character (it has field reversals and odd parity with respect to the Galactic plane), so it is called BSS-A model.

Discussed model employs cylindrical coordinates — the radial distance $r$, the position angle $\Theta$ and the vertical height $z$. The radial $B_r$ and azimuthal $B_{\Theta}$ components at the plane position $(r, \Theta)$ can be given by the following equations: $$B_{\Theta} = B_0(r) \cos \left( \Theta - \beta \ln \frac{r}{r_0}\right)
\cos p,$$ $$B_{r} = B_0(r) \cos \left( \Theta - \beta \ln \frac{r}{r_0}\right) \sin
p.$$ where $p$ denotes the pitch angle and according to [@stanev1] and [@han_new] it is about $-10^{\circ}$, $\beta = 1/ \tan p
\doteq -5.67$, $r_0$ is the Galactocentric distance of the maximum field strength at $l = 0^{\circ}$ (in the discussed model it has a value $r_0 = 9.0$ kpc) and for $B_0(r)$ it holds: $$B_0(r) = 3 \frac{R}{r},$$ where $R$ is the Galactocentric distance of the Sun, taken as 8.5 kpc.

The vertical ($z$) component of the field is taken as zero in approximate agreement with observations. Results of this model are depicted on Fig. \[modelgmf\] and the orientation of the whole system is also clear from this Figure.

The size and field strength in the Galactic 