Meteorology

For those who first get acquainted with meteorology

You know how daily temperature varies from your real experiences. Temperature varies on one-day cycle in this way it rises during the daytime and falls at night. The cause of this one-day cycle variation is the earth's surface heating by the sun. But this variation doesn't arise everywhere and become less with getting away from the ground. Can you imagine to how much height this one-day cycle variation arise?
There's another question. Have you experienced "building-induced wind"? We can hardly expect where the wind blows from and some might stagger unconsciously. As above, buildings and forests take on the role of obstacle and vary the wind flow around. Then, to how much altitude is the flow varied by these obstacles?
The answers to this two questions above are both 500~2000 meters, not agreeing with strictly. Above this altitude, there's no temperature's diurnal variation and wind blows straight except in case of typhoon or cyclone. Aren't you surprised by this low altitude? 500 meters takes only 3 minutes by foot! Some has never known this fact since "human cannot live away from the firm ground "(by Theta).

It is "planetary boundary layer" that meteorology subjects to study. Planetary boundary layer is "the layer in which the temperature and wind and others are varied by the interaction with earth's surface" as indicated by above examples. Although it is the closest thing for us, there are a lot of unexplained questions. It is caused by the irregularity of the flow as mentioned at example of "building-induced wind" above and this is refered to "turbulent flow" in meteorology. We know that much of the surface heat and water vapor are carried up in the sky by this turbulent flow. But we have never estimated its correct amount specifically in a way ···W, ···kg. It has been considered that the correct understanding of turbulent flow leads to advancement of the accuracy of reasional weather forecast (e.g., shower and others), so it is very important for meteorology.

Study contents

Here we introduce to you our specific study contents.

Heat budget

On the earth, heat energy is flowing in diverse ways. A big thing is, first of all, solar energy. If it were not for it, the earth would be far more colder than now. On another front, if solar energy colleted all the way on the earth, it would be terribly hot. Of course that never happens, solar energy is emitted into space with changing the form into different energy. Thus, heat budget is to calculate how much heat energy flow in and out. For simple example, on the equator and on the north pole, the amount of each solar energy is different and it is thought that each has quite different heat budget. Additionally, in the subject of heat-island phenomenon we often get the word recently, it comes under the spotlight that how much the amount of artificial exhaust heat of air-conditioner and others ascribed as the cause is.

Evapotranspiration

Tired of uncertain weather forecast? This is really worth a try. The water for the generation of cloud is caused by the evaporation from land surface or sea and the evapotranspiration from plants. One of the cause of weather forecast making a mistake is the estimating amount of evapotranspiration going wrong. While the amount of evapotranspiration in the region relatively simple like vast ocean or grassland is estimeted accurately, it is difficult to estimate in the region like Japan where buildings and mountains are forming a complicated weblike pattern and this is pain in the neck of meteorology (It's challenging!).
In addition, there are some places in the world in which default of water is a very deep problem although in Japan we are not so concerned about because it is surrounded by oceans. What is more, the area might come out in which default of water would be an issue for climate change by recent global warming. When we simulate such a future prospects, the estimation method is of advantege.

You were born in this watery planet and only in this planet you can study this!

Remote sensing

Remote sensing is sensing from remote place in the broad sense. In the area of meteorology, however, it means that seeing the earth on artificial satellite launched at several hundred kilometers from the ground. On the weather forecast, cloud motion is projected as "weather-satellite "Himawari"'s image", that is very one of remote sensing. This technology is considered as might be expected in the now, but when it broke out in it was viewed as a big technical innovation.
There is more things about the earth we can get to know. There are two reasons make that possible. One reason is (comparing to human) good vision. In our own day artificial satellite that has the best performance can see the motion of person. Another one reason is (analogy, too) distinguishing by using different colors better than humans. For example, while dog's eyes see only black and white, human's eyes see spectral hues (seven colors). That is, artificial satellite's sensor sees more colors than human (it is referred to as ultraviolet rays or infra-red rays that human cannot see). That said, seeing the earth by artificial satellite leads to the possibility to make a discovery human has never seen. This is still developing now and is a field with high future growth potential.


Last-modified: 2017-03-16 (Thu) 20:29:14 (494d)