Model simulations of carbon sequestration in the northwest Pacific by patch fertilization

Iron fertilization of nutrient-rich surface waters of the ocean is one possible way to help slow the rising levels of atmospheric CO₂ by sequestering it in the oceans via biological carbon export. Here, I use an ocean general circulation model to simulate a patch of nutrient depletion in the subpolar northwest Pacific under various scenarios. Model results confirm that surface fertilization is an inefficient way to sequester carbon from the atmosphere (Gnanadesikan et al., 2003), since only about 20% of the exported carbon comes initially from the atmosphere. Fertilization reduces future production and thus CO₂ uptake by utilizing nutrients that would otherwise be available later. Effectively, this can be considered as leakage when compared to a control run. This “effective” leakage and the actual leakage of sequestered CO₂ cause a significant, rapid decrease in carbon retention (only 30–45% retained after 10 years and less than 20% after 50 years). This contrasts markedly with the almost 100% retention efficiency for the same duration using the same model, when carbon is disposed directly into the northwest Pacific (Matsumoto and Mignone, 2005). As a consequence, the economic effectiveness of patch fertilization is poor in two limiting cases of the future price path of carbon. Sequestered carbon in patch fertilization is lost to the atmosphere at increasingly remote places as time passes, which would make monitoring exceedingly difficult. If all organic carbon from one-time fertilization reached the ocean bottom and remineralized there, acidification would be about −0.05 pH unit with O₂ depletion about −20 μmol kg⁻¹. These anomalies are probably too small to seriously threaten deep sea biota, but they are underestimated in the model because of its large grid size. The results from this study offer little to advocate purposeful surface fertilization as a serious means to address the anthropogenic carbon problem.     

溴素的有机化学──I．2，4，6－三溴苯甲酸溴代和非溴代芳酯的合成

用ｍ－氨基苯甲酸作原料，经溴代、重氮化、还原脱氨、酰氯化和酯化反应等步骤，合成了六种新型的三溴苯甲酸的溴代和非溴代芳酯，即；双（２，４，６－三溴苯甲酸）－２＇，３＇，５＇，６＇－四溴－１＇，４＇－苯二酯，２，４，６－三溴苯甲酸－２＇，３＇，４＇，５＇，６＇－五溴苯酯，２，４，６－三溴苯甲酸－２＇，４＇，６＇－三溴苯酯，２，４，６－三溴苯甲酸－４＇－溴苯酯，２，４，６－三溴苯甲酸－４＇－甲基苯酯和２，４，６－三溴苯甲酸苯酯．通过对产物中碳、氢、溴元素的定量分析以及红外吸收光谱和氢核磁共振谱的研究，验证了合成产物的结构。     

环台湾岛海域半日潮波特征的三维模拟

用1997版POM海洋模式,首次应用于环台湾岛海域的潮波数值研究.得到该海域的半日潮波主要为23°N以南西太平洋传来的胁振潮.影响台湾海峡的半日潮波分别由海峡南北口传入的两支潮波,且北支强于南支.福建沿岸湄州湾-兴化湾为最强潮区,其M₂分潮最大振幅可达240cm.最强潮流区位于澎湖水道,M₂分潮最大潮流达196cm/s.环台湾岛海域潮波潮流水平结构上除海峡北部原有一个圆流点外,还发现另外存在4个新的圆流点.潮流垂直结构上主要为右偏,接近底层处为左偏.     

Ice Sheet-Thermohaline Circulation Interactions in a Climate Model of Intermediate Complexity

