*Hajime Obata¹, Lutfi M. Firdaus², Asami S. Mashio³, Taejin Kim⁴, Jason McAlister⁵, Toshitaka Gamo¹ (1.Marine inorganic chemistry division, Atmosphere and Ocean Research Institute, University of Tokyo, 2.Graduate School of Science Education, University of Bengkulu, Bengkulu, Indonesia, 3.College of Science and Engineering, Kanazawa University, Kanazawa, Japan, 4.School of Earth and Environmental Sciences, Seoul National University, Korea, 5.Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Canada)

*Hajime Obata¹, Lutfi M. Firdaus², Asami S. Mashio³, Taejin Kim⁴, Jason McAlister⁵, Toshitaka Gamo¹ (1.Marine inorganic chemistry division, Atmosphere and Ocean Research Institute, University of Tokyo, 2.Graduate School of Science Education, University of Bengkulu, Bengkulu, Indonesia, 3.College of Science and Engineering, Kanazawa University, Kanazawa, Japan, 4.School of Earth and Environmental Sciences, Seoul National University, Korea, 5.Department of Earth, Ocean, and Atmospheric Sciences, University of British Columbia, Canada)