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1.
长江入河口区生源要素的浓度变化及通量估算   总被引:38,自引:4,他引:38  
利用近几十年长江大通断面的实测流量和生源要素(C、N、P、Si)资料,讨论了C、N、P、Si较长时间序列浓度的变化特征和长江入河口区的通量,结果表明,HCO3^-浓度比较稳定,波动较小;NO3^-,NO2^-,PO4^3-主要呈上升趋势;游离CO2,NH4^ 和SiO3^2-浓度表现出一定下降趋势;估算并研究了长江C、N、P、Si入河口区年内各月的平均通量,年际间各年的通量和多年平均的年均通量和主要变化特征;利用月通量序列以及相应的流量序列,拟合出可以利用已知的月均流量预测进入河口区的月通量的关系函数,这些研究是进行河口区生源要素收支平衡计算的重要基础。  相似文献   

2.
The results of continuous minute measurements of the surface concentrations of ozone, nitric oxide, nitrogen dioxide, carbon monoxide, and sulfur dioxide during the 2002–2004 period at the environmental station of the Oboukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP), and the Faculty of Geography, Moscow State University (MSU), are discussed. It is shown that the conditions of Moscow’s southwestern region remote from large local pollution sources reflect the general regularities of the variability of trace gases in an urban atmosphere. This is manifested in the mean annual value of the ratio NO/NO2 (a little less than 1), decreased daylight values of O3, increased values of the rest of the trace gases as compared to the background region, and the presence of a secondary nocturnal maximum in the diurnal cycle of O3. The features of the annual and diurnal cycles of the concentrations of the substances under analysis are discussed. In the diurnal cycle of the primary products of combustion (NO and CO), an excess of the morning maximum (over the evening one) is observed during both warm and transition periods and higher values of the night maximum (as compared to the daylight one) are noted for summer. The temperature stratification properties determined from the MSU long-term acoustic sounding data serve as a possible cause for both of the effects revealed. The annual cycle of the concentration of surface ozone is characterized by the highest values for spring and summer. The annual cycles of NO, NO2, CO, and SO2 do not demonstrate any obvious seasonal regularities. A significant seasonal variation of the ratio NO/NO2, which is associated with the oxidizing properties of the urban atmosphere, is revealed. The record high concentrations of trace gases in the atmosphere over Moscow are given, and the meteorological conditions for their accumulation are discussed.  相似文献   

3.
In the summer of 2010, the Moscow megacity during two months was within the zone of action of a blocking anticyclone. The accumulation of pollutants in a closed air mass sharply changed the surface air quality. At the end of July-the first half of August, the extreme situation became even more complicated, because the air from regions of turf and grass fires came into Moscow. According to measurement data of the Moscow IAP RAS station, the maximal hourly mean concentrations of chemically active gases NO, NO2, CO, O3, and SO2 were 175.9, 217.4, 15.8, 134.2, and 15.2 ppb, respectively. For NO2 and CO, these values are largest over the entire decadal period of observations at the station and many times exceed the MPC level (see table). The concentrations of greenhouse gases CO2, CH4, and nonmethane hydrocarbons also sharply increased. Analysis of the variability of gas contents in the surface air and in the atmospheric boundary layer showed a close relation between extreme changes in the atmospheric composition and its vertical stratification.  相似文献   

4.
长江河口淡水端溶解态无机氮磷的通量   总被引:15,自引:1,他引:15  
1998年2和9月在长江河口淡水端连续观测了DIN(NO3-,NO2-,NH4+),PO43-,流速和流向.结果表明,溶解态无机氮、磷浓度的时空变化较复杂;1998年2月NO3-,NO2-,NH4+和PO43-的月通量分别为168241,974.4,19335和2648t,9月的月通量分别为905678,8317,5797和6281t;1998年NO3-,NO2-,NH4+和PO43-年通量分别为497.1×104,3.911×104,10.22×104和4.155×104t.  相似文献   

5.
广西钦州内湾贝类养殖海区三氮的含量和百分组成   总被引:4,自引:1,他引:4  
本文根据1998年10月和1999年5月的调查资料,报道了钦州内湾帆类养殖海区三态氮的含量和百分组成。结果表明:NO3-N是本水域无机氮的主要存在形式;三态氮之间的相互转化以春季进行得比较充分,95.70%均已转化为NO3-N,基本达到了热力学平衡状态,NO3-N与NH4-N和NO2-N之间均具有显著的正相关关系;秋季,只有79.87%的无机氮转化为NO3-N,没有达到热力学平衡状态,但NO3-N与NH4-N却具有高度显著的负相关关系,与NO2-N的相关性较差。  相似文献   

