Particle Fluxes at the Australian Southern Ocean Time Series (SOTS) Achieve Organic Carbon Sequestration at Rates Close to the Global Median, Are Dominated by Biogenic Carbonates, and Show No Temporal Trends Over 20-Years
Particle Fluxes at the Australian Southern Ocean Time Series (SOTS) Achieve Organic Carbon Sequestration at Rates Close to the Global Median, Are Dominated by Biogenic Carbonates, and Show No Temporal Trends Over 20-Years
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澳大利亚南大洋时间序列 (SOTS) 的颗粒通量以接近全球中位数的速度实现有机碳固存，主要由生物碳酸盐组成，并且没有显示 20 年来的时间趋势
DOI：
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发表时间：
2020
影响因子：
2.9
通讯作者：
T. Trull
中科院分区：
文献类型：
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作者：
Cathryn A. Wynn‐Edwards;E. Shadwick;D. Davies;S. G. Bray;P. Jansen;R. Trinh;T. Trull
在1997年至2017年期间，在澳大利亚南部亚南极带（SAZ）（约47°S，约142°E，水深4600 m）的南大洋时间序列（SOTS）站点，使用标称深度为1000，2000和3800 m的系泊沉积物捕集器收集了颗粒通量。年综合质量通量显示出中等变异性，在1000米处为14 ± 6 g m-2 yr-1，在2000米处为20 ± 6 g m-2 yr-1，在3800米处为21 ± 4 g m-2 yr-1。颗粒有机碳（POC）通量与全球中位数相似，表明南大洋尽管具有高营养、低叶绿素的特点，但仍向深海输出了大量的碳。通量的年际变化大于由卫星观测估计的净初级生产力。颗粒组成主要由碳酸盐矿物（在所有深度>60%），蛋白石（在所有深度> 10%），和颗粒有机物（在1000米的17%，在3800米下降到10%），与季节和年际变化远远小于其通量大小。碳酸盐反泵效应使碳固存减少了0.88 ± 2%。在1000米的平均季节周期有一个双峰结构，一个较大的早春高峰（10月/11月）和一个较小的夏末（1月/2月）高峰。在两个较深的陷阱，这些峰值变得不那么明显，秋季到达的通量的比例更大。奇异值分解（SVD）表明，这种温和的季节结构占总方差的80%（SVD模式1），但其影响相对于描述季节时间变化的模式2和3也有显着变化。这种发生显着的年际变化的季节性，但相对恒定的年通量，可能是有用的，在选择适当的模型模拟环境-生态耦合及其在控制生物碳泵的作用。在质量或组分通量或SVD模式的时间序列中没有检测到时间趋势。SOTS的观测结果提供了一个重要的基线，未来的变化预计将导致变暖，分层，酸化在这一全球重要的地区。
Particle fluxes at the Southern Ocean time series (SOTS) site in the Subantarctic Zone (SAZ) south of Australia (∼47°S, ∼142°E, 4600 m water depth) were collected from 1997 – 2017 using moored sediment traps at nominal depths of 1000, 2000, and 3800 m. Annually integrated mass fluxes showed moderate variability of 14 ± 6 g m–2 yr–1 at 1000 m, 20 ± 6 g m–2 yr–1 at 2000 m and 21 ± 4 g m–2 yr–1 at 3800 m. Particulate organic carbon (POC) fluxes were similar to the global median, indicating that the Subantarctic Southern Ocean exports considerable amounts of carbon to the deep sea despite its high-nutrient, low chlorophyll characteristics. The interannual flux variations were larger than those of net primary productivity as estimated from satellite observations. Particle compositions were dominated by carbonate minerals (>60% at all depths), opal (∼10% at all depths), and particulate organic matter (∼17% at 1000 m, decreasing to ∼10% at 3800 m), with seasonal and interannual variability much smaller than for their flux magnitudes. The carbonate counter-pump effect reduced carbon sequestration by ∼8 ± 2%. The average seasonal cycle at 1000 m had a two-peak structure, with a larger early spring peak (October/November) and a smaller late summer (January/February) peak. At the two deeper traps, these peaks became less distinct with a greater proportion of the fluxes arriving in autumn. Singular value decomposition (SVD) shows that this temperate seasonal structure accounts for ∼80% of the total variance (SVD Mode 1), but also that its influence varies significantly relative to Modes 2 and 3 which describe changes in seasonal timings. This occurrence of significant interannual variability in seasonality yet relatively constant annual fluxes, is likely to be useful in selecting appropriate models for the simulation of environmental-ecological coupling and its role in controlling the biological carbon pump. No temporal trends were detected in the mass or component fluxes, or in the time series of the SVD Modes. The SOTS observations provide an important baseline for future changes expected to result from warming, stratification, and acidification in this globally significant region.
影响因子：
5.2
作者：
Cram, Jacob A.;Weber, Thomas;Deutsch, Curtis
通讯作者：
Deutsch, Curtis
影响因子：
5.2
作者：
Henson, Stephanie A.;Sanders, Richard;Madsen, Esben
通讯作者：
Madsen, Esben