We talked to the Japan Weather Association, which supplies Earthrium's global cloud images.
How do weather satellites help us?
Hayashi: It's over thirty years now since a weather satellite first photographed the Earth from above, and being able to look from outside our planet and see how clouds spread and moved was truly revolutionary. A single satellite can only cover a limited area, so these days several satellites combine to provide a picture of the state of cloud cover and movement across the whole of the Earth. We can now see how the atmosphere that surrounds the Earth is moving.
Goto: The World Meteorological Organization (WMO) acts as an international coordinator, for example standardizing data formats so data supplied for almost all regions of the world is of identical quality, and can be used freely. We all help each other to observe the weather: when for example the US GOES satellite malfunctioned, a European satellite was substituted, and when the Japanese Himawari satellite was coming to the end of its life, GOES took over its observation functions. Before satellite observation began, typhoons could only be monitored within the range of a radar situated on the summit of Mt. Fuji, which meant little was known about them until they were quite close. Now, satellites allow us to track a typhoon from the moment it looks like starting to form. This has made a huge difference to our knowledge of typhoons.
Hayashi: We have records of typhoons since 1951, but in the days before satellites, I imagine a lot were missed. Back then, it wasn't unknown for a fishing boat to suddenly encounter a small typhoon. That could no longer happen today.
Goto: Most weather forecasts these days are numerical forecasts, i.e. computer predictions. The accuracy of these forecasts is determined by the precision of the projection model on the computer, and the quantity and quality of the initial figures provided (the current weather status). Models are now by and large as accurate as it's possible to be, so the critical thing has become finding ways to improve the accuracy of those initial values. Terrestrial observation has its limits, being influenced for example by the location of the observation point, so data from satellites, which can provide truly global coverage, are making a huge contribution in this respect as well.
What does the movement of clouds tell us?
Hayashi: When forecasting weather, it is important to find out how the air 5km - 10km up is flowing three-dimensionally, which we can by tracking cloud movement. Clouds are the only means we have of seeing the movement of air. Watching clouds gives us a pretty good idea of how air in the vicinity of those clouds is moving. In contrast, if there is no cloud, it is very difficult to see how the air is moving.
Incidentally, everyone tends to think that clouds move, but actually that is not the case. For example, rain clouds that are now over Kyushu do not just move up to the Kanto area. The actual rain clouds disappear in 2-3 hours at most. It is the air condition (phase) that is conducive to rain that moves. Think of it then as not the clouds moving but the movement of air, with clouds forming and dissolving within that movement.
What would you like people to take from the cloud images?
Goto: I hope they'll help people to understand that the Earth is living and connected. People think of other countries as being a completely different world, but they're not, they are all connected. A phenomenon occurring in one place impacts in some form or another elsewhere. I believe it's important to encourage a sense that even if we are divided into many different countries, the atmosphere that surrounds the Earth is all connected.
Hayashi: It would be great if all elementary and junior high school pupils could see images of clouds around the world before they became adults. And even better if an accurate commentary was provided with those images. Just imagine the value of children growing up looking at satellite images every morning at school and being told hey, see this, this is a summer anticyclone, or whatever. Perhaps educational TV should broadcast something like that every morning.
Goto-san, Hayashi-san,
what kind of planet is Planet Earth to you?
Hayashi: A tiny little planet, I guess. In a universe this big, the Earth is this small. And we are even smaller. So why sweat the small stuff? I say get out there and live life to the full. The Earth gives us the ability to get through things.
Goto: An amazing planet that has given birth to and nurtured all forms of life for the past three or four billion years. My image of the Earth is of our mother, generously providing everything from the environment we need to go on living, to food and energy.
Hayashi: Once I suppose it was our grandparents that taught us these important things. I hope that by seeing these cloud images, people experience for themselves just how connected the world really is. And perhaps this might encourage them to take better care of the planet.
