共查询到19条相似文献，搜索用时 250 毫秒
1.
1998年 11月～ 1999年 10月间在中国科学院红壤站 (江西鹰潭 )农田小气候站进行了大气二氧化硫 (SO2 )、硫酸盐粒子 (SO2 -4)浓度采样和雨水样本收集 ,利用阻力模式和全年逐时气象资料计算 SO2 和 SO2 -4的干沉降速度 ,估算干沉降通量 ,利用降水资料和雨水中硫酸根离子浓度估计大气硫的湿沉降 ,从而定量研究大气硫沉降输入农田生态系统的通量 ,结果表明 :农田下垫面上 SO2 和 SO2 -4干沉降速度的年平均值分别是 0 .373± 0 .170 cm· s-1(月均值 0 .16 1～ 0 .5 45 cm·s-1)、0 .198± 0 .12 3cm· s-1(月均值 0 .15 2～ 0 .2 6 9cm· s-1)。农田下垫面硫年总沉降量为 10 .3g· m-2 ,其中干沉降占总沉降的 83.3%。硫的干沉降又以 SO2 的干沉降为主 ,占年干沉降总量的 92 .2 %。大气硫沉降输入占农田生态系统输入总量的 90 %以上 ,是农田生态系统获取硫素的一个重要途径 相似文献
2.
本文使用中国科学院常熟和鹰潭生态实验站和气象站的观测资料，应用区域酸沉降模式系统（RegADMS）和大叶阻力相似模型来研究华东地区不同下垫面条件上的大气硫沉降问题，定量估计了农田下垫面上大气硫化物的沉降通量。SO2和硫酸盐的干沉降速率使用大叶阻力相似模型来估计，使用与降水量有关的参数化方案来确定湿沉降系数。结果表明，常熟地区农田下垫面的大气硫沉降通量为19．0gm^-2 a^-1，其中干沉降占42％；而位于江西红壤地区的鹰潭站的大气硫沉降通量为10．4gm^-2a^-1，其中干沉降占83％。比较发现，两地硫干沉降通量绝对值相差不大，但其在总沉降通量中所占的份额有较大差异；常熟站的硫湿沉降通量比鹰潭站要大9．23gm^-2a^-1，该差异是由两地污染状况和气象条件的不同造成。华东地区的年硫沉降总量为1．88Mt（1Mt=10^6t），其中72．8％沉降在农田下垫面上。硫沉降中43％是干沉降，57％是湿沉降。 相似文献
3.
北京奥运会前后静稳天气条件下SO2和NO2干沉降模拟 总被引：1，自引：0，他引：1
利用中国科学院大气物理研究所北京325m气象塔气象要素和污染物浓度观测资料,采用气体干沉降阻力模型,对奥运会前后北京行政区内SO2和NO2的干沉降影响因子、干沉降速率、干沉降通量进行数值模拟。结果表明:1)随着大气稳定度、太阳辐射强度和下垫面类型的改变,北京SO2和NO2的干沉降速率有明显变化,表面阻力是影响气体干沉降速率变化的主要因子。2)SO2和NO2在白天的干沉降速率及通量普遍大于夜晚。3)静稳天气条件下,奥运会前北京地区一天可清除24tSO2和55.2tNO2,奥运会期间一天可清除10.8tSO2和50.4tNO2,这说明北京及周边地区的减排措施对改善奥运会期间的空气质量效果显著。 相似文献
4.
中国二氧化硫排放控制的效果评估 总被引：16，自引：0，他引：16
综合中国大陆二氧化硫排放源详细资料及国家所制定的酸雨控制区和二氧化硫控制区污染源控制排放目标,推算了1995年、2000年和2005年1.×1.网格的二氧化硫排放量;应用三维欧拉型污染物输送模式模拟计算了1995年硫沉降量和地面二氧化硫浓度的分布,以及依照控制目标实施后2000年和2005年控制区硫沉降和二氧化硫浓度的变化;根据中国硫沉降临界负荷的分布,计算了不同时期超临界负荷区和超临界负荷量.结果表明,2000年和2005年在二氧化硫排放量与1995年相比分别减少21.4%和28.4%的情况下,在我国大陆的硫沉降量分别下降了17%和24.7%;1995年中国超临界负荷区面积已达国土面积的32.7%,硫沉降超临界负荷总量占该年硫沉降总量的45.4%,危害相当严重;以目前的控制方案和控制目标,全国硫沉降超临界负荷总量比1995年减少12%～35.3%,超临界负荷区域面积减少0.3%～6.9%,超临界负荷区域面积减少非常有限. 相似文献
5.
