黑龙江省空中水资源的时空分布特征

应用黑龙江省80个气象台站1960～2007年的逐日气象资料,分析了黑龙江省整层大气可降水量和自然降水效率的时空分布特征。结果表明,黑龙江省大气可降水量分布区域差异较大,总体上呈现由南向北递减的分布趋势;自然降水率分布存在明显的差异,大兴安岭北部、小兴安岭山脉及其南端年平均降水效率相对较高,大庆、齐齐哈尔南部、绥化南部较小;全省年大气可降水量存在不规则波动,年际变化不大;年大气可降水量主要集中在夏秋两季,占全年的78.2%;大气可降水量的月际变化呈单峰结构,全年的整层大气可降水量主要集中在5～10月,占全年的84.2%。     

A neoproterozoic snowball earth

Negative carbon isotope anomalies in carbonate rocks bracketing Neoproterozoic glacial deposits in Namibia, combined with estimates of thermal subsidence history, suggest that biological productivity in the surface ocean collapsed for millions of years. This collapse can be explained by a global glaciation (that is, a snowball Earth), which ended abruptly when subaerial volcanic outgassing raised atmospheric carbon dioxide to about 350 times the modern level. The rapid termination would have resulted in a warming of the snowball Earth to extreme greenhouse conditions. The transfer of atmospheric carbon dioxide to the ocean would result in the rapid precipitation of calcium carbonate in warm surface waters, producing the cap carbonate rocks observed globally.     

江西千烟洲大气降水和河流酸化特征对比分析

摘要：对2013年江西千烟洲地区大气降水和河流进行采样对比分析,研究结果表明：（1）江西千烟洲地区降水呈现出酸性,同处亚热带森林地区的河流呈现出弱酸—弱碱性。（2）用[SO42-+NO3-]当量浓度估算出来的大气降水和河流酸度相差不大,降水和河流pH的差异主要与它们碱性物质含量不同有关。（3）江西千烟洲地区由于大量降水和地表森林覆盖度较高,大气中碱性气溶胶含量较少,对酸缓冲能力较弱;河流通过土壤淋溶出大量的Ca2+、Mg2+等阳离子,酸中和能力较高,对酸缓冲敏感。     

宁夏夏季各月降水的时空分布及与74类大气环流指数的关系初探

使用EOF方法,对宁夏全境具有代表性的19个气象观测站的1961～2008年夏季各月降水资料进行了时空分解,得到了夏季各月降水的EOF空间分布特征和时间系数变化趋势。利用国家气候中心资料室提供的1961～2008年共48年的74类月大气环流指数资料,对大气环流指数与宁夏夏季各月降水量之间的相关性进行了分析,得出了相关指数因子。利用最优子集回归方法(OSR)从相关因子中筛选出了最能拟合各月降水的4个关键因子,建立了最优子集回归预报方程,对1962～2008年共47年的夏季各月降水距平进行了回报,得出了各观测站夏季各月的历史拟合率。     

2015年武汉市PM2．5变化特征及其与气象要素的关系

利用空气质量监测数据和气象观测数据,采用统计分析方法,对武汉市2015年PM2．5变化特征及其与降水、气温、风速、气压和相对湿度的关系进行分析。结果表明,PM2．5浓度变化趋势呈U型,1～12月的浓度变化是逐渐先减小后增大;1～3、10～12月的浓度大于4～9月的浓度,其中1月浓度最大,7月浓度最小,冬季各个月份的浓度普遍比夏季高。 PM2．5浓度与月平均气温、月降水量呈现负相关关系,与月平均气压呈现正相关关系,最大风速和平均相对湿度对于PM2．5浓度的影响存在双重性。     

