The temporal evolution of the July 2009 Jupiter impact cloud

► Time evolution of July 2009 Jovian impact cloud analyzed from consistent IRTF data over 7 weeks. ► Mie particles ∼ 0.9 μm radius and imaginary refractive index 0.01-0.015 agree with previous papers. ► Dissipation timescales for first 26 days 4-16 times shorter than last 23 days. ► Opacity timescales in the near-infrared consistent with visible wavelengths. ► Dissipation by meridional shear of zonal wind, not vertical shear nor sedimentation/coagulation.