南京郊区大气氮化物浓度和氮沉降通量的研究 总被引：12，自引：0，他引：12
为研究南京郊区的大气氮化物污染状况,进而估算其大气氮沉降通量,2005年6月-2006年5月在南京大学浦口校区气象园进行了大气、气溶胶和雨水样本的收集,同步进行近地面气象观测.在实验室分析大气氮化物NOx、NH3和有机氮浓度、总悬浮颗粒物(TSP)中硝酸盐、亚硝酸盐、铵盐和有机氮的质量浓度、雨水中NO-3、NO-2、NH+4离子和有机氮的质量浓度,利用气象资料和大叶阻力相似模型计算大气氮化物的干沉降速度,进而定量估算大气氮沉降通量.研究结果表明:南京郊区大气中有机氮浓度水平较高,无机氮(氨态氮和硝态氮)浓度水平较低.大气氮沉降量较大,且湿沉降和有机沉降贡献率占主导地位,这取决于本地区的下垫面和污染状况,同时也与气象条件有密切关系. 相似文献
6.
福建省硫沉降量变化的分析与比较 总被引：4，自引：0，他引：4
应用中国科学院大气物理研究所建立的三维欧拉污染物输送模式模拟了1995、2000、2002年福建省本省排放源造成的和邻近省份排放源向其输送的硫沉降量,结果表明,福建省接收的硫沉降量有一半以上是由周围省份的远距离输送造成的。进而分析了每年4个季节硫沉降的变化特点,并结合福建省气象条件给出理论解释。最后,把这3年福建省SO2及SO42-年沉降量和各季节沉降量分别作了比较,结果显示,造成福建省SO2沉降的主要来源是本省的排放源,而SO42-沉降中外来源占很大比例,超过了50%。 相似文献
7.
利用CMAQ-Hg(Community Multi-scale Air Quality-Mercury)模式模拟了我国燃煤排放的大气汞在我国区域的沉降分布状况,其中气象模式为MM5.模式中包括了三种价态汞(气态元素汞(GEM)、气态活性汞(RGM)和颗粒汞(PHg))的气相、液相、非均相化学反应过程以及输送、干湿沉降等物理过程.中国燃煤排放的大气汞中RGM所占比例较高,约为58.4%～66.8%,这导致我国汞沉降量较大.模拟结果表明,在我国的西南地区、华东地区以及京津塘地区燃煤汞的沉降较高,在这些区域的沉降通量高达2～6μg m-2mon-1.燃煤大气汞排放形态对汞的沉降有重要影响,减少燃煤汞排放中RGM的比例能够显著降低我国区域汞的沉降通量. 相似文献
8.
利用CMAQ(Community Multi-scale Air Quality)模式模拟了中国西南和华南地区的硫沉降。模式中详细考虑了气象过程、气相与液相化学过程、非均相化学过程、气溶胶过程和干湿沉降过程对SO2输送、转化和沉降过程的影响。通过与IMPACTS小流域的观测资料的比较,显示了该模式系统能够较好地模拟SO2在大气中的转化以及干湿沉降过程。在此基础之上,分析了不同季节该区域的硫沉降和向外输送的情况,并且模拟了该区域2002年全年的硫沉降分布状况,这为该区域有效地污染治理奠定了基础。 相似文献
9.
典型大气污染物在不同下垫面上干沉积速率的动态变化及空间分布 总被引：17，自引：0，他引：17
利用中国科学院红壤生态试验站微气象站实测的梯度资料和大叶阻力相似沉积模型,计算了农田和森林下垫面大气污染物的干沉积速率,并将此模型嵌套到区域酸性沉降模式系统(RegADMS)中,模拟获得中国地区11种大气污染物干沉积速率的空间分布.结果表明:大气污染物干沉降速率(Vd)有明显的时间变化,物种的干沉积速率一般白天大于晚上,冬春季大于夏秋季节.大气污染物Vd也有明显的空间变化,中国地区SO2、HNO3、NO、NO2、NH3、O3、H2O2、TSP、PM10、SO2-4和NO-3年平均Vd分别为0.35士0.004、1.77±0.01、6.5 ×10-5±2.0×10-7、0.07±0.0007、0.28土0.003、0.20±0.001、0.54±0.002、7.2±0.0005、0.44±0.0005、0.25±0.0005、0.27±0.0008cm s-1.各种下垫面上粒子Vd差别不大,气体污染物在各下垫面上的Vd有所不同,表现为HNO3、NO2、O3的Vd在森林和草原上较大,而SO2、NH3、H2O2的Vd在水面上较大,NO的Vd都很小,且在各种下垫面上差别不大. 相似文献
10.
