A mechanism for horizontal zooplankton transport by vertical migration in tidal currents
A mechanism for horizontal zooplankton transport by vertical migration in tidal currents
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潮流中垂直迁移的浮游动物水平运输机制
DOI：
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发表时间：
1991
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通讯作者：
A. E. Hill
中科院分区：
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作者：
A. E. Hill
提出了一种机制，净水平运输可以诱导在一个纯粹的振荡，垂直剪切潮流中垂直迁移的生物。该机制包含两个要素。首先，对于所有合理的潮流剖面，净水平运输是诱导在任何生物垂直迁移的周期是一个确切的倍数的潮汐周期。(This是众所周知的选择性潮汐流输送过程的基础，其中迁移期和潮汐期完全相等。）新机制中的第二个要素是观察到昼夜迁移，垂直迁移的最常见形式，具有24小时的周期，因此是具有12小时周期的主要太阳半日潮分潮（S2）的精确倍数。S2和昼夜迁移周期之间的这种关系源于这两种现象都独立地锁定在太阳周期上。因此，昼夜垂直迁移可以与S2潮流成分相互作用，诱导迁移生物的长期水平运输。对于合理的潮流和垂直迁移参数，发现4 km d−1的水平输运率是可能的。净输送的方向取决于S2潮流相对于当地正午的相位。因此，提出的假设是，在S2阶段的地理变化是一个因素，负责创建区域，这是要么保留有利或否则为diel-migrating海洋生物。
A mechanism is proposed by which net horizontal transport can be induced in an organism which migrates vertically in a purely oscillatory, vertically sheared tidal current. The mechanism contains two elements. First, for all reasonable tidal current profiles, net horizontal transport is induced in any organism which migrates vertically with a period which is an exact multiple of the tidal period. (This is the basis for the widelyknown process of selective tidal stream transport where the migration period and the tidal period are exactly equal.) The second element in the new mechanism is the observation that diel migration, the most common form of vertical migration, has a period of 24 h and is therefore an exact multiple of the principal solar semi-diurnal tidal constituent (S2) which has a period of 12 h. This relation between the S2 and diel migration periods stems from the fact that both phenomena are independently locked to the solar cycle. Diel vertical migration can therefore interact with the S2 tidal current constituent to induce longterm horizontal transport in migrating organisms. For reasonable tidal current and vertical migration parameters it is found that horizontal transport rates of 4 km d−1 are possible. The direction of net transport depends upon the phase of the S2 tidal current relative to local noon. The hypothesis is therefore proposed that geographical variation in S2 phase is a factor responsible for creating regions which are either retention-favorable or otherwise for diel-migrating marine organisms.