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Context. In local helioseismology, the travel times of acoustic wavespropagating in opposite directions along the same meridian inform us abouthorizontal flows in the north-south direction. The longitudinal averages of thenorth-south helioseismic travel-time shifts vary with the sunspot cycle. Aims.We aim to study the contribution of inflows into solar active regions to thissolar-cycle variation. Methods. To do so, we identify the local flows aroundactive regions in the horizontal flow maps obtained from correlation trackingof granulation in SDO/HMI continuum images. We compute the forward-modeledtravel-time perturbations caused by these inflows using 3D sensitivity kernels.In order to compare with the observations, we average these forward-modeledtravel-time perturbations over longitude and time in the same way as themeasured travel times. Results. The forward-modeling approach shows that theinflows associated with active regions may account for only a fraction of thesolar-cycle variations in the north-south travel-time measurements.Conclusions. The travel-time perturbations caused by the large-scale inflowssurrounding the active regions do not explain in full the solar-cyclevariations seen in the helioseismic measurements of the meridional circulation.  Keywords: Sun: activity -- Sun: helioseismology

Contribution of flows around active regions to the north-south helioseismic travel-time measurements