Research

Pan-Arctic Water-Carbon Cycles

Grant-in-Aid for Scientific Research (S) Broad Section K【Abstract of the project 】

Thawing permafrost releases greenhouse gases such as methane enclosed in the frozen soil to the atmosphere, and it affects the global climate.
Thus, researches to understand the current situation and to predict future climate change are indispensable for humanity all over the world.

In order to predict the future of Arctic warming and estimate greenhouse gas budgets, it is necessary to conduct an integrated study on various factors such as Arctic sea ice extent, atmospheric water vapor flows, precipitation variation, changes in vegetation condition and river discharges in the surrounding continent of the Arctic.

We started this research project because there was no integrated research on the atmospheric- terrestrial water-carbon cycles in the region.

Cooperation of 4 teams

Atmospheric Research group
1) Water Vapor Tracing
2) Origin of Precipitated Water
3) Precipitation Analyses
4) Atmospheric Circulation Analyses
5) Future Projection

Integration group
1) Inundation Map
2) Vegetation Map
3) International Collaboration
4) Advisory Board
5) International Symposium

Terrestrial Modeling group
1) Terrestrial Water Tracing
2) Origin of River Water
3) Data Assimilation
4) Spatiotemporal Map of GHGs
5) Future Projection

Terrestrial Observation group
1) Hydrometeorological Variables
2) Greenhouse Gases (GHGs)
3) Vegetation
4) Permafrost
5) Satellite Remote Sensing

Research Questions

  1. How are atmospheric-terrestrial water cycles changing due to the Arctic sea ice retreat ?

  2. How will atmospheric-terrestrial water cycles change in near future ?

  3. How are inundation areas and vegetation conditions affected by the water cycle changes ?

  4. How do CO2 and CH4 budgets change ?

Flowchart of this research

To answer the above three questions,
We develop and improve an integrated model that numerically expresses atmospheric water circulation, terrestrial water circulation, vegetation dynamics, and permafrost surface conditions.

It then calculates the atmospheric-terrestrial water cycle in northern Eurasia from the past to the present and future.

In order to reduce the uncertainty of the integrated model, atmospheric, vegetation, permafrost, hydrological observations and greenhouse gas flux observations will be conducted in eastern Siberia and northern Mongolia, where long-term observation data is essential.

Utilizing satellite remote sensing data to broaden observation data, improve the integrated model by using it as a verification material for the calculation results of the integrated model, and create a time series map for the northern Eurasia inundation area and vegetation change area, and estimate the spatio-temporal variation of greenhouse gas emission and absorption.

Study Area

Northern Eurasia beyond the Ural Mountains
(Especially, northeast Eurasia, eastern Siberia and Mongolia)

As the permafrost devastation has progressed, the Thermokalst Lake has expanded and contracted, and the vegetation has undergone significant changes, including forest fires.

Expansion of Lake Thermokarst in the middle basin of the Lena River, eastern Siberia.
(Every 5 years, the same place was photographed in the same season. From Fedrov, Hiyama et al. 2014)

Research features

With Water Vapor Tracing,
・ Behavior of atmospheric water vapor originating from evaporating water in the Arctic Ocean
・ Behavior of atmospheric water vapor originating from terrestrial evaporation
will be revealed. And then you can see how they change due to climate change and land changes (vegetation conditions including forest fires and snow cover).

With the river model tracer experiment,
・ How precipitation brought to northern Eurasia flows into the Arctic Ocean through land water storage and river runoff
・ How much does the melting water of ground ice in permafrost contribute to fluctuations in land water storage and river runoff?
will be researched.

This research is innovative and unprecedented in the world because it creates scientific knowledge through the collaboration of meteorology, climatology, hydrology, permafrost science, and ecology.