作者着眼于城市气溶胶辐射效应与大气边界层的相互作用问题，针对地形复杂的兰州市及周边地区，开发应用了WRF（Weather Research and Forecasting，天气研究和预报）模式，使之与包含了大气气溶胶辐射效应和气溶胶粒子扩散的综合大气...作者着眼于城市气溶胶辐射效应与大气边界层的相互作用问题，针对地形复杂的兰州市及周边地区，开发应用了WRF（Weather Research and Forecasting，天气研究和预报）模式，使之与包含了大气气溶胶辐射效应和气溶胶粒子扩散的综合大气边界层数值模式嵌套起来。通过个例分析，揭示了冬季气溶胶辐射效应对边界层结构的定量影响。主要特征为夜间气溶胶的长波辐射效应使地面附近的气温增高，增温幅度为0．1～0．3K／h，使低空（25-300m）大气层冷却，降温幅度为0．08～0．15K／h，风速在150m以下减小；白天气溶胶的短波辐射效应使地面层内明显增温，1h内升温约0．5K，增温最大值在混合层顶500-600m高度。受增温影响，垂直风场和水平风场随之调整，风速在450m以下增大约0．1m／s左右，而在450m以上风速减小0．1m／s左右。展开更多
利用WRF(Weather Research and Forecasting)模式耦合单层城市冠层模式,研究了南京地区一次高温热浪过程(2013年8月5—10日)中气溶胶的辐射效应、城市扩张对边界层的影响和它们间的相互作用。结果显示,由于气溶胶的直接辐射效应,在白天...利用WRF(Weather Research and Forecasting)模式耦合单层城市冠层模式,研究了南京地区一次高温热浪过程(2013年8月5—10日)中气溶胶的辐射效应、城市扩张对边界层的影响和它们间的相互作用。结果显示,由于气溶胶的直接辐射效应,在白天,南京近地面温度平均降低约0.11℃,净辐射平均降低约12 W/m^2;城市扩张使近地面温度增加约1.7℃,在本次试验过程中,城市扩张的增暖效应明显强于气溶胶冷却效应。另外,由于城市扩张后产生了较强的增暖作用,加强了周围气流的辐合运动,城市区域风速平均增加约0.8 m/s。白天潜热通量的减少与感热通量的增加导致城市边界层内温度升高,并且城市增暖引起的上升运动将气溶胶抬升至更高层,使边界层更不稳定,气溶胶与城市边界层稳定性之间可能存在正反馈。展开更多
为解析大气污染物与气象的双向反馈机制及其对气象和环境的影响,建立基于Mie散射理论的气溶胶—光学性质模块,研制气象-化学双向耦合器,以嵌套网格空气质量预报模式NAQPMS(Nested Air Quality Prediction Modeling System)为基础,建立了...为解析大气污染物与气象的双向反馈机制及其对气象和环境的影响,建立基于Mie散射理论的气溶胶—光学性质模块,研制气象-化学双向耦合器,以嵌套网格空气质量预报模式NAQPMS(Nested Air Quality Prediction Modeling System)为基础,建立了NAQPMS和中尺度气象模式WRF(Weather Research and Forecasting Model)的双向耦合模式(WRF-NAQPMS)。利用此模式数值模拟了2013年9月27日至10月1日的北京-天津-河北地区一次秋季严重灰霾过程。结果表明,考虑气溶胶辐射反馈的双向耦合模式模拟的气象要素和细颗粒物(PM2.5)浓度与观测结果更为一致。灰霾期间,气溶胶直接辐射效应显著改变了边界层气象要素,北京-天津-河北地区地面接收的太阳短波辐射减少25%,2 m高度的温度平均下降1°C,湍流动能下降20%,10 m高度的风速降低超过0.2 m/s,边界层高度下降25%,使得边界层大气更加静稳,进而造成了重污染地区污染进一步加剧,如石家庄近地面细颗粒物浓度增加可达30%。分析表明灰霾与边界层气象要素之间存在一种正反馈机制,采用该机制的双向耦合模式有利于准确模拟和预报灰霾污染过程。展开更多
The authors quantify the radiative effect of black carbon （BC） on simulated aerosol concentrations during the heavily polluted haze event of 11-14 January 2013 in northern China using the chemistry version of the We...The authors quantify the radiative effect of black carbon （BC） on simulated aerosol concentrations during the heavily polluted haze event of 11-14 January 2013 in northern China using the chemistry version of the Weather Research and Forecasting Model （WRF-Chem）. As a result of the stable synoptic conditions, simulated concentrations of BC and PM2.5 averaged over the study period were about 8-16 μg m-3 and 80-100 μg m-3, respectively, in the control simulation （CTRL）. When BC emissions were doubled （2BC）, tripled （3BC）, and quad- rupled （4BC） relative to the CTRL run, the simulated concentrations of aerosols in different regions showed distinct changes. The radiative effect of BC was simulated to increase concentrations of aerosols over Tianjin （Doml） and southern Henan （Dora3）, but to decrease in southern Hebei （Dora2）. Relative to the CTRL simulation, concen- trations of PM2s over Doml, Dom2, and Dom3 were simulated in 4BC to change by ＋18.6 1μg m-3 （＋32.3%）, -5.7 μg m 3 （-7.3%）, and ＋7.2 μg m3 （＋12.6%）, respec- tively. The BC-induced increases in aerosol concentra- tions corresponded mainly to the reductions in planetary boundary layer height over Doml and Dom3. The reduc- tions of aerosol concentrations in Dora2 were mainly caused by the weakened wind convergence at 850 hPa and reduced concentrations of sulfate and nitrate associ- ated with the reduced surface-layer ozone levels and rela- tive humidity.展开更多
