Thermodynamics and hydrodynamics in an atoll reef system and their influence on coral cover
Thermodynamics and hydrodynamics in an atoll reef system and their influence on coral cover
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环礁系统的热力学和流体力学及其对珊瑚覆盖的影响
DOI：
10.1002/lno.10365
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发表时间：
2016
影响因子：
4.5
通讯作者：
R. Dunbar
中科院分区：
文献类型：
--
作者：
J. Rogers;S. Monismith;D. Koweek;W. Torres;R. Dunbar
我们提出了一个环礁系统的热力学和流体动力学的结果，并根据2012年至2014年在太平洋中部的帕尔米拉环礁的实地测量结果，对珊瑚覆盖的影响。我们发现，珊瑚覆盖的空间变化与温度变化的时间尺度上的天到星期。珊瑚覆盖率高（> 50%）的浅水阶地和礁后区的温度分布变化很大，但其平均周温度分布较低，与近海沃茨相似。维持这一低周温度的机制是平均平流，这在每周的时间尺度上变化，以响应波强迫。潮汐在驱动环礁上的水流方面也很重要，但它们对热量净输送的贡献并不显著。风和区域强迫一般不重要的驱动流内的环礁。浮力驱动的流动是重要的泻湖内，并在驱动跨海岸交换前礁环境。有利于高珊瑚覆盖率的物理因素不同，根据不同的流行的水动力制度：在backreef栖息地，在泻湖栖息地（天进入珊瑚礁系统），和较低的波应力forefreef栖息地的旅行时间短，温度低。鉴于气候变化导致的未来变暖，通过波浪驱动的平均流量保持较低温度的珊瑚礁局部地区将最有可能促进珊瑚的生存。
We present results of the thermodynamics and hydrodynamics of an atoll system and their effect on coral cover based on field measurements from 2012 to 2014 on Palmyra Atoll in the central Pacific. We found that spatial variations in coral cover were correlated with temperature variations on time scales of days to weeks. Shallow terrace and backreef sites with high coral cover (> 50%) had a highly variable temperature distributions, but their average weekly temperature distributions were lower and similar to offshore waters. The mechanism for maintaining this low weekly temperature was mean advection, which varied on a weekly timescale in response to wave forcing. Tides were also important in driving flow on the atoll, but their contribution to the net transport of heat was not significant. Wind and regional forcing were generally not important in driving flow inside the atoll. Buoyancy‐driven flows were important within the lagoons, and in driving cross‐shore exchange on forereef environments. The physical factors favoring high coral cover percentage varied according to the different prevailing hydrodynamic regimes: low temperatures in backreef habitats, short travel times in lagoon habitats (days since entering the reef system), and lower wave stress on forereef habitats. In light of future warming from climate change, local areas of reefs which maintain lower temperatures through wave‐driven mean flows will have the best likelihood of promoting coral survival.