Type I migration coefficient f_I as functions of the planet mass and disk radius. The red (blue) means the migration is outward (inward). Left and right columns: typical disk models with Ṁ_g = 3 × 10⁻⁸ M_⊙ yr⁻¹ around M_⋆ = 1 M_⊙ stars, and Ṁ_g = 3 × 10⁻¹⁰ M_⊙ yr⁻¹ around a M_⋆ = 0.1 M_⊙, respectively. Top and bottom rows: disk turbulent viscosity α_t of 10⁻³ and 10⁻⁴. The black line refers to the zero-torque location, the magenta and cyan lines are r_ice and r_tran, respectively. Other parameters are α_g = 10⁻², κ₀ = 10⁻² and . The effect of outward migration is weaker for planets in less turbulent disks and/or around less massive stars.