《大气和海洋科学快报》2020,(3)
作为农业集约化和经济快速发展的地区之一,华北地区较高的氮沉降不容忽视。本文利用卫星观测的对流层柱浓度和大气化学传输模型模拟的剖面信息,研究了华北地区氮沉降的空间格局和季节特征。结果表明,华北地区总氮沉降通量为16.3–106.5 kg N ha~(-1)yr~(-1),平均为54.5±17.2 kg N ha~(-1)yr~(-1)。高值区主要集中在城市和农田,低值区主要集中在人类活动较少的森林和草地。在总氮沉降量中,湿沉降量占36%;颗粒物干沉降量占12%;气态干沉降占52%。对于干沉降来说,气态HNO_3和颗粒物NO_3~-在冬季和秋季较高,春季和夏季较低。与之相反,气态NH_3和颗粒物NH_4~+在春季和夏季较高,冬季和秋季较低。这可能是NO_x和NH_3排放源和排放强度的季节差异造成的。另外,气态NO2沉降没有明显的季节变化。湿沉降主要受降水影响,呈现夏季高,冬季低的季节变化。本研究为华北地区总氮沉降提供了客观的空间格局和季节特征的见解。 相似文献
11.
次网格对流参数化效果对水平分辨率的敏感生试验 总被引：3，自引：0，他引：3
使用单向嵌套的五层有限域模式进行了次网格对流参数化效果对水平分辨率的敏感性试验.使最细网格覆盖主要降水区,并依次嵌套.设计了四种水平分辨率不同的网格,其水平格距分别为381,190.5,95.25及47.625km.对同一降水个例使用上述各种网格分别作了24小时累计降水量预报(积分48小时)试验.结果表明:(1)总降水量(降水最大值及等面积平均最大值)随网格距的减小而增大.当水平格距减小为50km左右时,便可以很好地预报出一般天气尺度降水的落区及雨量分布;(2)随水平分辨率的提高,次网格对流凝结对总降水的 相似文献
12.
Maryam Gharaylou Peyman Zawar-Reza Abbas-Ali A. Bidokhti Majid-M. Farahani 《Meteorology and Atmospheric Physics》2013,122(3-4):145-158
A one-dimensional Explicit Time-dependent Tilting cloud Model (ETTM) that separates updraft and downdraft columns and takes into account the effect of cloud tilting on precipitation is introduced and incorporated into the Advanced Regional Prediction System (ARPS). Results of the stand-alone ETTM are compared with that of cloud resolving simulations using the ARPS mesoscale model. Inter-comparison is performed by qualitative examination of simulated parameters such as vertical distribution of fluxes of mass, heat, and moisture. Although there is a great degree of similarity between the vertical profiles, ETTM systematically underestimates magnitudes of all fluxes. Sensitivity tests carried with ETTM show that the effect of varying cloud radius and tilting angle is considerable on the simulated cloud behavior. Increasing the cloud radius, results in a corresponding increase in fluxes of mass, heat, and moisture, while increasing the cloud tilt angle has the opposite effect. Since ETTM showed promise as a suitable sub-grid cumulus parameterization scheme; it was incorporated into ARPS as an additional cumulus parameterization scheme (CPS) to be available for the wider community. Results of simulations using ETTM and other CPSs already available in ARPS were compared for 2, 4 and 10 km grid spacings to assess its utility. Simulation results of the 2 km grid showed that at this resolution, the simulated time series of updraft velocities using the new scheme (ETTM) compared well with the results of other schemes in the ARPS model. The simulations with horizontal resolution of 4 km that was compared with the convection resolving reference run (No-CPS-2KM) showed almost consistent results for all schemes except for one using KF scheme. The results of the simulation with the ETTM scheme and other schemes in the model with resolution of 10 km showed that at this resolution, there is not significant difference between the uses of these schemes. 相似文献
13.
