The International Space Station. Credit: NASA

Sunday, October 6, 2013

Un demi-siècle de conquête spatiale à Charleroi

Un demi-siècle de conquête spatiale à Charleroi

A HOT TOWER FORMS IN TROPICAL DEPRESSION 11


 FROM:  NASA

Tropical Depression 11 formed in the central Atlantic Ocean and NASA's TRMM satellite passed overhead and gathered information  and identified a "hot tower" that indicated it would strengthen. The depression became Tropical Storm Jerry on Sept. 30 at 10:30 a.m. EDT.  A "hot tower" is a tall cumulonimbus cloud that reaches at least to the top of the troposphere, the lowest layer of the atmosphere. It extends approximately nine miles (14.5 km) high in the tropics. The hot towers in Tropical Depression 11 were reaching heights of 16 km/9.9 miles high around the depression's center. These towers are called "hot" because they rise to such altitude due to the large amount of latent heat. Water vapor releases this latent heat as it condenses into liquid. NASA research shows that a tropical cyclone with a hot tower in its eye wall was twice as likely to intensify within six or more hours, than a cyclone that lacked a hot tower. Those hot towers also drop heavy rainfall.  mage Credit: NASA/SSAI, Hal Pierce.