共查询到20条相似文献，搜索用时 328 毫秒
1.
本文用高斯(正态)模式(G·S)、SCIM模式,GDM模式以及GCDM模式,分别计算了南京大厂区在各种稳定度条件下SO_2瞬时浓度,并与SO_2的实测浓度作了对比分析。结果表明:GCDM模式的计算误差最小,并与实测浓度有较好的一致性。 相似文献
2.
应用高斯模型和ADMS-城市模型分别计算了辽阳地区在不同条件下的SO2日均浓度 ,并与实测浓度进行了对比分析。结果表明 ,应用ADMS-模型可以得到与实测浓度较一致的结果 相似文献
3.
4.
《气象与环境学报》2017,(1)
为了检验CUACE模式指导产品在合肥地区的预报性能,本文利用合肥地区PM_(2.5)、PM_(10)、O_3监测资料对中国气象局下发的2014年3月至2015年2月合肥地区空气质量CUACE模式指导产品的预报效果进行了检验。结果表明:2014年3月至2015年2月合肥地区CUACE模式指导产品AQI和PM2.5浓度的预报值接近实测值,PM_(10)浓度预报值略小于实测值,O_3浓度的预报值明显偏大,但O_3浓度的预报值与实测值相关性最好,AQI、PM_(2.5)浓度和PM_(10)浓度预报值与实测值之间的相关系数均为0.3—0.4。实测空气质量等级为良时,CUACE模式空气质量等级预报的TS评分最高,漏报率和空报率最小;实测首要污染物为PM_(2.5)时,CUACE模式首要污染预报TS评分最高,漏报率和空报率最小。CUACE模式的预报性能并未随预报时效的延长而降低,CUACE模式指导产品总体预报效果较好,可为合肥市空气质量预报提供指导。 相似文献
5.
利用美国Licor-6200光合作用测定仪,对黄淮海地区代表性冬小麦品种鲁麦23号叶片光合作用速率进行了较为全面的测定,分别确定了冬小麦叶片光—光合作用响应曲线和CO2—光合作用响应曲线,在此基础上,建立了叶片光合作用模式,并进而建立了一个具有瞬时时间尺度,空间积分为叶片尺度的冬小麦冠层模式,利用模式分别分析了大气中CO2浓度升高和温度变化对冠层光合作用的不同影响,并在此基础上进一步进行了综合数值分析。单因子分析表明:晴天状况下,冠层光合速率随CO2浓度升高而上升,当CO2浓度由330×10-6上升至660×10-6时,冠层光合日总量可增加19.7%;冠层光合速率随辐射增加而增大,辐射量增加10.0%,冠层光合日总量可增加6.7%;冠层光合速率随温度升高而下降,温度升高1℃,冠层光合日总量减少2.9%。多因子综合数值分析表明:在辐射量较大的气候背景下,冠层光合日总量对温度和CO2变化响应更加敏感。本文的实测数据为研究气候变化对中国农业影响提供了最基本的可靠模型参数,冠层光合模型为未来改进作物模型提供了理论基础。 相似文献
6.