Characteristics of Heavy Metal Circulation in Biosphere

In order to control heavy metal pollution effectively, this paper reviews heavy metal source and transport characteristics in heavy metal circulation in bio- sphere, including geochemical cycle and biological cycle of heavy metals. The inter- body of geochemical cycle of heavy metals includes soil, gas as well as water body, and the interbody of biological cycle of heavy metals includes environment, plant, microorganisms and animals. As to macro-cycle, transportation character in each interbody is different. Heavy metal circulation in different interbody interacts with each other and is in dynamic balance. Heavy metals in soil include two parts, i.e. active and inert forms, which are in dynamic equilibrium. This equilibrium may be affected by different physicochemical factors. Heavy metal content at different soil depth reflects historical accumulation level of heavy metal. In contrast to agri- cultural eco-system itself, industrial and urban activities are of great menace. Fluvial transport and atmospheric input are significant pathways of heavy metal circulation. Sludge plays an accumulative role of heavy metals, and can release its heavy met- als to water body causing secondary pollution. Balance of heavy metal immobiliza- tion and release is interrupted by physicochemical characters and microbial activity. Temperature can influence atmospheric heavy metal content, and volatile heavy meal precipitation is an indLspensable source in soil and water body. In regard to micro-cycle, plants is the main part in heavy metal cycle, microorganisms play roles in accelerator and animals in recipient. Specific transportation and assigned location of heavy metal in plants are adopted to keep internal heavy metal equilibrium.     

张掖大气降水的δ~（18）O特征及水汽来源

利用全球同位素监测网（GNIP）张掖站的大气降水环境同位素数据,分析了张掖大气降水中δ18O的变化规律,通过分析其与气温和降水之间的关系,发现δ18O月加权平均值表现出很好的温度效应,且其与降水成正相关关系,这与张掖干旱半干旱气候有关。对张掖大气降水线的研究发现,当地大气降水线（LMWL）比全球降水线（GMWL）及中国降水线的斜率和截距都低。冬秋季降水线的斜率低于春夏季,原因是局地蒸发的水汽在春夏季占有较大的比重,并且受海洋性水汽影响较大。利用降水同位素资料结合后向轨迹法（Backwards Trajectory）对张掖水汽来源进行推断,结果表明,张掖全年以西风带大陆性水汽为主,春夏季还会受到海洋性水汽的影响,同时由于较高的温度,春夏季受局地蒸发性水汽的影响相当明显。     

塔里木盆地降水中稳定同位素变化特征浅析——以和田地区为例

通过分析1988～1992年间和田降水样品的D和18O,建立了该地区的大气降水方程,并与全国及全球降水线性方程进行对比,揭示该降水方程的特征。结果表明,和田降水来源复杂;大气降水的18O与月平均气温相关性显著,与雨量效应(降水量效应)显著相关,降水中温度效应明显,且在很大程度上掩盖了雨量效应。和田降水中δ18O的季节变化与温度的季节变化基本一致,温度是制约降水中稳定同位素变化的主要影响因子。     

Atmospheric warming and the amplification of precipitation extremes

Climate models suggest that extreme precipitation events will become more common in an anthropogenically warmed climate. However, observational limitations have hindered a direct evaluation of model-projected changes in extreme precipitation. We used satellite observations and model simulations to examine the response of tropical precipitation events to naturally driven changes in surface temperature and atmospheric moisture content. These observations reveal a distinct link between rainfall extremes and temperature, with heavy rain events increasing during warm periods and decreasing during cold periods. Furthermore, the observed amplification of rainfall extremes is found to be larger than that predicted by models, implying that projections of future changes in rainfall extremes in response to anthropogenic global warming may be underestimated.     

牡丹江市污染物浓度变化与气象要素关系分析

利用牡丹江市(2005—2011年)大气污染物(SO2、NO2、PM10)浓度实际监测数据及同期地面气象要素场资料、天气图资料,分析了污染物浓度变化与气象条件的关系。结果表明,夏季降水对污染物的稀释有一定影响,1.0 mm以下降水对污染物的稀释作用不明显。但降水量R≥10 mm时降水对污染物的稀释作用较大,一些污染物浓度减少概率占60%以上。当风速小于1 m/s时,污染物浓度明显偏大,冬季浓度是夏秋季节浓度的2倍多。     

Isotopic evidence for reduced productivity in the glacial southern ocean

Records of carbon and nitrogen isotopes in biogenic silica and carbon isotopes in planktonic foraminifera from deep-sea sediment cores from the Southern Ocean reveal that the primary production during the last glacial maximum was lower than Holocene productivity. These observations conflict with the hypothesis that the low atmospheric carbon dioxide concentrations were introduced by an increase in the efficiency of the high-latitude biological pump. Instead, different oceanic sectors may have had high glacial productivity, or alternative mechanisms that do not involve the biological pump must be considered as the primary cause of the low glacial atmospheric carbon dioxide concentrations.     

