Diurnal cycles of 2 m height temperature (left), specific humidity (middle) and relative humidity (right) in observations (top), simulations
(middle) and their differences (bottom), over different underlying surfaces averaged from 2006 to 2009. Observations over urban area, wood land
and crop land are from AMS sites of No. 1 (Guanghua East-Street), No. 3, (Arboretum) and No. 4 (Hehei University), respectively