本文利用气体组分及大气气溶胶在线监测系统(MARGA ADI 2080)观测武汉市2018年1月9—26日大气气溶胶中的8种水溶性离子(NH+4、NO-3、SO2-4、Cl-、K+、Ca2+、Na+和Mg2+),结合气象要素数据,使用主成分分析(PCA)、正定矩阵因子分析法(PMF)、HYSPLIT后向轨迹模式、潜在源区贡献(PSCF)和浓度权重轨迹(CWT),对霾污染过程中水溶性离子进行了全面的来源解析,探究了霾不同阶段下来源差异和空间分布特征。结果表明:(1)本次霾污染中的8种水溶性离子和4种污染气体,PCA解析出的源和占比分别为二次源和燃煤源的混合源(41.28%)、工业排放和土壤扬尘混合源(27.73%)和机动车排放源(9.63%),PMF解析出的源和占比分别为燃煤与土壤扬尘混合源(18.57%)、机动车排放源(20.74%)、二次源(18.30%)、光化学污染源(22.24%)和燃煤源(20.15%)。(2)霾在不同阶段下水溶性离子和4种污染气体的来源存在差异,在清洁天和霾消散阶段,光化学的贡献最高,占比分别为31.42%和36.07%;在霾发生阶段燃煤与土壤扬尘源的贡献最高,其贡献为40.94%;在霾发展阶段,最大的控制源为二次源,贡献占比为37.51%。(3)此次武汉市霾污染中PM2.5浓度和NH+4、NO-3和SO2-4的潜在源区为皖豫鄂三省和赣湘鄂三省交界处。霾污染中PM2.5的主要影响范围是武汉市南部和北部省份,NO-3、NH+4和SO2-4的主要影响区域为武汉市东北方向的城市、湖南省和江西省。 相似文献
7.
在“双碳”目标背景下，从国家层面到地方层面，区域、城市、行业企业都在制定和实施双碳目标行动计划。CO2模拟因其客观性和高时空分辨率等优势，在城市碳排放研究中深受重视。本研究以京津冀地区为研究区域，采用Picarro仪器高精度观测的2019—2020年CO2数据，利用WRF模式进行CO2传输模拟，分析了CO2浓度变化的季节特征，评估了模式在城区中心、城郊及背景3个观测站点的模拟效果，并对边界层高度及化石燃料碳排放等可能影响CO2浓度的因素进行了研究。3个观测站点分别为北京中国科学院大气物理研究所325 m气象塔观测站（北京站）、河北香河观测站（香河站）和上甸子区域本底观测站（上甸子站）。模拟结果表明：上甸子站优于香河站，香河站优于北京站，在冬季尤其明显；CO2浓度的高值区主要分布在城区、电厂和工业区，尤其是唐山、石家庄和邯郸地区，大量交通、工业排放导致CO2浓度明显上升，且高值区的范围在冬季最大；就日平均变化和日变化而言，边界层高度与CO2浓度存在相反变化趋势；3个站点的化石燃料碳排放（FFECO2）与近地面总CO2浓度存在正相关关系，冬春季的相关性高于夏秋季，且FFECO2的占比从大到小依次为北京站、香河站、上甸子站；CO2传输模拟的不确定性存在空间差异和季节变化。 相似文献
8.
利用Euler平流扩散方程和K模式闭合方案的数值解,讨论了混合层厚度、风速和稳定度3因子对银川市冬季地面SO2浓度分布的影响。结果表明,在极不稳定层结(A级)下混合层厚度增加250m时能使地面SO2浓度减少40%～75%,而在稳定层结下混合层厚度增加200m时仅减少20%的浓度;而当混合层厚度和风速分别增加250m和3.8m·s-1、层结由稳定(F)变为极端不稳定(A),并且当混合层最大厚度和最大风速分别限制在650m和4m·s-1时,老城西部地面浓度减少了90%,稀释效应最显着。 相似文献
9.
利用瓦里关和上甸子大气本底站观测的月平均CO2浓度数据对GOSAT卫星反演的CO2浓度数据进行验证,结果表明GOSAT产品与台站观测数据有较好的一致性.利用2009年6月—2011年5月GOSAT反演的CO2浓度数据,分析了江苏地区CO2浓度的时空变化特征,结果表明:1)975 hPa高度层CO2浓度高于850 hPa高度层,CO2浓度的水平变化要小于垂直变化;2)在季节变化上,CO2浓度冬季最高,夏季最低,这可能与植被光合作用的强弱变化有关;比较前后两年的CO2浓度数据,夏季和秋季的增速较快,冬季和春季的增速较慢;3)在日变化上,发现徐州和南京站02时CO2浓度最高,14时CO2浓度最低,这可能也与植被光合作用的强弱有关. 相似文献
10.
