Benthic fluxes of dissolved inorganic carbon in the Tinto–Odiel system (SW of Spain)     

T. Ortega  R. PonceJ. Forja  A. Gómez-Parra 《Continental Shelf Research》2008

The benthic fluxes (diffusive and with chambers) of dissolved inorganic carbon (DIC), dissolved oxygen (DO) and total alkalinity (TA) have been calculated in summertime in the estuary system formed by the mouths of the Tinto and Odiel rivers (SW of Spain). An increase of DIC in interstitial water with depth was found for all stations showing values of up to 28 mM at a depth of 5 cm. The diffusive fluxes of DIC and TA obtained ranging between 1.8–7.8 and 1.5–7.3 mmol m⁻² d⁻¹, respectively. These intervals are in agreement with those found for other coastal systems. Considering the plots of DIC vs. alkalinity (ΔDIC/ΔTA) in the first 30 cm of interstitial water, it was deduced that sulphate reduction and the oxidation of sulphides seem to have special relevance in the sediments of the stations studied. The benthic fluxes of inorganic carbon and DO measured by benthic chambers were variable, presenting elevated values (309–433 mmol DIC m⁻² d⁻¹ and 50–120 mmol DO m⁻² d⁻¹). The most elevated fluxes of DIC were seen at the stations with high anthropogenic influence (close to populated areas and industrial discharges). A great proportion of these fluxes are due to CaCO₃ dissolution processes, which constitute an estimated 49% of total DIC flux. DIC and DO benthic flux quotients were far in excess of unity, indicating the significance processes of anaerobic degradation of organic material at the stations studied.  相似文献   

Water column characterisation on the Azores platform and at the sea mounts south of the archipelago     

C Palma  AI Lillebø  C Borges  M Souto  E Pereira  AC Duarte  MP Abreu 《Marine pollution bulletin》2012,64(9):1884-1894

This study provides data concerning the hydrography and water chemistry of the Atlantic region between 29-38° N and 27-31° W, and establishes background values for dissolved Cu, Cd, Pb and As. Three water masses were identified: the Eastern North Atlantic Central Water (ENACW), the Mediterranean Water (MW) and the North Atlantic Deep Water (NADW). The ENACW exhibits a clear meridional gradient of temperature and salinity, with comparatively high values at the southern sites and lower values on the Azores platform. The ENACW, which includes the euphotic zone, also had comparatively high concentrations of oxygen and lower concentrations of nutrients and metals. The Cu, Cd and Pb results suggest that new background concentrations for OSPAR Region V (the Wider Atlantic) should be established as follows: 0.15-13nM for Cu, 0.05-1.4nM for Cd and 0.03-5nM for Pb. The background concentrations of As for OSPAR Region V should be 7-28nM.  相似文献   

Water mass distribution in Fram Strait and over the Yermak Plateau in summer 1997     

B. Rudels  R. Meyer  E. Fahrbach  V. V. Ivanov  S. Østerhus  D. Quadfasel  U. Schauer  V. Tverberg  R. A. Woodgate 《Annales Geophysicae》2000,18(6):687-705

The water mass distribution in northern Fram Strait and over the Yermak Plateau in summer 1997 is described using CTD data from two cruises in the area. The West Spitsbergen Current was found to split, one part recirculated towards the west, while the other part, on entering the Arctic Ocean separated into two branches. The main inflow of Atlantic Water followed the Svalbard continental slope eastward, while a second, narrower, branch stayed west and north of the Yermak Plateau. The water column above the southeastern flank of the Yermak Plateau was distinctly colder and less saline than the two inflow branches. Immediately west of the outer inflow branch comparatively high temperatures in the Atlantic Layer suggested that a part of the extraordinarily warm Atlantic Water, observed in the boundary current in the Eurasian Basin in the early 1990s, was now returning, within the Eurasian Basin, toward Fram Strait. The upper layer west of the Yermak Plateau was cold, deep and comparably saline, similar to what has recently been observed in the interior Eurasian Basin. Closer to the Greenland continental slope the salinity of the upper layer became much lower, and the temperature maximum of the Atlantic Layer was occasionally below 0.5 °C, indicating water masses mainly derived from the Canadian Basin. This implies that the warm pulse of Atlantic Water had not yet made a complete circuit around the Arctic Ocean. The Atlantic Water of the West Spitsbergen Current recirculating within the strait did not extend as far towards Greenland as in the 1980s, leaving a broader passage for waters from the Atlantic and intermediate layers, exiting the Arctic Ocean. A possible interpretation is that the circulation pattern alternates between a strong recirculation of the West Spitsbergen Current in the strait, and a larger exchange of Atlantic Water between the Nordic Seas and the inner parts of the Arctic Ocean.  相似文献   

