Relative phase between tidal and solar cycles influences the heating of a coral atoll lagoon

The residence time of water within reef-lagoon systems is of first-order importance to biogeochemical cycles and reef ecosystem functions. Circulation, mixing, and water renewal within these systems is highly dependent upon the geometry of the reef as well as wave, tide, and wind forcing. We are motivated to understand the physical driving a recent warming event as well as observed hypoxia-related fish kills and seagrass dieoff events in Dongsha Atoll lagoon, a 28 km wide coral atoll in the South China Sea. Though extensive work has been done on hypoxia events in temperate coastal systems, there remains a lack of understanding regarding the dynamics of these events in shallow tropical waters. Hydrographic observations were collected in summer 2019 to examine circulation and ocean-lagoon exchange in Dongsha Atoll lagoon. We construct a heat budget for the Dongsha Atoll lagoon to understand the physical processes governing lagoon circulation and ocean-lagoon exchange. We examine the influ..., The presented observations are part of a larger study of internal wave propagation around Dongsha Atoll Sinnett et al. 2022; Ramp et al. 2022). We used measurements of currents, pressure, and temperature in and surrounding the lagoon (channels, reef flat, forereef), as well as meteorological measurements taken on Pratas Island collected from 20 May 2019 - 09 June 2019.
Water temperature in the lagoon was measured on two fixed vertical moorings in the north and south lagoon, two vertically profiling moorings (WireWalkers, Rainville and Pinkel (2001)) in the east and west lagoon, and on bottom moored thermistors at various locations around the lagoon. Water temperature was measured in both the north channel (NCH) and south channel (SCH) on fixed vertical moorings and on the reef flat by a bottom moored thermistor. determined from a pre-deployment calibration bath. Corrected temperatures are within 0.055 $\degC$. Additionally, water temperature and salinity were measured with depth approxi..., , # Relative phase between tidal and solar cycles influences the heating of a coral atoll lagoon.

The presented observations are part of a larger study of internal wave propagation around Dongsha Atoll Sinnett et al. 2022; Ramp et al. 2022). We used measurements of currents, pressure, and temperature in and surrounding the lagoon (channels, reef flat, forereef), as well as meteorological measurements taken on Pratas Island collected from 20 May 2019 - 09 June 2019.

Water temperature in the lagoon was measured on two fixed vertical moorings in the north and south lagoon, two vertically profiling moorings (WireWalkers, Rainville and Pinkel (2001)) in the east and west lagoon, and on bottom moored thermistors at various locations around the lagoon. Water temperature was measured in both the north channel (NCH) and south channel (SCH) on fixed vertical moorings and on the reef flat by a bottom moored thermistor. determined from a pre-deployment calibration bath. Corrected temperatures are...

礁湖系统（reef-lagoon systems）内水体的停留时间（residence time）对生物地球化学循环（biogeochemical cycles）与珊瑚礁生态系统功能（reef ecosystem functions）具有一级重要性。此类系统内的环流、混合与水体更新高度依赖于珊瑚礁的几何形态，以及波浪、潮汐与风强迫。本研究旨在厘清驱动东沙环礁（Dongsha Atoll）泻湖近期暖化事件的物理过程，以及当地观测到的缺氧性鱼类死亡与海草衰退现象——该环礁为南海（South China Sea）范围内宽28千米的珊瑚环礁。尽管针对温带近岸系统（temperate coastal systems）的缺氧事件已有大量研究，但目前对浅热带海域（shallow tropical waters）此类事件的动力学机制仍缺乏足够认知。
2019年夏季我们开展了水文观测（hydrographic observations），以探究东沙环礁泻湖的环流与洋-泻湖交换（circulation and ocean-lagoon exchange）过程。我们构建了东沙环礁泻湖的热收支（heat budget）模型，以解析控制泻湖环流与洋-泻湖交换的物理过程。我们探究了[原文截断]。本文呈现的观测数据属于东沙环礁周边内波传播（internal wave propagation）更大规模研究的一部分（Sinnett等人，2022；Ramp等人，2022）。我们使用了泻湖及周边区域（水道、礁坪与礁前坡，channels, reef flat, forereef）的海流、压强与温度（currents, pressure, and temperature）观测数据，以及2019年5月20日至6月9日在东沙岛（Pratas Island）获取的气象观测（meteorological measurements）数据。
泻湖内的水温通过多类设备测得：北泻湖与南泻湖各布设1套固定垂直锚系（fixed vertical moorings），东泻湖与西泻湖各布设1套垂直剖面锚系（vertically profiling moorings，WireWalkers，Rainville与Pinkel，2001），同时在泻湖周边多处位置部署了海底锚系热敏电阻器（bottom moored thermistors）。北水道（NCH）与南水道（SCH）的水温通过固定垂直锚系测得，礁坪的水温则由海底锚系热敏电阻器获取。数据通过部署前校准槽（pre-deployment calibration bath）得到校正，校正后水温的误差在0.055℃以内。此外，我们还在不同深度测量了水温与盐度[原文截断]。

本文呈现的观测数据属于东沙环礁周边内波传播更大规模研究的一部分（Sinnett等人，2022；Ramp等人，2022）。我们使用了泻湖及周边区域（水道、礁坪与礁前坡）的海流、压强与温度观测数据，以及2019年5月20日至6月9日在东沙岛获取的气象观测数据。

泻湖内的水温通过多类设备测得：北泻湖与南泻湖各布设1套固定垂直锚系，东泻湖与西泻湖各布设1套垂直剖面锚系（WireWalkers，Rainville与Pinkel，2001），同时在泻湖周边多处位置部署了海底锚系热敏电阻器。北水道与南水道的水温通过固定垂直锚系测得，礁坪的水温则由海底锚系热敏电阻器获取。数据通过部署前校准槽得到校正，校正后的水温[原文截断]。

# 潮汐与太阳周期的相对相位对珊瑚环礁泻湖升温的影响