依据一种基于建筑用地比例和土地利用信息熵的城乡站点划分方法,将西安市环境与气象站点划分为城区、郊区和两类乡村站,讨论其PM2.5的城乡分布特征及与城市热岛效应强度(Urban Heat Island Intensity,UHII)间的相关关系。结果表明,不同季节西安市呈现不同的PM2.5城乡分布特征和日变化特征,两类乡村站点PM2.5差异明显且下风向乡村站点(乡村D)对应的UHIID对城区和乡村的影响程度大于上风向乡村站点(乡村U)对应的UHIIU。在城区较多本地排放的影响下,乡村PM2.5浓度与 UHIIU(或UHIID)相关系数均大于城区。随着UHIID的增加,城乡PM2.5相对浓度差值(RUPIID)整体呈下降趋势且UHIID与RUPIID在春夏秋季显著负相关。UHIID增大,城区近地面PM2.5的水平扩散能力减弱,但PM2.5的垂直扩散能力较乡村更强,从而UHIID通过影响PM2.5的传输扩散特征,进一步影响西安市RUPIID。 相似文献
11.
A periodically synchronous scheme suitable for coupling atmosphere and ocean models with high internal variability is presented. The performance of the scheme is tested by means of a simple zero-dimensional non-linear energy balance model with stochastic forcing. The equilibrium behaviour and the response to changes in the model parameters are analysed. The response experiments are similar to CO2 doubling and transient CO2 experiments. The best results are obtained using a method with weighted means of the air-sea fluxes which are calculated during the synchronously coupled periods. 相似文献
12.
S. G. Tsyro 《Russian Meteorology and Hydrology》2008,33(5):300-309
This paper provides performance evaluation of the EMEP (Cooperative Programme for the Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe) model, formulated in [1], and presents model calculation results. A satisfactory agreement is found between calculated and observed PM10 and PM2.5 concentrations (i.e., particulate matter with diameters smaller than 10 and 2.5 μm) and their chemical composition for different parts of Europe for the years 2001–2004. The model manages to reproduce observed regional gradients of background PM10 and PM2.5, with spatial correlations being 0.70 and 0.80, respectively, while the temporal correlation coefficients between modeled and measured daily PM vary mostly between 0.4 and 0.8 at EMEP sites. The agreement between calculated and observed aerosol number concentrations is worse than for mass concentrations. Model calculated PM10 and PM2.5 concentrations and chemical composition in Europe for the year 2004 are presented, as well as their interannual variations in the period 2000–2004. Further, contributions of different sources to PM10 and PM2.5 are estimated. Model results show that in 2004, background PM10 and PM2.5 exceeded EU critical levels and WHO recommended guidelines in a number of European regions. They also show that the transboundary transport contributes considerably to PM pollution in the European countries. 相似文献
13.
Assessment of the changes in extreme vulnerability over East Asia due to global warming 总被引：1，自引：0，他引：1
A number of indices have been employed to describe weather extremes on the basis of climate regimes and public concerns. In this study, we combined these traditional indices into four groups according to whether they relate to warm (Twarm), cold (Tcold), wet (Pwet), or dry (Pdry) extremes. Analysis of the combined indices calculated for the daily temperatures and precipitation at 750 meteorological stations in Korea, China, and Japan for 1960s?C2000s shows increasing trends in Twarm and Pdry events and decreasing trends in Tcold events in recent decades, particularly in the northern part of East Asia. A notable regional variation is an increase in the Pwet events in the Korean Peninsula. We applied the same analysis to a 200-year global climate model simulation for 1900?C2099 using the National Center for Atmospheric Research-Community Climate System Model 3. During the 20th century, the changes in Twarm and Tcold calculated from the model data are largely consistent with those calculated from the observations, especially in northern East Asia. The model projections for the 21st century indicate statistically significant increasing Twarm and decreasing Tcold trends in extreme events over the region. Results obtained from historical archives and model simulations using our combined weather extreme indices suggest that northern East Asia will be subject to increased warm and dry extremes and the Korea Peninsula will experience more wet extremes. 相似文献
14.
