The Influence of Coastal-Trapped Waves on the Inner Continental Shelf: Temperature and Circulation Patterns

先前的研究表明，北美西海岸海平面、沿陆架速度和水温的大幅波动是由于海岸困波造成的。这些海浪向极地传播，周期为数天至数周，主要由风的波动驱动，是一种机制，通过这种机制，一个地方的风会影响其他地方的沿海海洋。据观察，下加利福尼亚州偏远地区的风波动导致南加州湾的暖水团和冷水团向岸上输送，影响到海带森林的营养供应、幼虫运输、内部潮汐温度波动的强度，以及沿海污染和有害藻华的捕获或冲刷。海岸截留波也会影响西海岸内潮孔的频率和强度。这项研究将检验这样一个假设，即在圣巴巴拉海峡和北海峡群岛周围，由下加利福尼亚州的风波动产生的沿大陆架压力梯度作为海岸捕获波到达，是环流和温度变化的主要来源。它将回答以下问题：1)下加利福尼亚州的风波动对海岸压力、速度、温度和分层有什么影响？2)点概念如何影响海岸气压、速度和温度波动的传播？3)由于海岸困波，内部潮汐和钻孔是否受到温跃层浅滩的影响？这项以过程为导向的研究将利用现有的观测数据，包括i) 18年的系泊部署，以及ii)从下加利福尼亚州到加利福尼亚州旧金山的卫星风、沿海温度和海平面数据。它将包括将观测到的海平面梯度与下加利福尼亚州偏远地区的风进行比较，并将观测到的海岸附近的速度和温度信号与已证实的由压力梯度驱动的流动动力学模型进行比较。这些将有助于确定由于沿海被困波的通过而引起的温跃层深度的区域波动是否增强或抑制了内部潮汐温度波动，并有助于从动力学角度了解下加利福尼亚州偏远风对沿海海洋的影响。更广泛的影响海岸截流波在世界范围内都存在，但它们对海岸附近水温以及跨大陆架和沿大陆架环流的影响还没有得到很好的描述。圣巴巴拉海峡和北海峡群岛支持重要的渔业和海带森林生态系统，并包含几个基于生态系统管理的海洋保护区。下加利福尼亚州的风通过海岸截留波机制的影响可能对该地区生产海带森林生态系统的生物颗粒，营养物质和幼虫的输送很重要。因此，这项研究将有利于海洋保护区的管理和规划，以及其他跨学科研究，如美国国家科学基金会支持的圣巴巴拉海岸长期生态研究项目。它还将通过支持一名新研究者的女性PI来帮助保持科学的多样性。

Previous studies show that substantial fluctuations in sea level, along-shelf velocity, and water temperature along the West Coast of North America are due to coastal-trapped waves. These waves propagate poleward, have periods of days to weeks, are mainly driven by wind fluctuations, and are a mechanism by which winds in one location influence the coastal ocean in other locations far away. Remote wind fluctuations in Baja California have been observed to cause transport of warm and cold water masses onshore in the Southern California Bight, with implications for nutrient supply to kelp forests, larval transport, strength of internal tidal temperature fluctuations, and trapping or flushing of coastal pollution and harmful algal blooms. Coastal-trapped waves are also suggested to affect the frequency and strength of internal tidal bores all along the West Coast.This study will test the hypothesis that in the Santa Barbara Channel and around the Northern Channel Islands, along-shelf pressure gradients arriving as coastal-trapped waves generated by wind fluctuations in Baja California are a dominant source of variability in circulation and temperature. It will answer the questions 1) What effect do wind fluctuations in Baja California have on coastal pressure, velocity, temperature, and stratification? 2) How does Point Conception affect the propagation of fluctuations in coastal pressure, velocity, and temperature? and 3) Are internal tides and bores affected by thermocline shoaling due to coastal-trapped waves? This process-oriented study will utilize existing observations from i) mooring deployments covering 18 years, and ii) satellite winds and coastal temperature and sea-level data extending from Baja California to San Francisco, California. It will include comparisons of observed sea-level gradients to remote winds in Baja California, and of observed velocity and temperature signals near the coast to proven dynamical models of flow driven by a pressure gradient. These will help determine whether regional fluctuations in thermocline depth due to the passage of coastal-trapped waves enhance or inhibit internal-tidal temperature fluctuations, and lead to a dynamical understanding of the effects of remote winds in Baja California on the coastal ocean.BROADER IMPACTSCoastal-trapped waves occur worldwide, but their effect on water temperature near the shore and cross-shelf and along-shelf circulation is not well-described. The Santa Barbara Channel and Northern Channel Islands support important fisheries and kelp forest ecosystems and contain several Marine Protected Areas under ecosystem-based management. The influence of winds in Baja California via the coastal-trapped wave mechanism is probably important for delivery of biogenic particles, nutrients, and larvae to productive kelp forest ecosystems in the region. Therefore this study will benefit management and planning of marine protected areas as well as other interdisciplinary research such as at the NSF-supported Santa Barbara Coastal Long-Term Ecological Research project. It will also help maintain diversity in the sciences by supporting a female PI who is a new investigator.