Variability of nutrients and carbon dioxide in the Antarctic Intermediate Water between 1990 and 2014     

Essowè Panassa  J. Magdalena Santana-Casiano  Melchor González-Dávila  Mario Hoppema  Steven M.A.C van Heuven  Christoph Völker  Dieter Wolf-Gladrow  Judith Hauck 《Ocean Dynamics》2018,68(3):295-308

Antarctic Intermediate Water (AAIW) formation constitutes an important mechanism for the export of macronutrients out of the Southern Ocean that fuels primary production in low latitudes. We used quality-controlled gridded data from five hydrographic cruises between 1990 and 2014 to examine decadal variability in nutrients and dissolved inorganic carbon (DIC) in the AAIW (neutral density range 27 < γ _n <? 27.4) along the Prime Meridian. Significant positive trends were found in DIC (0.70 ± 0.4 μmol kg^??1 year^??1) and nitrate (0.08 ± 0.06 μ mol kg^??1 year^??1) along with decreasing trends in temperature (??0.015 ± 0.01^°C year^??1) and salinity (??0.003 ± 0.002 year^??1) in the AAIW. Accompanying this is an increase in apparent oxygen utilization (AOU, 0.16 ± 0.07 μ mol kg^??1 year^??1). We estimated that 75% of the DIC change has an anthropogenic origin. The remainder of the trends support a scenario of a strengthening of the upper-ocean overturning circulation in the Atlantic sector of the Southern Ocean in response to the positive trend in the Southern Annular Mode. A decrease in net primary productivity (more nutrients unutilized) in the source waters of the AAIW could have contributed as well but cannot fully explain all observed changes.  相似文献   

Changes in the mode of Southern Ocean circulation over the last glacial cycle revealed by foraminiferal stable isotopic variability     

Ulysses S Ninnemann  Christopher D Charles 《Earth and Planetary Science Letters》2002,201(2):383-396

Benthic foraminiferal oxygen and carbon isotopic records from Southern Ocean sediment cores show that during the last glacial period, the South Atlantic sector of the deep Southern Ocean filled to roughly 2500 m with water uniformly low in δ¹³C, resulting in the appearance of a strong mid-depth nutricline similar to those observed in glacial northern oceans. Concomitantly, deep water isotopic gradients developed between the Pacific and Atlantic sectors of the Southern Ocean; the δ¹³C of benthic foraminifera in Pacific sediments remained significantly higher than those in the Atlantic during the glacial episode. These two observations help to define the extent of what has become known as the ‘Southern Ocean low δ¹³C problem’. One explanation for this glacial distribution of δ¹³C calls upon surface productivity overprints or changes in the microhabitat of benthic foraminifera to lower glacial age δ¹³C values. We show here, however, that glacial-interglacial δ¹³C shifts are similarly large everywhere in the deep South Atlantic, regardless of productivity regime or sedimentary environment. Furthermore, the degree of isotopic decoupling between the Atlantic and Pacific basins is proportional to the magnitude of δ¹³C change in the Atlantic on all time scales. Thus, we conclude that the profoundly altered distribution of δ¹³C in the glacial Southern Ocean is most likely the result of deep ocean circulation changes. While the characteristics of the Southern Ocean δ¹³C records clearly point to reduced North Atlantic Deep Water input during glacial periods, the basinal differences suggest that the mode of Southern Ocean deep water formation must have been altered as well.  相似文献   

Simulation of annual biogeochemical cycles of nutrient balance, phytoplankton bloom(s), and DO in Puget Sound using an unstructured grid model     

Tarang Khangaonkar  Brandon Sackmann  Wen Long  Teizeen Mohamedali  Mindy Roberts 《Ocean Dynamics》2012,62(9):1353-1379

