利用气象与化学模块在线耦合的模式WRF-Chem V3.5(Weather Research and Forecasting Model coupled to Chemistry Version 3.5)对1323号台风Fitow进行了模拟,设计无人为排放源、含人为排放源和人为排放源增加的三组模拟试验,对比分析...利用气象与化学模块在线耦合的模式WRF-Chem V3.5(Weather Research and Forecasting Model coupled to Chemistry Version 3.5)对1323号台风Fitow进行了模拟,设计无人为排放源、含人为排放源和人为排放源增加的三组模拟试验,对比分析了人为气溶胶对台风的影响。结果表明:人为气溶胶对台风移动路径影响较小。人为气溶胶增加,台风强度减弱,台风主体总累积降水量减少,靠近陆地阶段台风主体降水率减少。气溶胶的增多可提供更多的凝结核,台风外围云水增加,更多的云水可上升至冻结层以上形成过冷水,促进冰相粒子的形成,释放的潜热增加,使外围对流增强,降水增加。台风外围对流的发展,使低层入流的暖湿空气更多的在外围上升,向台风中心的入流减弱,眼墙的发展减弱,降水减少,台风强度减弱。台风外围的对流发展弱于眼墙的对流,降水仍以眼墙区为主,使累积降水量和降水率整体上表现为减少。展开更多
采用新一代on-line空气质量模式Weather Research Forecasting Model with Chemistry(WRF-chem)模拟探究中国气溶胶污染对4个季节净辐射量、温度、大气边界层高度和降水量等气象要素的影响.模型验证结果表明:WRF-chem可反映出我国四季...采用新一代on-line空气质量模式Weather Research Forecasting Model with Chemistry(WRF-chem)模拟探究中国气溶胶污染对4个季节净辐射量、温度、大气边界层高度和降水量等气象要素的影响.模型验证结果表明:WRF-chem可反映出我国四季气象条件和PM_(10)的浓度分布特点.由于气溶胶气候效应作用,受气溶胶污染影响,2006年1、4、7、10月月均净辐射量下降约10 W/m^2,月均温度下降0.15℃,月均PBL高度下降15 m.月均净辐射量、温度、PBL高度显著下降的区域集中在京津冀、长江三角洲、珠江三角洲、山东半岛、武汉及周边、长株潭和成都-重庆等气溶胶浓度较高的地区,秋季下降量最高,春季最低.与其他气象要素不同,气溶胶污染使得降水量有所增加.通过与美洲、欧洲等地区的相关研究对比发现,由于我国气溶胶污染较为严重,气溶胶对气象要素的影响更加显著.展开更多
A WRF-Chem model including a comprehensive gas-phase nitrogen chemistry module was used to simulate a severe dust event appearing in the eastern China on 19-25 March, 2002. The modeling result well reproduced PM10 con...A WRF-Chem model including a comprehensive gas-phase nitrogen chemistry module was used to simulate a severe dust event appearing in the eastern China on 19-25 March, 2002. The modeling result well reproduced PM10 concentrations in various distances from the dust sources and the transport pathway of the dust strom. The results showed that both the concentrations and the dry deposition fluxes of PM10 increased over the China seas during the dust event following the passage of a cold front system. The maximum fluxes of PM10 in the Yellow Sea and the East China Sea during the dust event were 5.5 and 8.4 times of those before the event, respectively. However, the temporal variations of the dry deposition fluxes of particulate inorganic nitrogen differed over the Yellow Sea from those over the East China Sea. Nitrate and ammonium in the whole northern China rapidly decreased because of the intrusion of dust-loaded air on 19 March. The dust plume arrived in the Yellow Sea on 20 March, decreasing the particulate inorganic nitrogen in mass concentration accordingly. The minimum dry deposition fluxes of nitrate and ammonium in the Yellow Sea were about 3/5 and 1/6 of those before the dust arrival, respectively. In contrast, when the dust plume crossed over the Yangtze Delta area, it became abundant in nitrate and ammonium and increased the concentrations and dry deposition fluxes of particulate inorganic nitrogen over the East China Sea, where the maximum dry deposition fluxes of nitrate and ammonium increased approximately by 4.1 and 2.6 times of those prior to the dust arrival.展开更多
In this study, the dependence of dust budgets on dust emission schemes is investigated through the simulation of dust storm events, which occurred during 14–25 March 2002, over East Asia, by the Weather Research and ...In this study, the dependence of dust budgets on dust emission schemes is investigated through the simulation of dust storm events, which occurred during 14–25 March 2002, over East Asia, by the Weather Research and Forecasting with Chemistry(WRF/Chem) model coupled with six dust emission schemes. Generally, this model can reasonably reproduce the spatial distribution of surface dust concentration; however, the simulated total dust budget differs significantly with different emission