Thermal Structure and Dynamics of Saturn’s Northern Springtime Disturbance

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Science  19 May 2011:
DOI: 10.1126/science.1204774


Saturn’s slow seasonal evolution was disrupted in 2010–2011 by the eruption of a bright storm in its northern spring hemisphere. Thermal infrared spectroscopy showed that within a month, the resulting planetary-scale disturbance had generated intense perturbations to atmospheric temperatures, winds and composition between 20o and 50oN over an entire hemisphere (140,000 km). The tropospheric storm cell produced effects that penetrated hundreds of kilometers into Saturn’s stratosphere (1 mbar). Stratospheric subsidence at the edges of the disturbance produced "beacons" of infrared emission and longitudinal temperature contrasts of 16 K. The disturbance substantially altered atmospheric circulation, transporting material vertically over great distances, modifying stratospheric zonal jets, exciting wave activity and turbulence, and generating a new cold anticyclonic oval in the centre of the disturbance at 41oN.