Nutrient pollution from rivers, nonpoint source runoff, and nearly 100 wastewater discharges is a potential threat to the ecological health of Puget Sound with evidence of hypoxia in some basins. However, the relative contributions of loads entering Puget Sound from natural and anthropogenic sources, and the effects of exchange flow from the Pacific Ocean are not well understood. Development of a quantitative model of Puget Sound is thus presented to help improve our understanding of the annual biogeochemical cycles in this system using the unstructured grid Finite-Volume Coastal Ocean Model framework and the Integrated Compartment Model (CE-QUAL-ICM) water quality kinetics. Results based on 2006 data show that phytoplankton growth and die-off, succession between two species of algae, nutrient dynamics, and dissolved oxygen in Puget Sound are strongly tied to seasonal variation of temperature, solar radiation, and the annual exchange and flushing induced by upwelled Pacific Ocean waters. Concentrations in the mixed outflow surface layer occupying approximately 5–20?m of the upper water column show strong effects of eutrophication from natural and anthropogenic sources, spring and summer algae blooms, accompanied by depleted nutrients but high dissolved oxygen levels. The bottom layer reflects dissolved oxygen and nutrient concentrations of upwelled Pacific Ocean water modulated by mixing with biologically active surface outflow in the Strait of Juan de Fuca prior to entering Puget Sound over the Admiralty Inlet. The effect of reflux mixing at the Admiralty Inlet sill resulting in lower nutrient and higher dissolved oxygen levels in bottom waters of Puget Sound than the incoming upwelled Pacific Ocean water is reproduced. By late winter, with the reduction in algal activity, water column constituents of interest, were renewed and the system appeared to reset with cooler temperature, higher nutrient, and higher dissolved oxygen waters from the Pacific Ocean.  相似文献   

Seasonal variability of surface fCO2 in the Strait of Gibraltar     

Mercedes de la Paz  Abelardo Gómez-Parra  Jesús Forja 《Aquatic Sciences - Research Across Boundaries》2009,71(1):55-64

  相似文献   

Seasonal variations in the inorganic carbon system in the Pearl River (Zhujiang) estuary     

Xianghui Guo  Wei-Jun Cai  Weidong Zhai  Minhan Dai  Yongchen Wang  Baoshan Chen 《Continental Shelf Research》2008

Seasonal variations in the inorganic carbon system in the Pearl River estuary are examined based on data from five surveys during the spring, summer, fall, and winter seasons. Both total dissolved inorganic carbon (DIC) and total alkalinity (TAlk) values in the freshwater end-members are high in the dry season (>2700 μmol kg⁻¹ for DIC and >2400 μmol kg⁻¹ for TAlk) and substantially lower in the wet season (DIC and TAlk were ∼1000 and 700 μmol kg⁻¹, respectively). Riverine DIC flux and drainage basin weathering rates, however, are significantly higher in the wet season (611×10⁹ mol yr⁻¹ and 13.6×10⁵ mol km⁻² yr⁻¹) than in the dry season (237×10⁹ mol yr⁻¹ and 5.3×10⁵ mol km⁻² yr⁻¹).  相似文献   

The distribution of ²²⁶Ra in the Atlantic Ocean     

W.S. Broecker  J. Goddard  J.L. Sarmiento 《Earth and Planetary Science Letters》1976,32(2):220-235

Based on results obtained during the GEOSECS program the primary features of the distribution of²²⁶Ra in the Atlantic Ocean can be defined. Outside the Antarctic no significant variation has been found in the²²⁶Ra content of surface waters. Eighty samples yield an average of 7.4 dpm/100 kg (normalized to a salinity of 35.00‰). Deep waters in the central Atlantic have²²⁶Ra contents several dpm/100 kg higher than expected from the mixing of Antarctic Bottom Water (21.3 dpm/100 kg) and basal North Atlantic Deep Water (10.3 dpm/100 kg). These excesses correlate well with deficiencies in O₂ and excesses in SiO₂. The intermediate water²²⁶Ra maximum in the South Atlantic is associated with the inflow of low-oxygen Circumpolar Intermediate Water beneath the Antarctic Intermediate Water.  相似文献   

Geosecs II,the 1970 North Atlantic station: Hydrographic features,oxygen, and nutrients     

D.W. Spencer 《Earth and Planetary Science Letters》1972

Profiles of salinity, temperature, oxygen and nutrients for a station at 35°46.5′N and 67°59.8′W show the influence of the five major sources of deep water in the North Atlantic Ocean. The presence of distinct, identifiable cores of water types, far removed from their sources, together with linear relationships between salinity and both oxygen and silicate in the deep water suggest that horizontal mixing processes predominate over vertical dissipation and in situ production or loss processes in determining the distribution of these tracers in the deep western Atlantic Ocean.  相似文献   

