首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 671 毫秒
1.
The operational Asian Dust Aerosol Model (ADAM)1 in Korea Meteorological Administration has been modified to the ADAM2 model to be used as an operational forecasting model all year round not only in Korea but also in the whole Asian domain (70-160°E and 5-60°N) using the routinely available World Meteorological Organization (WMO) surface reporting data and the Spot/vegetation Normalized Difference Vegetation Index (NDVI) data for the period of 9 years from 1998 to 2006. The 3-hourly reporting WMO surface data in the Asian domain have been used to re-delineate the Asian dust source region and to determine the temporal variation of the threshold wind speed for the dust rise. The dust emission reduction factor due to vegetation in different surface soil-type regions (Gobi, sand, loess, and mixed soil) has been determined with the use of NDVI data. It is found that the threshold wind speed for the dust rise varies significantly with time (minimum in summer and maximum in winter) and surface soil types with the highest threshold wind speed of 8.0 m?s?1 in the Gobi region and the lowest value of 6.0 m?s?1 in the loess region. The statistical analysis of the spot/vegetation NDVI data enables to determine the emission reduction factor due to vegetation with the free NDVI value that is the NDVI value without the effect of vegetation and the upper limit value of NDVI for the dust rise in different soil-type regions. The modified ADAM2 model has been implemented to simulate two Asian dust events observed in Korea for the periods from 31 March to 2 April 2007 (a spring dust event) and from 29 to 31 December 2007 (a winter dust event) when the observed PM10 concentration at some monitoring sites in the source region exceeds 9,000 μg m?3. It is found that ADAM2 model successfully simulates the observed high dust concentrations of more than 8,000 μg m?3 in the dust source region and 600 μg m?3 in the downstream region of Korea. This suggests that ADAM2 has a great potential for the use of an operational Asian dust forecast model in the Asian domain.  相似文献   

2.
The Asian dust Aerosol Model 2 (ADAM2) with the MM5 meteorological model has been employed to study long-range transport process of Asian dust and to estimate dust emission, deposition (wet and dry) and concentration over the Asian dust source region and the downwind regions for dust events observed in Korea during the period of 20–29 December 2009, which is one of the dust events chosen by the 3rd Meeting of Working Group for Joint Research on Dust Sand Storm among Mongolia, China, Japan and Korea to study intensively for the development of an early warning system in Asia. It is found that the model simulates quite well the starting and ending times of dust events and the peak dust concentrations with their occurrence times both in the source region and downwind regions. The dust emission in the dust source region is found to be associated with a developing synoptic weather system accompanied with strong surface winds over the source region that usually travels east to southeastward across the source region and then turns to move northeastward toward the north western Pacific Ocean. The dust emitted in the source region is found to be split into two parts: one is transported southeastward to the East China Sea in front of the surface high pressure system and experiencing enhanced deposition due to the sinking motion induced by the southeastward traveling the surface high pressure system whereas, the other moves northeastward toward the surface low pressure system and then lifted upward to form a upper-level high dust concentration layer that results in a favorable condition for the long-range transport of dust. It is also found that the maximum ten-day total dust emission of about 23 t km?2 occurs in the domain Northwestern China (NWC). However, the maximum ten-day total dust deposition of 21 t km?2 with the maximum mean surface concentration of 555 μg m?3 and the column integrated mean concentration of 2.9 g m?2 occurs in the domain Central-northern China (CNC). The column-integrated PM10 concentration is found to increase toward northeastward especially in the domain North northeastern China (NNEC) due to the upper-level transported high PM10 concentration. The ten-day total dust deposition, mean surface PM10 and column integrated PM10 concentrations in the downwind domains are found to decrease away from the source region from 2.44 t km?2, 112 μg m?3 and 1.68 g m?2, respectively in the domain YES to 0.06 t km?2, 2.1 μg m?3 and 0.4 g m?2, respectively in the domain Northwestern Pacific 1 (NWP1). Much of the total dust deposition is largely contributed by wet deposition in the far downwind region of the seas while that is contributed by dry deposition in the source region.  相似文献   

