Relation between the BBF position (Y_GSM) and MLT for each Tsyganenko model. The solid black line is the linear regression, while the dashed red line is the linear regression shifted ±1 h. The solid red line indicates the mean value. Panels (a–d) correspond to the Northern Hemisphere, and panels (e–h) correspond to the Southern Hemisphere. The colorbar represents the IMF clock angle: Blue: IMF pointing towards dusk, Red: IMF pointing towards dawn, Gray: IMF pointing northward, and Black: IMF pointing southward.