NASA’s Terra satellite passed over the Southern Pacific Ocean and captured a visible image of extra-tropical cyclone Harold.
NASA’s Terra satellite passed over the Southern Pacific Ocean and captured a visible image of extra-tropical cyclone Harold.
On April 10, the visible image captured by the Moderate Resolution Imaging Spectroradiometer or MODIS instrument that flies aboard NASA’s Terra satellite showed that extra-tropical cyclone Harold was elongated from strong northwesterly wind shear. Wind shear had pushed the bulk of clouds and convection (rising air that forms the thunderstorms that make up a tropical cyclone) to the southeast of the center. Sheared convection and initial frontal features indicate that the system is undergoing extra-tropical transition.
In general, wind shear is a measure of how the speed and direction of winds change with altitude. Tropical cyclones are like rotating cylinders of winds. Each level needs to be stacked on top each other vertically in order for the storm to maintain strength or intensify. Wind shear occurs when winds at different levels of the atmosphere push against the rotating cylinder of winds, weakening the rotation by pushing it apart at different levels.
Read more at NASA / Goddard Space Flight Center
Image: On April 10, the MODIS instrument that flies aboard NASA’s Terra provided a visible image of Extra-tropical Cyclone Harold in the Southern Pacific Ocean. Credit: NASA Worldview, Earth Observing System Data and Information System (EOSDIS).
