摘要
为了探讨人为热源和城市绿化对城市边界层的影响,本文在RAMS模式中引入周期性日变化的人为热源和人工改变下垫面状况,初步模拟分析了人为热源和城市绿化对城市边界层结构的影响。结果表明:人为热源具有明显的增温效应,增强了城市的湍流交换,白天增加了大气不稳定度,促进了混合层的发展,夜间降低了大气稳定度,减弱了城市夜间逆温。城市绿化减小了地表反照率,增加了到达地面的净辐射,模拟期间土壤冻结,增加的净辐射其中一部分以感热的形式来加热大气;绿化后地气之间的湍流交换增强,增加了大气不稳定度,减弱了白天高空逆温;本文还讨论了不同绿化布局对白天高空逆温的影响以及人为热源和城市绿化之间的非线性相互作用。
To study the impact of anthropogenic heat and urban greenbelts on urban boundary layer structure of valley city in winter, we incorperate a new anthropogenic heat source into the surface energy budget and changed the land surface parameter in RAMS. The numerical simulation results show that anthropogenic heat release leads to the increase of temperature and turbulent energy. In daytime it increases the atmospheric instability, resulting in the increase of the mixed-layer height, while at nighttime it weakens the radiation inversion. Afforestation changes the mountain-valley local circulation system, destabilizes the atmosphere. The amount of net solar radiation and sensible heat flux is higher in the afforestation soil than that in the bare soil in permafrost area in winter. When the increasing of forests increases the air temperature and turbulent energy in daytime will increase, and this impact could be transported up results in a weaker elevated temperature inversion in lower level. The effect of different greenbelts on the temperature inversion in daytime and the nonlinear interaction of anthropogenic heat and afforestaion are also discussed.
出处
《高原气象》
CSCD
北大核心
2009年第2期268-277,共10页
Plateau Meteorology
基金
中国科学院寒区旱区环境与工程研究所引进人才基金项目“兰州市绿化对气候与环境影响效应的数值试验研究”(0684291001)
中国科学院“西部之光”项目,“兰州市南北两山绿化气候环境效益评估的观测和数值模拟研究”(2005403)
中国科学院百人计划项目(O827631001)共同资助
关键词
人为热源
绿化
城市边界层
数值模拟
Anthropogenic heat
Afforestation
Urban Boundary Layer
Numerical simulation
