Subsurface Flows near Four Emerging Active Regions Studied with Ring-Diagram Analysis

We study the temporal variation of subsurface flows associated with four emerging active regions. Two of them, AR 10314 and AR 10488, emerge near disk center and the other two, AR 10365 and AR 10375, are older regions where new flux emerges during their disk passage. We measure the horizontal subsurface flows from high-resolution Global Oscillation Network Group (GONG+) data using ring-diagram analysis and derive the vertical flow component. Before flux emergence, we find upflows in AR 10314, while the other emerging region, AR 10488, shows only weak vertical flows hinting at upflows. Both aging regions, AR 10365 and AR 10375, show initially downflows, as expected from already established regions. When new flux emerges, the weaker one of the two, AR 10365, shows upflows, while AR 10375 shows stronger downflows. In strong active regions, such as AR 10375 and AR 10488, strong downflows are present after the region has been established.