Accretion Disks Phase Transitions: 2-D or not 2-D?
  We argue that the proper way to treat thin-thick accretion-disk transitions should take into account the 2-D nature of the problem. We illustrate the physical inconsistency of the 1-D vertically integrated approach by discussing a particular example of the convective transport of energy. 
Marek A. Abramowicz, Gunnlaugur Bjornsson, Igor V. Igumenshchev