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1.
Although the annual global sea-air CO2 flux has been estimated extensively with various wind-dependent-k parameteri- zations, uncertainty still exists in the estimates. The sea-state-dependent-k parameterization is expected to improve the uncertainty existing in these estimates. In the present study, the annual global sea-air CO2 flux is estimated with the sea-state-dependent-k parameterization proposed by Woolf (2005), using NOAA/NCEP reanalysis wind speed and hindcast wave data from 1998 to 2006, and a new estimate, -2.18 Gt C year-1, is obtained, which is comparable with previous estimates with biochemical methods. It is in- teresting to note that the averaged value of previous estimates with various wind-dependent-k parameterizations is almost identical to that of previous estimates with biochemical methods by various authors, and that the new estimate is quite consistent with these av- eraged estimates. 相似文献
2.
The physiological responses of Nitzschia palea Kvtzing, a freshwater diatom, to elevated CO2 were investigated and compared with those of a marine diatom, Chaetoceros muelleri Lemmermann previously reported. Elevated CO2 concentration to 700 μl/L increased the dissolved inorganic carbon （D!C） and lowered the pH in the cultures of N. palea, thus enhancing the growth by 4%-20% during the whole growth period. High CO2-grown N. palea cells showed lower levels of dark respiration rates and higher Ik values. Light-saturated photosynthetic rates and photosynthetic efficiencies decreased in N. palea with the doubling CO2 concentration in airflow to the bottom of cultures, although the doubling CO2 concentration in airflow to the surface cultures had few effects on these two photosynthetic parameters. N. palea cells were found to be capable of using HCO5 in addition to gaseous CO2, and the CO2 enrichment decreased their affinity for HCO5 and CO2. Although doubled CO2 level would enhance the biomass of N. patea and C. muelleri to different extents, compared with the marine diatom, it had a significant effect on the specific growth rates of N. palea. In addition, the responses of photosynthetic parameters of IV. palea to doubled CO2 concentration were almost opposite to those of C. muelleri. 相似文献
3.
There is limited information available on CO2 concentration and flux over marsh. The objective of this work was to characterize CO2 concentration and flux within and above marsh plant (Carex lasiocarpa Ehrh. and C. pseudocuraica F. Schm) canopy at heights 0.5, 1.0 and 1.5 m. CO2 concentration was measured sequentially every 3 hours by using an infrared gas analyzer. Soil and air temperature, wind speed,
net radiation and soil heat flux were also measured simultaneously. Extremely daily minimum and maximum CO2 concentration ranged from 250 to 754 μmd/mol for the 4-year work. The typical minimum and maximum values ranged from 314
to 464 μmol/mol at the height of marsh plant (about 0.5 m) during the fruiting period and mature date. The seasonal changes
in CO2 concentration show that the minimum CO2 concentration occurred in the fruiting period and mature date, and both of their minimum values were 314 μmol/mol. This illustrates
that CO2 consumed by photosynthesis was stable during the period. The flux of CO2 can be thought as a turbulent diffusion phenomenon. By micrometeorological methods, the diurnal CO2 fluxes were measured in the flowering period, fruiting period, early mature date, late mature date and yellow-ripe stage.
Their values were −0.18, 38.15,24.13,10.9 and 4.91 μmol/mol respectively. 相似文献
4.
Partial pressure of CO2 （pCO2） was investigated in the Changjiang （Yangtze River） Estuary, Hangzhou Bay and their adjacent areas during a cruise in August 2004, China. The data show that pCO2 in surface waters of the studied area was higher than that in the atmosphere with only exception of a patch east of Zhoushan Archipelago. The pCO2 varied from 168 to 2 264 μatm, which fell in the low range compared with those of other estuaries in the world. The calculated sea-air CO2 fluxes decreased offshore and varied from -10.0 to 88.1 mmol m^-2 d^-1 in average of 24.4 ± 16.5 mmol m^-2 d^-1. Although the area studied was estimated only 2 × 10^4 km^2, it emitted （5.9 ± 4.0） × 10^3 tons of carbon to the atmosphere every day. The estuaries and their plumes must be further studied for better understanding the role of coastal seas playing in the global oceanic carbon cycle. 相似文献
5.
