  The Sun has a Near-Surface Shear Layer (NSSL), within which the angular
velocity decreases rapidly with radius. We provide an explanation of this layer
based on the thermal wind balance equation. Since convective motions are not
affected by solar rotation in the top layer of the convection zone, we argue
that the temperature falls at the same rate at all latitudes in this layer.
This makes the thermal wind term very large in this layer and the centrifugal
term has also to become very large to balance it, giving rise to the NSSL. From
the values of differential rotation $\Omega (r<r_c, \theta)$ at radii less than
a radius $r_c$, we can calculate the temperature difference $\Delta T (r,
\theta)$ with respect to the standard solar model at different points of the
convection zone, by making use of the thermal wind balance equation. Then we
again use this equation in the top layer to calculate $\Omega (r>r_c, \theta)$
there from $\Delta T (r, \theta)$. We carry on this exercise using both an
analytical expression of the differential rotation and the actual data provided
by helioseismology. We find that our theoretical results of the NSSL match the
observational data reasonably well for $r_c \approx 0.96~{\rm R_{\odot}}$,
giving an estimate of the radius till which the convective motions are affected
by the solar rotation.
