Wet deposition of excess sulfate at Macquarie Island, 54° S     

G. P. Ayers  S. L. Ramsdale 《Journal of Atmospheric Chemistry》1988,7(4):317-323

Annual wet deposition of excess sulfate at Macquarie Island has been estimated from 5 months of rainwater composition data covering the Austral summer of 1985/86. The resulting figure of 2.1±0.6 mmol/m²/yr is at the low end of previous estimates of maritime excess sulfate deposition by precipitation. Within estimated uncertainty limits this figure is consistent with the DMS emission flux which would be predicted for latitude 50°–60° S, based solely on available Northern Hemispheric DMS measurements.Temporarily at the International Meteorological Institute, Stockholm University, S-106 91, Stockholm, Sweden.  相似文献   

四川省宁南县城后山泥石流激发雨强     

李德基  张德华 《山地学报》1994,(1)

根据宁南县城后山垂直剖面观测资料，对本区降雨的垂直变化及泥石流激发雨强作了探讨。当地暴雨泥石流发生所需的１０分钟雨强ｉ＿（１０ｍｉｎ）和前期降水量Ｐａ组合为：：ｉ＿（１０ｍｉｎ）≥１５ｍｍ∩Ｐａ≥５０ｍｍ，或ｉ＿（ｍｉｎ）≥１０ｍｍ∩Ｐａ≥６５ｍｍ，或ｉ＿（１０ｍｉｎ）≥５ｍｍ∩Ｐａ≥９０ｍｍ。超过上述各组合值就有可能暴发泥石流。  相似文献   

Formic and acetic acids in atmospheric condensate in Wilmington,North Carolina     

Joan D. Willey  Carol A. Wilson 《Journal of Atmospheric Chemistry》1993,16(2):123-133

Formic and acetic acids occurred in atmospheric condensate with concentrations similar to rainwater collected in Wilmington, North Carolina, during the sampling period from June to October of 1990. Atmospheric concentrations of these acids (calculated from the condensate concentrations) were higher in continental versus maritime air masses. Concentrations of formic and acetic acids were correlated with each other in both condensate and air. Traffic was a source of acetic acid and of bisulfite to atmospheric condensate in this study.  相似文献   

云、雨水酸度和离子浓度与其微物理参数的关系   总被引：3，自引：0，他引：3       下载免费PDF全文

刘奇俊  丁国安  汤洁  房秀梅  吴凡  苏维瀚 《气象学报》1993,51(2):195-202

本文1987年5-6月和1989年5-6月庐山地区的实测资料,分析了云、雨水酸度和离子浓度与其微物理量间的关系。结果表明,云、雨滴大小、含水量、谱宽等微物理量的演变直接影响着其酸度和离子浓度。  相似文献   

9012台风倒槽结构与暴雨中尺度系统          下载免费PDF全文

楼茂园 《气象》1993,19(3):7-12

利用高空资料、地面资料和红外卫星云图资料,对发生在浙江中北部的9012台风倒槽暴雨的机制进行分析,揭示了该台风倒槽的结构和暴雨的环境场。并进一步研究了产生暴雨的中尺度暴雨云团及其周围的垂直气流分布与地面降水的对应关系。对暴雨云团所对应的高、中、低(地面)层系统亦进行了分析。  相似文献   

9216号热带风暴的初步分析     

韩春深 《气象》1993,19(7):27-30

对9216号热带风暴在9月1日02时中心分裂的原因,作了初步探讨,认为东南低空急流使热带风暴倒槽区的气旋性环流加强,以及低涡的吸引合并,是产生新中心的原因。青岛产生大暴雨的条件,是充沛的水汽,强烈的上升运动和长波槽东移影响。  相似文献   

1990 年京津冀三次暴雨的分析   总被引：5，自引：1，他引：5       下载免费PDF全文

刘延英  许晨海 《应用气象学报》1993,4(3):349-355

本文分析了1990年京津冀地区三次暴雨过程，结果发现:（1）三次暴雨是属于相伴有冷锋的高空槽影响的暴雨；（2）暴雨开始前约10小时雨区的西南方存在湿有效能量高能舌，高能舌的西方和北方有能量和水汽的积聚；（3）对流层低层的锋生和地形对气流的抬升作用是触发暴雨开始的直接原因。  相似文献   

