the residual has units $\frac{\text{Pa}}{\text{m}}
\text{m}^{\text{dim}}$ (most easily established by considering the
term $(\nabla \cdot \mathbf v, p)_{\Omega}$ and considering that the
-pressure has units $\text{Pa}=\frac{\text{kg}}{\text{m\; s}^2}$ and
+pressure has units $\text{Pa}=\frac{\text{kg}}{\text{m}\;\text{s}^2}$ and
the integration yields a factor of $\text{m}^{\text{dim}}$), whereas
the second part of the residual has units
$\frac{\text{m}^{\text{dim}}}{\text{s}}$. Taking the norm
consistent first. In our case, this means that if we want to solve the system
of Stokes equations jointly, we have to scale them so that they all have the
same physical dimensions. In our case, this means multiplying the second
-equation by something that has units $\frac{\text{Pa\; s}}{\text{m}}$; one
+equation by something that has units $\frac{\text{Pa}\;\text{s}}{\text{m}}$; one
choice is to multiply with $\frac{\eta}{L}$ where $L$ is a typical lengthscale
in our domain (which experiments show is best chosen to be the diameter of
plumes — around 10 km — rather than the diameter of the
viscosity of the material that flows into the area vacated under the
rebounding continental plates.
- Using this technique, values around $\eta=10^{21} \text{Pa \; s}
- = 10^{21} \frac{\text{N\; s}}{\text{m}^2}
- = 10^{21} \frac{\text{kg}}{\text{m\; s}}$ have been found as the most
+ Using this technique, values around $\eta=10^{21} \text{Pa}\;\text{s}
+ = 10^{21} \frac{\text{N}\;\text{s}}{\text{m}^2}
+ = 10^{21} \frac{\text{kg}}{\text{m}\;\text{s}}$ have been found as the most
likely, though the error bar on this is at least one order of magnitude.
While we will use this value, we again have to caution that there are many