CHEMICAL WEATHERING PROCESSES AND ATMOSPHERIC CO2 CONSUMPTION OF HUANGHE RIVER AND CHANGJIANG RIVER BASINS 总被引：3，自引：0，他引：3
Rock weathering plays an important role in studying the long-term carbon cycles and global climatic change. According to the
statistics analysis, the Huanghe (Yellow) River water chemistry was mainly controlled by evaporite and carbonate weathering,
which were responsible for over 90% of total dissolved ions. As compared with the Huanghe River basin, dissolved load of the
Changjiang (Yangtze) River was mainly originated from the carbonate dissolution. The chemical weathering rates were estimated
to be 39.29t/(km2·a) and 61.58t/(km2·a) by deducting the HCO
3
−
derived from atmosphere in the Huanghe River and Changjiang River watersheds, respectively. The CO2 consumption rates by rock weathering were calculated to be 120.84×103mol/km2 and 452.46×103mol/km2annually in the two basins, respectively. The total CO2 consumption of the two basins amounted to 918.51×109mol/a, accounting for 3.83% of the world gross. In contrast to other world watersheds, the stronger evaporite reaction and
infirm silicate weathering can explain such feature that CO2 consumption rates were lower than a global average, suggesting that the sequential weathering may be go on in the two Chinese
drainage basins.
Foundation item: Under the auspices of Ministry of Science and Technology Project of China (No. G1999043075)
Biography: LI Jing-ying (1974-), female, a native of Xinye of Henan Province, Ph.D., associate professor, specialized in environmental
geochemistry. E-mail: wxxljy2001@public.qd.sd.cn 相似文献
6.
The process-oriented model Forest-DNDC describing biogeochemical cycling of C and N and GHGs （greenhouse gases） fluxes （CO2, NO and N2O） in forest ecosystems was applied to simulate carbon sequestration and GHGs emissions in Abies fabric forest of the Gongga Mountains at southeastern edge of the Tibetan Plateau. The results indicated that the simulated gross primary production （GPP） of Abies fabric forest was strongly affected by temperature. The annual total GPP was 24,245.3 kg C ha^-1 yr^-1 for 2005 and 26,318.8 kg C ha^-1 yr^-1 for 2006, respectively. The annual total net primary production （NPP） was 5,935.5 and 4,882.2 kg C ha^-1 yr^-1 for 2005 and 2006, and the annual total net ecosystem production （NEP） was 4,815.4 and 3,512.8 kg C ha^-1 yr^-1 for 2005 and 2006, respectively. The simulated seasonal variation in CO2 emissions generally followed the seasonal variations in temperature and precipitation. The annual total CO2 emissions were 3,109.0 and 4,821.0 kg C ha^-1 yr^-1 for 2005 and 2006, the simulated annual total N2O emissions from forest soil were 1.47 and 1.36 kg N ha^-1 yr^-1 for 2005 and 2006, and the annual total NO emissions were 0.09 and o.12 kg N ha^-1 yr^-1 for 2005 and 2006, respectively. 相似文献
7.
This study on the sectional and vertical distribution of dissolved oxygen (DO) and the O2 fluxes across the sea-air interface in East China Sea (ESC) waters shows that the waters were in steady state and that the
difference of DO was great in upper and bottom waters in Apr. 1994; but that seawater mixing was strong and the difference
of DO was small in upper and bottom waters in Oct. 1994. The above conclusions were specially obvious in continental shelf
waters under 100 m. The DO maximum in subsurface layer waters appeared only at several stations and in general the DO in the
waters decreased with depth. The horizontal distributions of O2 fluxes across the sea-air interface appeared in stripes in Leg 9404 when most regions covered were supersaturated with O2 seawater to air flux was large, and that on section No. 1 was 1.594 L/m2·d. The horizontal distribution of O2 fluxes across the sea-air interface appeared lumpy in Leg 9410, when most regions covered were unsaturated with O2·O2 was dissolved from air to seawater, and the fluxes were 0.819 L/m2·d on section No. 1 in Leg 9310, 0.219 L/m2·d in Leg 9410. The main reasons for DO change in surface layer seawater were the mixture of upper and bottom layer water,
and the exchange of O2 across the sea-air interface. The variation of DO by biological activity was only 20% of total change of DO.