Nathalie Poisson Maria Kanakidou Paul J. Crutzen 《Journal of Atmospheric Chemistry》2000,36(2):157-230
The impact of natural and anthropogenicnon-methane hydrocarbons (NMHC) on troposphericchemistry is investigated with the global,three-dimensional chemistry-transport model MOGUNTIA.This meteorologically simplified model allows theinclusion of a rather detailed scheme to describeNMHC oxidation chemistry. Comparing model resultscalculated with and without NMHC oxidation chemistryindicates that NMHC oxidation adds 40–60% to surfacecarbon monoxide (CO) levels over the continents andslightly less over the oceans. Free tropospheric COlevels increase by 30–60%. The overall yield of COfrom the NMHC mixture considered is calculated to beabout 0.4 CO per C atom. Organic nitrate formationduring NMHC oxidation, and their transport anddecomposition affect the global distribution of NO
x
and thereby O3 production. The impact of theshort-lived NMHC extends over the entire tropospheredue to the formation of longer-lived intermediateslike CO, and various carbonyl and carboxyl compounds.NMHC oxidation almost doubles the net photochemicalproduction of O3 in the troposphere and leads to20–80% higher O3 concentration inNO
x
-rich boundarylayers, with highest increases over and downwind ofthe industrial and biomass burning regions. Anincrease by 20–30% is calculated for the remotemarine atmosphere. At higher altitudes, smaller, butstill significant increases, in O3 concentrationsbetween 10 and 60% are calculated, maximizing in thetropics. NO from lightning also enhances the netchemical production of O3 by about 30%, leading to asimilar increase in the global mean OH radicalconcentration. NMHC oxidation decreases the OH radicalconcentrations in the continental boundary layer withlarge NMHC emissions by up to 20–60%. In the marineboundary layer (MBL) OH levels can increase in someregions by 10–20% depending on season and NO
x
levels.However, in most of the MBL OH will decrease by10–20% due to the increase in CO levels by NMHCoxidation chemistry. The large decreases especiallyover the continents strongly reduce the markedcontrasts in OHconcentrations between land and oceanwhich are calculated when only the backgroundchemistry is considered. In the middle troposphere, OHconcentrations are reduced by about 15%, although dueto the growth in CO. The overall effect of thesechanges on the tropospheric lifetime of CH4 is a 15%increase from 6.5 to 7.4 years. Biogenic hydrocarbonsdominate the impact of NMHC on global troposphericchemistry. Convection of hydrocarbon oxidationproducts: hydrogen peroxides and carbonyl compounds,especially acetone, is the main source of HO
x
in theupper troposphere. Convective transport and additionof NO from lightning are important for the O3 budgetin the free troposphere. 相似文献
15.
S. Schmid 《Theoretical and Applied Climatology》1993,47(1):33-50
Summary A climatology of flow patterns and NOx concentrations for Southern Bavaria is determined by use of a mesoscale model. Emissions of the main regional emitters of NOx are prescribed in the model. A simple parameterization of the chemical processes is applied. The climatologies are obtained by performing model simulations of typical dispersion situations and weighting the results according to the frequency of their occurrence. The computed NOx and wind statistics agree satisfactorily with the available observations. Thus, the modelled NOx climatology is believed to be realistic. During daytime, NOx is mainly concentrated above the emission areas, whereas at night the NOx distribution is more uniform and the contamination of the surroundings increases. The contamination during the winter half-year is about twice that of summer half-year. The highest average annual NOx concentration of 64 ppb is found in the region of Munich. The calculated mean NOx distribution is useful for supplementing the sparse observational data. Additionally, the model simulations allow the determination of the contributions of emitters to the NOx contamination at any given location.With 25 Figures 相似文献
16.
