004

Sasakawa, M., Ooki, A., Ui, T., and Uematsu, M. (Ocean Research Institute, The university of Tokyo)
Temporal variation of atmospheric trace components over the northwestern North Pacific during a Kosa event
13th Annual V.M. Goldschmidt Conference, Kurashiki, Japan, September 7-12, 2003 Geochimica Et Cosmochimica Acta, 67 (18), A412-A412, 2003.

Sasakawa, M., Ooki, A., and Uematsu, M.
(Ocean Research Institute, The university of Tokyo)
Aerosol size distribution during sea fog and its scavenge process of chemical substances over the northwestern North Pacific
Scientific Conference of the International Global Atmospheric Chemistry Project (IGAC), Crete Greece, 18-25 September 2002, p

M. Uematsu, K. Matsumoto, A. Ooki, M. Sasakawa
Temporal variations of marine aerosol composition and particle number over the Western North Pacific
The International Association for the Physical Sciences of the Oceans (IAPSO) / The International Association for the Biological Oceanography (IABO) Joint Assembly, Mar del Plata, Argentina, October 22-26, 2001

Sasakawa, M. and Uematsu, M.
(Ocean Research Institute, The university of Tokyo)
Removal process of nitrogen compounds by oceanic rain and sea fog over the northwestern North Pacific
Fifth IOC/WESTPAC International Scientific Symposium, Seoul, 27-31 August 2001

Sasakawa, M. and Uematsu, M.
Chemical composition of acidic sea fog over the northern North Pacific and its marginal seas
2000 Fall Meeting American Geophysical Union, San Francisco, 15-19 December 2000, F150-151

Uematsu, M., Ohta, K., Sasakawa, M., Kamiya, H. Matsuba, A., Kajii, Y.
Impact of Forest Fire in far Eastern Siberia to the Marine Atmosphere Over the Northwest North Pacific in the Spring of 2000
2000 Fall Meeting American Geophysical Union, San Francisco, 15-19 December 2000, F261

Uematsu, M. and Sasakawa, M.
Chemical composition of sea fog over the northwestern North Pacific
Sixth Scientific Conference of the International Global Atmospheric Chemistry Project (IGAC), Bologna Italy, 13-17 September 1999, p84

Matsumoto, K., Sasakawa, M. and Uematsu, M.
Measurement of carbonaceous aerosols in marine atmosphere over the northwestern North Pacific Ocean
Sixth Scientific Conference of the International Global Atmospheric Chemistry Project (IGAC), Bologna Italy, 13-17 September 1999, p97