Contribution No. 2716 from Institute of Oceanology, Chinese Academy of Sciences. 相似文献
8.
TOPEX/POSEIDON altimeter data from October 1992 to June 2002 are used to calculate the global barotropic M
2 tidal currents using long-term tidal harmonic analysis. The tides calculated agree well with ADCP data obtained from the
South China Sea (SCS). The maximum tide velocities along the semi-major axis and semi-minor axis can be computed from the
tidal ellipse. The global distribution of M
2 internal tide vertical energy flux from the sea bottom is calculated based on a linear internal wave generation model. The
global vertical energy flux of M
2
internal tide is 0.96 TW, with 0.36 TW in the Pacific, 0.31 TW in the Atlantic and 0.29 TW in the Indian Ocean, obtained
in this study. The total horizontal energy flux of M
2 internal tide radiating into the open ocean from the lateral boundaries is 0.13 TW, with 0.06 TW in the Pacific, 0.04TW in
the Atlantic, and 0.03 TW in the Indian Ocean. The result shows that the principal lunar semi-diurnal tide M
2 provides enough energy to maintain the large-scale thermohaline circulation of the ocean.
Supported by the National Basic Research Program of China (973 Program, No. 2005CB422303), the International Cooperation Program
(No. 2004DFB02700), and the National Natural Science Foundation of China (No. 40552002). The TOPEX/POSEIDON data are provided
by Physical Oceanography Distributed Active Archive Center (PO DACC) 相似文献
9.
Effect of anthropogenic CO2 on the pH and the saturation states of calcite and aragonite of seawater
Growth of phytoplankton, zooplankton and probably most other marine organisms as well, is likely to be affected by the pH
of seawater. Growth of calcareous shells and skeletons is less likely to be affected by the saturation states of calcite and
aragonite but the dissolution is.
The increase of CO2 in the oceans due to burning of fossil fuel and clearing of forests is decreasing the pH of seawater and the degrees of saturation
for calcite and aragonite wordwide. This paper presents the results of the first attempt to estimate the vertical distribution
of anthropogenic CO2, and the decreases in pH and the degrees of saturation of calcite and aragonite in seawater near Taiwan. Most effects are
very small except for the possible dissolution of aragonite on the upper continental slope starting around 2050 AD. 相似文献
10.
Concentrations and distribution of trace metals of PM<Subscript>10</Subscript> and TSP particles collected in the qingdao area 总被引：1，自引：0，他引：1
Aerosol samples of PM10 (particulate matter with aerodynamic diameters less than 10μm) and TSP (total suspended particles) were simultaneously collected
from April 2001 to March 2002 at the top of Mount Baguan on the downtown campus of Ocean University of China, Qingdao, China.
The concentrations of Al, Fe, Mn, Cu, Pb and Zn were determined by means of inductively coupled plasma atomic emission spectrometry
(ICP-AES). The monthly variability of the mass concentrations of aerosol particles and the concentrations of trace metals
are presented and discussed. The distribution pattern of these metals in PM10 and TSP is also discussed. During the observation period, the mass concentration of PM10 at this site ranged from 13.80 to 306.42 μgm−3, while that of TSP ranged from 31.02 to 568.82μgm−3. Both PM10 and TSP reached their highest concentrations in springtime, while the lowest values occurred in summertime. The concentrations
of crustal metals followed the same variation pattern, while those of anthropogenic metals did not. A closer examination led
to the conclusion that anthropogenic metals are mainly from local sources. The average concentration ratios of anthropogenic
metals in PM10 to TSP were higher than the average mass ratio of PM10 to TSP, suggesting that there was a higher proportion of anthropogenic metals on smaller particles although there were a
few exceptions. For crustal metals, however, the metal concentration ratios were close to the particle mass ratio, indicating
that the distribution of crustal metals was much more homogeneous on aerosol particles with different sizes. The correlation
analysis indicated that Al, Fe and Mn were originated from similar sources and were mainly controlled by the particle mass,
while Cu, Pb and Zn were predominated by local anthropogenic sources, with Pb and Zn having similar origins. 相似文献
11.
