近50年疏勒河流域山区的气候变化及其对出山径流的影响   总被引：3，自引：0，他引：3  

蓝永超  胡兴林  肖生春  文军  王国亚  邹松兵  喇承芳  宋洁 《高原气象》2012,31(6):1636-1644

利用祁连山区水文站和气象站的观测数据,分析了近50年河西走廊西部疏勒河流域山区的气候变化及其对出山径流的影响。结果表明,受全球变暖的影响,疏勒河山区气候持续向暖湿转化,且各季气温均呈持续的上升趋势,山区降水量总体上亦呈增加趋势,年际波动比较剧烈。在各季降水量中,除夏季外其他各季降水量的增加比较显著,海拔3 000m以上中高山地带夏季降水量变化不大,3 000m以下中低山地带夏季降水量略有减少。受山区降水,尤其是3 000m以下中低山地带的降水量显著增加与气温上升所引起的冰雪融水补给的影响,疏勒河出山径流呈持续的增加趋势。由于夏季降水量并未增加,在年径流总量中所占比重最大的夏季径流量的增加主要是由于气温上升所引起的冰雪融水补给的增加所致。  相似文献   

INTEX-B NO2排放源在中国地区的应用与检验          下载免费PDF全文

张敏  边海  韩素芹  张华  崔振雷  朱彬 《气象与环境学报》2012,28(1):65-70

将INTEX-B排放源应用到空气质量模型Model3-CMAQ中,对中国地区对流层NO₂的浓度分布进行了数值模拟,并与OMI卫星对流层NO₂资料进行了对比和验证。结果表明：将INTEX-B排放源应用到Model3-CMAQ模式,模拟的NO₂浓度在中国地区的分布、季节变化规律与卫星资料所得结果一致。敏感性试验表明,工业及电厂排放对NO₂的浓度贡献最大,而交通排放的贡献相对较小,两种排放均主要集中在京津、长江三角洲等经济发达地区。  相似文献   

RegCM3模式对青藏高原夏季气温和降水的模拟   总被引：9，自引：4，他引：5       下载免费PDF全文

屈鹏  杨梅学  郭东林  陈楚雄 《高原气象》2009,28(4):738-744

利用RegCM3模式对青藏高原1991—2000年10年夏季（6~8月）的地面气温和降水进行了模拟, 其模拟结果与CRU资料的对比分析表明: RegCM3模式的模拟能再现高原地面气温和降水的基本特征, 特别是气温, 能捕捉到高原北部夏季升温明显高于南部, 东北部升温最大; 在夏季3个月中, 模拟结果和CRU在6月份最为吻合, 7月份两者均为夏季气温最高月份和升温幅度最大月份, 8月份两者相差较大。RegCM3模式能够模拟出高原降水分布的基本特征和主要干湿中心, 由于高原降水的复杂性和模式对降水描述能力的不足, 降水模拟要差于气温。  相似文献   

1951—2005年营口市气温变化特征分析   总被引：1，自引：0，他引：1       下载免费PDF全文

金巍  曲岩  才奎志 《气象与环境学报》2009,25(3):39-43

对1951—2005年营口市年和逐月平均气温和极端气温变化特征的分析表明：近55 a来营口市年平均气温呈递增趋势,其中平均最低气温的增温趋势最强、平均气温次之、平均最高气温最弱。极端最高气温与年平均气温的变化趋势不同,呈现出前30 a递减、近30 a递增,近20 a气候变暖更为突出;各月极端最高气温变率差异不明显。近55 a营口市年极端最低气温呈递增趋势,近30 a较近55 a显著递增,但近20 a则稳定少动;各月极端最低气温均呈递增趋势,冬季递增趋势最强、夏季最弱;城市化发展及工业化引起的热岛效应是营口市显著增温的重要原因,而全球变暖的大背景则进一步加强了增温趋势。  相似文献   