6.
根据 2 0 0 0年夏季在北京 32 5 m铁塔上的一次梯度观测实验 ,给出 8m,12 0 m和 2 80 m三层上的 NO、NO2 、O3 浓度的观测结果。对 NO,NO2 ,O3 小时平均浓度的日变化和垂直分布规律进行了分析 ,结果发现 :(1)各高度上的 NO,NO2 ,O3 浓度均有明显的日变化特征 ,阴雨天的日变化更加复杂 ;(2 ) O3 在晴朗白天有单、双及三峰型分布 ;(3)相对于 12 0 m和 2 80 m,近地面 8m处的 NO浓度最高 ,而 O3 浓度最低 ;(4) NO2 、O3 日平均浓度日变化振幅 12 0 m处最大 ;(5 )中午前后 NO,NO2 ,O3 浓度均在 12 0 m最高。  相似文献   

7.
Dark respiration (non-photorespiratory mitochondrial respiration),which occurs both in the light and in darkness,is vital for growth and survival of algae and plays a critical role in modulating the carbon balance of them.In the present study,we have investigated dark respiration in the light (R L) and in darkness (R D) in three marine macroalgal species,Hizikia fusiformis (phaeophyta),Gracilaria lemaneiformis (Rhodophyta) and Ulva lactuca (Chlorophyta),cultured at 20℃ using aeration with two CO 2 conditions:current ambient (CO 2 concentration about 380 μl/L) and elevated CO 2 (approximately 720 μl/L) air.R L was estimated by using the Kok method,whereas R D was determined as the rate of O 2 influx at zero light.The results showed that both R L and R D were unchanged for the elevated CO 2-grown algae relative to ambient CO 2 concentration for all the algal species tested.However,R L was significantly lower than R D across all the algal species and growth CO 2 treatments,demonstrating that daytime respiration was partly depressed by the light.The percentage of inhibition of respiration by light was similar between ambient and elevated CO 2 grown algae.The ratio of respiration to photosynthesis,which tended to decrease when estimated using R L instead of R D,was not altered for the elevated relative to ambient CO 2 concentration.The results suggest that R L,rather than R D,is a more accurate estimate of nonphotorespiratory carbon loss in marine macroalgae during the daytime.It would not be anticipated that elevated atmospheric CO 2 would exert a substantial influence on respiratory flux either in the light or in darkness in these particular marine macroalgal species.  相似文献   

8.
东海表层水二氧化碳及其海气通量   总被引:19,自引:2,他引:19  
1994年春、秋季在东海进行了两个航次的调查,采用气相色谱法和CO2采样系统测定了表层水和大气CO2分压。结呆表明,东海大部分海区CO2处于不饱和状态,可视为大气CO2的汇点。东海陆采区表层水CO2分压呈明显的季节变化趋势,即春季近岸低,大洋高;秋季西北部高,大洋低。黑潮区表层水CO2分压较低,无明显的季节性变化。利用通量模式,估算了大气输入东海海域的CO2通量为45.1g/(m2·a)。  相似文献   

9.
郭水伙 《台湾海峡》2009,28(1):71-76
据南海环境调查资料,研究了南海水体NO3-N、NO2-N、NH4-N、DIN含量及无机氮组成的垂直变化规律.结果表明:NO3-N、NO2-N、NH4-N、DIN含量范围和均值分别为0.00~43.9,12.32;0.00~1.69,0.07;0.17-14.87,1.32;0.35~45.92,13.73μmol/dm^3.其含量分布与垂直变化特征与深海、大洋的相似,表明南海水是太平洋的变性水体.NO3-N、DIN含量的垂直分布跃层出现于75~500m间,夏季的跃层强度分别为6.61X10-’、6.68×1012Ixmol/(dm’·m),冬季的均为5.65×10^-2μmol/(dm^3·m);NO2-N含量的最大值多出现于75~100m之间,NH4-N含量的最大值出现在0m层.在浮游植物活动较旺盛的真光层中,NH4-N为无机氮的主要存在形态(平均占比为64.4%).真光层以下NO3-N为无机氮的主要存在形态(平均占比≥90.8%).对三项无机氮含量与其他生源要素、水文因子的相关分析结果表明,NO3-N含量与PO4-P、TDP、TP、SiO3-Si、S均呈显著正相关,与pH、DO、O2%、t则呈显著负相关.  相似文献   