闽粤台沿海北西西向最新构造带与大震构造背景   总被引：3，自引：0，他引：3       下载免费PDF全文

毕福志  袁又申 《地震地质》1990,12(2):183-192,T001

闽粤台沿海自台湾运动以来逐渐形成了多条北西西向隆起—拗陷的最新活动构造带,与已知的北东—北北东向隆起、拗陷带构成了区域性镶嵌构造格局。 研究区内除板块相互碰撞、俯冲及上地幔物质上涌形成大震构造背景外,莫霍面隆起或隆起断距大、低速层厚、地壳变薄、近两、三千年地表抬升差异活动显著以及台东近海有北西西向构造活动等,也都是发生大震的重要构造背景  相似文献   

Model studies of the impact of chemical inhomogeneity on SO2 oxidation in warm stratiform clouds     

Xing Lin  William L. Chameides 《Journal of Atmospheric Chemistry》1991,13(2):109-129

A one-dimensional, time-dependent model of the physics and chemistry of a warm stratiform cloud is used to study the possible impact of chemical inhomogeneity among cloud and raindrops on the oxidation of SO₂ in clouds. The effects of chemical inhomogeneity are examined using two contrasting models: In Model 1 a bulk-solution parameterization is adopted which effectively treats all cloud and raindrops as if they are chemically homogeneous; in Model 2 we allow the cloud and raindrops to have a dichotomous distribution. The dichotomous distribution in Model 2 is simulated by assuming that the two groups of cloud droplets nucleate from two chemically distinct populations of condensation nuclei; one being acidic and the other being alkaline. While the two models yield essentially identical results when the ambient levels of H₂O₂ are greater than the ambient levels of SO₂, the rate of conversion of SO₂ to sulfuric acid and the amount of sulfate removed in the precipitation can be significantly enhanced in Model 2 over that of Model 1 under conditions of oxidant limitation (i.e., H₂O₂ < SO₂). This enhancement is critically dependent upon the fraction of alkaline nuclei assumed to be present in Model 2 and arises from the rapid increase in the aqueous-phase reaction between O₃+S_IV at high pH. Our results suggest that cloud models which adopt a bulk-solution parameterization for cloud droplet chemistry, may underestimate the amount of in-cloud SO₂ oxidation under oxidant-limited conditions.  相似文献   

On the scavenging of SO2 by cloud and rain drops: IV. A wind tunnel and theoretical study of the absorption of SO2 in the ppb(v) range by water drops in the presence of H2O2     

A. Waltrop  S. K. Mitra  A. I. Flossmann  H. R. Pruppacher 《Journal of Atmospheric Chemistry》1991,12(1):1-17

An experimental study involving the Mainz vertical wind tunnel is described where the rate of SO₂ removed from the air by freely suspended water drops was measured for SO₂ concentrations in the gas phase ranging between 50 and 500 ppb, and for various H₂O₂ concentrations in the liquid phase. In a first set of experiments, the pH inside the SO₂ absorbing drops was monitored by means of colour pH indicators added to the drops. In a second set of experiments, the amount of SO₂ scavenged by the drops was determined as sulfate by an ionchromatograph after the drops had been removed from the vertical air stream of the wind tunnel after various times of exposure to SO₂. The results of our experimental study were compared with the theoretical gas diffusion model of Walcek and Pruppacher which was reformulated for the case of SO₂ concentrations in the ppbv(v) range for which the main resistance to diffusion lies in the gas phase surrounding the drop. Excellent agreement between experiment and theory was obtained. Encouraged by this agreement, the theory was used to investigate the rate of sulfate production inside a drop as a function of pH. The sulfate production rate, which includes transport and oxidation, was compared with the production rate based on bulk equilibrium, as cited in the literature.  相似文献