The authors examine the equilibrium climatic response to the direct radiative effect （DRE） of mineral dust and sea salt aerosols in a doubled-CO2 climate with two-way coupling of aerosol-climate interactions.In resp...The authors examine the equilibrium climatic response to the direct radiative effect （DRE） of mineral dust and sea salt aerosols in a doubled-CO2 climate with two-way coupling of aerosol-climate interactions.In response to the drier and windier conditions,dust emissions increase by 26％ in the Sahara Desert and by 18％ on the global scale relative to present day.Sea salt emissions increase in high latitudes （＞60°） but decrease in middle latitudes （30°-60°） of both hemispheres due to the poleward shift of westerlies,leading to a 3％ decrease in global emissions.The burdens of dust and sea salt increase by 31％ and 7％ respectively,because reductions in rainfall over the tropical oceans increase the lifetime of particles in the warmer climate.The higher aerosol loading in the doubled-CO2 climate reinforces aerosol DRE by -0.2 W m-2,leading to an additional cooling of 0.1℃ at the surface compared with the climatic effects of aerosols in present day.The additional cooling from changes in natural aerosols compensates for up to 15％ of the regional warming induced by doubled CO2.展开更多
文摘作者着眼于城市气溶胶辐射效应与大气边界层的相互作用问题，针对地形复杂的兰州市及周边地区，开发应用了WRF（Weather Research and Forecasting，天气研究和预报）模式，使之与包含了大气气溶胶辐射效应和气溶胶粒子扩散的综合大气边界层数值模式嵌套起来。通过个例分析，揭示了冬季气溶胶辐射效应对边界层结构的定量影响。主要特征为夜间气溶胶的长波辐射效应使地面附近的气温增高，增温幅度为0．1～0．3K／h，使低空（25-300m）大气层冷却，降温幅度为0．08～0．15K／h，风速在150m以下减小；白天气溶胶的短波辐射效应使地面层内明显增温，1h内升温约0．5K，增温最大值在混合层顶500-600m高度。受增温影响，垂直风场和水平风场随之调整，风速在450m以下增大约0．1m／s左右，而在450m以上风速减小0．1m／s左右。
文摘利用WRF(Weather Research and Forecasting)模式耦合单层城市冠层模式,研究了南京地区一次高温热浪过程(2013年8月5—10日)中气溶胶的辐射效应、城市扩张对边界层的影响和它们间的相互作用。结果显示,由于气溶胶的直接辐射效应,在白天,南京近地面温度平均降低约0.11℃,净辐射平均降低约12 W/m^2;城市扩张使近地面温度增加约1.7℃,在本次试验过程中,城市扩张的增暖效应明显强于气溶胶冷却效应。另外,由于城市扩张后产生了较强的增暖作用,加强了周围气流的辐合运动,城市区域风速平均增加约0.8 m/s。白天潜热通量的减少与感热通量的增加导致城市边界层内温度升高,并且城市增暖引起的上升运动将气溶胶抬升至更高层,使边界层更不稳定,气溶胶与城市边界层稳定性之间可能存在正反馈。
文摘为解析大气污染物与气象的双向反馈机制及其对气象和环境的影响,建立基于Mie散射理论的气溶胶—光学性质模块,研制气象-化学双向耦合器,以嵌套网格空气质量预报模式NAQPMS(Nested Air Quality Prediction Modeling System)为基础,建立了NAQPMS和中尺度气象模式WRF(Weather Research and Forecasting Model)的双向耦合模式(WRF-NAQPMS)。利用此模式数值模拟了2013年9月27日至10月1日的北京-天津-河北地区一次秋季严重灰霾过程。结果表明,考虑气溶胶辐射反馈的双向耦合模式模拟的气象要素和细颗粒物(PM2.5)浓度与观测结果更为一致。灰霾期间,气溶胶直接辐射效应显著改变了边界层气象要素,北京-天津-河北地区地面接收的太阳短波辐射减少25%,2 m高度的温度平均下降1°C,湍流动能下降20%,10 m高度的风速降低超过0.2 m/s,边界层高度下降25%,使得边界层大气更加静稳,进而造成了重污染地区污染进一步加剧,如石家庄近地面细颗粒物浓度增加可达30%。分析表明灰霾与边界层气象要素之间存在一种正反馈机制,采用该机制的双向耦合模式有利于准确模拟和预报灰霾污染过程。