10.
深海探测溶解CO2气体异常.可以为寻找热液口提供一个很好的证据.本文设计的基于自制的聚二甲基硅氧烷胶与Zn-Al型水滑石复合膜为离子载体的溶解CO2探测电极属于电势型CO2电极,适用于对深海中溶解形式的CO2的测量,具有体积微小、便于与pH、盐度、温度、氧化还原电位等多种传感器集成在同一探头腔内,实施在线探测等优点.实验室条件下.将该溶解CO2探测电极与银,氯化银参比电极分别接在Keithley 6517A高阻抗电位计输入端进行测试,测试结果表明:该电极对不同浓度的碳酸氢钠溶液具有良好的响应信号,响应时间大约在30s-1 min.检测限在10-1-10-4mol·L-1.  相似文献   

11.
根据2007年11月在东海和南黄海海域表层海水测得的TCO2和TA数据,计算了表层海水pCO2,结合现场环境对表层海水CO2体系各参数的分布进行了讨论,探讨了pCO2与海水温度及叶绿素的相关性,利用Wanninkhof(1992)提出的通量模式并采用加权平均法估算了整个调查海域的海-气CO2的净通量。结果表明:观测海域表层海水CO2系统各参量的分布呈明显的不均匀性,在水团的混合处往往是各参量的高值或低值中心。由相关性分析可知,pCO2的分布主要受海水温度的影响,生物活动的影响较弱。受秋季较大风速的影响,调查海域表现为强的CO2源,秋季可向大气释放CO2约为556×104tC。  相似文献   

12.
秋季北黄海表层海水CO_2分压分布及其影响因素探讨   总被引:2,自引:0,他引:2  
根据2007年10月在北黄海走航连续观测所得pCO2数据,结合水文、化学和生物等要素的同步观测资料,对该海域pCO2分布及其影响因素进行了探讨.结果表明:秋季北黄海表层海水pCO2值在354~435 μatm之间,统计平均值为395 μatm.受河流输入影响的辽南沿岸流区域,山东半岛以北沿岸受渤海沿岸水输入影响的泥沙沉积区,是大气CO2的源区;在北黄海中部,黄海混合水范围内,由于强烈的生物活动,形成了较大范围的大气CO2汇区;而黄海混合水的其他区域仍然是大气CO2的源.总体来说,秋季北黄海表现出大气CO2弱源的性质.  相似文献   

13.
IrocrIowThere is a linkage in shallow marine systerns between sea-noor biOgaxhemical pmeessesand water column pnductivity (Bereson et al., l998). Benthic fluxes provide a significantsource of nutrients to the overlying water tO supPOrt primary pnduction and play a role in de-.creasing oxygen concentrations (van et al., l999; Cowan and Boynton, l996; Berelson etal., 1998; Friedl et al., l998; Zabel et al., l998). TherefOre, it is imPOrtant to define theediment di8genetic pathways for the …  相似文献   

14.
海水中-氧化氮的化学发光法测定   总被引:1,自引:0,他引:1  
基于鲁米诺-H2O2混合溶液作为发光液与海水中NO发生反应产生发光信号的原理,提出了一种测定海水中痕量NO的化学发光法.确定了化学发光法测定NO的最佳条件:pH9.2、浓度1×10-2 mol/dm3的碳酸盐为缓冲体系,鲁米诺浓度为8.4×10-5 mol/dm3,H2O2浓度为1×10-2 mol/dm3,测定温度为...  相似文献   

15.
Based on 5 831 continuous in situ measurements of the partial pressure of carbon dioxide on the sea surface p(CO2),related parameters of the sea surface temperature(SST) and chlorophyll-a(Chl a) concentration in 2010 winter,spring and summer of the Huanghai Sea and the Bohai Sea,the inherent relations among them are investigated preliminarily.This study reveals that the seasonal variability of SST and Chl a concentration has a significant influence on p(CO2).The authors have proposed a new algorithm to estimate p(CO2) from SST and Chl a concentration measurements.Compared with the vessel data,the root mean square error(RMSE) of p(CO2) retrieved by using the new model is 13.45 μatm(1atm=101.325 kPa) and the relative error is less than 4%.Then,SST and Chl a concentration data observed by satellite are used to retrieve p(CO2) in the Huanghai Sea and the Bohai Sea;and a better accuracy can be obtained if the quality control for sea surface chlorophyll-a concentration observed by satellite is used.The RMSE of retrieved p(CO2) data with quality control and that without quality control are 15.82 μatm and 31.74 μatm,respectively.  相似文献   

