  This investigation is directed to understand the asymmetry in $\Delta$X
variations caused due to the relative roles played by IMF Bz and IMF By in a
particular interval (22:22 - 22:55 UT), during the main phase of a strong
geomagnetic storm event of April 06, 2000 (Ap = 236). Two pairs of antipodal
stations, being part of the SuperMAG network, are considered here. Ionospheric
convection maps from SuperDARN network are used to understand spatio-temporal
evolution of the DP2 ionospheric convection patterns over high-latitudes. The
two-dimensional maps of equivalent currents are used to show signatures of
global DP2 currents associated with the interplay effect between the two IMF
components. Observations show increases in the difference in $\Delta$X
variations between nearly antipodal stations from the Japanese-European/African
sector with respect to the same between the nearly antipodal stations from the
Pacific/American-Indian sector. This asymmetry is observed during the period
when the absolute magnitude of IMF By is larger than that of IMF Bz resulting
in a significant and conspicuous enhancement in IMF |By/Bz|. It is suggested
that the distortions in DP2 cells and associated rotation of electrodynamic
day-night divider, bring one pair of stations under the same DP2 cell and one
station of the other pair under a different DP2 cell and throat flow region
leading to the asymmetry in $\Delta$X variations between the antipodal
stations. Therefore, the work highlights the importance of the interplay
between IMF Bz and IMF By in determining the ionospheric impact over low
latitudes during strong geomagnetic conditions.
