今夏は、気圧の低い湖畔一周ウォーキングを予定

　梅雨の最中ですが、今日から暫く太平洋高気圧が張り出し、日本列島は真夏のような猛暑になると予報されてます。雨も降った後のため、気温のみならず、湿度も５０％を超え不快です。一方、高気圧にも気をつけたいところですが、一般住宅にあっては気圧への対処はできません。私の部屋は現在１０１3hPaで丁度１気圧です。

　しかし、気圧への対処が全くできない訳ではありません。ご存じの通り、気圧とは上空の空気の重さであり、高度が増すほど空気が減り、気圧も下がります。ですから、気圧の低い所へ行きたい場合は山へ行けばよいのです。私たちは山でペットボトルの水を飲んで蓋を閉めたまま下山すると、平地ではペットボトルが凹んでいた経験をします。これは山の気圧が低かったことを証明してます。

　気温の場合は「標高が１００m高くなると、およそ１°C下がる」と言われます。例えば、群馬県の榛名湖付近のように海抜１０８４m付近であれば、平地の高崎市街地より１０°ほど下がることになります。同様に気圧については、標高1000ｍ地点では平地に比べ約9割の気圧といわれますから、榛名湖付近では９００hPa前後でしょう。赤城大沼の 標高は1345mですから、気温は平地より１３°ほど低くなり、気圧ももっと低くなるでしょう。

　今夏は暫くぶりに榛名湖や赤城大沼へ水色の愛車で訪れ、健康を期して気圧の低い湖畔を一周ウォーキングしてみます。たまには、一人でなく誰かと涼しい湖畔を一周したいです。

Dear my friends

　Although we are in the middle of the rainy season in Japan, the Pacific high pressure system will extend for a while from today, and the Japanese archipelago will experience scorching heat like midsummer, I guess. After the rain, not only the temperature but also the humidity is over 50%, which is uncomfortable. On the other hand, we want to be careful of high pressure, but in the ordinary house, it is impossible to change the air pressure. My room is currently at 1013 hPa, which is exactly 1 atmosphere.

　However, this does not mean that we cannot deal with the air pressure at all. As you know, air pressure is the weight of the air in the upper atmosphere, and the higher the altitude, the less air. Therefore, if we want to go to a place with lower air pressure, we should go to the mountain. We have experienced that when we drink water of a plastic bottle in the mountain and go down with the lid closed, the plastic bottle is dented on the plain. This proves that the air pressure on the mountain was low.

　When it comes to temperature, it is said that "for every 100m increase in altitude, the temperature drops by about 1°C." For example, at around 1,084m above sea level of Lake Haruna in Gumma Prefecture, the air pressure is about 10° lower than in the flat area of ​​Takasaki-City. Similarly, the air pressure at the altitude of 1,000m at around Lake Haruna, is said to be about 90% of the flat place. It would normally be around 900hPa. Lake Akagi-Onuma is at the altitude of 1,345m, so the temperature will be about 13° lower than at sea level, and the air pressure will be even lower.

　This summer, I will be visiting Lake Haruna and Lake Akagi-Onuma in my light blue coupe after a long interval, and walking around the lakeside where the air pressure is low, praying my health. Sometimes I'd like to go around the cool lakeside with a sweetheart in heart, not alone.