滨州市(鲁北地区)干旱气候特征及趋势分析

利用滨州市1971~2000年降水、气温、湿度等资料,解析滨州市(鲁北地区)干旱化趋势。结果表明,滨州市降水量每10年减少26mm。升温达0.03℃/a,夏秋季温度升高,其中20世纪90年代比70年代高出0.5℃以上,特别是冬季竟高出了1.4℃。这与全国乃至全球变暖趋势一致。通过对滨州1971~2000年观测资料中有关数据的计算,滨州市近30年气候变化已呈现出年降水量总体上持续降低、气温总体上持续升高,且当地水热平衡已明显呈现出新的关系和规律的状况。滨州市年湿润指数呈明显下降趋势,气候干旱化。湿润指数平均10年减少0.057,主要原因是降水量逐年减少,气温逐年上升。受其影响,蒸散量平均每10年增加26.85 mm。滨州市这种干旱化趋势与副高综合指数、副高面积和强度指数的年代际变化与极涡中心平均纬度和平均经度的年代际变化有直接关系。     

四川盆地夏季区域性极端降水事件特征及其成因

利用四川盆地1981-2015年夏季102个气象台站逐日降水资料, NCEP/NCAR逐日再分析资料,分析了四川盆地区域性降水及极端降水事件的时空特征,对极端降水事件发生的环流场进行合成分析,讨论其环流异常特征.研究表明:近35年四川盆地总降水量及夏季降水量时空变化特征较为一致;盆地夏季区域性极端日降水量的99%分位阈值为40.5 mm/d, 2005年开始极端日降水事件明显增多,区域性极端降水事件多发于7月下旬以及8月中旬;极端日降水事件呈现低层辐合、高层辐散的环流结构;端日降水事件的形成与四川盆地的大气净加热以及周边大范围地区的净冷却形成的加热场异常梯度有关.     

柴河流域典型区域大气降尘量年内变化特征研究

[目的]研究柴河流域大气降尘总量和可燃物总量随时间的年内变化规律。[方法]以滇池南部柴河小流域为研究区域,选择该流域居民点、化工区、砂石生产区、水源地4种典型区域测定大气降尘量和降尘可燃物量,探讨该流域大气降尘污染状况及其年内变化规律。[结果]居民点、化工区、砂石生产区及水源地4个区域中,砂石生产区降尘量(降尘可燃物量)最高,水源地最低,而化工区和居民点降尘量低于砂石生产区,高于水源地;在所选取的4个区域中,一年降尘量(降尘可燃物量)最高值出现在旱季,最低值出现在雨季,其他月份降尘量(降尘可燃物量)也有变化,但变化幅度不大,说明气象条件对降尘含量影响较大;相关性分析表明,砂石生产区降尘量与降尘可燃物量呈极显著相关,水源地降尘量与降尘可燃物量呈显著相关,居民点和化工区降尘量与降尘可燃物量均呈正相关。[结论]该研究为柴河流域大气污染状况提供科学依据     

生物活性菌剂对烤烟生长影响的研究

为研究生物活性菌剂的使用对烤烟生长的影响,在试验田中施用3种不同剂量的生物活性菌剂,并以不施用生物活性菌剂试验田为对照,对烤烟农艺性状、抗病性、经济性状、原烟外观质量、内在质量等方面进行测定。单因素方差分析和差异性检验结果显示,使用生物活性菌剂的试验田烤烟农艺学性状、抗病性、经济效益和内在化学成分等方面均不同程度地好于对照,2.25 L/hm2用量试验处理下的烤烟农艺性状、抗病性、经济效益和内在化学成分等方面显著好于0.75 L/hm2和1.5 L/hm2用量下的表现。以上结果表明,生物活性菌剂的施用对于烤烟农艺性状、抗病性、经济效益和内在化学成分等方面有显著的促进作用。     

