The Equatorial Line Observations Campaign: Physical Oceanography within the Maritime Continent

海洋大陆（MC）是全球天气和气候系统在亚季节至年代际尺度上影响全球大气变率的关键区域，也是麦登-朱利安涛动（MJO）的核心区域。尽管如此，MC区域大气、海洋和陆地表面的多尺度相互作用观测很少，理解也很差，在模式中也没有得到很好的体现，导致在降水等大范围预报中存在较大的系统误差。MJO向东通过MC传播是MJO生命周期中最不可预测的部分。MC岛屿通过促进陆地-空气-海洋相互作用，特别是在昼夜时间尺度上，为这种传播创造了自然屏障。该项目是为了支持MC的物理海洋学测量，作为跨学科赤道线观测（ELO）实地活动的一部分。ELO野外活动的主要目标是利用收集的原位、遥感和最先进的数值模型来表征CCKW和MJO在MC区域传播期间的大气对流和上层海洋温度的日循环。对MC区域的海气相互作用的更好理解将导致在人口稠密地区（即MC）进行预报的进步。提高天气和气候预报的可靠性将使决策者、战略规划者、保险业和粮食安全行业受益，这些行业使用这些预测进行决策。来自美国、英国和印度尼西亚的科学家之间的合作将有助于所有参与机构的研究多样性和能力建设，这对参与该项目的早期职业研究人员有很大的好处。ELO的数据和结果将在会议、青年运动讲习班和出版物上广泛传播。ELO观测网将包括沿赤道的三个陆基站和两个海洋站，从东印度洋到苏门答腊，横跨卡里玛塔海峡到婆罗洲。该实验设计允许在横跨MC的CCKW和MJO事件期间对大气和海洋的动力和热力学特性进行连贯的观测。将部署气象和海洋仪器来测量上层海洋分层、地表通量、降水和大气分层，以表征CCKW和MJO存在时的耦合海气变率。在该项目的物理海洋学部分，将在Karimata海峡的浅水区部署两个系泊的离散温度和盐度传感器链。目的是研究与日对流有关的上层海洋暖层分层演变及其变率。该团队特别感兴趣的是，在到达婆罗洲之前，卡里马塔海峡的浅海如何成为传播CCKW和MJO系统的先决条件。他们将讨论暖层内的海洋上层昼夜温度对夜间近海传播期间大气对流演变（增强或衰减）的重要性，以及夜间降水对海洋屏障层发展和随后几天暖层发展的影响。

The Maritime Continent (MC) is a critical region in the global weather and climate system forcing global atmospheric variability on sub-seasonal to decadal time scales, and is the core region for the Madden-Julian Oscillation (MJO). Nonetheless the multi-scale interactions of the atmosphere, ocean and land surfaces in the MC region are sparsely observed, poorly understood and badly represented in models, leading to large systematic errors in extended range forecasts such as precipitation. Propagation by the MJO eastward through the MC is the least predictable part of the MJO lifecycle. The MC islands create a natural barrier to this propagation by fostering land-air-sea interaction, especially on diurnal time scales. This project is to support the physical oceanography measurements of the MC as part of the interdisciplinary Equatorial Line Observations (ELO) field campaign. The main objective of the ELO field campaign is to use the collected in situ, remotely sensed and state-of-the-art numerical models to characterize diurnal cycles of atmospheric convection and upper ocean temperature during CCKW and MJO propagation across the MC region. An improved understanding of the air-sea interactions in the MC region would result in the advancement of forecasting in a densely populated region (i.e., MC). Improved reliability of weather and climate forecasts will benefit the policymakers, strategic planners, insurance industry and food security industries that use these predictions for decision-making. Collaboration between scientists from the USA, UK and Indonesia will contribute to research diversity and capacity building among all the involved institutions with great benefit for the early career researchers involved in this project. The data and results from ELO will be widely disseminated at conferences, YMC workshops and in publications.The ELO observational network will consist of three land-based and two ocean-based stations along the equator spanning from the eastern Indian Ocean to Sumatra and across the shallow Karimata Strait to Borneo. This experimental design allows for coherent observations of dynamical and thermodynamical properties of the atmosphere and ocean during CCKW and MJO events across the MC. Meteorological and oceanographic instruments will be deployed to measure upper ocean stratification, surface fluxes, precipitation and atmospheric stratification to characterize the coupled air-sea variability in the presence of CCKWs and the MJO. In this physical oceanography component of the project, two moored chains of discrete temperature and salinity sensors will be deployed within the shallow waters of Karimata Strait. The purpose is to study the evolution of the upper ocean warm layer stratification associated with the diurnal convection and its variability. In particular, the team is interested in how the shallow seas in the Karimata Strait might precondition the propagating CCKW and MJO systems before reaching Borneo. They will address the importance of diurnal upper ocean temperature within the warm layer on the evolution (enhancement or decay) of atmospheric convection during its nighttime offshore propagation and in turn the impact of nocturnal precipitation on oceanic barrier layer development and subsequent development of a warm layer in the following days.