尺度适应(scale-aware)的物理过程是现代数值预报发展的一种趋势,本文针对GRAPES_Meso(Global/Regional Assimilation and Prediction Enhanced System)模式没有考虑物理过程尺度适应的现状,首先在KFeta(Kain-Fritsch Eta)积云对流参数化方案中引进了尺度适应过程,对该方案的对流时间尺度、格点垂直速度以及夹卷率进行了基于尺度适应参数化的改进。为研究尺度适应KFeta方案与原KFeta方案对不同分辨率模式模拟结果的影响,选取了一次华南飑线过程进行数值模拟和影响分析。结果表明:在3 km、5 km、10 km、20 km水平分辨率的GRAPES_Meso模式中,尺度适应KFeta方案相比原方案,对降水强度及落区分布的模拟有一定的正效果,随着模式水平分辨率提高,次网格降水减少、格点降水增多、对流层中低层夹卷略有增强,对原来存在的对流层高层及低层偏冷的偏差有一定的改进,对流活跃区域的上升气流强度、云中水凝物含量更符合真实的天气系统演变。综合来看,改进后的方案更适用于高分辨率数值预报模式,该研究结果可以为尺度适应对流参数化方案的应用及数值模式强降水预报性能的优化提供有益的参考。 相似文献
14.
地基微波辐射计资料的等值线自动绘制方法 总被引：1，自引：0，他引：1
利用美国国家大气研究中心（National Center for Atmospheric Research,NCAR）中尺度模式（WRF-ARW）以及美国国家海洋和大气管理局（NOAA）三维变分同化系统GSI（Gridpoint StatisticalInterpolation）,对2005年6月20-21日发生在广东省中部的一场致洪暴雨进行了模拟。与雨量计观测的和卫星反演的降水混合资料相比,模式能够成功地模拟出降水的位置和强度。但数值模拟的效果很大程度上取决于3个条件：模式分辨率;物理过程方案;初始条件。在此次暴雨的模拟中,采用Eta Ferrier微物理方案、内层区域4km细分辨率与外层区域12km粗分辨率组成双层嵌套网格和卫星辐射资料同化的初始化方案是非常合适的。 相似文献
15.
On the role of resolution and topography in the simulation of East Asia precipitation 总被引：13，自引：0，他引：13
Xuejie Gao Ying Xu Zongci Zhao J. S. Pal F. Giorgi 《Theoretical and Applied Climatology》2006,86(1-4):173-185
Summary In this paper, we investigate the role that horizontal resolution plays in the simulation of East Asia precipitation. Two
sets of numerical experiments are performed using the Regional Climate Model (RegCM2) nested in one-way mode within the CSIRO
global coupled atmosphere-ocean model. In the first set we use the actual RegCM2 topography at the selected model resolutions,
which are 45, 60, 90, 120, 180, 240 and 360 km. In the second set of the experiments, the same coarse CSIRO model topography
is used in all simulations using the different resolutions of the first set. The results demonstrate that the simulation of
East Asian precipitation improves as the horizontal resolution is increased. Moreover, it is shown that the simulations using
a higher resolution along with the coarse CSIRO topography perform better than the simulations using a coarser model resolution
with corresponding model topography. This suggests that over East Asia adequate spatial resolution to resolve the physical
and dynamical processes is more important than topography. Lastly, the results indicate that model resolutions of 60 km or
higher are needed to accurately simulate the distribution of precipitation over China and East Asia. 相似文献
16.
A number of remotely sensed land cover datasets with spatial resolutions ~〈 1 km have recently become available or are in the process of being mapped. The application of these higher resolution and more up-to-date land cover datasets in chemical transport models （CTMs） is expected to improve the simulation of dry deposition and biogenic emissions of non-methane volatile organic compounds （NMVOCs）, which affect ozone and other secondary air pollutants. In the present study, we updated the land cover dataset in the nested-grid GEOS-Chem CTM with the 1 km resolution GLC2000 land cover map and examined the resulting changes in the simulation of surface ozone and sulfate over China in July 2007. Through affecting the dry deposition velocities of ozone and its precursors, using GLC2000 in the dry deposition module can decrease the simulated surface ozone by 3% （up to 6 ppb） over China. Simulated surface sulfate shows an increase of 3% in northwestern China and a decrease of 1% in northern China. Applying GLC2000 in the biogenic emissions of the NMVOC module can lead to a 0.5--4.5 ppb increase in simulated surface ozone over East China, mainly driven by the larger cove~：age of broadleaf trees in East China in the GLC2000 dataset. Our study quantifies the large sensitivity to land cover dataset~ with different spatial resolutions and time periods of simulated secondary air pollutants over China, supporting ongoing research efforts to produce high resolution and dynamically updated land cover datasets over China, as well as for the globe. 相似文献
17.