øystein Hov Asgeir Sorteberg Norbert Schmidbauer Sverre Solberg Frode Stordal David Simpson Anne Lindskog Hans Areskoug Pedro Oyola Heikki Lättilä Niels Z. Heidam 《Journal of Atmospheric Chemistry》1997,28(1-3):173-193
Observations and model calculations of the concentration of hydrocarbonsat five Scandinavian rural sites during March–June 1993are reported.Decreasing concentrations from March to June are observedat all sites. The highest concentrations of hydrocarbons were found in air massescoming in from the southwest to southeast, indicating that long rangetransport fromcontinental Europe and the U.K. is important in pollution episodes. An episode of elevated concentrations of hydrocarbons observed at three of the sites in the middle of Marchis described and discussed in relation to the synoptic situation and thepresenceof other chemical compounds (NO2, PAN, total nitrate andozone).A Lagrangian numerical model is used to calculate the concentrations of theindividual hydrocarbons at the fivesites and comparison with observations is made.The calculated concentrations for nonmethane hydrocarbons with quite longchemicallifetimes agree well with the observations.For the sum of observed and calculated hydrocarbons the correlationcoefficientsare in the range of 0.65–0.88 for the five sitesand the ratio between calculated and measured concentrations was0.72–0.97, indicating thatthe European VOC emission inventory is quite well estimated. 相似文献
17.
A. Zastawny 《Meteorology and Atmospheric Physics》2006,92(1-2):153-159
Summary Using the HITRAN database from 2003, the absorption of solar and thermal radiation by the atmosphere is calculated. The results
are presented in the form of spectral densities of absorption yield of the atmosphere and its components, and fractions of
absorbed energy of the solar radiation and thermal radiation in the atmosphere by each of its components separately and together.
Finally, the obtained results are discussed in the context of the lately published model of Earth’s radiation budget-MAP 85(4),
275–281 (2004). The shares of atmospheric components in the greenhouse effect and in the absorption of solar radiation are
calculated. The percentage contributions of the more important atmospheric components in the greenhouse effect are as follows:
clouds 66, water vapor 25, CO2 6.7, N2O 0.7, CH4 0.7. 相似文献
18.
Operational model for direct determination of evapotranspiration for well watered crops in Mediterranean region 总被引：1，自引：0，他引：1
Direct calculation of actual evapotranspiration ETc based on Penman-Monteith type models gives more accurate values than indirect models, which need the determination of reference evapotranspiration and crop coefficient. However, the direct models need the measurement of weather variables above the crop, which is limiting and not easily feasible in practice. An operational version of a known ETc direct model is described and tested. This new version is based on the determination of the weather variables collected in a standard agro-meteorological station. The original and the operational versions of the ETc model were validated on two crops with contrasting height: soybean (0.8 m) and sweet sorghum (3 m). For soybean, ETc calculated with the two versions gave results very similar at both hourly and daily scales. For sweet sorghum, ETc calculated with the operational version is good at daily scale and not as good, although acceptable, at the hourly scale. 相似文献
19.
Lightning is thought to represent an important source of tropospheric reactive nitrogen species NOx (NO + NO2),but estimates of global production of NOx by lightning varyconsiderably. We evaluate the production of NOx by lightning using a global chemical/transport model, satellite lightning observations, and airborne NOx measurements. Various model calculations are conducted toassess the global NOx production rate of lightning by comparing the model calculations with airborne measurements. The results show that the simulated NOx in the tropical middle and upper troposphere are very sensitiveto the amount and altitude of the lightning NOx used in the model. A global lightning NOx production of 7 Tg N yr–1uniformly distributed in convective clouds or 3.5 Tg N yr–1 distributedin the upper cloud regions produces good agreement between calculated and measured NOx concentrations in the tropics. 相似文献
20.
Taking advantage of the relation of lateral Lagrangian time scale TLY with the stability and height,we establish a three-dimensional random dispersion model and simulate the dispersing process of a ground source within the surface layer.The results calculated show that under the condition of stable stratification our model is obviously better improved than those obtained by assuming TLY to be constant,while under unstable condition,not much improved. 相似文献