A laboratory experiment was conducted to assess the bioaccumulation of Pb2+ and its effects on growth, morphology and pigment contents of Spirulina (Arthrospira) platensis. The specimen cultured in Zarrouk liquid medium was treated with various initial metal concentrations (0, 5, 10, 30, 50 and
100 μg mL−1). The growth of S. platensis was adversely affected by Pb2+ at high concentrations (30, 50 and 100 μg mL−1). However, at low concentrations (5 μg mL−1), Pb2+ could stimulate its growth slightly. The pigment contents (chlorophyll α and β carotene) were decreased in a dose-dependent
manner. The highest reductions (67% and 53% respectively in chlorophyll α and β carotene) were observed in 100 μg mL−1 treatment group. The LC50 (96 h) of Pb2+ was measured as 75.34 μg mL−1. Apart from a few cases of filament breakages at elevated concentrations (50 and 100 μg mL−1), morphological abnormalities are not specific. Metal bioaccumulation increased with Pb2+ concentrations, but decreased with exposure time. The maximum accumulated amount was 188 mg g−1 dry weight. The bioconcentration factor (BCF) reached to a peak at day 2, followed by a gradual reduction for all the exposure
concentrations. S. platensis is able to tolerate considerably high Pb2+ concentrations. Consequently it can be used as a potential species to remove heavy metal from contaminated waters. 相似文献
12.
The extruded protoplasm from the coenocytic green alga, Bryopsis hypnoides Lamouroux, was able to reform a cell wall and develop further into a mature alga in seawater. In this paper, the influence of albumen on the ability of aggregation and on the photosynthesis of protoplasm was examined. Results show that the protoplasm of B. hypnoides could aggregate in either albumen or chicken egg, which is similar to that in seawater. However unlike in seawater, the aggregation from B. hypnoides in albumen and chicken egg failed to develop into a mature individual. Interestingly, the protoplasm of B. hypnoides could maintain its photosynthetic O2 evolution in albumen and chicken egg, while the time in chicken egg was longer than that in albumen. 相似文献
13.
Inorganic carbon utilization in the non-calcifying marine microalgae,Nannochloropsis oculata, Phaeodactylum tricornutum andPorphyridium purpureum was compared with high- and low-calcifying strains ofEmiliania huxleyi grown in artificial seawater medium aerated with either air (0.03% V/V CO2) or CO2-free air. For high-calcifying strain ofE. oculata andP. tricornutem, similar growth patterns were observed in air-and CO2-free air-grown cultures.P. purpureum showed a less final cell density in CO2-free air than in air-grown culture. However, low-calcifying strain ofE. huxleyi was able to grow only in air-grown culture, but not in CO2-free air-grown culture.
Measurements of alkalinity, pH, concentration of dissolved inorganic carbon (DIC) and free CO2 showed different patterns of DIC utilization. WithN. oculata, P. tricornutum andP. purpureum the pattern of DIC utilization was characterized by an increase of pH and a decrease of DIC but a constant alkalinity in
the cultures aerated with air or CO2-free air, suggesting that bicarbonate utilization was concomitant with an efflux of OH−. Both alkalinity and pH were maintained rather constant in air-grown culture of low-calcifying strain ofE. huxleyi, suggesting that diffusive entry of CO2 could meet the requirement of DIC for its photosynthesis and growth. High-calcifying strain ofE. huxleyi, however, showed a pattern of decrease of alkalinity and DIC but an almost constant pH, indicating that bicarbonate was the
major form of inorganic carbon utilised by this organism and bicarbonate uptake is unlikely to be accompanied by an efflux
of OH−.
The final pH values reached byN. oculata, P. tricornutum andP. purpureum in a closed system were 10.75, 10.60 and 9.85 respectively, showing that bicarbonate utilisation is concomitant with an efflux
of OH−. While the final pH of 8.4 in high-calcifyingE. huxleyi suggests that bicarbonate utilization was not accompanied by an efflux of OH−.
