Estimates of particle- and thorium-cycling rates in the northwest Atlantic Ocean
Estimates of particle- and thorium-cycling rates in the northwest Atlantic Ocean
复制标题
西北大西洋粒子和钍循环率的估计
DOI：
10.1029/93jc02378
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发表时间：
1994
影响因子：
--
通讯作者：
J. Sarmiento
中科院分区：
文献类型：
--
作者：
R. Murnane;J. Cochran;J. Sarmiento
我们利用已发表的结果汇编和钍和粒子循环的守恒方程，提供了西北大西洋13个深度的粒子循环速率常数及其误差的最小二乘估计。粒子聚集和分解的预测速率随水柱的变化而变化。基于对数正态概率分布，水柱中最低和最高聚集率（β2）和分解率（β - 2）的均值和标准差分别为8±27 y - 1 < β2 < 18±90 y - 1, 580±2000 y - 1 < β - 2 < 3×103±104y - 1。这些速率的中位数为2.1 y−1 < β2 < 3.2y−1,149 y−1 < β−2 < 156 y−1。预测的钍吸附速率常数（k1 = 5.0±1.0 × 104 m3 kg−1 y−1）和解吸速率常数（k−1 = 3.1±1.5 y−1）与先前的估计一致。粒子和钍守恒方程中时间依赖项和输运项之和的最小二乘估计与守恒方程中其他项的数量级相同。迫使这个和等于零会改变预测的利率。更好地估计钍活性和粒子浓度的时间依赖性，以及圆锥状有机物的浓度和通量，将有助于限制β2和β - 2的估计。
We provide least squares estimates of particle-cycling rate constants and their errors at 13 depths in the Northwest Atlantic Ocean using a compilation of published results and conservation equations for thorium and particle cycling. The predicted rates of particle aggregation and disaggregation vary through the water column. The means and standard deviations, based on lognormal probability distributions, for the lowest and highest rates of aggregation (β2) and disaggregation (β−2) in the water column are 8±27 y−1 < β2 < 18±90 y−1, and 580±2000 y−1 < β−2 < 3×103±104y−1. Median values for these rates are 2.1 y−1 < β2 < 3.2y−1, and 149 y−1 < β−2 < 156 y−1. Predicted rate constants for thorium adsorption (k1 = 5.0 ± 1.0 × 104 m3 kg−1 y−1) and desorption (k−1 = 3.1±1.5 y−1) are consistent with previous estimates. Least squares estimates of the sum of the time dependence and transport terms from the particle and thorium conservation equations are on the same order as other terms in the conservation equations. Forcing this sum to equal zero would change the predicted rates. Better estimates of the time dependence of thorium activities and particle concentrations and of the concentration and flux of paniculate organic matter would help to constrain estimates of β2 and β−2.