Comparisons among three different cases. The distributions of temperature (panels a–c), total velocity the in x − y plane () (panels d–f), and the joint PDF of temperature and density (panels g–i) are presented. Panels a, d and g are for Case 5, panels b, e and h are for Case 5a, and panels c, f and i are for Case 5b. The maximum AMR refinement levels in Case 5, 5a, and 5b are 5, 3, and 3, respectively. The ambipolar diffusion effect is not included in Case 5 and 5a, but it is included in Case 5b.