主要评估了美国国家大气研究中心的NCAR CESM(Community Earth System Model,NCAR)和中国科学院的CAS ESM(Earth System Model,Chinese Academy of Sciences)两个地球系统模式对亚洲东部夏季气候态的模拟性能。使用NCAR CESM和CAS ESM...主要评估了美国国家大气研究中心的NCAR CESM(Community Earth System Model,NCAR)和中国科学院的CAS ESM(Earth System Model,Chinese Academy of Sciences)两个地球系统模式对亚洲东部夏季气候态的模拟性能。使用NCAR CESM和CAS ESM各两种不同的水平分辨率,一共进行了4组长达19年(1998~2016年)的数值积分试验,并通过对2 m气温、降水强度和降水日变化等的分析,比较了这两个模式在亚洲东部的模拟性能。结果表明,CAS ESM和NCAR CESM均能模拟出夏季2 m气温和降水强度的大尺度分布特征,但整体上模拟得到的地表面气温偏暖、降水强度偏弱。对于降水日变化而言,观测的日降水峰值在陆地上主要发生在下午到傍晚时段,在海洋上则出现在午夜到凌晨时段。两组低分辨率试验模拟的陆地降水峰值出现过早,且无法模拟出四川盆地的夜间降水峰值和部分海洋地区凌晨或上午的降水峰值。提高分辨率对模式的模拟性能有显著的提升作用。高分辨率下,NCAR CESM和CAS ESM对陆地和海洋的降水日变化模拟性能都明显提高。对降水日变化的定量化分析表明,高分辨率CAS ESM模式对整个亚洲东部降水日变化的模拟最优。目前模式对海陆风的模拟还不太理想,未来要进一步提高模式模拟性能,需要重点完善与气温、降水过程相关的物理参数化方案。展开更多
In this study,fog simulations were conducted using the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) in and around the Yodo River Basin,Japan.The purpose is to investigate the MM5 performance of fog simulatio...In this study,fog simulations were conducted using the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) in and around the Yodo River Basin,Japan.The purpose is to investigate the MM5 performance of fog simulation for long-term periods.The simulations were performed for January,February,March,and July,2005 with a coarse 3-kin and a nested fine 1-km grid domains. Results of the simulations were compared with data from ten meteorological observatories,fog sampling site in Mt.Rokko,and visibility measurem...展开更多
The inlcrunnual variation of the vertical distribution of ozone in the tropical stratosphere and its quasi—biennial oscillation (QBO) is analyzed using HALOE data. The results are compared with the wind QBO. A numeri...The inlcrunnual variation of the vertical distribution of ozone in the tropical stratosphere and its quasi—biennial oscillation (QBO) is analyzed using HALOE data. The results are compared with the wind QBO. A numerical experiment is carried out to study the effects of wind QBO on the distribution, and variation of ozone in the stratosphere by using (he NCAR interactive chemical, dynamical, and radiative two—dimensional model (SOCRATES). Data analysis shows that the location of the maximum ozone mixing ratio in the stratosphere changes in the meridional and vertical directions, and assumes a quasi—biennial period. The meridional and vertical motion of the maximum mixing ratio leads to a QBO of column ozone and its hemispheric asymmetry. The QBO of the location of the maximum is closely connected with the zonal wind QBO. The data analysis also shows that in the tropical region, the phase of the QBO for ozone density changes many times with height. Numerical simulation shows that the meridional circulation induced by the wind QBO includes three pairs of cells in the stratosphere, which have hemispheric symmetry. The transport of ozone by the induced meridional circulation in various latitudes and heights is the main dynamic cause for the ozone QBO. Cells of the induced circulation in the middle stratosphere (25-35 km) play an important role in producing the ozone QBO.展开更多