3.
The Asian dust forecasting model, Mongolian Asian Dust Aerosol Model (MGLADAM), has been operated by the National Agency for Meteorology and Environmental Monitoring of Mongolia since 2010, for the forecast of Asian dust storms. In order to evaluate the performance of the dust prediction model, we simulated Asian dust events for the period of spring 2011. Simulated features were compared with observations from two sites in the dust source region of the Gobi desert in Mongolia, and in the downstream region in Korea. It was found that the simulated wind speed and friction velocity showed a good correlation with observations at the Erdene site (one of the sites in the Gobi desert). The results show that the model is proficient in the simulation of dust concentrations that are within the same order of magnitude and have similar start and end times, compared with PM10 observed at two monitoring sites in the Gobi regions. Root Mean Square Error (RMSE) of the dust simulation ranges up to 200 μg m?3 because of the high concentrations in source regions, which is three times higher than that in the downstream region. However, the spatial pattern of dust concentration matches well with dust reports from synoptic observation. In the downwind regions, it was found that the model simluated all reported dust cases successfully. It was also found that the RMSE in the downwind region increased when the model integration time increased, but that in the source regions did not show consistent change. It suggests that MGLADAM has the potential to be used as an operational dust forecasting model for predicting major dust events over the dust source regions as well as predicting transported dust concentrations over the downstream region. However, it is thought that further improvement in the emission estimation is necessary, including accurate predictions in surface and boundary layer meteorology. In the downwind regions, background PM10 concentration is considerably affected by other aerosol species, suggesting that a consideration of anthropogenic pollutants will be required for accurate dust forecasting.  相似文献   

4.
An uni-modal Lagrangian Dust Model (LDM) was developed to simulate the dust concentrations and source-receptor (SR) relationships for recent Asian dust events that occurred over the Korean Peninsula. The following dust sources were used for the S-R calculation in this study: S-I) Gurbantunggut desert, S-II) Taklamakan desert, S-III) Tibetan Plateau, S-IV) Mu Us Desert, S-V) Manchuria, and S-VI) Nei Mongol and Gobi Desert. The following two 8-day dust simulation periods were selected for two case studies: (Period A) March 15–22, 2011, and (Period B) April 27–May 4, 2011. During two periods there were highly dense dust onsets observed over a wide area in Korea. Meteorological fields were generated using the WRF (Weather Research and Forecasting) meteorological model, and Lagrangian turbulent properties and dust emission were estimated using FLEXPART model and ADAM2 (Asian Dust Aerosol Model 2), respectively. The simulated dust concentrations are compared with point measurements and Eulerian model outputs. Statistical techniques were also employed to determine the accuracy and uncertainty associated with the model results. The results showed that the LDM compared favorably well with observations for some sites; however, for most sites the model overestimated the observations. Analysis of S-R relationships showed that 38–50% of dust particles originated from Nei Mongol and the Gobi Desert, and 16–25% of dust particles originated from Manchuria, accounting for most of the dust particles in Korea. Because there is no nudging or other artificial forcing included in the LDM, higher error indicators (e.g., root mean square error, absolute gross error) were found for some sites. However, the LDM was able to satisfactorily simulate the maximum timing and starting time of dust events for most sites. Compared with the Eulerian model, ADAM2, the results of LDM found pattern correlations (PCs) equal to 0.78-0.83 and indices of agreement (IOAs) greater than 0.6, suggesting that LDM is capable of estimation of dust concentrations with the quantitative information on the S-R relationships that can be easily obtained by LDM.  相似文献   

