Research Project (5)

Studies on greenhouse gas cycles in the Arctic and their responses to climate change

Principal Investigator: Shuji Aoki (Tohoku University)


To elucidate temporal and spatial variations of the concentrations of carbon dioxide, methane, nitrous oxide and other greenhouse gases as well as their isotopes and oxygen concentration in the atmosphere in the higher latitudes of the Northern Hemisphere, we make comprehensive observations by using land stations and aircraft. Although it is believed that the Arctic Ocean also plays an important role in the variations of greenhouse gases and their related constituents, the role of the Arctic Ocean is not well known. Therefore, we are making oceanographic observations using the research vessel Mirai.

These observational data are analyzed, using almost all of the high-resolution atmospheric chemistry transport models developed in Japan, to quantify the distributions and variations of sources and sinks of the greenhouse gases in the Arctic region. We are trying to combine the highresolution atmospheric chemistry transport models with a terrestrial ecosystem model and an oceanic dissolved carbon transport model. By conducting simulations to see how these combined models are able to reproduce observed annual changes in concentrations and isotopes, we will gain a clearer understanding of the circulation process of the greenhouse gases in the Arctic, and how the circulation of the greenhouse gases responds to climate change.

By analyzing ice cores and firn air sampled from Greenland and other locations, we can reconstruct the changes in the concentrations and isotopes of the greenhouse gases from the past to the present. By analyzing these data, we can learn about the changes in sources and sinks of the greenhouse gases in the past, as well as how each type of source has responded to climate change. This work will contribute to our understanding of the various processes involved in changes to greenhouses gases in the Arctic.

Through this research, we are contributing to the achievement of strategic research target ②Understanding the Arctic system for global climate and future change.

Ny-Alesund Station in the Svalbard Archipelago, where we are making observations of greenhouse gases