A BIOGEOCHEMICAL STUDY OF THE COCCOLITHOPHORE, EMILIANIA-HUXLEYI, IN THE NORTH-ATLANTIC
A BIOGEOCHEMICAL STUDY OF THE COCCOLITHOPHORE, EMILIANIA-HUXLEYI, IN THE NORTH-ATLANTIC
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DOI：
10.1029/93gb01731
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发表时间：
1993-12-01
影响因子：
5.2
通讯作者：
VANDERWAL, P
中科院分区：
文献类型：
--
作者：
HOLLIGAN, PM;FERNANDEZ, E;VANDERWAL, P
1991年6月，对东北大西洋埃米利亚尼亚·赫胥黎（Emiliania huxleyi）颗石藻的大面积水华（约250,000平方公里）的生物地球化学特性进行了调查。卫星（NOAA-AVHRR）图像显示，水华最初集中在北纬60度-63度和西纬13度-28度，持续了大约3周。卫星测量的反射率的空间变化与表面测量的光束衰减系数、颗粒无机碳水平和球粒石密度有很好的相关性。在富含颗石藻的水域中，光合作用和钙化的速率都相对较低，这表明在实地观察时，该种群处于发育的后期阶段。与海洋的平均水平相比，地表水中的二甲基硫化物（DMS）水平较高，在光合作用、钙化和微型浮游动物放牧速率相对较高的局部区域浓度最高。估计的DMS到大气的空间平均通量为1122 nmol m-2 h-1，略大于1987年6 - 7月同一地区测定的通量。coccolite的生产（1 × 10(6)吨方解石- c）对CO2系统的状态产生了重大影响，导致与碱度和水温变化相关的表面CO2分压相对增加高达50 μ atm。在20-40公里的水平距离上，二氧化碳分压的梯度高达100 μ atm。这些发现的环境意义与赫胥黎的时空分布进行了讨论。
The biogeochemical properties of an extensive bloom (approximately 250,000 km2) of the coccolithophore, Emiliania huxleyi, in the north east Atlantic Ocean were investigated in June 1991. Satellite (NOAA-AVHRR) imagery showed that the bloom was centered initially at 60-degrees-63-degrees-N by 13-degrees-28-degrees-W and lasted approximately 3 weeks. Spatial variations in satellite-measured reflectance were well correlated with surface measurements of the beam attenuation coefficient, levels of particulate inorganic carbon, and coccolith density. Rates of both photosynthesis and calcification were typically relatively low within the coccolithophore-rich waters, suggesting the population was in a late stage of development at the time of the field observations. Levels of dimethyl sulphide (DMS) in surface waters were high compared to average ocean values, with the greatest concentrations in localized areas characterized by relatively high rates of photosynthesis, calcification, and grazing by microzooplankton. The estimated spatially averaged flux of DMS to the atmosphere was 1122 nmol m-2 h-1, somewhat greater than that determined for the same region in June-July 1987. Coccolith production (1 x 10(6) tonnes calcite-C) had a significant impact on the state of the CO2 system, causing relative increases of up to 50 muatm in surface pCO2 in association with alkalinity and water temperature changes. Gradients in pCO2 were as great as 100 muatm over horizontal distances of 20-40 km. The environmental implications of these findings are discussed in relation to the spatial and temporal distributions of E. huxleyi.