Peter P. Sullivan James C. McWilliams Chin-Hoh Moeng 《Boundary-Layer Meteorology》1996,80(1-2):167-202
A method for performing nested grid calculations with a large-eddy simulation code is described. A common numerical method is used for all meshes, and the grid architecture consists of a single outer or coarse grid, and nested or fine grids, which overlap in some common region. Inter-grid communication matches the velocity, pressure and potential temperature fields in the overlap region. Resolved and sub-grid scale (SGS) turbulent fluxes and kinetic energy on the fine grid are averaged to the coarse grid using a conservation rule equivalent to Germano's identity used to develop dynamic SGS models.Simulations of a slightly convective, strong shear planetary boundary layer were carried out with varying surface-layer resolutions. Grid refinements in the (x, y, z) directions of up to (5, 5, 2) times were employed. Two-way interaction solutions on the coarse and fine meshes are successfully matched in the overlap region on an instantaneous basis, and the turbulent motions on the fine grid blend smoothly into the coarse grid across the grid interface. With surface-layer grid nesting, significant increases in resolved eddy fluxes and variances are found. The energy-scale content of the vertical velocity, and hence vertical turbulent fluxes, appear to be most influenced by increased grid resolution. Vertical velocity spectra show that the dominant scale shifts towards higher wavenumbers (smaller scales) and the magnitude of the peak energy is increased by more than a factor of 3 with finer resolution. Outside of the nested region the average heat and momentum fluxes and spectra are slightly influenced by the fine resolution in the surface layer. From these results we conclude that fine resolution is required to resolve the details of the turbulent motions in the surface layer. At the same time, however, increased resolution in the surface layer does not appreciably alter the ensemble statistics of the resolved and SGS motions outside of the nested region. 相似文献
18.
This study investigated the predictability of a squall line associated with a quasi-stationary front on 23 April 2007 in South China through deterministic and probabilistic forecasts. Our results show that the squall-line simulation was very sensitive to model error from horizontal resolution and uncertainties in physical parameterization schemes. At least a 10-km grid size was necessary to decently capture this squall line. The simulated squall line with a grid size of 4.5 km was most sensitive to long-wave radiation parameterization schemes relative to other physical schemes such as microphysics and planetary boundary layer. For a grid size from 20 to 5 km, a cumulus parameterization scheme degraded the squall-line simulation (relative to turning it off), with a more severe degradation to grid size <10 km than >10 km. The sensitivity of the squall-line simulation to initial error was investigated through ensemble forecast. The performance of the ensemble simulation of the squall line was very sensitive to the initial error. Approximately 15% of the ensemble members decently captured the evolution of the squall line, 25% failed, and 60% dislocated the squall line. Using different combinations of physical parameterization schemes for different members can improve the probabilistic forecast. The lead time of this case was only a few hours. Error growth was clearly associated with moist convection development. A linear improvement in the performance of the squall line simulation was observed when the initial error was decreased gradually, with the largest contribution from initial moisture field. 相似文献
19.
不同降水方案对"03.7"一次暴雨过程模拟的影响 总被引：4，自引：0，他引：4
观测和数值模拟研究已经表明,潜热释放对中国东部夏季梅雨锋系统及其锋面降水的维持和发展发挥着非常重要的作用.然而,目前对于梅雨锋降水模拟中各种降水方案的相互协调和系统评估方面的工作仍不多见,为了增进对梅雨锋暴雨模拟中降水过程的认识,作者针对2003年7月4～5日一次梅雨锋暴雨过程,构造了四组试验,利用MM5模式考察了两种分辨率(36 km、12 km),各种隐/显式方案搭配下,对所生成的雨带、雨量和降水类型的配置进行了仔细的研究,得到了一些有意义的结论,为今后更好地使用模式、利用数值模式来认识中尺度降水过程中的气象问题打下基础.主要结论包括:模拟总降水的水平分布和强度,以及显式降水和隐式降水的划分对积云参数化方案的选择非常敏感.但对特定积云参数化方案而言,降水的模拟对36 km、12 km水平分辨率不敏感(除Betts-Miller方案外);在中尺度网格分辨率10～50 km范围内,不同积云参数化方案对梅雨锋降水分布和降水量模拟的影响比不同显式方案带来的变化大得多. 相似文献