Observations are also conducted on airplanes, on helicopters, on flying balloons, on ships or at highlands at an altitude of more than 2000 m (where an atmospheric layer called free troposphere exists, and the layer has an air flow different from that of others, because no friction with the ground surface exists there). |
飛行機、ヘリコプター、気球、船舶を利用した観測、2,000m以上の高地(対流圏と呼ばれる大気の層で地面との摩擦が無いため、大気が他とは異なった流れになっている)での観測もある。 |