利用融合火点排放源、人为源和生物源的WRF-Chem(Weather Research and Forecasting Model coupled with Chemistry)模式,模拟2015年9月30日08:00(北京时间)起的72 h发生在淮河流域的一次农作物秸秆大面积露天焚烧过程,研究了农作物秸...利用融合火点排放源、人为源和生物源的WRF-Chem(Weather Research and Forecasting Model coupled with Chemistry)模式,模拟2015年9月30日08:00(北京时间)起的72 h发生在淮河流域的一次农作物秸秆大面积露天焚烧过程,研究了农作物秸秆焚烧释放的气态污染物和颗粒物对区域城市空气质量的影响。通过有无火点两组试验分析了此次秸秆焚烧对流域内河南、山东、江苏和安徽四省83座城市CO、PM10(空气动力学当量直径小于等于10μm的颗粒物,即可吸入颗粒物)、PM2.5(空气动力学当量直径小于等于2.5μm的颗粒物,即细颗粒物)和O3浓度的定量影响,结果表明:(1)融合NCAR-FINN(Fire Inventory from NCAR)火点排放资料的WRF-Chem模式较好地再现了此次秸秆焚烧及火点烟羽扩散过程。同时结合EDGAR-HTAP(Emission Database for Global Atmospheric Research on Hemispheric Transport of Air Pollution)人为源和MEGAN(Model of Emission of Gases and Aerosols from Nature)生物源的WRF-FIRE(考虑火点排放试验)对流域内城市大气污染物的模拟效果较为理想,尤其对秸秆焚烧释放的污染物CO、PM10和PM2.5和产生的二次污染物O3浓度的模拟。(2)秸秆焚烧所释放的污染物造成流域内城市一次污染物CO、PM10和PM2.5浓度的增加,火点中心和下风向城市增幅最为明显,最大小时浓度增幅达到3倍标准差。气态污染物CO和相比PM10粒径更小的PM2.5可随风扩散至更远的地区,对城市浓度影响更大。(3)此外,秸秆焚烧也使得火点中心城市和下风向城市二次污染物O3浓度增加,但小时浓度增幅极值区分布在火点下风向烟羽末端太阳光照充足的地区,最大小时浓度增幅接近3倍标准差。秸秆焚烧对区域城市空气质量的影响存在明显的空间分布差异且对城市各大气污染成分的影响也不相同。展开更多
Researchers have paid much attention to the influence of the tropical zonal wind quasi-biennial oscillation (QBO) on tropical methane,while generally ignoring the change in extra-tropical methane.The present study ana...Researchers have paid much attention to the influence of the tropical zonal wind quasi-biennial oscillation (QBO) on tropical methane,while generally ignoring the change in extra-tropical methane.The present study analyzed the interannual changes in the methane mixing ratio in extra-tropics of both the Southern Hemisphere (SH) and Northern Hemisphere (NH) using Halogen Occultation Experiment (HALOE) satellite data.The results show that interannual changes in extra-tropical methane exhibit QBO features in both hemispheres that are obviously different from those in the tropics.The extra-tropical methane QBO perturbations usually occur in two layers and are longitudinally asymmetrical about the equator.The amplitude of the methane QBO disturbance in the extra-tropics is smaller than that in the tropics from 10 to 1 hPa but much larger in the layer from 30 to 10 hPa.The interannual relative changes in the methane mixing ratio are similar in both the NH extra-tropics and the tropics in the middle and upper stratosphere.Using the National Center for Atmospheric Research two-dimensional,interactive chemical dynamical radiative model (SOCRATES),simulation was conducted to investigate the mechanism of the extra-tropical methane QBO.The results indicate that the tropical stratospheric zonal wind QBO results in the QBO of the induced residual circulation.It is the transport of methane by the induced residual circulation that causes the methane QBO in the extra-tropics.The induced residual circulations in the middle and upper stratosphere are not always longitudinally symmetrical about the equator,resulting in different distribution of the methane QBO in the SH and NH extra-tropics.展开更多
文摘主要评估了美国国家大气研究中心的NCAR CESM(Community Earth System Model,NCAR)和中国科学院的CAS ESM(Earth System Model,Chinese Academy of Sciences)两个地球系统模式对亚洲东部夏季气候态的模拟性能。使用NCAR CESM和CAS ESM各两种不同的水平分辨率,一共进行了4组长达19年(1998~2016年)的数值积分试验,并通过对2 m气温、降水强度和降水日变化等的分析,比较了这两个模式在亚洲东部的模拟性能。结果表明,CAS ESM和NCAR CESM均能模拟出夏季2 m气温和降水强度的大尺度分布特征,但整体上模拟得到的地表面气温偏暖、降水强度偏弱。对于降水日变化而言,观测的日降水峰值在陆地上主要发生在下午到傍晚时段,在海洋上则出现在午夜到凌晨时段。两组低分辨率试验模拟的陆地降水峰值出现过早,且无法模拟出四川盆地的夜间降水峰值和部分海洋地区凌晨或上午的降水峰值。提高分辨率对模式的模拟性能有显著的提升作用。高分辨率下,NCAR CESM和CAS ESM对陆地和海洋的降水日变化模拟性能都明显提高。对降水日变化的定量化分析表明,高分辨率CAS ESM模式对整个亚洲东部降水日变化的模拟最优。目前模式对海陆风的模拟还不太理想,未来要进一步提高模式模拟性能,需要重点完善与气温、降水过程相关的物理参数化方案。
文摘In this study,fog simulations were conducted using the Fifth-Generation NCAR/Penn State Mesoscale Model (MM5) in and around the Yodo River Basin,Japan.The purpose is to investigate the MM5 performance of fog simulation for long-term periods.The simulations were performed for January,February,March,and July,2005 with a coarse 3-kin and a nested fine 1-km grid domains. Results of the simulations were compared with data from ten meteorological observatories,fog sampling site in Mt.Rokko,and visibility measurem...
