厄尔尼诺现象和浙江近海鲐鲹鱼渔获量变化关系──长江口ENSO渔场学问题之二   总被引：12，自引：0，他引：12  

洪华生  何发祥  杨圣云 《海洋湖沼通报》1997,(4)

本文研究浙江近海1970年到1992年鲐鱼渔获量变化与Elnino现象的关系，结合捕捞强度，长江中下游汛期（4—9月）降水量距平年际变化综合分析，探讨浙江近海鲐鱼渔获量变动规律，为合理开发渔业资源提供科学依据。  相似文献   

Objective Analysis on Large-scale Circulation Type and Its Links to Precipitation over China     

Liang Chen  Jianping Duan  Zhuguo Ma 《地球科学进展》2018,33(4):396-403

Atmospheric circulation anomaly is a direct cause of weather and climate change. In the past, most researches for the relationship between Weather Type (WT) and precipitation have mainly focused on the subjective classification and diagnosis. Compared to the subjective analysis, objective classification uses more consistent index and standard unification, thus, we can get more WTs, and it has been widely used in many areas. By using daily 12UTC Sea Level Pressure (SLP), Precipitable Water (PW), and 700 hPa wind speed (UV700) data from ECMWF’s Interim Reanalysis, the classification of WTs over China was performed with the method of obliquely rotated T-mode principle component analysis. WT and its link to precipitation over China were further analyzed. The results show that the influence of different WTs on precipitation is not uniform over China, and also show distinctly difference in different seasons. A common feature is that WTs great impact on the regions and months with large precipitation, while less impact on regions and months have with less precipitation. In addition, precipitation trends originating from WT intensity changes are much more deterministic, significant, and predictable than trends from WT frequency changes.  相似文献   

Study of occurrence states and precipitation mechanism of tellurium in Huangtun Au -Cu -bearing breccia pipe in Luzong Basin,Anhui, eastern ChinaSCIEI北大核心CSCD     

王彪  范裕  周涛发  李飞  赵永建  钟镇海  刘冠宇  高轩昊 《岩石学报》2023,(10):3048-3068

隐爆角砾岩筒型金(铜)矿床作为重要的金矿床类型,常伴生关键金属碲的矿化,然而对于此类矿床中碲的分布、分配特征及沉淀机制研究仍较为薄弱。黄屯矿床是长江中下游成矿带近年来发现的最为典型的隐爆角砾岩筒型金铜矿床,伴生有大量的碲化物产出。本文在详细的野外地质工作和岩相学观察基础上,发现碲在矿床中发生了显著富集。通过对黄屯矿床不同蚀变类型矿石及主要富碲矿物开展全岩及微区地球化学分析,明确了碲的分布、分配特征以及初步讨论了碲的沉淀机制。黄屯矿床成矿阶段从早到晚可划分为钠钙硅酸盐、钾硅酸盐、绿泥石-碳酸盐和伊利石-蒙脱石阶段,在不同深度形成了相应的蚀变带,并发育有不同强度的金铜矿化。黄屯矿床伴生的碲储量约有118.71t,平均品位为5.3g/t,达到中型规模,具备重要的综合利用价值。钾硅酸盐蚀变带碲的分布比例最高,占总储量约92.37%,平均品位约为9.6g/t。钾硅酸盐蚀变带内约有89%~99%的碲呈独立矿物,主要以微米级、纳米级的碲铋矿包体的形式分布在黄铁矿中,剩余部分则以类质同象的形式赋存在黄铁矿和黄铜矿内。减压沸腾引起流体温度骤降导致硫化物沉淀,和沸腾过程中释放大量气相H_(2)S,共同导致流体的f(Te_(2))/f(S_(2))比值升高,可能是黄屯矿床中碲沉淀富集的主要机制。  相似文献   

济南泉域地下水位动态及其对降水响应的交叉小波分析   总被引：8，自引：0，他引：8  

祁晓凡  杨丽芝  韩晔  尚浩  邢立亭 《地球科学进展》2012,27(9):969-978

利用1988—2009年济南泉域8个地下水位动态观测点不同时段观测资料及1998—2009年降水数据,采用连续小波变换、交叉小波变换方法对济南泉域地下水位动态的多时间尺度特征、相互关系及其对降水的响应进行了分析。结果表明:①济南泉域地下水位动态存在显著的0.82～1.16 a的主振荡周期,低频部分仅在部分年份存在1.95～3.09 a的振荡周期;②含水岩组富水性对地下水位动态存在影响,研究区主径流方向上弱富水性地段地下水位动态时滞较强富水性地段长,强富水性地段4个观测孔地下水位波动时序基本一致;③地下水位动态对降水的响应滞后明显,为73.06～134.42 d,总体表现为地下水径流路径越长,响应越滞后;④基于地下水位动态与基于降水—地下水位动态交叉小波变换得到的观测点对水位动态的滞后时间多数一致,同一径流路径上局部点对滞后时间之和与全局点对有很好的对应关系。交叉小波分析可定量评价泉域地下水位动态及其与降水的相关关系。  相似文献   