5.
The Asian Dust Aerosol Model 2 with the MM5 meteorological model has been employed to estimate the dust emission, dust concentration, and wet and dry deposition of dust in the Asian region for the month of March in 2010. It is found that the model simulates quite reasonably the dust (PM10) concentrations both in the dust source region and the downstream region of Korea. The starting and ending times of most dust events and their peak concentration occurrence times are well simulated. The monthly mean maximum surface dust concentration (PM10) is found to be 267???g?m?3 in the domain of central northern China (CNC). Monthly total maximum dust emission of more than 32?t km?2 and that of deposition of more than 25.4?t km?2 (dry deposition of 24?t km?2 and wet deposition of 1.4?t km?2) are found to occur in the domain CNC, whereas the monthly mean minimum surface dust concentration (PM10) is found to be 0.2???g?m?3 in the domain of the Tibetan Plateau, where the monthly total dust emission (4?kg?km?2) and the monthly total dust deposition (9?kg?km?2) are found to be minimum. This monthly total dust deposition of 9?kg?km?2 (dry deposition of 7?kg?km?2 and wet deposition of 2?kg?km?2) is as large as 2.25 times of that of emission (4?kg?km?2), suggesting net dust influx toward the Tibetan Plateau from the surrounding dust source regions. It is also found that the ratio of the total dust deposition to the total dust emission in the source region increases toward the downstream direction from 0.4 in the upstream source region of Taklimakan to 0.80 in the downstream source region of northeastern China. More than 90% of the total dust deposition is found to be contributed by dry deposition due to the lack of precipitation in the dust source region. The monthly mean dust concentration (PM10) is found to decrease with distance away from the dust source region. The monthly mean dust concentration of 62???g?m?3 over the Yellow Sea (YES) decreases to 4.3???g?m?3 over the Northwestern Pacific Ocean (NWP). The monthly total dust deposition in the downstream region is also found to decrease away from the source region from 2.33?t km?2 (dry deposition of 1.36?t km?2 and wet deposition of 0.97?t km?2) over the domain YES to 1.45?t km?2 (dry deposition of 0.16?t km?2 and wet deposition of 1.30?t km?2) over the domain NWP. A large amount of the total dust deposition over the seas is contributed by wet deposition (more than 90%), causing a small decreasing rate of the total dust deposition with distance from the source region. The estimated dust deposition could adversely impact the eco-environmental system significantly in the downstream regions of the Asian dust source region, especially over the seas.  相似文献   

6.
There are few dust simulation studies for East Asian dust events that took place in the wintertime, when the surface conditions of the dust source region differ from those of the springtime. The soil water turns into ice when the temperature falls below freezing, and the ice might prohibit wind erosion by increasing the binding strength between soil particles. However, the contribution of frozen soil to reducing dust outbreaks remains unclear. This study investigates the effect of frozen soil on dust emission through a case study of a severe wintertime East Asian dust event that originated on 23 and 24 December 2009 in Southern Mongolia and Inner Mongolia and reached Korea on 25 and 26 December 2009 using WRF/Chem with a new dust emission scheme. Model simulations with and without the effect of frozen soil were conducted. A temperature below 0°C and relative soil saturation exceeding 40% were used for frozen soil criteria, and the frozen soil was prohibited from emitting dust. The dust concentrations derived from the simulation without the effect of frozen soil were about three times higher than the observed PM10 concentrations, while the results from the simulation with the frozen-soil effect were quite similar to those of the observation data. The simulation of the wintertime East Asian dust event with the frozen-soil effect improved the model representation. The sensitivity tests for frozen soil indicate that the criteria of frozen soil used in this study are appropriate for this case study.  相似文献   

7.
Episode Simulation of Asian Dust Storms with an Air Quality Modeling System   总被引：1，自引：0，他引：1  
A dust deflation module was developed and coupled with the air quality modeling system RAMS-CMAQ to simultaneously treat all the major tropospheric aerosols（i.e.,organic and black carbons,sulfate,nitrate, ammonia,soil dust,and sea salt）.Then the coupled system was applied to East Asia to simulate Asian dust aerosol generation,transport and dry/wet removal processes during 14-25 March 2002 when two strong dust storms occurred consecutively.To evaluate model performance and to analyze the observed features of dust aerosols over the East Asian region,model results were compared to concentrations of suspended particulate matter of 10μm or less(PM10;1-h intervals) at four remote Japanese stations and daily air pollution index （API） values for PM10 at four large Chinese cities.The modeled values were generally in good agreement with observed data,and the model reasonably reproduced two dust storm outbreaks and generally predicted the dust onset and cessation times at each observation site.In addition,hourly averaged values of aerosol optical thickness（AOT） were calculated and compared with observations at four Aerosol Robotic Network （AERONET） stations to assess the model’s capability of estimating dust aerosol column burden.Analysis shows that modeled and observed AOT values were generally comparable and that the contribution of dust aerosols to AOT was significant only with regard to their source regions and their transport paths.  相似文献   