文摘The inlcrunnual variation of the vertical distribution of ozone in the tropical stratosphere and its quasi—biennial oscillation (QBO) is analyzed using HALOE data. The results are compared with the wind QBO. A numerical experiment is carried out to study the effects of wind QBO on the distribution, and variation of ozone in the stratosphere by using (he NCAR interactive chemical, dynamical, and radiative two—dimensional model (SOCRATES). Data analysis shows that the location of the maximum ozone mixing ratio in the stratosphere changes in the meridional and vertical directions, and assumes a quasi—biennial period. The meridional and vertical motion of the maximum mixing ratio leads to a QBO of column ozone and its hemispheric asymmetry. The QBO of the location of the maximum is closely connected with the zonal wind QBO. The data analysis also shows that in the tropical region, the phase of the QBO for ozone density changes many times with height. Numerical simulation shows that the meridional circulation induced by the wind QBO includes three pairs of cells in the stratosphere, which have hemispheric symmetry. The transport of ozone by the induced meridional circulation in various latitudes and heights is the main dynamic cause for the ozone QBO. Cells of the induced circulation in the middle stratosphere (25-35 km) play an important role in producing the ozone QBO.
文摘利用融合火点排放源、人为源和生物源的WRF-Chem(Weather Research and Forecasting Model coupled with Chemistry)模式,模拟2015年9月30日08:00(北京时间)起的72 h发生在淮河流域的一次农作物秸秆大面积露天焚烧过程,研究了农作物秸秆焚烧释放的气态污染物和颗粒物对区域城市空气质量的影响。通过有无火点两组试验分析了此次秸秆焚烧对流域内河南、山东、江苏和安徽四省83座城市CO、PM10(空气动力学当量直径小于等于10μm的颗粒物,即可吸入颗粒物)、PM2.5(空气动力学当量直径小于等于2.5μm的颗粒物,即细颗粒物)和O3浓度的定量影响,结果表明:(1)融合NCAR-FINN(Fire Inventory from NCAR)火点排放资料的WRF-Chem模式较好地再现了此次秸秆焚烧及火点烟羽扩散过程。同时结合EDGAR-HTAP(Emission Database for Global Atmospheric Research on Hemispheric Transport of Air Pollution)人为源和MEGAN(Model of Emission of Gases and Aerosols from Nature)生物源的WRF-FIRE(考虑火点排放试验)对流域内城市大气污染物的模拟效果较为理想,尤其对秸秆焚烧释放的污染物CO、PM10和PM2.5和产生的二次污染物O3浓度的模拟。(2)秸秆焚烧所释放的污染物造成流域内城市一次污染物CO、PM10和PM2.5浓度的增加,火点中心和下风向城市增幅最为明显,最大小时浓度增幅达到3倍标准差。气态污染物CO和相比PM10粒径更小的PM2.5可随风扩散至更远的地区,对城市浓度影响更大。(3)此外,秸秆焚烧也使得火点中心城市和下风向城市二次污染物O3浓度增加,但小时浓度增幅极值区分布在火点下风向烟羽末端太阳光照充足的地区,最大小时浓度增幅接近3倍标准差。秸秆焚烧对区域城市空气质量的影响存在明显的空间分布差异且对城市各大气污染成分的影响也不相同。
基金National Basic Research Program of China (2010CB428603)
文摘Researchers have paid much attention to the influence of the tropical zonal wind quasi-biennial oscillation (QBO) on tropical methane,while generally ignoring the change in extra-tropical methane.The present study analyzed the interannual changes in the methane mixing ratio in extra-tropics of both the Southern Hemisphere (SH) and Northern Hemisphere (NH) using Halogen Occultation Experiment (HALOE) satellite data.The results show that interannual changes in extra-tropical methane exhibit QBO features in both hemispheres that are obviously different from those in the tropics.The extra-tropical methane QBO perturbations usually occur in two layers and are longitudinally asymmetrical about the equator.The amplitude of the methane QBO disturbance in the extra-tropics is smaller than that in the tropics from 10 to 1 hPa but much larger in the layer from 30 to 10 hPa.The interannual relative changes in the methane mixing ratio are similar in both the NH extra-tropics and the tropics in the middle and upper stratosphere.Using the National Center for Atmospheric Research two-dimensional,interactive chemical dynamical radiative model (SOCRATES),simulation was conducted to investigate the mechanism of the extra-tropical methane QBO.The results indicate that the tropical stratospheric zonal wind QBO results in the QBO of the induced residual circulation.It is the transport of methane by the induced residual circulation that causes the methane QBO in the extra-tropics.The induced residual circulations in the middle and upper stratosphere are not always longitudinally symmetrical about the equator,resulting in different distribution of the methane QBO in the SH and NH extra-tropics.
