F. Giorgi et al., A seasonal cycle simulation over eastern Asia and its sensitivity to radiative transfer and surface processes, J GEO RES-A, 104(D6), 1999, pp. 6403-6423
A multiseasonal simulation over eastern Asia and its sensitivity to cloud r
adiation and surface processes is analyzed. The model used is the NCAR Regi
onal Climate Model (RegCM), the period of simulation is 13 months in length
, and the emphasis of the analysis is on surface climatology, monsoon circu
lations, cloudiness, surface solar radiation, and top of the atmosphere out
going longwave radiation. The model reproduces the basic features of the se
asonal evolution of east Asia climate, but it overpredicts the intensity of
the mature phase of the eastern Asia monsoon. Surface solar radiation is c
omparable with observations, while outgoing longwave radiation is mostly un
derestimated. Different formulations of large-scale cloud-producing mechani
sms are shown to significantly affect cloud profiles, the surface and top o
f the atmosphere radiation budgets, and as a consequence, the simulated sur
face climatology. Variations in surface characteristics affect precipitatio
n simulation in different ways during the cold/dry and warm/wet seasons. Th
is paper emphasizes the importance of examining cloud radiation processes i
n regional climate models in greater detail than has been done in past stud
ies.