CCM3模式中LSM积雪方案的改进研究 (Ⅱ):全球模拟试验分析

Inprovement Study on Snow Scheme in LSM Scheme of NCAR CCM3 Model(Ⅱ): The GCM Simulation Experiment Analyses

为了进一步检验新LSM积雪方案的气候模拟性能,经文献[1]单站模拟检验后,在本文中又进一步将其加入CCM3模式中,分别积分近两年。模拟结果表明:原LSM和新LSM积雪方案虽然都能再现全球气候的主要平均特征,但经改进后的新积雪方案对全球积雪气候、降水等要素场及环流等的气候模拟性能比原LSM积雪方案更好些。

To further test the simulation performance of the forementioned new LSM scheme, the snow scheme has been also incorporated into NCAR CCM3, a nearly two year integrals with the new LSM (hereafter NCCM3) and the old LSM snow scheme (OCCM3) have been run respectively, utilizing at 00GMT on December 16 as the initial time and the well-adjusted simulated atmospheric forcing, the soil tempetature and humidity, as well as the snow thickness at the time as the initial condition. The intercomparisons among the circulation, precipitation, and variety of snow variables simulated by NCCM3 and OCCM3 and observed show: (1) After introducing the new LSM snow scheme, the circulation, air temperature and SLP simulated by NCCM3 are somewhat better than those by OCCM3. (2) The snow mass and snow depth simulated by NCCM3 are a little larger than those by OCCM3. But the formers are closer to their observed values. The NCCM3 better simulate the main seasonal change features of the total snow mass over Eurasia, North America. The NCCM3 simulation also well reproduce well the February mean snow cover distribution features over Northern Hemisphere inthemostsnowy period, especially over North America. (3) In contrast to the OCCM3 simulation, the NCCM3 simulation also has better behavior in the surface temperature, surface sensible flux, and precipitation.