Please tell us about your field of expertise.

My research focuses on terrestrial vegetation and its response to environmental changes by using satellite remote sensing. More specifically, I estimate plant photosynthesis (gross primary production) from satellite data and monitor plant phenology, such as leaf bud expansion and leaf fall.

Ground-based observation is critical to remote-sensing research. Therefore, I visit field sites and measure leaf and canopy spectral reflectance, chlorophyll content of individual leaves, leaf area, and biomass. By combining these measurements with physical radiative transfer models, I develop algorithms that link observations made on the ground with satellite data collected from space.

What inspired you to pursue this research?

Ever since childhood, I have retained a question: “Why are leaves green?” Science taught me that the green color is driven by leaf pigments necessary for photosynthesis (i.e., chlorophyll). However, I could not find an answer, either in high school or at university, to the deeper question of why terrestrial higher plants evolved to be green.

After graduating from university, I initially joined a private company, later married, and became a full-time homemaker. For many years, I was away from research. However, when childcare and caregiving responsibilities became somewhat less demanding, I decided to live for myself as well—not only to care for somebody else. I then returned to research to explore my question of the “evolution of green in leaves,” a question that had interested me since childhood.

I then encountered researchers and projects that used ground-based vegetation observations to validate satellite data. This gradually expanded my connections within the satellite remote-sensing community. Before I knew it, I had arrived at my current research: observing the Earth’s “green” from space on a broad, macroscopic scale.

What do you find rewarding about your work?

We have an observation network extending across Japan, from Hokkaido to Okinawa. We regularly visit the field sites ourselves to maintain the equipment and collect data, which requires considerable hands-on, painstaking work. What I find rewarding is seeing the ground-validation data produced through this steady effort become connected with vast datasets collected by satellites in space.

Moreover, the “satellite” includes many different types of observation systems. The available information varies depending on the satellite’s orbit, field of view, and spatial resolution. Selecting and combining the most appropriate datasets for a particular purpose is another fascinating aspect of the research.

How does your work connect with other research at Gtech?

Until now, my research has mainly focused on natural vegetation, such as forests and grasslands. At Gtech, I am shifting that perspective toward agricultural land. By combining the microscopic expertise of other researchers in fields such as microbiology and soil science with my macroscopic perspective based on satellite data, I expect that we can develop entirely new research approaches.

In addition to data from JAXA’s Global Change Observation Mission–Climate satellite, known in Japan as Shikisai, which I have used for global-scale research, data from the Himawari meteorological satellites can also be applied to vegetation monitoring because they observe the area around Japan at high frequency.

By selecting and combining these research tools appropriately, I hope to monitor vegetation not only in Japan but also across Southeast Asia and accurately assess the effects of climate change on agricultural land.

What goals or mission do you have for this research?

Because much of my previous research has focused on the “green in leaves,” I have tended to concentrate on the active growing season of plants. Agriculture, however, involves many other stages and perspectives. Rice is planted and harvested, after which ratoon shoots may emerge, and fields must then be managed in preparation for the following year.

At Gtech, I intend to learn from researchers who specialize in agricultural land and broaden my research by examining aspects that I have not previously focused on. I am genuinely looking forward to the discoveries that may result.

Gtech primarily focuses on agricultural land (rice paddy, dry field, and pasture), but forestry, although categorized somewhat differently, also plays an important role in addressing climate change. By making use of the broad observational perspective unique to satellites, I hope to contribute to research in this area as well.

A message for those interested in Gtech

Climate change, including rising temperatures and increasing atmospheric carbon dioxide, is not necessarily entirely negative for plants, because these changes can make photosynthesis more active under such conditions.

However, we humans must protect the environment in which we can live comfortably. To do so, each of us needs to take action. You may think that raising your air-conditioner setting by just one degree will make no difference, but consider this: the present concentration of oxygen in the Earth’s atmosphere is the result of ancient, microscopic photosynthetic organisms—cyanobacteria—repeatedly carrying out photosynthesis and accumulating oxygen little by little over an immense period of time.

I therefore hope that everyone will value the cumulative effect of even very small actions. When you feel discouraged, remember the long history of the organisms that helped create the atmosphere we have today.

A message for students

My message is simple: do not give up and do not stop questioning.

At the age of 39, I entered the world of research because I could not let go of a question I had carried with me since childhood. Of course, there are times when circumstances make something genuinely difficult or impossible. There can be many reasons—financial constraints, age, gender, or differences in country, region, and personal environment.

However, do not decide after a single failure that you have reached your limit. Producing results is not the only thing that matters. Please keep alive the small flame within you that says, “That is strange,” or “That is interesting.” As long as that flame does not go out, I believe it will eventually lead you somewhere.