Distribution of oil concentrations in the Gulf of Mexico estimated from the Connectivity Modeling System simulation of the Deepwater Horizon 2010 oil spill; with wind drift

The dataset contains the post-processed results of the 2010 Deepwater Horizon oil spill incident at Macondo well in the Gulf of Mexico, as estimated from the simulations using the latest updated version of the oil application of the Connectivity Modeling System (CMS) or oil-CMS. In this version, the specified hydrocarbon pseudo-components are in the same droplet. The post-processing analysis yielded 4-D spatiotemporal data of the daily oil concentrations on a regular horizontal and vertical grid for the 167-day simulation period. CMS has a Lagrangian, particle-tracking framework, computing particle evolution and transport in the ocean interior. CMS simulation start date: April 20, 2010, 0000 UTC, and particles were tracked for 167 days. Oil particles release location: 28.736N, 88.365W, depth is 1222m or 300m above the oil well. 3000 particles were released every 2 hours, for 87 days, equivalent to total of 3132000 oil particles released during the simulation. Initial particle sizes were determined at random by the CMS in the range of 1-500 micron. Each particle contained three (3) pseudo-components accounting for the differential oil density as follows: 10% of light oil with the density of 800kg/m^3, 75% of the oil with 840 kg/m^3, and 15% of a heavy oil with 950 kg/m^3 density. The half-life decay rates of oil fractions were 30 days, 40 days, and 180 days, respectively. Ocean hydrodynamic forcing for the CMS model was used from the HYbrid Coordinate Ocean Model (HYCOM) for the Gulf of Mexico region on a 0.04-deg. horizontal grid and 40 vertical levels from the surface to 5500m. It provided daily average 3-D momentum, temperature and salinity forcing fields to the CMS model. The surface wind drift was also accounted for as follows. Wind stress components were used from the 0.5-degree Navy Operational Global Atmospheric Prediction System (NOGAPS), and 3% of their values were added to the top level ocean velocity components, considering the wind stress rotation. The transport and evolution of the oil particles were tracked by the oil-CMS model during the 167 days of the simulation, recording each particle’s horizontal position, depth, diameter, and density into the model output every 2 hours. Model data need to be post-processed to obtain oil concentrations estimates. The post-processing algorithm took into the account the total amount of oil spilled during the 87-day incident as estimated from the reports (730000 tons), and the assumptions about the oil particle size distribution at the time of the release as estimated in the prior studies. The current dataset assumes the oil was not treated with the chemical dispersants, and the modal peak in initial particle distribution is between 50-70 micron. The data for the oil concentrations are daily average values in ppb units. Horizontal 0.01-degree grid covers the Gulf of Mexico (25N-30.75N, 84W-93W), and vertical grid extends from the surface to the depth of 2400m at 20m increments. Daily oil concentrations are also estimated for the following vertical layers: 0-1m, 1-20m, 20-50m, 50-200m, and 200-200m; a separate file is for the layer of 0-1m and for the 0-20m layer; a separate file for the 0-1m surface layer concentrations is also provided for a greater region extending east of the Florida Peninsula (79W). Post-processed NetCDF files were created using Matlab software package, v. R2014b, and used compression to keep file size small. Maximum compression, or ‘DeflateLevel’ = 9 was used in most of the files. Numerical simulations and post-processing were performed using a Pegasus supercomputer at the Center of Computational Science, University of Miami, during the period of 2016-2017.本数据集包含墨西哥湾马孔多（Macondo）油井2010年深水地平线（Deepwater Horizon）漏油事件的后处理结果，该结果基于最新更新版连通性模拟系统（Connectivity Modeling System，CMS）石油模块（简称oil-CMS）的模拟估算得到。该版本中，指定的烃类假组分均处于同一油滴内。后处理分析得到了为期167天的模拟周期内，规则水平与垂直网格上的每日石油浓度四维时空数据。CMS采用拉格朗日粒子追踪框架，计算海洋内部的粒子演化与输运过程。CMS模拟起始时间为2010年4月20日0000协调世界时（UTC），粒子追踪时长为167天。石油粒子释放位置为28.736°N、88.365°W，井深1222米（或油井上方300米处）。每2小时释放3000个粒子，持续87天，模拟期间累计释放石油粒子总计3132000个。初始粒子尺寸由CMS在1~500微米范围内随机确定。每个粒子包含3种假组分，以表征石油密度差异：占比10%的轻质油（密度800kg/m³）、占比75%的常规石油（密度840kg/m³），以及占比15%的重质油（密度950kg/m³）。三类油组分的半衰期分别为30天、40天与180天。CMS模型的海洋动力强迫数据来自墨西哥湾海域的混合坐标海洋模型（HYbrid Coordinate Ocean Model，HYCOM），该数据采用0.04°水平网格，包含从海面至5500米的40个垂直层，每日为CMS模型提供三维动量、温度与盐度强迫场。同时还纳入了海面风漂流校正：风应力分量来自0.5°分辨率的海军作战全球大气预报系统（Navy Operational Global Atmospheric Prediction System，NOGAPS），考虑风应力旋转效应后，将其值的3%叠加至顶层海洋速度分量中。在167天的模拟周期内，oil-CMS模型追踪了石油粒子的输运与演化过程，每2小时将每个粒子的水平位置、深度、直径与密度记录至模型输出文件中。需对模型数据进行后处理以得到石油浓度估算结果。后处理算法参考了报告中估算的87天漏油事件总溢油量（730000吨），以及前人研究中得到的溢油初始粒径分布假设。本数据集假设未使用化学分散剂处理溢油，且初始粒径分布的众数峰值处于50~70微米区间内。石油浓度数据为以ppb为单位的日平均值。水平网格分辨率为0.01°，覆盖墨西哥湾海域（25°N~30.75°N，84°W~93°W）；垂直网格从海面延伸至2400米深度，层间距为20米。同时还估算了以下垂直分层的每日石油浓度：0~1米、1~20米、20~50米、50~200米以及200~200米。0~1米层与0~20米层分别采用单独文件存储；还为佛罗里达半岛以东的更大海域（79°W区域）提供了单独的0~1米表层浓度数据文件。后处理得到的NetCDF文件采用Matlab R2014b软件包生成，并使用压缩技术以减小文件体积，多数文件采用最大压缩级别（DeflateLevel=9）。数值模拟与后处理工作于2016-2017年间，在迈阿密大学计算科学中心的Pegasus超级计算机上完成。