1951~2010年云贵高原大理和丽江气温、降水的气候特征分析   总被引：2，自引：0，他引：2  

刘翔卿  王雷  刘阳  孙绩华 《气候与环境研究》2018,23(5):513-523

利用大理和丽江气象站1951~2010年的逐日气象资料,分析了横断山脉东部气温、降水的气候特征。结果表明,1991年以后,大理和丽江地区均存在显著增温的趋势（0.58和0.55℃/10 a）,明显高于同时期中国平均气温的增加幅度;而在1991年之前,大理和丽江的年平均气温呈现下降或微弱上升的趋势（-0.14和0.07℃/10 a）。与夏季平均气温的增温幅度相比,冬季平均气温的增温更显著,且其变化趋势与年均气温的气候特征是一致的。大理和丽江年总降水及各季节降水量在1951~2010年并没有明显增加或减少的趋势。大理和丽江雨季开始的时间分别为第28候和第30候,持续时间分别约为5.5和4.5个月。20世纪80年代以后,丽江年平均风速的减小强度明显大于大理,这是因为丽江站地处城区,城市化剧烈,地表粗糙度增加显著。日照时数与云量呈反相的季节变化,降水量的多年平均的逐候变化与日照时数、总云量、尤其是低云云量相关,随风速增大而减小。  相似文献   

The Effect of Stratification on the Aerodynamic Roughness Length and Displacement Height   总被引：1，自引：0，他引：1  

S. S. Zilitinkevich  I. Mammarella  A. A. Baklanov  S. M. Joffre 《Boundary-Layer Meteorology》2008,129(2):179-190

The roughness length, z _0u , and displacement height, d _0u , characterise the resistance exerted by the roughness elements on turbulent flows and provide a conventional boundary condition for a wide range of turbulent-flow problems. Classical laboratory experiments and theories treat z _0u and d _0u as geometric parameters independent of the characteristics of the flow. In this paper, we demonstrate essential stability dependences—stronger for the roughness length (especially in stable stratification) and weaker but still pronounced for the displacement height. We develop a scaling-analysis model for these dependences and verify it against experimental data.  相似文献   

Source identification of PM_2.5 particles measured in Gwangju, Korea   总被引：1，自引：0，他引：1  

Hanlim Lee  Seung S. Park  Kyung W. Kim  Young J. Kim   《Atmospheric Research》2008,88(3-4):199-211

The UNMIX and Chemical Mass Balance (CMB) receptor models were used to investigate sources of PM_2.5 aerosols measured between March 2001 and February 2002 in Gwangju, Korea. Measurements of PM_2.5 particles were used for the analysis of carbonaceous species (organic (OC) and elemental carbon (EC)) using the thermal manganese dioxide oxidation (TMO) method, the investigation of seven ionic species using ion chromatography (IC), and the analysis of twenty-four metal species using Inductively Coupled Plasma (ICP)-Atomic Emission Spectrometry (AES)/ICP-Mass Spectrometry (MS). According to annual average PM_2.5 source apportionment results obtained from CMB calculations, diesel vehicle exhaust was the major contributor, accounting for 33.4% of the measured PM_2.5 mass (21.5 μg m^− 3), followed by secondary sulfate (14.6%), meat cooking (11.7%), secondary organic carbon (8.9%), secondary nitrate (7.6%), urban dust (5.5%), Asian dust (4.4%), biomass burning (2.8%), sea salt (2.7%), residual oil combustion (2.6%), gasoline vehicle exhaust (1.9%), automobile lead (0.5%), and components of unknown sources (3.4%). Seven PM_2.5 sources including diesel vehicles (29.6%), secondary sulfate (17.4%), biomass burning (14.7%), secondary nitrate (12.6%), gasoline vehicles (12.4%), secondary organic carbon (5.8%) and Asian dust (1.9%) were identified from the UNMIX analysis. The annual average source apportionment results from the two models are compared and the reasons for differences are qualitatively discussed for better understanding of PM_2.5 sources.Additionally, the impact of air mass pathways on the PM_2.5 mass was evaluated using air mass trajectories calculated with the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) backward trajectory model. Source contributions to PM_2.5 collected during the four air mass patterns and two event periods were calculated with the CMB model and analyzed. Results of source apportionment revealed that the contribution of diesel traffic exhaust (47.0%) in stagnant conditions (S) was much higher than the average contribution of diesel vehicle exhaust (33.4%) during the sampling period. During Asian dust (AD) periods when the air mass passed over the Korean peninsula, Asian dust and secondary organic carbon accounted for 25.2 and 23.0% of the PM_2.5 mass, respectively, whereas Asian dust contributed only 10.8% to the PM_2.5 mass during the AD event when the air mass passed over the Yellow Sea. The contribution of biomass burning to the PM_2.5 mass during the biomass burning (BB) event equaled 63.8%.  相似文献   