Contribution No. 3557 from the Institue of Oceanology, Chinese Academy of Sciences.
This work was supported by NERC grant GRE3/7853 U. K. and partly supported by Bio-Engineering Center, SSTC 96-C01-05-01. 相似文献
14.
Yang Ji-song Liu Jing-shuang Yu Jun-bao Wang Jin-da Qin Sheng-jin Li Xin-hua 《中国地理科学(英文版)》2005,15(3):262-268
Soil respiration is a main dynamic process of carbon cycle in wetland. It is important to contribute to global climate changes.
Water table and nutritious availability are significant impact factors to influence responses of CO2 emission from wetland soil to climate changes. Twenty-four wetland soil monoliths at 4 water-table positions and in 3 nitrogen
status have been incubated to measure rates of CO2 emission from wetland soils in this study. Three static water-table controls and a fluctuant water-table control, with 3
nitrogen additions in every water-table control, were carried out. In no nitrogen addition treatment, high CO2 emissions were found at a static low water table (I) and a fluctuant water table (IV), averaging 306.7mg/(m2·h) and 307.89mg/(m2·h), respectively, which were 51%–57% higher than that at static high water table (II and III). After nitrogen addition, however,
highest CO2 emission was found at II and lowest emission at III. The results suggested that nutritious availability of wetland soil might
be important to influence the effect of water table on the CO2 emission from the wetland soil. Nitrogen addition led to enhancing CO2 emissions from wetland soil, while the highest emission was found in 1N treatments other than in 2N treatments. In 3 nutritious
treatments, low CO2 emissions at high water tables and high CO2 emissions at low water tables were also observed when water table fluctuated. Our results suggested that both water table
changes and nutritious imports would effect the CO2 emission from wetland.
Foundation item: Under the auspices of the National Natural Science Foundation of China (No. 90211003) and the Knowledge Innovation
Program of Chinese Academy of Sciences (No. KACX3-SW-332)
Biography: YANG Ji-song (1978-), male, a native of Chengwu of Shandong Province, Ph.D. candidate, specialized in environmental
ecology and wetland biogeochemistry. E-mail: yangjisong@neigae.ac.cn 相似文献
15.
Soil respiration is CO2 evolution process from soil to atmosphere, mainly produced by soil micro-organism and plant roots. It is affected not only
by biological factors (vegetation, micro-organism, etc.) and environmental factors (temperature, moisture, pH, etc.), but
also more and more strongly by man-made factors. Based on literature survey, main factors affecting soil respiration were
reviewed. The relationship of soil respiration to latitude and to mean annual temperature were analyzed by using the data
measured from forest vegetation in the world. As a result, soil respiration rate decreased exponentially with an increase
of latitude, and increased with increasing temperature. Following the relationship between soil respiration and temperature,
Q10 value (law of Van Hoff) was obtained as 1.57 in the global scale.
This project was supported by National Natural Science Foundation of China to FJY (No. 3940003). 相似文献
16.
YU Xiuli LI Xiujun XU Linshu WANG Ming ZHANG Jitao JIANG Ming WANG Guodong 《中国地理科学(英文版)》2016,26(4):518-526
In order to study the diurnal variation of soil CO_2 efflux from temperate meadow steppes in Northeast China, and determine the best time for observation, a field experiment was conducted with a LI-6400 soil CO_2 flux system under five typical plant communities(Suaeda glauca(Sg), Chloris virgata(Cv), Puccinellia distans(Pd), Leymus chinensis(Lc) and Phragmites australis(Pa)) and an alkali-spot land(As) at the meadow steppe of western Songnen Plain. The results showed that the diurnal variation of soil CO_2 efflux exhibited a single peak curve in the growing season. Diurnal maximum soil respiration(Rs) often appeared between 11:00 and 13:00, while the minimum occurred at 21:00–23:00 or before dawn. Air temperature near the soil surface(Ta) and soil temperature at 10 cm depth(T10) exerted dominant control on the diurnal variations of soil respiration. The time-windows 7:00–9:00 could be used as the optimal measuring time to represent the daily mean soil CO_2 efflux at the Cv, Pd, Lc and Pa sites. The daily mean soil CO_2 efflux was close to the soil CO_2 efflux from 15:00 to 17:00 and the mean of 2 individual soil CO_2 efflux from 15:00 to 19:00 at the As and Sg sites, respectively. During nocturnal hours, negative soil CO_2 fluxes(CO_2 downwards into the soil) were frequently observed at the As and Sg sites, the magnitude of the negative CO_2 fluxes were 0.10–1.55 μmol/(m~2·s) and 0.10–0.69 μmol/(m~2·s)at the two sites. The results implied that alkaline soils could absorb CO_2 under natural condition, which might have significant implications to the global carbon budget accounting. 相似文献
17.
