Vertical light profiling data (NESP TWQ 2.1.9, AIMS)

The aim of the study was to obtain light and turbidity vertical profile data through the water column in Cleveland Bay over a four-day period and during maintenance dredging to use for developing an empirical spectral solar irradiance model.

This dataset consists of 95 data files (spreadsheets). One file (.xlsx format) contains the spectral attenuation coefficient for downwelling light, Kd (lambda), for the 94 different vertical profiles taken within Cleveland Bay. In addition, individual raw data files from the USSIMO Hyperspectral Irradiance Sensor for each profile are provided (.csv format).

Methods:

Over a 4-d period (12–15 September 2016), and during a period of routine maintenance dredging, 94 light and turbidity vertical profiles were measured through the water column in Cleveland Bay using a USSIMO multispectral radiometer (In Situ Marine Optics, Perth, Australia) and IMO-NTU turbidity sensor. The USSIMO incorporates a Carl Zeiss UV/VIS miniature monolithic spectrometer module as the internal light recording device providing irradiance measurement values at nanometer spectral spacing.

For each vertical profile the irradiance just-below surface incident irradiance Ed (0-, lambda) and the light attenuation coefficient Kd (lambda) were determined using the Beer-Lambert law. These data were used to calculate the wavelength specific light attenuation coefficients for downwelling light, Kd (lambda), using the relationship,

E(lambda,z)=E(lambda,0) exp (-K_d (lambda),z)

Where: E (lambda,z) is the spectral downwelling irradiance at depth z, and E (lambda,0) is the spectral downwelling irradiance just below the ocean’s surface. The accelerometer in the USSIMO was used to assess if the instrument was vertical and stable and the first 0.2 m of all deployments was discarded prior to calculating Kd.

Kd values, along with the latitude and longitude for each station and the date and time of day the vertical profiling occurred can be found in the spreadsheet (.xlsx format). Each individual raw data file (.csv format) from the USSIMO sensor contains normalised Ed values (e.g. in-water Ed divided by above-water reference Ed), as well as the latitude and longitude for each station and the date and time of day the vertical profiling occurred.

Limitations of the data:
The value of NaN appears in the spreadsheet NewDataset1_ALL_Kd_DATA.xlsx for spectral attenuation coefficient for downwelling light, Kd (lambda). It describes values too low under highly turbid conditions to reliably calculate the Kd value.

Format:

This dataset contains a single Excel file with a size of 46 KB and 94 csv files ranging in size from 11 to 202 KB.

Data Dictionary:
Spreadsheet NewDataset1_ALL_Kd_DATA.xlsx
Row headings include: Date, Local Time, Latitude, Longitude, Station ID, vertically averaged Kd (550 nm).
The heading lambda(nm) [in cell A7] is noting that 400 to 700 below are wavelengths in nanometres (nm).

Data Location:

This dataset is filed in the eAtlas enduring data repository at: data\nesp2\2.1.9-Dredging-marine-response

本研究旨在于为期四天的常规维护疏浚作业期间，在克利夫兰湾（Cleveland Bay）的水柱中获取光与浊度垂直剖面数据，用于构建经验式光谱太阳辐照度模型。

本数据集共包含95个数据文件（电子表格）。其中1个.xlsx格式文件涵盖了在克利夫兰湾内获取的94组垂直剖面的下行光光谱衰减系数Kd(λ)。此外，还提供了对应每个剖面的USSIMO高光谱辐照度传感器原始数据文件（.csv格式）。

研究方法：
2016年9月12日至15日（共4天）的常规维护疏浚作业期间，研究团队使用USSIMO多光谱辐射计（澳大利亚珀斯In Situ Marine Optics公司）与IMO-NTU浊度传感器，在克利夫兰湾的水柱中完成了94组光与浊度垂直剖面测量。USSIMO内置卡尔蔡司（Carl Zeiss）UV/VIS微型单片光谱仪模块作为内部光采集装置，可实现纳米级光谱间隔的辐照度测量。

针对每组垂直剖面，研究人员基于比尔-朗伯定律（Beer-Lambert law）计算得到海面下入射辐照度Ed(0-,λ)与光衰减系数Kd(λ)。并通过下述关系式推导得出下行光的波长特异性衰减系数Kd(λ)：
E(λ,z)=E(λ,0) exp(-K_d(λ)·z)
其中：E(λ,z)为深度z处的光谱下行辐照度，E(λ,0)为海洋表面正下方的光谱下行辐照度。USSIMO内置的加速度计用于评估仪器是否处于垂直稳定状态，所有测量剖面的前0.2米数据均在计算Kd前予以剔除。

.xlsx格式电子表格中包含了Kd值、各测量站位的经纬度以及垂直剖面测量的日期与时刻。USSIMO传感器的单条.csv格式原始数据文件则包含归一化Ed值（例如水下Ed除以水面参考Ed），以及各测量站位的经纬度与垂直剖面测量的日期和时刻。

数据局限性：
在NewDataset1_ALL_Kd_DATA.xlsx电子表格中，下行光光谱衰减系数Kd(λ)存在NaN值，该值代表在高浊度条件下，相关数值过低而无法可靠计算得到Kd值。

数据格式：
本数据集包含1个大小为46KB的Excel文件，以及94个大小介于11KB至202KB之间的.csv文件。

数据字典：
电子表格NewDataset1_ALL_Kd_DATA.xlsx的行标题包含：日期、本地时间、纬度、经度、站位ID、垂直平均Kd(550nm)。单元格A7中的标题λ(nm)表明，其下方的400至700为以纳米（nm）为单位的波长。

数据存储位置：
本数据集存储于eAtlas持久化数据仓库的以下路径：data
esp22.1.9-Dredging-marine-response