The largest temperature anisotropy in the cosmic microwave background (CMB)
is the dipole, which has been measured with increasing accuracy for more than
three decades, particularly with the Planck satellite. The simplest
interpretation of the dipole is that it is due to our motion with respect to
the rest frame of the CMB. Since current CMB experiments infer temperature
anisotropies from angular intensity variations, the dipole modulates the
temperature anisotropies with the same frequency dependence as the thermal
Sunyaev-Zeldovich (tSZ) effect. We present the first, and significant,
detection of this signal in the tSZ maps and find that it is consistent with
direct measurements of the CMB dipole, as expected. The signal contributes
power in the tSZ maps, which is modulated in a quadrupolar pattern, and we
estimate its contribution to the tSZ bispectrum, noting that it contributes
negligible noise to the bispectrum at relevant scales.