Influences of two convective schemes on the radiative energy budget in GAMIL1.0

The Grid-point Atmospheric Model of IAP LASG version 1.0 (GAMIL1.0) is used to investigate the impacts of different convective schemes on the radiative energy budget. The two convective schemes are Zhang and McFarlance (1995)/Hack (1994) (ZM) and Tiedtke (1989)/Nordeng (1994) (TN). Two simulations are performed: one with the ZM scheme (EX_ZM) and the other with the TN scheme (EX_TN). The results indicate that during the convective process, more water vapor consumption and temperature increment are found in the EX_ZM, especially in the lower model layer, its environment is therefore very dry. In contrast, there is a moister atmosphere in the EX_TN, which favors low cloud formation and large-scale condensation, and hence more low cloud fraction, higher cloud water mixing ratio, and deeper cloud extinction optical depth are simulated, reflecting more solar radiative flux in the EX_TN. This explains why the TN scheme underestimates the net shortwave radiative flux at the top of the atmosphere and at surface. In addition, convection influences longwave radiation, surface sensible and latent heat fluxes through changes in cloud emissivity and precipitation.