The role of the exchanges through the Strait of Gibraltar on the budget of elements in the Western Mediterranean Sea: consequences of human-induced modifications     

Gómez F 《Marine pollution bulletin》2003,46(6):685-694

The role of the Strait of Gibraltar on the exchanges of substances between Mediterranean Sea and the Atlantic Ocean is reviewed. The previous estimations have been recalculated by using a similar water flux and compared with the river and atmospheric inputs to the Western Mediterranean Sea. The man-induced changes in the dimensions of the Strait of Gibraltar increasing (planning the sill) or reducing of the cross-section by a total or partial dam are discussed. A total dam will control the sea-level rise in the Mediterranean Sea, but an annual increase of major nutrient concentrations of 1-2% could be expected, lower than the rate of increase of the river and atmospheric inputs in the Western Mediterranean Sea. The increase of the cross-section of the Strait by increasing the depth (planning) at the sill could compensate the increase of the external nutrient inputs.  相似文献   

The seasonal variability of the northern Benguela undercurrent and its relation to the oxygen budget on the shelf     

V. Mohrholz  C.H. Bartholomae  A.K. van der Plas  H.U. Lass 《Continental Shelf Research》2008

The seasonal variations in the advection and mixing of water masses in the northern Benguela were studied in relation to the oxygen minimum zone over the Namibian shelf. The used data set consists of hydrographic and current measurements from an oceanographic mooring 20 nm off Walvis Bay, monthly CTD transects from the Namibian 23°S monitoring line and recent large-scale hydrographic surveys. The current time series showed an intermittent southward continuation of the Angola Current (AC) through the Angola–Benguela frontal zone (ABFZ) into the northern Benguela, commonly known as poleward undercurrent. In austral summer hypoxic, nutrient rich South Atlantic central water (SACW) from the Angola Gyre is transported into the northern Benguela, whereas during the winter season the oxygen rich Eastern SACW (ESACW) spreads northward. The water mass analysis reveals a mixing between both water masses in the northern Benguela between the ABFZ and the Lüderitz upwelling cell (27°S). The oxygen balance over the Namibian shelf depends to a high extent on the water mass composition of the upper central water layer, controlled by the large scale and local circulation. The deviation of the measured oxygen concentration from its mixing concentration, calculated with the source water mass properties, was used to quantify the oxygen consumption. A new local definition SACW was derived to exclude biogeochemical processes, taking place in the Angola Gyre. The oxygen deficit in the northern Benguela central water amounted to about 60–80 μmol l⁻¹ at the shelf edge and increased up to 150 μmol l⁻¹ on the shelf, due to local oxygen consumption. In the austral summer anoxic bottom waters are observed at the central Namibian shelf, which correlate to an SACW fraction >55%. Periods with high SACW fraction in the water mass composition were congruent with hydrogen sulphide events detected by remote sensing.  相似文献   

Neodymium isotopic variations in seawater     

Donald J. Piepgras  G.J. Wasserburg 《Earth and Planetary Science Letters》1980,50(1):128-138

New data for the direct measurement of the isotopic composition of neodymium in Atlantic Ocean seawater are compared with previous measurements of Pacific Ocean seawater and ferromanganese sediments from major ocean basins. Data for Atlantic seawater are in excellent agreement with Nd isotopic measurements made on Atlantic ferromanganese sediments and are distinctly different from the observed compositions of Pacific samples. These results clearly demonstrate the existence of distinctive differences in the isotopic composition of Nd in the waters of the major ocean basins and are characteristic of the ocean basin sampled. The average ε_Nd(0) values for the major oceans as determined by data from seawater and ferromanganese sediments are as follows: Atlantic Ocean,ε_Nd(0) ? ?12 ± 2; Indian Ocean,ε_Nd(0) ? ?8 ± 2; Pacific Ocean,ε_Nd(0) ? ?3 ± 2. These values are considerably less than ε_Nd(0) value sources with oceanic mantle affinities indicating that the REE in the oceans are dominated by continental sources. The difference in the absolute abundance of¹⁴³Nd between the Pacific and Atlantic Oceans corresponds to ～10⁶ atoms¹⁴³Nd per gram of seawater. The correspondence between the¹⁴³Nd/¹⁴⁴Nd in seawater and in the associated sediments suggests the possible application of this approach to paleo-oceanography.Distinctive differences in ε_Nd(0) values are observed in the Atlantic Ocean between deep-ocean water associated with North Atlantic Deep Water and near-surface water. This suggests that North Atlantic Deep Water may be relatively well mixed with respect to Nd isotopic composition whereas near-surface water may be quite heterogeneous, reflecting different sources for surface waters relative to deep water. This suggests that it may be possible to distinguish the sources of water masses within an ocean basin on the basis of Nd isotopic composition.The Nd isotopic variations in seawater are used to relate the residence time of Nd and mixing rates between the oceans.  相似文献   