土壤温湿状况对黄河源区水循环过程的影响     

彭雯  高艳红  王婉昭 《地球科学进展》2012,27(11):1252-1261

众多研究表明黄河源区受气候变化影响,土壤活动层逐渐下降。土壤温、湿度是陆面过程及地球系统中的重要物理量,它们通过影响地表能量和物质交换而影响大气环流和降水等。利用WRF（Weather Research and Forecasting）模式,选取2个典型年分别设计了2个控制试验和2个敏感性试验来探讨土壤初始状况变化对区域水循环的影响,通过再循环降水率定量描述不同气候背景下陆面对黄河源区水循环的影响,并尝试从环流角度进一步分析土壤初始状况改变对源区水循环影响的物理机制。结果表明：陆面对水循环的影响受大尺度环流背景场影响较大,较弱的环流背景下再循环降水率较强环流背景大5%左右。土壤初始状况对水循环要素有一定程度的影响。土壤初始温度升高/降低,水汽通量增多/减少,后期降水增大/减小。不同环流背景下,土壤记忆时间不同,在弱的环流背景下,土壤记忆时间要长,初始状况扰动可持续1～2个月。  相似文献   

Links between NAO fluctuations and inter-annual variability of winter-months precipitation in the Seine River watershed (north-western France)     

Nicolas Fritier  Nicolas MasseiBenoit Laignel  Alain DurandBastien Dieppois  Julien Deloffre 《Comptes Rendus Geoscience》2012,344(8):396-405

The inter-annual to multi-decadal winter variability (DJFM) of precipitation on the Seine River watershed (France) was analysed using continuous wavelet transform analysis and compared to the winter North Atlantic Oscillation Index (NAOI). Nine weather stations were used over the 1951 to 2004 period and confirmed the homogeneity of inter-annual fluctuations for all stations but one. Wavelet coherence between SLP over the Icelandic and Azores regions and precipitation highlighted coherence for different scales of variability according to the centre of action considered. Segmentation and wavelet analysis and coherence between precipitation and NAOI over a long period of time (1873–2004) showed: i) increasing variability across the last century at most time scales, especially for NAOI; ii) the existence of change points for the mean and variance of both signals; iii) overall discontinuity of the coherence whatever the scale considered, especially between ∼1910 and ∼1955 for inter-decennial to pluri-decennial scales.  相似文献   

A mass balance approach to estimate the dilution and removal of the pollutants in stream water polluted by acid mine drainage     

J.-Y. Yu 《Environmental Geology》1998,36(3-4):271-276

 A few simple mass balance equations were developed to simultaneously estimate how much the pollutants from acid mine drainage (AMD) in stream water are diluted and removed during their migration. The application of the equations requires knowledge of the variations in the concentrations of the dissolved pollutants and the stoichiometry of the precipitation reaction of the pollutants when none of the pollutant shows a conservative behavior along the stream path. The calculation should be restricted to the pollutants showing much higher concentrations in the polluted main stream water than in the combining or diluting water of the same target area. The mass balance equations were applied to estimate the dilution factor and precipitation fractions of pollutants in Imgok Creek such as Fe, SO₄ and Al from the AMD of Yeongdong mine. The results show that the estimation, especially for SO₄ and Al, significantly depends on the kinds of the precipitates. When FeOHSO₄ and AlOHSO₄ are assumed to precipitate, the maximum removal fractions of SO₄ and Al by precipitation are respectively 34% and 46% of the original input, which is much higher than the values estimated when SO₄ is considered to be perfectly conservative. It indicates that the stoichiometry of precipitation reaction is very important in the interpretation of the pollutant dilution and migration and assessment of environmental impacts of AMD. The applicability of the mass balance equations may still need to be verified. However, examining the calculated dilution factor and precipitation fractions with the equations can provide invaluable information on not only the behavior but also unexpected input of the pollutants in the stream water polluted by AMD and other point sources. Received: 12 November 1997 · Accepted: 30 March 1998  相似文献   

