May 16, 2013

Weather on the Outer Planets Only Goes So Deep




Weizmann Institute researchers and their colleagues set an upper limit for the thickness of jet streams on Uranus and Neptune

What is the long-range weather forecast for the giant planets Uranus and Neptune? These planets are home to extreme winds blowing at speeds of over 1000 km/hour, hurricane-like storms as large around as Earth, immense weather systems that last for years and fast-flowing jet streams. Both planets feature similar climates, despite the fact that Uranus is tipped on its side with the pole facing the sun during winter. The winds on these planets have been observed on their outer surfaces; but to get a grasp of their weather systems, we need to have an idea of what is going on underneath. For instance, do the atmospheric patterns arise from deep down in the planet, or are they confined to shallower processes nearer the surface? New research at the Weizmann Institute of Science, the University of Arizona and Tel Aviv University, which was published online today in Nature, shows that the wind patterns seen on the surface can extend only so far down on these two worlds.