Dense water generation on a shelf: the case of the Adriatic Sea     

Ivica Vilibić  Nastjenjka Supić 《Ocean Dynamics》2005,55(5-6):403-415

The paper overviews recent and past studies of preconditioning, generation and spreading of North Adriatic Dense Water (NAdDW), by analysing both transient episodes and climatological data. The importance of wind stress, heat and water fluxes, and particularly river discharges during the preconditioning and generative period is emphasized, as well as the advection of saline levantine intermediate water from the southeast. After the generation, NAdDW affects deep and bottom layers of the middle and south Adriatic Sea, flowing as a dense current and mixing with the adjacent waters; it can be traced even in the Otranto Strait, contributing to the formation of deep water in the Eastern Mediterranean. Objective shortcomings and the projections in NAdDW investigations are also discussed, due to their high importance in the circulation of the Adriatic Sea, which may relate other similar basins around the world.  相似文献   

Dissolved chromium in the northwest Atlantic Ocean     

J.A. Campbell  P.A. Yeats 《Earth and Planetary Science Letters》1981,53(3):427-433

Total dissolved chromium concentrations have been determined for four vertical profiles from Baffin Bay, the Labrador Sea and the northwest Atlantic Ocean. Chromium concentrations of 3.3 to 5.2 nM are found. While the vertical distribution of chromium in the study area is largely controlled by advective processes, the profiles show a small depletion in surface water with increase to a more constant level at depth. Surface depletion and correlations between chromium and nutrients indicate biogeochemical cycling of chromium. At one station, close to the Gibbs fracture zone, a distinct chromium maximum is observed. This feature centred at 3200 m is deeper than the core of the ambient water mass which is advected westward from the Eastern Basin of the Atlantic Ocean through the Gibbs fracture zone.  相似文献   

“NO”, a conservative water-mass tracer     

Wallace S. Broecker 《Earth and Planetary Science Letters》1974,23(1):100-107

A composite property, 9NO₃ + O₂, is proposed as a conservative water-mass tracer. The coefficient 9 is chosen so that the increase in “NO” resulting from nitrate introduction during respiration just balances the consumption of dissolved oxygen gas. Because of the pronounced difference in the preformed nitrate content of deep water produced at the northern and southern ends of the Atlantic Ocean “NO” provides an independent means of disentangling the degree of mixing of various water types in the deep sea. Evidence based on data obtained during the Atlantic Geosecs program is presented to demonstrate the sensitivity and reliability of this conservative tracer.  相似文献   

Inorganic carbon dynamics during northern California coastal upwelling     

Andrea J. Fassbender  Christopher L. Sabine 《Continental Shelf Research》2011,31(11):1180-1192

Coastal upwelling events in the California Current System can transport subsurface waters with high levels of carbon dioxide (CO₂) to the sea surface near shore. As these waters age and are advected offshore, CO₂ levels decrease dramatically, falling well below the atmospheric concentration beyond the continental shelf break. In May 2007 we observed an upwelling event off the coast of northern California. During the upwelling event subsurface respiration along the upwelling path added ∼35 μmol kg⁻¹ of dissolved inorganic carbon (DIC) to the water as it transited toward shore causing the waters to become undersaturated with respect to Aragonite. Within the mixed layer, pCO₂ levels were reduced by the biological uptake of DIC (up to 70%), gas exchange (up to 44%), and the addition of total alkalinity through CaCO₃ dissolution in the undersaturated waters (up to 23%). The percentage contribution of each of these processes was dependent on distance from shore. At the time of measurement, a phytoplankton bloom was just beginning to develop over the continental shelf. A box model was used to project the evolution of the water chemistry as the bloom developed. The biological utilization of available nitrate resulted in a DIC decrease of ∼200 μmol kg⁻¹, sea surface pCO₂ near ∼200 ppm, and an aragonite saturation state of ∼3. These results suggest that respiration processes along the upwelling path generally increase the acidification of the waters that are being upwelled, but once the waters reach the surface biological productivity and gas exchange reduce that acidification over time.  相似文献   