江苏冬季降水相态气候分布特征及预报方法探讨   总被引：7，自引：4，他引：3       下载免费PDF全文

孙燕  严文莲  尹东屏  刘安宁 《气象科学》2013,33(3):325-332

利用1981-2010年南京、徐州、射阳逐日探空资料和地面观测资料,在分析冬季雨日、雪日、雨夹雪日气候特点的基础上,运用厚度分析的方法进一步研究江苏冬季不同降水相态的预报指标.结果表明:厚度分析能被用来识别降水相态(雨、雪),1 000～850 hPa厚度阈值1 292 gpm可以作为江苏冬季区分雨、雪的一个重要参考指标.同时结合地面温度和850 hPa温度可以较准确的判定降水的相态,即1 000～ 850 hPa厚度≤1 292 gpm,且T850≤-3℃,T≤2℃时,判定为雪;反之,则为雨.另外,地面湿球温度在雨雪区分上也是一个很有参考价值的指标.  相似文献   

2010-2011年鞍山市能见度特征          下载免费PDF全文

赵胡笳  马雁军  朱轶明  高清源 《气象与环境学报》2013,29(1):18-22

利用2010年6月至2011年5月鞍山大气成分观测站的能见度资料,统计分析能见度与PM₁₀、PM_2.5、PM_1.0质量浓度、风速、降水强度和气溶胶光学厚度等气象要素的相关性。结果表明：鞍山市能见度月均值从8月份开始呈上升趋势,11月份达到峰值后开始显著下降,2月份达到最低值,自3月开始又出现较大幅度增长,进入夏季后略有下降;PM_2.5/PM₁₀、PM_1.0/PM₁₀比值与能见度呈反相关,能见度增大,PM_2.5/PM₁₀、PM_1.0/PM₁₀比值减小,且PM_1.0/PM₁₀的减小趋势更大,说明影响能见度的颗粒物以细粒子为主。平均风速与能见度变化趋势基本一致,与PM_2.5/PM₁₀、PM_1.0/PM₁₀的变化趋势呈反相关。随着雨强的增大,降水日能见度平均值随之减小,降水前一日和后一日的能见度平均值均大于降水日,且降水前一日及后一日的能见度改变量及改变率的绝对值随着降水强度的增加而增加。波长指数的变化说明影响鞍山能见度变化的污染物粒子整体较稳定,能见度与AOD成明显的反相关。  相似文献   

过去2000年亚澳夏季风降水百年际变化特征及成因的模拟研究     

井云清  刘健  万凌峰  张宏栎 《气象学报》2020,78(1):60-71

利用地球系统模式（CESM）开展过去2000 年气候模拟试验,在利用观测资料、再分析资料对模拟资料进行检验的基础上,探讨百年时间尺度上亚澳夏季风降水的时、空变化特征及其成因,对于认识百年尺度气候变化规律、定量区分自然因子和人类活动对亚澳夏季风的影响具有重要意义。结果表明:过去2000 年亚澳夏季风降水和温度的波动较为一致,暖期降水多,冷期降水少。两者相关系数为0.83,达到99%置信度。此外,亚澳夏季风降水存在105、130、180 a的百年尺度周期。亚澳夏季风降水经验正交函数分解第一模态在印度洋北部呈南北反向的分布型态,在东亚地区呈负、正、负的分布型态;第二模态在印度洋北部呈正、负、正的分布型态,在东亚地区呈全区一致型的分布型态。经验正交函数分解第一特征向量和第二特征向量的正、负值中心大多出现在印度洋北部地区,南北呈不对称分布。亚澳夏季风降水的105 a周期主要受火山活动和土地利用/覆盖的影响,130 a周期主要受太阳辐射、气候系统内部变率的影响,180 a周期主要受火山活动的影响。从经验正交函数分解第一特征向量来看,整个亚澳夏季风降水主要受土地利用/覆盖、太阳辐射的影响;第二特征向量表明亚澳夏季风降水在百年际空间变化上主要受太阳辐射和气候系统内部变率的影响;第三特征向量表明亚澳夏季风降水在百年际空间变化上主要受气候系统内部变率和温室气体的影响。该研究对揭示百年际时间尺度气候变化特征、辨识影响气候变化的自然因素与人为因素、理解其影响气候的物理机制等具有重要意义,也为应对该区域气候变化提供了参考依据。   相似文献