schemes. Moreover, uncertainties in the simulated dust budget vary among regions. It is suggested that the dust emission scheme affects the regional dust budget directly through its impact on the total emitted dust amount; however, the inflow and outflow of dust aerosols simulated by different schemes within a region also depend on the geographical location of the dust emission region. Furthermore, the size distribution of dust particles for a specific dust emission scheme has proven to be important for dust budget calculation due to the dependence of dust deposition amount on dust size distribution.展开更多
Dust storm is one of the important natural disasters, which can have significant impact on terrestrial ecosystem, global climate, air quality and human health. In Mar. 19-23, 2010, a serious dust storm occurred over E...Dust storm is one of the important natural disasters, which can have significant impact on terrestrial ecosystem, global climate, air quality and human health. In Mar. 19-23, 2010, a serious dust storm occurred over East Asia. It started from Mongolia, initially extending to the east, turning to the South of China, then back to the Northeast Asia. About 20% of the areas in China suffered from this severe dust event and the air was heavily polluted with massive airborne particulates. The Air Pollution Index (API) in many cities exceeded 500 when dust storm passed by, while the maximum surface PM10 concentration reached 1900 µg/m3 in east area. The coarse particles were dominated in PM10, with fine particles named as PM2.5 only accounting for 5% - 20% at cities along the dust moving track in South and East China. MODIS and CALIPSO satellite data were used to investigate the horizontal and vertical patterns of optical parameters of dust aerosol. The average AOD reached 2 - 2.5 on dust days in most southeast regions. The dust can be transported up to 5 Km with maximum aerosol extinction coefficient of 0.35 - 0.4 at 1 - 3 Km in vertical. Synoptic weather was analyzed to understand the meteorological conditions and the backward trajectories were calculated to investigate the movements of air mass. The WRF-Chem model (Version 3.2) was applied to simulate the transport and deposition of the dust aerosols. The performance of Shaw (2008) and Chin (2002) parameterization schemes for dust emissions in WRF-Chem were evaluated. Modeling results were compared with the CUACE-Dust and RegCCMS. Investigations show that WRF-Chem has capability on simulations on dust emission, long range transport and deposition. Shaw (2008) scheme gives more reasonable spatial distribution of dust aerosols, while Chin (2002) scheme presents more better results in terms of PM10 surface concentration simulation. It is suggested that two schemes can be used at the same time in terms of simulation of dust pattern and concentration.展开更多
文摘利用气象与化学模块在线耦合的模式WRF-Chem V3.5(Weather Research and Forecasting Model coupled to Chemistry Version 3.5)对1323号台风Fitow进行了模拟,设计无人为排放源、含人为排放源和人为排放源增加的三组模拟试验,对比分析了人为气溶胶对台风的影响。结果表明:人为气溶胶对台风移动路径影响较小。人为气溶胶增加,台风强度减弱,台风主体总累积降水量减少,靠近陆地阶段台风主体降水率减少。气溶胶的增多可提供更多的凝结核,台风外围云水增加,更多的云水可上升至冻结层以上形成过冷水,促进冰相粒子的形成,释放的潜热增加,使外围对流增强,降水增加。台风外围对流的发展,使低层入流的暖湿空气更多的在外围上升,向台风中心的入流减弱,眼墙的发展减弱,降水减少,台风强度减弱。台风外围的对流发展弱于眼墙的对流,降水仍以眼墙区为主,使累积降水量和降水率整体上表现为减少。
文摘采用新一代on-line空气质量模式Weather Research Forecasting Model with Chemistry(WRF-chem)模拟探究中国气溶胶污染对4个季节净辐射量、温度、大气边界层高度和降水量等气象要素的影响.模型验证结果表明:WRF-chem可反映出我国四季气象条件和PM_(10)的浓度分布特点.由于气溶胶气候效应作用,受气溶胶污染影响,2006年1、4、7、10月月均净辐射量下降约10 W/m^2,月均温度下降0.15℃,月均PBL高度下降15 m.月均净辐射量、温度、PBL高度显著下降的区域集中在京津冀、长江三角洲、珠江三角洲、山东半岛、武汉及周边、长株潭和成都-重庆等气溶胶浓度较高的地区,秋季下降量最高,春季最低.与其他气象要素不同,气溶胶污染使得降水量有所增加.通过与美洲、欧洲等地区的相关研究对比发现,由于我国气溶胶污染较为严重,气溶胶对气象要素的影响更加显著.