Fluxes of inorganic carbon from two forested catchments in the Appalachian mountains     

Fred Worrall  Wayne T. Swank  Tim Burt 《水文研究》2005,19(15):3021-3035

This study uses long‐term records of stream chemistry, discharge and air temperature from two neighbouring forested catchments in the southern Appalachians in order to calculate production of dissolved CO₂ and dissolved inorganic carbon (DIC). One of the pair of catchments was clear‐felled during the period of the study. The study shows that: (1) areal production rates of both dissolved CO₂ and DIC are similar between the two catchments even during and immediately after the period of clear‐felling; (2) flux of total inorganic carbon (dissolved CO₂+ DIC) rises dramatically in response to a catchment‐wide acidification event; (3) DIC and dissolved CO₂ are dominantly released on the old water portion of the discharge and concentrations peak in the early autumn when flows in the study catchments are at their lowest; (4) total fluvial carbon flux from the clear‐felled catchment is 11·6 t km⁻² year⁻¹ and for the control catchment is 11·4 t km⁻² year⁻¹. The total inorganic carbon flux represents 69% of the total fluvial carbon flux. The method presented in the study provides a useful way of estimating inorganic carbon flux from a catchment without detailed gas monitoring. The time series of dissolved CO₂ at emergence to the stream can also be a proxy for the soil flux of CO₂. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

河库连续体中溶解性无机碳及其同位素的时空分异特征——以澜沧江云南段为例     

袁博  吴巍  郭梦京  周孝德  谢曙光 《湖泊科学》2020,32(1):173-186

河流及水库等水生态系统中的溶解性无机碳(DIC)是全球碳循环与大气、陆地和海洋之间碳相互作用的重要组成部分.以澜沧江云南段上游天然河段及下游梯级水库群形成的连续体为研究对象,分析了河库连续体表层水体中水化学特征、溶解性无机碳浓度及其碳同位素时空分布特征.研究结果表明:河库连续体水体中溶解无机碳(DIC)及其同位素(δ13 C DIC)组成特征总体表现为:DIC浓度丰水期较低,枯水期较高,平均值分别为2.59±0.44和3.30±0.37 mmol/L;δ13 C DIC值丰水期偏负、枯水期偏正,平均值分别为-8.52‰±0.38‰和-6.95‰±0.53‰,与自然河流的季节变化特征相似.水体DIC来源主要包括土壤及水体有机质分解生成的CO 2、碳酸盐风化和水气界面CO 2的交换过程.澜沧江河库连续体中DIC浓度及δ13 C DIC组成的时空异质性特征与流域岩性、土壤生物地球化学过程以及微生物活动强度等均有较大关系.当前,澜沧江梯级水库群建库时间短,梯级联合运行下调度复杂,水文条件多变,梯级水库对河流重要生源要素——碳累积影响方面的“水库效应”还不明显.  相似文献   

基于FVCOM的太湖梅梁湾夏季水温、溶解氧模拟及其影响机制初探   总被引：6，自引：1，他引：5  

欧阳潇然  赵巧华  魏瀛珠 《湖泊科学》2013,25(4):478-488

水体中的溶解氧是表征水生生态系统健康与否的重要参数之一.本研究基于太湖2008年8月16 20日的风速、风向、短波辐射等气象场资料以及实测的相关水质参量,利用FVCOM(即非结构化网格有限体积近海海洋模型)模式对太湖梅梁湾三维水温以及水体中溶解氧进行模拟,模拟结果与实测值基本吻合,水温的验证回归方程为y=1.02x,R²为0.690;溶解氧的R²为0.760.同时对溶解氧浓度的时空分布,梅梁湾溶解氧的"源"和"汇"及其贡献进行了分析.结果表明:太阳辐射、风速是影响水温日成层现象的重要因子;受水温和光照的影响,夏季梅梁湾的溶解氧存在垂直差异,呈现出"双峰双谷"的日变化特征;浮游植物光合作用制氧是水中溶解氧的最重要来源,水下光衰减直接控制着初级生产力的垂直分布;浮游植物呼吸及死亡是溶解氧的最大消耗者,余下依次为底泥耗氧、碳化需氧、细菌呼吸耗氧和硝化作用耗氧.  相似文献