基金supported by the National Basic Research Program of China (973 Program, Grant No. 2014CB441202)the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA05100503)
文摘The authors quantify the radiative effect of black carbon （BC） on simulated aerosol concentrations during the heavily polluted haze event of 11-14 January 2013 in northern China using the chemistry version of the Weather Research and Forecasting Model （WRF-Chem）. As a result of the stable synoptic conditions, simulated concentrations of BC and PM2.5 averaged over the study period were about 8-16 μg m-3 and 80-100 μg m-3, respectively, in the control simulation （CTRL）. When BC emissions were doubled （2BC）, tripled （3BC）, and quad- rupled （4BC） relative to the CTRL run, the simulated concentrations of aerosols in different regions showed distinct changes. The radiative effect of BC was simulated to increase concentrations of aerosols over Tianjin （Doml） and southern Henan （Dora3）, but to decrease in southern Hebei （Dora2）. Relative to the CTRL simulation, concen- trations of PM2s over Doml, Dom2, and Dom3 were simulated in 4BC to change by ＋18.6 1μg m-3 （＋32.3%）, -5.7 μg m 3 （-7.3%）, and ＋7.2 μg m3 （＋12.6%）, respec- tively. The BC-induced increases in aerosol concentra- tions corresponded mainly to the reductions in planetary boundary layer height over Doml and Dom3. The reduc- tions of aerosol concentrations in Dora2 were mainly caused by the weakened wind convergence at 850 hPa and reduced concentrations of sulfate and nitrate associ- ated with the reduced surface-layer ozone levels and rela- tive humidity.
基金supported by the National Basic Research Program of China(973 program,Grant 2010CB951901)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant XDA05100503)
文摘The authors examine the equilibrium climatic response to the direct radiative effect （DRE） of mineral dust and sea salt aerosols in a doubled-CO2 climate with two-way coupling of aerosol-climate interactions.In response to the drier and windier conditions,dust emissions increase by 26％ in the Sahara Desert and by 18％ on the global scale relative to present day.Sea salt emissions increase in high latitudes （＞60°） but decrease in middle latitudes （30°-60°） of both hemispheres due to the poleward shift of westerlies,leading to a 3％ decrease in global emissions.The burdens of dust and sea salt increase by 31％ and 7％ respectively,because reductions in rainfall over the tropical oceans increase the lifetime of particles in the warmer climate.The higher aerosol loading in the doubled-CO2 climate reinforces aerosol DRE by -0.2 W m-2,leading to an additional cooling of 0.1℃ at the surface compared with the climatic effects of aerosols in present day.The additional cooling from changes in natural aerosols compensates for up to 15％ of the regional warming induced by doubled CO2.
