This color-coded chart represents the temporal evolution of the deviations in the rotation rate. The reference for the deviation is an eleven-year average of the differential rotation rate. The blue and green colors represent faster than average rotation rates while the red and yellow colors represent slower than average rotation rates. The zone between blue and red has an enhanced rate of shear and is where active magnetic regions appear at the beginning of the solar cycle.
Data in the form of latitude and longitude dependent velocity deviations is available as three files: z181a.dat, z182a.dat and z183a.dat in a text file format. These files have been updated on Mar. 24, 2005 to include recent observations. The sign convention has changed relative to earlier files in that the faster than average was previously taken to be negative and is now positive. A brief explanation of this data is in the pdf file: torsional_data.
The Torsional Oscillation time-dependent patterns have been extracted and interpreted in an oral presentation to the AGU fall 2011 meeting.