Bibliografisk note

Funding Information:
This work was supported by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT), the global environment research fund of the Japanese Ministry of the Environment (A-1101 and 2-1403), the Japan Society for the Promotion of Science (JSPS) KAKENHI grants 12J06736 and 23221001, and the GRENE Arctic Climate Change Research Project, and the Arctic Challenge for Sustainability (ArCS) project. The authors thank T. Miyoshi and H. Nara for operating an AMS during the field campaign in Tokyo and M. Irwin for laboratory support. The data used in this study will be available upon request to the authors (ohata@eps.s.u-tokyo.ac.jp).