【摘要】 利用BATS-SAST模式对加拿大Sk-OJP森林站2001/2002,2002/2003,2003/2004年度及Sk_HarvestJP空旷站2003/2004年度4个积雪季节进行模拟.针对Sk-OJP森林站积雪深度模拟偏小的不足,在长波辐射及降水量的计算方案中考虑透过冠层的部分;考虑由雨、雪密度不同引起冠层上单位面积截留量的变化以及风速和冠层温度对冠层积雪卸载过程的影响,对冠层截留模型进行了改进.针对Sk_HarvestJP空旷站积雪深度模拟偏大的不足,对地表积雪覆盖率的计算方案进行了调整.结果表明:模式能够对2种不同下垫面积雪变化过程做出合理描述;调整后的模式对Sk_OJP森林站积雪深度模拟增加;新冠层截留模型通过改变冠层截留量来影响冠层下积雪深度的变化,积雪深度的模拟在融化阶段改进最为显著;调整后的模式对Sk_HarvestJP空旷站积雪覆盖率模拟变小,由于积雪覆盖率与地表反照率之间存在着正反馈关系,地面接收的太阳辐射增大,积雪深度的模拟变小.更多还原

【Abstract】 A BATS-SAST model was employed to simulate the snow deposition processes in the four snow deposition cases in Canada,i.e.,Sk_OJP 2001/02,2002/03,2003/04 and Sk_HarvestJP 2003/04. At Sk_OJP site the long wave radiation scheme and precipitation scheme were modified. Considering different interceptions between rain and snowfall and effect of wind and canopy temperature on snow download,the canopy interception model was improved. At Sk_HarvestJP site the snow cover fraction scheme was modified. Results show that the model is able to simulate the basic processes of snow cover reasonably. The modified model,which considers the part of the transmitted through the canopy in computing long wave radiation and precipitation at Sk_OJP site,can make the simulation of snow depth more and closer to the observation. The improved canopy interception model,which influences the variation of snow depth under canopy by changing canopy interception,has a great improvement on simulation of snow depth,especially on the ablation period of snow cover. At Sk_HarvestJP site,the snow depth was lessened simulated by the improved model.更多还原