The knowledge of contemporary climatic change over the Qinghai-Xizang (Tibet) Plateau (QXP) has been inadequate for a long
time due to lack of enough observational data. In this paper, on the basis of monthly temperature and precipitation data in
1961–1990 from 48 stations on the QXP, the temperature data are extended backward to 1901 with an empirical orthogonal function
(EOF) method, microscopic characteristics of contemporary climatic change over the QXP are analyzed, and the response of the
plateau climate to global warming is discussed in combination with atmospheric general circulation model (GCM) outputs. The
results show that the plateau climate, as a whole, has been warming since the early part of this century, that the precipitation
has generally been increasing during the recent 30 years, and that these climatic trends seem to be related to the enhanced
green-house effect induced by increasing CO2 concentration in the atmosphere.
This work is supported by the National and CAS (the Chinese Academy of Sciences) Tibet Research Project. 相似文献
18.
The meiotic process in Noctiluca scintillans were observed under light microscope.Some abnormal cell divisions, incompletely separated “zoospores” and the changes of the zoospores are described in this paper. Together with the fmdings of field samplings and the previous results by other researchers, the process of meiosis in N. scintillans was supposed to be a pathway to reduce the extra high density of NH3-N within the cell in order to ensure normal population growth. 相似文献
19.
One isolate of Brachiomonas submarina was tested for its ability to grow heterotrophicly on 5 different organic compounds. Sodium acetate and glucose were found
to be effective in supporting the growth. Sodium acetate was chosen as the organic nutrient to test the combined effects of
organic and inorganic solutions on the growth and fatty acid composition of Brachiomonas submarina. The best growth rates were achieved at 3 mmol L−1 CH3COONa and 0.88 mmol L−1 NaNO3 in heterotrophic condition, and 4 mmol L−1 CH3COONa and 3.52 mmol L−1 NaNO3 in mixotrophic condition. The differences between fatty acid contents were significant. The total polyunsaturated fatty acids
(T. P. U. F. As) varied from 55.79% to 67.72% in heteritrophic growth and from 52.39% to 65.55% in mixotrophic growth. It
is concluded that CH3COONa and NaNO3 at 3 mmol L−1 and 3.52 mmol L−1 should respectively be used in order to achieve the highest growth rate and fatty acid content. 相似文献
20.
The effects of several nutritional factors on the growth and eicosapentaenoic acid (EPA) production of diatom Nitzschia laevis were studied. 4 LDM (quadrupled concentration of the nutrient salt) was the optimal concentration of nutrient salt for the
growth and EPA production of N. laevis. The growth of N. laevis was inhibited when the glucose concentration was either lower than 10 gL−1 or higher than 15 gL−1. Both sodium nitrate and urea were good nitrogen sources for the growth and EPA production, while ammonium chloride seriously
decreased the dry cell weight (DW) and the EPA content. Silicate seriously influenced the growth of N. laevis. The maximum DW of 2.34 gL−1 was obtained in the presence of 150 mgL−1 Na2SiO3·9H2O. The EPA content remained almost the same when the silicate concentration was lower than 150 mgL−1; however, higher silicate concentrations resulted in a steady decrease of EPA content. Low medium salinity (⩽29) did not
seem to influence the DW of N. laevis, and high salinity resulted in a decrease of DW. The highest EPA content (4.08%) and yield (110 mgL−1) were observed at the salinity of 36 and 29, respectively. 相似文献