神府煤田大柳塔矿区高分辨率地震勘探     

刘昌铨  刘保金  孙振国 《东北地震研究》1994,(4)

利用高分辨率地震反射法，在地表沙丘、沙垅无规则分布的神府煤田大柳塔矿区为采掘巷道作业，勘探垂直断距２ｍ以上至５ｍ的断层分布。试验观测结果取得了良好的效果。  相似文献   

Lower Tropospheric Warm Air Advection Patterns Associated with Heavy Rainfall over the Appalachian Region*     

Charles E. Konrad  Vernon Meentemeyer 《The Professional geographer》1994,46(2):143-155

A synoptic climatology of warm season heavy rainfall is developed from patterns of 850 mb thermal advection over the Appalachian region. Heavy rain events are categorized according to the position and orientation of a warm air advection (WAA) ridge, a feature found in nearly two-thirds of the events. Numerous study events occur within the conditionally unstable region of the WAA ridge. In fact, numerous occurrences of heavy rainfall are tied to a superpositioning of a WAA and air mass instability ridge in the vicinity or upstream of the heavy rain area.  相似文献   

ANALYSIS OF SURFACE AIR TEMPERATURE RECORDED IN LAHORE AND MIANWALI OVER THE PAST THREE DECADES          下载免费PDF全文

Mian M. Munir  K. Hussain  M. S. Zafar 《Acta Meteorologica Sinica》1995,9(1):123-128

Surface air temperatures recorded over the past three decades at the weather stations located in Lahore (anindustrialized and densely populated city) and Mianwali (a small and sparsely populated city) were analyzed in order tostudy their climatic trend.Lahore,where meteorological data are recorded at two weather stations (city station and air-port station) indicates a cooling trend,of about 0.5℃ per record period of 1953—1992,for the airport station (31°31′N,74°24′E) and a slight warming trend,of about 0.2℃,for the city station (31°33′N,74°20′E) for the record period of 1950—1992.The Mianwali weather station (32°33′N,71°31′E) also shows a slight cooling trend,of about 0.4℃ per recordperiod of 1959—1992.The climatic variability at these stations was studied by computing seasonal and annual tempera-ture anomalies.The results are explained in terms of the local environmental conditions.  相似文献   

Multi-phase flow modeling of air sparging   总被引：3，自引：0，他引：3  

M. I. J. van Dijke  S. E. A. T. M. van der Zee  C. J. van Duijn 《Advances in water resources》1995,18(6)

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Measurements of Trace Gases in the Inflow of South China Sea Background Air and Outflow of Regional Pollution at Tai O, Southern China     

T. Wang  H. Guo  D. R. Blake  Y. H. Kwok  I. J. Simpson  Y. S. Li 《Journal of Atmospheric Chemistry》2005,52(3):295-317

We present a 16-month record of ozone (O₃), carbon monoxide (CO), total reactive nitrogen (NO_y), sulphur dioxide (SO₂), methane (CH₄), C₂ – C₈ non-methane hydrocarbons (NMHCs), C₁ – C₂ halocarbons, and dimethyl sulfide (DMS) measured at a southern China coastal site. The study aimed to establish/update seasonal profiles of chemically active trace gases and pollution tracers in subtropical Asia and to characterize the composition of the `background' atmosphere over the South China Sea (SCS) and of pollution outflow from the industrialized Pearl River Delta (PRD) region and southern China. Most of the measured trace gases of anthropogenic origin exhibited a winter maximum and a summer minimum, while O₃ showed a maximum in autumn which is in contrast to the seasonal behavior of O₃ in rural eastern China and in many mid-latitude remote locations in the western Pacific. The data were segregated into two groups representing the SCS background air and the outflow of regional continental pollution (PRD plus southern China), based on CO mixing ratios and meteorological conditions. NMHCs and halocarbon data were further analyzed to examine the relationships between their variability and atmospheric lifetime and to elucidate the extent of atmospheric processing in the sampled air parcels. The trace gas variability (S) versus lifetime (τ) relationship, defined by the power law, S_lnx = Aτ^{− b}, (where X is the trace gas mixing ratio) gives a fit parameter A of 1.39 and exponent b of 0.42 for SCS air, and A of 2.86 and b of 0.31 for the regional continental air masses. An examination of ln[n-butane]/ln[ethane] versus ln[propane]/ln[ethane] indicates that their relative abundance was dominated by mixing as opposed to photochemistry in both SCS and regional outflow air masses. The very low ratios of ethyne/CO, propane/ethane and toluene/benzene suggest that the SCS air mass has undergone intense atmospheric processing since these gases were released into the atmosphere. Compared to the results from other polluted rural sites and from urban areas, the large values of these species in the outflow of PRD/southern China suggest source(s) emitting higher levels of ethyne, benzene, and toluene, relative to light alkanes. These chemical characteristics could be unique indicators of anthropogenic emissions from southern China.  相似文献   

