Measured and forward-modeled travel-time shifts as a function of distance and latitude. The top row shows maps of the three measured travel-time shifts, δτ′_sn;23, δτ′_sn;24, and δτ′_sn;23+24, from left to right. The middle row shows the same δτ′_sns as the top row but antisymmetrized about the equator. The bottom row shows the forward-modeled travel-time shifts derived from the MC1, MC2, and MC3 flow models, from left to right, in combination with that from model LC1. All maps of the measured and forward-modeled travel-time shifts are Gaussian smoothed with a FWHM of 7.2° in latitude and in distance. The data used to plot the top row are available at the CDS.