16.
Photobiological H2 from marine cyanobacterial strains is widely accepted to be an ideal clean and renewable energy source. Using the two Korean N2-fixing unicellular cyanobacterial strains (Cyanothece sp. KNU CB MAL-031 and Cyanothece sp. KNU CB MAL-058) and the Synechococcus sp. Miami strain BG043511 we performed flask-scale experiments to measure the effect of CO and HCN addition on photobiological H2 production. For the test, 1, 5, 10 and 30% v/v of CO in the N2 atmosphere was applied. Enhancement of H2 production was remarkable at 1–5% concentration range of CO addition. At CO concentrations over 5% no further cost-effective enhancement of H2 production was detectable, which suggests to us that 1–5% CO addition should be adopted for practical photobiological H2 production by the cyanobacterial strains. Maximum enhancement of the photobiological H2 production by CO additions was 2–6 times over the control flasks without CO. When 3 ppm of HCN was injected into the cell suspension of BG043511, the enhancement of hydrogen production was 50–60% of that under 5% CO. Present result implies the possible recycling of waste CO and HCN for the enhancement of the photobiological H2 production using marine cyanobacterial strains.  相似文献   

17.
通过2004年9月至10月对南海北部水域的现场调查,分析了表层海水中溶解氧、叶绿素a、pH值和营养盐等水质因子的空间分布分布特征,并讨论了它们之间的相互关系。结果表明:在南海北部海区的表层海水中,各水质因子在空间分布上大多呈现块状分布,且东西两侧的海水有较为明显的差异;海水中的溶解氧、pH值均表现出与海水温度相反的分布趋势;海水中的叶绿素a(Chla)和众多的水质因子表现出多元相关性,说明水体中浮游植物的生长繁殖是众多水质因子在南海北部综合作用的结果,而Chla和水体中亚硝酸盐的高相关性,说明南海北部水体中浮游植物的生长和亚硝酸盐有着比其他营养盐因子更为密切的联系。  相似文献   

18.
Atmospheric CO_2 is one of key parameters to estimate air-sea CO_2 flux. The Orbiting Carbon Observatory-2(OCO-2) satellite has observed the column-averaged dry-air mole fractions of global atmospheric carbon dioxide(XCO_2)since 2014. In this study, the OCO-2 XCO_2 products were compared between in-situ data from the Total Carbon Column Network(TCCON) and Global Monitoring Division(GMD), and modeling data from CarbonTracker2019 over global ocean and land. Results showed that the OCO-2 XCO_2 data are consistent with the TCCON and GMD in situ XCO_2 data, with mean absolute biases of 0.25×10-6 and 0.67×10-6, respectively. Moreover, the OCO-2 XCO_2 data are also consistent with the CarbonTracker2019 modeling XCO_2 data, with mean absolute biases of 0.78×10-6 over ocean and 1.02×10-6 over land. The results indicated the high accuracy of the OCO-2 XCO_2 product over global ocean which could be applied to estimate the air-sea CO_2 flux.  相似文献   

19.
郭水伙 《台湾海峡》1995,14(4):320-327
据1984年5月至1985年2月调查资料,计算了该水体中二氧化碳体系各分量的含量,研究了它们与pH,HCO^-3/CO^2-3,Alk,DIN,PO^3-4-9,Chl-aDO,S,t等环境因子的相关性。结果表明PCO3,CO2(T),HCO^-3,CO^2-3与pH,HCO^-3/CO^2-3呈极显著的线性相关;HCO^-3,CO^2-3ΣCO2与Alk也呈非常显著的线性相关。  相似文献   

20.
The dynamics of meteorological parameters, of sodar data on the temperature stratification of the atmospheric boundary layer, and of surface contents of pollutants (nitrogen oxides, carbon monoxide, and ozone) during the passage over Moscow of a structurally complex prominent cold front are discussed. It is shown that the cold front passage is accompanied by stepwise increases in the NO, NO2, and CO surface contents. A probable cause of this phenomenon is a quick entrainment of smoke plumes from high-altitude sources of pollution into the surface turbulent air near the frontal boundary. Intense advection of cold air at the rear of the cyclone can lead to the development of an unstable stratification in the atmospheric boundary layer even in the nighttime. Under these conditions, the minute-scale variability of contents of trace gases increases abruptly as compared to that occurring in the frontal zone of the cyclone prior to the passage of the front. This effect is statistically significant. The dynamics of surface ozone reflects an increase in its background concentrations in arctic air masses.  相似文献   

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