8.
A data assimilation (DA) system using ground PM10 observation for Asian Dust Aerosol Model version 2 (ADAM2), which is the operational dust forecasting model of Korea Meteorological Administration (KMA), has been developed with the optimal interpolation (OI) method. The observations are provided by the PM10 network operated by KMA. Three DA experiments are performed to simulate a dust event observed in Korea from 1 March to 31 May 2009 with different assimilation cycles of 24 (DA24), 12 (DA12), and 06 hours (DA06). 48-hour forecasts from the adjusted Initial Condition (IC) of dust concentration are compared with control simulation (CTL) and observation from independent stations. It is found that CTL simulates spatial patterns of dust emitted and transported associated with a developing low pressure system over the dust source regions quite well, compared with satellite measurement. However, it appears that there is considerable uncertainty in estimating the concentration of dust. With IC adjustment, the model simulates improved dust concentration, showing considerably reduced RMSE, particularly for the prediction within 12 hours of forecast. At the same time, it is shown that the time interval of DA affects the predictability of ADAM2, so that DA06 appears to have better predictability within a 12-hour simulation, reducing RMSE by 50% compared with CTL. This suggests that assimilating PM10 to the dust prediction model using OI has the potential to predict air quality in Korea when the cycle of assimilation is sufficiently short.  相似文献   

9.
The physical processes of the feedback mechanism of direct shortwave radiative forcing of the Asian dust aerosol on dust emission has been examined using simulated results with the coupled (with dust shortwave radiative forcing) and the non-coupled model (without dust shortwave radiative forcing) based on the MM5 model and the Asian Dust Aerosol Model on 19 March 2002. The results indicate that a significant dust emission reduction occurs in the high dust concentration (HDC) region of the dust source region whereas an enhanced dust emission appears in the downstream of the dust source region. It is found that Asian dust aerosols raised during the daytime by the strong surface wind cause negative shortwave radiative flux near the surface, which in turn reduces the sensible heat flux causing the cooling of the air, thereby enhancing stable stratification. The dynamic adjustment of the negative radiative flux of the dust induces a positive pressure anomaly over the HDC region and a negative pressure anomaly toward the synoptic low pressure center, resulting in a dipole shape of pressure anomaly field near the surface. The associated secondary circulation of this pressure anomaly together with the reduction of turbulent intensity due to the reduced sensible heat flux reduces the low-level wind speed thereby reducing dust emission in the upstream of the HDC region of the dust source region (Region I), while enhancing the low-level wind speed in the downstream region (Region II), which in turn enhances dust emission. This enhanced dust emission is smaller than the emission reduction in the upstream, resulting in overall dust emission reduction during the daytime.  相似文献   

10.
The Asian dust events in 2008 (May 24–June 4 in 2008) and in 2009 (March 12–25, October 13–26, and December 15–28 in 2009) were analyzed with the lidar network observations, surface observations in China, Korea, Japan, and Mongolia, and with the chemical transport model CFORS. Transport of Asian dust and mixing of dust with air pollution aerosols were studied. The event of May 24 to June 4 in 2008 was a significant event unusually late in the spring dust season. The dust event of March 12–25, 2009 was an interesting example of elevated dust layer, and transport of dust from the elevated dust layer to the ground by the boundary layer activity was observed with the lidars and surface observations in Japan. The concentration of air pollution aerosols was relatively high during the dust event, and the results suggest that vertical structure as well as transport path is important for the mixing of dust and air pollution aerosols. The dust events in October and December 2009 were examples of dust events in autumn and winter. The online mode CFORS reproduced the observation data generally well, except for the event of May 24 to June 4 in 2008. The results of the fourdimensional variational assimilation of the lidar network data reproduced the dust concentration in Korea and Japan reasonably in that event.  相似文献   