A vertically integrated dynamic ice sheet model is coupled to the atmosphere-ocean-sea ice-land surface climate model recently developed by Wang and Mysak (2000). The background lateral (east-west) ice sheet discharge rate used by Gallee et al. (1992) is reduced and the planetary emissivity is increased (to parameterize the cooling effect of a decrease of the atmospheric CO₂ concentration), in order to build up substantial ice sheets during a glacial period and hence set the stage for ice sheet-thermohaline circulation (THC) interactions. The following iceberg calving scheme is then introduced: when the maximum model height of the North American ice sheet reaches a critical value (2400 m), a prescribed lateral discharged rate is imposed on top of the background discharge rate for a finite time. Per a small prescribed discharge rate, repeated small iceberg calving events occur, which lead to millennial-scale climate cycles with small amplitudes. These are a crude representation of Dansgaard-Oeschger oscillations. Over one such cycle, the zonally averaged January surface air temperature (SAT) drops about 1.5°C at 72.5°N. However, a large prescribed lateral discharge rate leads to the shut down of the THC. In this case, the January SAT drops about 5°C at 72.5°N, the sea ice extent advances equatorward from 57.5° to 47.5°N and the net ice accumulation rate at the grid of maximum ice sheet height is reduced from 0.24 to 0.15 m/y. Since data strongly suggest that a collapsed THC was not a steady state during the last glacial, we restore the THC by increasing the vertical diffusivity in the North Atlantic Ocean for a finite time. The resulting climate cycles associated with conveyor-on and conveyor-off phases have much larger amplitudes; furthermore, the strong iceberg calving events lead to a larger loss of ice sheet mass and hence the period of the oscillations is longer (several thousand years). This revised version was published online in August 2006 with corrections to the Cover Date.     

围隔实验中海洋浮游植物对石油烃污染物中正构烷烃的生物富集

本文应用海洋围隔生态实验研究了浮游植物对石油烃污染物生物富集动力学过程 ,提出了“水相差法”测定海洋浮游植物体内石油烃浓度 ,以及包括石油烃挥发和生物生长等影响因素的石油烃生物富集动力学模型 ,并利用非线性拟合技术得到了海洋浮游植物对 0 #柴油 WAF中正构烷烃的生物富集动力学参数 kup,kel和 BCFPOC,结果与 Kováts色谱保留指数具有很好的相关性 ,与利用生物分析平衡法测定的文献数据基本一致。本模型及实验方法简便可靠 ,可在现场实验中广泛应用 ,得到的动力学参数应用于多介质环境模型和生态动力学模型 ,用以研究石油烃污染物中正构烷烃在海洋环境中的迁移变化规律     

秋茄和榕树叶片中正构烷烃分布和单体化合物δ13C值及其光合作用

对深圳福田、阳江、海南新竹红树林秋茄Kandelia candel及海口榕树Ficusm icrocarpa叶中类脂物进行萃取,分离出正构烷烃,通过气相色谱(GC)及色谱-质谱(GC MS)分析,测出了正构烷烃的碳数分布和相对含量.气相色谱-稳定同位素比质谱仪(GC-IRMS)测定了正构烷烃单体化合物的稳定同位素组成δ13C.秋茄叶和榕树叶正构烷烃的碳数分布均为C17C33,主要集中在C23-C31(＞90%).化合物含量最高为C27的有深圳福田秋茄、海南新竹秋茄、海口榕树,而阳江秋茄为C25.单体化合物的稳定同位素δ13C深圳福田秋茄为-31.42‰-34.48‰,阳江秋茄为-31.69‰-33.62‰,海南新竹秋茄为-30.30‰-33.04‰,海口榕树为-29.92‰33.56‰;平均值分别为-32.95‰、32.67‰、31.67‰、-31.74‰.结果表明,秋茄和陆地植物榕树的光合作用都是通过C3途径,是典型C3植物.     

长江口三维潮流数值计算及动力分析

采用三维动力学数学模型对长江口潮流场进行了计算，对长江口潮流流态在一个潮周期内逐时进行了分析，并对长江口南支盐水倒灌从动力学角度进行了初步探讨。计算结果表明：文中模型较好地重演长江口潮流场，可以用于大型复杂河口工程实际中的潮流场的计算和分析。     

Comparison of high spatial resolution trace metal distributions with model simulations for surface waters of the Gulf of Cadiz

A multidisciplinary study in the Gulf of Cadiz is revisited, using additional diagnostic modelling tools. The dissolved trace metal (Cu, Ni, Zn, Co) distributions in the Gulf of Cadiz are analysed using modelled tracer evolutions, field observations and the concept of tracer ages. This study shows that a significant part of the observed metal distributions can be explained by the metal inputs of three river systems (Guadiana, Rio Tinto and Odiel, Guadalquivir) discharging into the Gulf of Cadiz, while the remainder of the signal is most likely associated with the benthic metal remobilisation along the shelf of this coastal region.