The Relative Impact of Regional Scale Land Cover Change and Increasing CO2 over China   总被引：2，自引：0，他引：2  

Mei ZHAO  Andrew J. PITMAN 《大气科学进展》2005,22(1):58-68

A series of 17-yr equilibrium simulations using the NCAR CCM3 (T42 resolution) were performed to investigate the regional scale impacts of land cover change and increasing CO2 over China. Simulations with natural and current land cover at CO2 levels of 280,355, 430, and 505 ppmv were conducted. Results show statistically significant changes in major climate fields (e.g. temperature and surface wind speed) on a 15-yr average following land cover change. We also found increases in the maximum temperature and in the diurnal temperature range due to land cover change. Increases in CO2 affect both the maximum and minimum temperature so that changes in the diurnal range are small. Both land cover change and CO2 change also impact the frequency distribution of precipitation with increasing CO2 tending to lead to more intense precipitation and land cover change leading to less intense precipitation-indeed, the impact of land cover change typically had the opposite effect versus the impacts of CO2. Our results provide support for the inclusion of future land cover change scenarios in long-term transitory climate inodelling experiments of the 21st Century. Our results also support the inclusion of land surface models that can represent future land cover changes resulting from an ecological response to natural climate variability or increasing CO2. Overall, we show that land cover change can have a significant impact on the regional scale climate of China, and that regionally, this impact is of a similar magnitude to increases in CO2 of up to about 430 ppmv. This means that that the impact of land cover change must be accounted for in detection and attribution studies over China.  相似文献   

近40a江苏省冬季气温异常的演变及其涨气背景场特征   总被引：6，自引：1，他引：6  

吴志伟  朱筱英  孙瑞林 《南京气象学院学报》2001,24(4):581-586

通过1961－1998年江苏省11个站点冬季平均气温的EOF分析，探讨江苏省冬温异常的演变特征，并分析其同期及前期500hPa高度距均，海温距平场的特征，指出冬季异常冷年，同期与前期500mPa高度距平场主要表现为亚洲－太平洋地区阻塞形势发展，经向环流加强，同期至前期6个月赤道东太平洋海温为持续负距平。而暖冬同期与前期500hPa高度距平场的特征特征是，西太平洋海温为持续负距平。而暖冬同期与前期500hPa高度距平场的特征是，西太平洋副高势力较强，亚欧大陆中高纬 纬向环流占优势，同期赤道东太平洋海温具有厄尔尼诺的特征，但前期赤道东太平洋海温距平具有由负向正转变特征。  相似文献   

宁波市气候变化对水资源的影响     

钱燕珍  张建勋  胡亚旦  何彩芬  罗林 《气象》2001,27(6):51-54

通过对宁波市水资源有关参数的计算，了解宁波水资源状况，根据工农业和生活用水，经济发展规划对水资源的需求，分析了宁波市气候和气候变化对水资源的影响，为更好地促进水资源向可利用水资源的转化，利用和开发好水资源提出了建议。  相似文献   

气团分类及其与贵州气候灾害的关系     

李玉柱  吉廷艳  杨利群 《气象》2001,27(11):27-30

通过对贵州3站点历年逐日地面气象要素进行统计分类，分析影响贵州的气团活动规律，并对贵州气候灾害与各类气团活动频数作相关分析。结果表明：贵州气候受多种气团活动的影响，各型气团对应特定的天气特征及一定的环流背景。另外，气候灾害与某些气团活动变化具有很好的相关性，这对进一步研究贵州气候变化及气候灾害成因具有一定的现实意义。  相似文献   

兰州市气象与污染环境背景综述   总被引：2，自引：0，他引：2  

杨民  王锡稳  李文莉  王鹏祥  王小燕 《干旱气象》2001,19(4):11-15

利用 196 0～ 2 0 0 0年气候统计资料和 1975～ 2 0 0 0年环境监测资料 ,从地理位置、大、小尺度气候背景、兰州市区污染源概况及主要污染物的时空分布等方面 ,分析该市的气候与污染环境背景 ,为兰州市空气质量预报方法和模式的建立提供依据  相似文献