11.
This study investigated meteorological, physical, and chemical characteristics of 2 severe Hwangsa (Asian dust, maximum average of PM10 above 1000 μg m?3) observed in Seoul, the capital city of Korea, during 30～31st May, 2008 (DSS2008) and 25～26th December, 2009 (DSS2009). DSS2008 and DSS2009 had a same source region and route. However, they have different meteorological conditions. DSS2009 had a shorter travel time from the source region to Korea and shorter duration time in Korea than DSS2008 due to a strong winter Siberian anticyclone. One of DSS2008 sample was affected by not only Asian dust but also a long-range transported haze due to consecutive influx after low pressure passed while DSS2009 sample collected only dust aerosol. For both cases, the mass concentration of coarse particles (PM10-1) increased by 3～14 times compared to that during non Asian dust period, however, that of fine particles (PM1) increased only in DSS2008. For DSS2008 water-soluble ion balance between anions and cations in fine mode was close to 1:1 while cations were higher than anions in coarse mode. NH4 + and Ca2+ were found to be the main contributing factors for the neutralization. Cl? loss was observed about 60% indicating an active interaction of Na+ with pollutants. Reconstruction of chemical compositions showed relatively high concentrations of secondary pollutants (NH4NO3 and (NH4)2SO4), CaCO3, and Ca(NO3)2 compared to that during non Asian dust period. DSS2009 exhibited the typical characteristics of Asian dust having a high concentration of Ca2+ with higher equivalent concentration of cations than anions in all size bins. Cl? loss was hardly observed. The secondary pollutants were lower than that of non Asian dust cases. The result of reconstruction of ionic components indicated the CaCO3 derived from soil particle, CaSO4, and Ca (NO3)2 were dominant in DSS2009.  相似文献   

12.
This study aimed to develop the seasonal forecast models of Korean dust days over South Korea in the springtime. Forecast mode was a ternary forecast (below normal, normal, above normal) which was classified based on the mean and the standard deviation of Korean dust days for a period of 30 years (1981-2010). In this study, we used three kinds of monthly data: the Korean dust days observed in South Korea, the National Center for Environmental Prediction in National Center for Atmospheric Research (NCEP/NCAR) reanalysis data for meteorological factors over source regions of Asian dust, and the large-scale climate indices offered from the Climate Diagnostic Center and Climate Prediction Center in NOAA. Forecast guidance consisted of two components; ordinal logistic regression model to generate trinomial distributions, and conversion algorithm to generate ternary forecast by two thresholds. Forecast guidance was proposed for each month separately and its predictability was evaluated based on skill scores.  相似文献   

13.
利用PSU/NCAR的非静力中尺度气象预报模式MM5对北方地区气象场进行模拟,通过对2001年3月21日发生并影响北京地区的沙尘过程的数值实验表明,该模式能够较好地模拟和预测北方沙尘天气的时空演变特征。低值系统以及其低层辐合、高层辐散的垂直结构,可以产生很强的上升气流,形成地面起沙和沙尘上扬,而强风是沙尘输送的动力条件。利用轨迹模式对空气质点轨迹进行了模拟研究,可以较好地反映沙尘的发生源区和输送路径,与卫星监测和天气系统分析是一致的。并编写软件用于演示气象场的动态效果。  相似文献   

14.
利用常规气象观测资料以及环保监测数据,对2010年4月8日辽宁沙尘天气过程的高低空天气形势和主要气象要素进行探讨,并对沈阳地区的空气污染状况进行分析。结果表明：沙尘天气过程主要是受贝加尔湖地区东移冷空气和蒙古低压的共同影响,强大的蒙古气旋造成地面强变压导致地面风速加大,是形成沙尘天气的动力因子;沙尘天气来临前后,风速、能见度和湿度等发生急剧变化;在沙尘天气影响下,沈阳地区的PM10浓度迅速上升,而大风等有利的扩散条件,造成黑碳、气态污染物SO2和NO2浓度出现不同程度的下降。  相似文献   

