UCLA

Northwest China (NWC) is a typical arid and semi-arid region. In this study, the main summer climate features over NWC are presented and the performance of an atmospheric general circulation model (NCEP GCM/SSiB) over this region is evaluated. Satellite-derived vegetation products are applied in the model. Based on comparison with observational data and Reanalysis II data, the model generally captures major features of the NWC summer energy balance and circulation. These features include: a high surface temperature center dominating the planetary boundary layer; widespread descending motion; an anticyclone (cyclone) located in the lower and middle (upper) troposphere, covering most parts of central NWC; and the precipitation located mainly in the high elevation areas surrounding NWC.