基金supported by the National Science Foundation of China (No.40976063)International Cooperative Projects of MOST (No.2010DFA91350)
文摘A WRF-Chem model including a comprehensive gas-phase nitrogen chemistry module was used to simulate a severe dust event appearing in the eastern China on 19-25 March, 2002. The modeling result well reproduced PM10 concentrations in various distances from the dust sources and the transport pathway of the dust strom. The results showed that both the concentrations and the dry deposition fluxes of PM10 increased over the China seas during the dust event following the passage of a cold front system. The maximum fluxes of PM10 in the Yellow Sea and the East China Sea during the dust event were 5.5 and 8.4 times of those before the event, respectively. However, the temporal variations of the dry deposition fluxes of particulate inorganic nitrogen differed over the Yellow Sea from those over the East China Sea. Nitrate and ammonium in the whole northern China rapidly decreased because of the intrusion of dust-loaded air on 19 March. The dust plume arrived in the Yellow Sea on 20 March, decreasing the particulate inorganic nitrogen in mass concentration accordingly. The minimum dry deposition fluxes of nitrate and ammonium in the Yellow Sea were about 3/5 and 1/6 of those before the dust arrival, respectively. In contrast, when the dust plume crossed over the Yangtze Delta area, it became abundant in nitrate and ammonium and increased the concentrations and dry deposition fluxes of particulate inorganic nitrogen over the East China Sea, where the maximum dry deposition fluxes of nitrate and ammonium increased approximately by 4.1 and 2.6 times of those prior to the dust arrival.
基金jointly supported by the Strategic Priority Research Program of Chinese Academy of Sciences(XDA05110200)the International Science and Technology Cooperation Program of China(2011DFG23450)
文摘In this study, the dependence of dust budgets on dust emission schemes is investigated through the simulation of dust storm events, which occurred during 14–25 March 2002, over East Asia, by the Weather Research and Forecasting with Chemistry(WRF/Chem) model coupled with six dust emission schemes. Generally, this model can reasonably reproduce the spatial distribution of surface dust concentration; however, the simulated total dust budget differs significantly with different emission schemes. Moreover, uncertainties in the simulated dust budget vary among regions. It is suggested that the dust emission scheme affects the regional dust budget directly through its impact on the total emitted dust amount; however, the inflow and outflow of dust aerosols simulated by different schemes within a region also depend on the geographical location of the dust emission region. Furthermore, the size distribution of dust particles for a specific dust emission scheme has proven to be important for dust budget calculation due to the dependence of dust deposition amount on dust size distribution.
文摘Dust storm is one of the important natural disasters, which can have significant impact on terrestrial ecosystem, global climate, air quality and human health. In Mar. 19-23, 2010, a serious dust storm occurred over East Asia. It started from Mongolia, initially extending to the east, turning to the South of China, then back to the Northeast Asia. About 20% of the areas in China suffered from this severe dust event and the air was heavily polluted with massive airborne particulates. The Air Pollution Index (API) in many cities exceeded 500 when dust storm passed by, while the maximum surface PM10 concentration reached 1900 µg/m3 in east area. The coarse particles were dominated in PM10, with fine particles named as PM2.5 only accounting for 5% - 20% at cities along the dust moving track in South and East China. MODIS and CALIPSO satellite data were used to investigate the horizontal and vertical patterns of optical parameters of dust aerosol. The average AOD reached 2 - 2.5 on dust days in most southeast regions. The dust can be transported up to 5 Km with maximum aerosol extinction coefficient of 0.35 - 0.4 at 1 - 3 Km in vertical. Synoptic weather was analyzed to understand the meteorological conditions and the backward trajectories were calculated to investigate the movements of air mass. The WRF-Chem model (Version 3.2) was applied to simulate the transport and deposition of the dust aerosols. The performance of Shaw (2008) and Chin (2002) parameterization schemes for dust emissions in WRF-Chem were evaluated. Modeling results were compared with the CUACE-Dust and RegCCMS. Investigations show that WRF-Chem has capability on simulations on dust emission, long range transport and deposition. Shaw (2008) scheme gives more reasonable spatial distribution of dust aerosols, while Chin (2002) scheme presents more better results in terms of PM10 surface concentration simulation. It is suggested that two schemes can be used at the same time in terms of simulation of dust pattern and concentration.