15.
利用内蒙古科尔沁沙地和沈阳地区同步气象要素梯度观测和地面大气颗粒物(PM2.5和PM10)质量浓度观测资料, 分析了中国北方地区2020年5月10日一次大范围扬沙天气过程微气象学和沙尘输送特征。结果表明: 受大尺度天气系统影响, 此次沙尘天气过程中科尔沁沙地不同高度(< 20 m)风速均明显增加, 各层相对湿度和浅层地表含水量有所降低, 较强湍流动力作用配合干燥的土壤和大气环境有利于沙源地区地表大量的沙尘粒子释放到大气中。此后这些沙尘粒子随较强的西北气流集中在2—3 km以下高度向下游地区输送。受沙尘输送的影响, 沈阳地区10日小时平均PM10浓度最高达817 μg·m-3, 能见度减小至3.7 km。此外, 科尔沁沙地起沙过程中能见度与摩擦速度存在明显的反相关关系(相关系数R2=0.93), 与湍流动力学热通量相关性相对较小, 表明湍流动力作用在此次起沙过程占主导作用。  相似文献   

16.
Landscape characteristics influence meteorological factors, thus affect the occurrence and nature of dust storm events. The present study investigates the spatiotemporal characteristics of six meteorological factors(wind velocity, wind direction, air temperature, relative humidity(RH), photo synthetically active radiation(PAR), and solar radiation) over different landscape types(shifting-sand frontier, semi-fixed sandy land, fixed sandy land, and the inner region of an oasis) before and after dust storms during four typical dust storm events in an oasis-desert ecotone in Cele, Xinjiang, China. The results show that the average wind velocity decreased significantly from the shifting-sand frontier to the inner oasis, which was mainly attributable to the vegetation coverage. Before the dust storm events, there were obvious differences in air temperature and RH either in the horizontal or vertical direction over the different landscape types. However, these factors were very similar during and following the dust storm events. PAR and solar radiation were significantly reduced during the dust storm events and the subsequent sand-blowing and floating-dust conditions. This effect was much stronger than during similar weather conditions without dust storm events such as sand-blowing and overcast and/or rainy days. Additionally, the variation in the meteorological factors among the different landscapes was also affected by the prevailing wind direction during the dust storm events. However, the landscape type slightly changed the prevailing wind direction, with the greatest dispersion distribution of wind direction in the inner oasis. The findings of this study are helpful for understanding the function of landscape types in the occurrence of dust storms, as well as for providing a theoretical basis for prevention of dust storms.  相似文献   

17.
Long-term variations and trends of atmospheric aerosols in the East Asian region were analyzed by using aerosol optical depth (AOD or τ), and ångström exponent (AE or α) obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) from 2001 to 2010. The increased emission of anthropogenic fine aerosols in east China resulted in the high AOD in this region during summer. The steady increasing emission of anthropogenic fine aerosols caused an increasing trend of AOD in east China, and the large-scale transport of sandstorms and smoke plume caused by forest fires affected intense inter-annual variations of AOD in the East Asian region. While in the central part of South Korea, located in the lee side of the East Asian continent, AE tended to rise to a level higher than in east China, the ground-based mass concentrations continued to decline. A noticeable decrease of PM10 mass concentration in spring and winter in central Korea is most likely attributable to decreases in sandstorms in the source region of East Asia. However, the ratio of PM2.5 mass concentration to PM10 increases overall with a high level in summer. Aerosol types were classified into dust, smoke plume, and sulphate by using satellite data over Cheongwon in central Korea. The columnar AOD, with different aerosol types, was compared with the ground-based mass concentrations at Cheongwon, and the relatively high level of the correlations presented between PM2.5 and AOD produced in sulphate. Growth and increases of fine hygroscopic aerosols generated as gas-to-particle conversion particularly in summer contribute to increases of columnar AOD in the East Asian region.  相似文献   