北京奥运会期间NO2浓度降低原因分析   总被引：1，自引：0，他引：1  

晏平仲  王喜全  王自发  吴其重 《气候与环境研究》2010,15(5):609-615

2002～2008年,北京市城区和近郊8月的NO2月均浓度大体呈现逐年下降趋势,其中前5年二者均以每年约10%的降幅下降,2008年发生显著下降,降幅达40%左右。利用嵌套网格空气质量模式系统(NAQPM/IAP),采用敏感性试验方法,评估了气象条件与污染控制措施对北京奥运会期间大气NO2浓度降低的影响,评估不同污染控制措施对NO2浓度降低的作用。研究结果表明,污染控制措施是NO2浓度降低的主要影响因素,其中面源的污染控制措施对于NO2浓度降低的作用最明显。  相似文献   

The Role of Planetary Boundary-Layer Parameterizations in the Air Quality of an Urban Area with Complex Topography   总被引：3，自引：1，他引：2  

Elizabeth Bossioli  Maria Tombrou  Aggeliki Dandou  Eleni Athanasopoulou  Kostas V. Varotsos 《Boundary-Layer Meteorology》2009,131(1):53-72

The effect of different planetary boundary-layer (PBL) parameterization schemes on the spatial distribution of atmospheric pollution over the complex topography of the greater Athens area is investigated. Four PBL schemes originally implemented in a numerical meteorological model and a fifth one simulating the urban effect are examined. Two different atmospheric conditions are analyzed; a typical summer and a typical winter pollution episode. The relative importance of chemical and physical processes of the pollution predictions is discussed using process analysis. It is revealed that, for primary pollutants, a local scheme seems more adequate to represent the maximum observed concentrations while, completely different in structure, a non-local scheme reproduces the mean observed values in the basin. Concerning secondary pollutants, peak concentration differences, due to the different PBL schemes, are smoothed out. Nevertheless, the PBL scheme selection shapes the horizontal and the vertical extension of maximum values. The non-local and semi non-local schemes are superior to the others, favouring strong vertical mixing and transport towards the surface. The stronger turbulence accommodated effectively by the semi non-local urban scheme enhances ozone production along the sea-breeze axis and preserves the high ozone concentrations during the nighttime hours in the urban core.  相似文献   

Improvement of Vertical Diffusion Analytic Schemes Under Stable Atmospheric Conditions     

Amela Jeričević  Željko Večenaj 《Boundary-Layer Meteorology》2009,131(2):293-307

Based on gradient transport theory or K-theory, turbulent transport in the atmosphere has long been parameterized using the eddy diffusivity. Due to its simplicity, this approach has often been applied in many numerical models but rarely tested with observations. Here, the widely used O’Brien cubic polynomial approach has been validated together with an exponential approach against eddy diffusivity profiles determined from measurements and from large-eddy simulation data in stable conditions. Verification is completed by analyzing the variability effects on pollutant concentrations of two different vertical diffusion (K(z)) schemes incorporated in an atmospheric chemical model. It is shown that the analytical, exponential solution agrees better with observations than the O’Brien profile and should be used henceforth in practical applications.  相似文献