ABRACOS 1 cruise - Physical datasets

physical data associated with the abraco cruise. the abracos (acoustics along the brazilian coast) cruise aims to begin an integrated approach to monitoring the tropical marine ecosystems in the brazilian nordeste region in order to better understand the connectivity between the sub-systems composing it. in particular, this cruise should fill this gap and improve understanding of the degree of connectivity which exists between the oceanic islands and the continental margin in the nordeste of brazil, as well as within the continental platform. in this context, the main objective of the abracos cruise consisted in drawing up a 3d characterization of abiotic and biotic compartments and their interactions in the brazilian nordeste. specific objectives: objective 1 - characterization of island and coastal dynamics. measurement of hydrological characteristics and currents (rosette, ctd, adcp) should enable the circulation and characteristics of water masses to be described. these data will be more specifically used to study the physical connections between 1) the oceanic islands and coastal ecosystems and 2) the coast along the ocean and coastal zones. the in-situ measurements obtained will also be used to validate high resolution regional hydrodynamic models (e.g. roms model) which will be implemented. in-situ data acquired during the abracos cruise will be supplemented by satellite data for sea surface heights (e.g. aviso), surface temperature and chlorophyll (e.g. modis) and wind (e.g. ascat). however, it should be noted that the resolution of the products usually used and land-ocean interferences on altimetry and backscatter data will not allow these products to be used at less than 30-50 km from the coast. we will be able to partially eliminate this problem by using new "alongtrack" processing of altimetric data performed by the center for topographic studies of the ocean and hydrosphere in toulouse. these data will be used to document the geostrophic (from sea level) ageostrophic (from wind) components of surface circulation and their variability in coastal zones. objective 2 - ecosystem acoustics. acoustic tools can provide the simultaneous acquisition of quantitative and qualitative data, at different spatial-temporal scales, in numerous biotic and abiotic compartments of an ecosystem. these data can be used to characterize the ecosystem in three dimensions and directly study interactions between compartments. active acoustics have rarely been used in tropical coastal zones. the multifrequency (38, 70, 120, and 200 khz) acoustic data acquired during the abracos cruise will be used to create an initial 3d characterization of island and coastal ecosystems in the brazilian nordeste region, simultaneously characterizing the seabed and water column, when possible. the french team proposing this has sound experience in the field and developed the open source 'echopen' software in brest (www.france-nord.ird.fr/lesressources/outils-informatiques) which can separate the various sources of acoustic echoes (e.g. zooplankton, gelatinous organisms and fish) from multifrequency acoustic data. in order to calibrate the 'echopen brésil' version, acoustic observations from the abracos cruise must be combined with sampling using micronekton, mesopelagic and bottom trawls (leg 2 only) and sampling of zooplankton at fixed stations (bongo and wp2 plankton nets and phytoplankton nets). to validate the 'echopen substrat' tool we will use sampling done with bottom trawl, substrate grab and video camera observations. objective 3 - biodiversity and trophic structure. as indicated, acoustic observations will be complemented by in-situ sampling of planktonic, pelagic (mid-water trawls) and demersal-benthic (bottom trawl) organisms. this will involve establishing how hydrological conditions determine the vertical distribution of organisms and therefore interactions. one part of the sampled organisms will be conserved in formaldehyde then identified by taxonomists at the federal university of rio de janeiro (ufrj) to be added to brazilian collections. the remainder of the samples will be used to obtain biological information. along with the classic biological measurements (size, weight, sex, maturity, etc.) specimens of entire organisms (plankton) and soft tissues (muscles) will be taken in order to titrate various trophic tracers: stable isotopes of carbon, nitrogen and insofar as possible mercury. in addition, particulate organic matter (pom) will be collected by filtration (samples taken by rosette) to titrate the amounts of stable isotopes. spatial variations in these tracers will make it possible to highlight the relative positions of these organisms in the food web and variations in food sources through the local pom signatures. measurements of methylmercury (mehg), a neurotoxin which accumulates in the food chain, will also be[...]

与 abraco 游轮相关的物理数据。Abracos 游轮（巴西海岸声学）旨在启动对巴西东北部热带海洋生态系统进行综合监测的方法，以更好地理解构成该系统的子系统之间的连通性。特别是，本次游轮旨在填补这一空白，并加深对巴西东北部海洋岛屿与大陆边缘之间，以及大陆平台内部的连通程度理解。在此背景下，Abracos 游轮的主要目标是对巴西东北部的非生物和生物舱室及其相互作用进行三维描述。具体目标：目标1 - 岛屿和海岸动力学特征。水文特征和流速（如罗塞特、CTD、ADCP）的测量将能够描述水团的循环和特征。这些数据将被更具体地用于研究以下物理连接：1）海洋岛屿与海岸生态系统之间的连接，以及2）海洋沿海和沿海区域的海岸线。所获得的现场测量数据还将用于验证实施的高分辨率区域水动力模型（如ROMS模型）。在Abracos游轮期间获取的现场数据将由卫星数据（如AVISO）补充，用于测量海面高度、表面温度和叶绿素（如MODIS）以及风力（如ASCAT）。然而，需要注意的是，通常使用的产品分辨率以及海陆界面对高度计和后向散射数据的影响，将不允许这些产品在距离海岸线30-50公里以内使用。通过使用图卢兹海洋和大气地形研究中心执行的新“沿轨道”高度计数据处理，我们将能够部分消除这个问题。这些数据将被用于记录海岸区域表面环流的地转（从海平面）和非地转（从风力）成分及其变率。目标2 - 生态系统声学。声学工具能够在不同的时空尺度上，对生态系统的众多生物和非生物舱室同时进行定量和定性数据的采集。这些数据可用于对生态系统进行三维表征，并直接研究舱室之间的相互作用。主动声学在热带沿海区域很少被使用。在Abracos游轮期间获取的多频（38、70、120和200千赫）声学数据将被用于创建巴西东北部岛屿和海岸生态系统初始的三维表征，在可能的情况下，同时表征海底和水柱。提出此建议的法国团队在野外拥有丰富的经验，并在布勒斯特（www.france-nord.ird.fr/lesressources/outils-informatiques）开发了开源的'echopen'软件，该软件可以分离多频声学数据中的各种声波回波源（例如浮游动物、胶状生物和鱼类）。为了校准'echopen brésil'版本，声学观测数据必须与微浮游动物、中层浮游动物和底拖网（仅第二阶段）的采样以及固定站点（bongo和wp2浮游动物网和植物网）的浮游动物采样相结合。为了验证'echopen substrat'工具，我们将使用底拖网、底质抓取和视频相机观测进行的采样。目标3 - 生物多样性和营养结构。如前所述，声学观测将由现场浮游生物、浮游动物（中层拖网）和底栖-底栖生物（底拖网）的采样所补充。这将涉及确定水文条件如何决定生物的垂直分布，从而确定相互作用。所采集的生物样本中的一部分将被保存于甲醛中，并由里约热内卢联邦大学（UFRJ）的分类学家进行鉴定，以便添加到巴西收藏中。其余样本将被用于获取生物学信息。除了经典的生物学测量（大小、重量、性别、成熟度等）外，还将采取整个生物体（浮游生物）和软组织（肌肉）的样本，以滴定各种营养示踪剂：碳、氮的稳定同位素以及尽可能多的汞。此外，通过过滤（罗塞特采集的样品）收集颗粒有机物质（POM），以滴定稳定同位素的含量。这些示踪剂的时空变化将有助于突出这些生物在食物网中的相对位置以及食物来源的变化。甲基汞（Mehg）的测量，一种在食物链中积累的神经毒素，也将被[...]