18.
Landscape characteristics influence meteorological factors, thus affect the occurrence and nature of dust storm events. The present study investigates the spatiotemporal characteristics of six meteorological factors (wind velocity, wind direction, air temperature, relative humidity (RH), photo synthetically active radiation (PAR), and solar radiation) over different landscape types (shifting-sand frontier, semi-fixed sandy land, fixed sandy land, and the inner region of an oasis) before and after dust storms during four typical dust storm events in an oasis-desert ecotone in Cele, Xinjiang, China. The results show that the average wind velocity decreased significantly from the shifting-sand frontier to the inner oasis, which was mainly attributable to the vegetation coverage. Before the dust storm events, there were obvious differences in air temperature and RH either in the horizontal or vertical direction over the different landscape types. However, these factors were very similar during and following the dust storm events. PAR and solar radiation were significantly reduced during the dust storm events and the subsequent sand-blowing and floating-dust conditions. This effect was much stronger than during similar weather conditions without dust storm events such as sand-blowing and overcast and/or rainy days. Additionally, the variation in the meteorological factors among the different landscapes was also affected by the prevailing wind direction during the dust storm events. However, the landscape type slightly changed the prevailing wind direction, with the greatest dispersion distribution of wind direction in the inner oasis. The findings of this study are helpful for understanding the function of landscape types in the occurrence of dust storms, as well as for providing a theoretical basis for prevention of dust storms.  相似文献   

19.
非结构网格空气质量模式对东亚强沙尘暴的初步模拟研究   总被引：1，自引：0，他引：1  
基于中国科学院大气物理研究所自主研发的嵌套网格空气质量数值预报模式(NAQPMS)和英国帝国理工学院应用计算与建模小组(AMCG)研制的有限元流体模式(Fluidity),构建了非结构网格沙尘传输模式(Fluidity-Dust),并模拟再现了2010年3月19~22日东亚强沙尘暴整个暴发、演变的三维立体动态过程,从整体上对这次沙尘事件有了全新的直观认识和了解。通过利用FY-2D卫星沙尘反演资料及MODIS(Moderate Resolution Imaging Spectroradiometer)卫星反演的气溶胶光学厚度(AOD)资料,可对模拟结果进行整体上对比验证;同时,利用中国9个城市站点的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)地面观测资料以及日本多个站点的激光雷达资料,逐一对比分析了不同地区PM10的时空分布以及沙尘传输经过时的垂直分布情况;并与NAQPMS模式的沙尘模拟结果进行了模式间的对比分析。对比结果均表明:该模式具有较好的模拟能力,能很好地模拟再现整个沙尘暴过程,为今后进一步运用自适应变网格技术以实现对沙尘暴的高精度追踪模拟奠定了基础。不同模式比较是量化模拟不确定性的重要方法。以往沙尘输送模式比较研究表明:起沙量模拟的不确定性是沙尘暴数值模拟的最大不确定来源。本文通过两个具有相同起沙方案的模式对同一沙尘事件的模拟,发现不同的平流方案以及不同的沉降计算也会对沙尘过程模拟产生重要影响。  相似文献   

20.
以实况资料作初始场,利用改进的MM4中尺度模式对西北地区2001年4月8~9日强沙尘暴天气过程的位势涡度、涡度、垂直速度、螺旋度等热、动力物理量的水平和垂直分布特征进行了分析,发现各物理量场在沙尘暴发展的不同时期有着很好的配置,物理量量值及其分布特征的变化与沙尘暴天气的形成、发展、消弱的不同时期有着很好的对应。通过改变秦岭及河西走廊地形进行数值模拟试验,发现秦岭地形对此次沙尘暴天气系统影响很弱,而河西走廊地形对沙尘暴天气系统影响较大,河西走廊狭窄的地形为沙尘暴形成提供了有利的地理环境。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号