Current STEM is a good photochemical model, with the SAPRC99 mechanism (218 reactions), and all of the 30 photolysis rates are explicitly computed through its on-line TUV. For our TRACE-P and ACE-ASIA experiences, this model was reliable. In this page, we include 4-layer horizontal plots of STEM simulation for several primary species. Of course we can dig out more information from its forecasting products. Welcome to send us comments.