Retroviral DNA integration directed by HIV integration protein in vitro

Efficient retroviral growth requires integration of a DNA copy of the viral RNA genome into a chromosome of the host. As a first step in analyzing the mechanism of integration of human immunodeficiency virus (HIV) DNA, a cell-free system was established that models the integration reaction. The in vitro system depends on the HIV integration (IN) protein, which was partially purified from insect cells engineered to express IN protein in large quantities. Integration was detected in a biological assay that scores the insertion of a linear DNA containing HIV terminal sequences into a lambda DNA target. Some integration products generated in this assay contained five-base pair duplications of the target DNA at the recombination junctions, a characteristic of HIV integration in vivo; the remaining products contained aberrant junctional sequences that may have been produced in a variation of the normal reaction. These results indicate that HIV IN protein is the only viral protein required to insert model HIV DNA sequences into a target DNA in vitro.     

Iron isotope constraints on the Archean and Paleoproterozoic ocean redox state

The response of the ocean redox state to the rise of atmospheric oxygen about 2.3 billion years ago (Ga) is a matter of controversy. Here we provide iron isotope evidence that the change in the ocean iron cycle occurred at the same time as the change in the atmospheric redox state. Variable and negative iron isotope values in pyrites older than about 2.3 Ga suggest that an iron-rich global ocean was strongly affected by the deposition of iron oxides. Between 2.3 and 1.8 Ga, positive iron isotope values of pyrite likely reflect an increase in the precipitation of iron sulfides relative to iron oxides in a redox stratified ocean.     

两场短时强降水过程的对比分析

采用概念模型预报法,从降水实况、天气形势、物理量特征、雷达回波演变等方面,对2008年6月12和14日厦门的两次短时强降水过程进行对比分析。结果表明,这两场短时强降水过程具有完全不同的天气背景,因而反映大气热力、动力特征的各种物理量表现不同,其雷达回波特征及演变过程也有所不同,说明厦门的两次强降水过程有不同的形成机制和演变过程。因此,预报中要结合多种资料准确把握预报着眼点。     

The sulfur cycle

Even granting our uncertainties about parts of our model of the sulfur cycle, we can draw some conclusions from it: 1) Man is now contributing about one half as much as nature to the total atmospheric burden of sulfur compounds, but by A.D. 2000 he will be contributing about as much, and in the Northern Hemisphere alone he will be more than matching nature. 2) In industrialized regions he is overwhelming natural processes, and the removal processes are slow enough (several days, at least) so that the increased concentration is marked for hundreds to thousands of kilometers downwind. 3) Our main areas of uncertainty, and ones that demand immediate attention because of their importance to the regional air pollution question, are: (i) the rates of conversion of H(2)S and SO(2) to sulfate particles in polluted as well as unpolluted atmospheres; (ii) the efficiency of removal of sulfur compounds by precipitation in polluted air. And for a better understanding of the global model we need to know: (i) the amount of biogenic H(2)S that enters the atmosphere over the continents and coastal areas; (ii) means of distinguishing man-made and biogenic contributions to excess sulfate in air and precipitation; (iii) the volcanic production of sulfur compounds, and their influence on the particle concentration in the stratosphere; (iv) the large-scale atmospheric circulation patterns that exchange air between stratosphere and troposphere (although absolute amounts of sulfate particles involved are small relative to the lower tropospheric burden); (v) the role of the oceans as sources or sinks for SO(2).     

油松人工林养分循环的研究——Ⅲ.养分元素生物循环和林分养分的平衡

在1983年4月至1984年10月两个生长季中,我们对河北隆化的一片油松人工林养分元素生物循环进行了研究,同时,实测了林分养分元素的输入、输出量。实验林分养分总积累量(五种元素总量为575.46公斤/公顷,林木年吸收量为122.72公斤/公顷,归还量为69.9公斤/公顷·年,养分归还主要是以枯落物形式到达林地,这部分占总归还量的86％。以归还/吸收作为循环速率参数,各元素平均为0,57。林分养分的输入、输出主要受降雨和林地状况影响,由于实验地区年均降雨量较小(<500毫米),近几年又连续受旱,大气输入养分量及林分输出养分量均较小。林分的养分平衡,氮、磷略有盈余,钾、钙、镁有少量亏损。