2025ApJ...991..149L

The behavior of lithium (Li) in Population I main-sequence stars challenges standard stellar theory. Two phenomena stand out: the solar Li problem, which extends to Li depletion in solar analogs, and the Li dip observed in mid-F stars within open clusters. Building on the meridional-circulation-driven radial mixing framework previously developed to explain Li-enriched red clump stars, we explore its relevance to Li depletion on the main sequence. First, our models reproduce the observed A(Li)-age correlation in solar analogs. Through detailed isochrone analysis, we find good agreement between the simulated and observed A(Li)-T_eff relationships within the solar analog parameter space. However, the predicted solar Li abundance (∼1.5 dex) is still higher than current solar measurements. Second, our models partially explain the Li dip phenomenon in mid-F cluster stars. The models accurately reproduce Li distributions on the cool side of the Li dip in most clusters and capture the Li behaviors on the hot side observed in systems like the Hyades. However, we identify limitations in the models' ability to fully reproduce the dip morphology, particularly due to the rotation velocity distribution of sample stars in this temperature zone.