Continuous optical chlorophyll-a and turbidity data along R/V SONNE cruise SO300/2@en

Underway optical chlorophyll-a and turbidity data were collected along the cruise track with Sea-Bird Scientific ECO FLNTU sensors installed within two autonomous measurement systems, called self-cleaning monitoring boxes (SMBs). The SMBs measure alternatingly. While one box is measuring, the other one is being cleaned. The boxes switched generally every 6 hours. The water inlet for the SMBs is at about 4 m below sea surface. Observed chlorophyll-a and turbidity data were both quality controlled. Analysis of the chlorophyll-a data during parallel operation of the sensors in the two boxes showed a significant offset between the sensors. The correlation between the two sensors during parallel operation time, however, is not very high due to the overall very narrow parameter range. Therefore, results from the sensor comparison for expedition SO300/1 were used to align the data resulting in a consistent chlorophyll-a time series. A comparison for the corrected chlorophyll-a with satellite data using the GlobColour CHL1 product is additionally provided. The Pearson correlation coefficient is low due to the overall small parameter range. Most data points lie at the 1:1 line within their measurement uncertainty. Details on all quality control steps and the comparison with satellite data can be found in the data processing report. Note that the instruments are factory-calibrated, however, no post-calibration was performed due to missing reference data. The resulting data set contains the original data and corresponding quality flags achieved by the quality control algorithm, and, in case of chlorophyll-a, also the corrected data with corresponding quality flag. The data source is given through the name of the active SMB. The data set contains data during transit time and station work. We recommend to use ship's speed to filter for only transit data.本数据集沿巡航航迹采集了走航式光学叶绿素a与浊度数据，所用设备为Sea-Bird Scientific公司的ECO FLNTU传感器，该传感器搭载于两套自主测量系统——自清洁监测箱（self-cleaning monitoring boxes，SMBs）中。两套系统交替开展测量：当其中一套监测箱处于工作状态时，另一套正执行清洁作业，二者通常每6小时完成一次切换。监测箱的进水口位于海面下约4米处。所获取的叶绿素a与浊度数据均通过了质量控制流程。对两套监测箱内传感器并行运行期间的叶绿素a数据开展分析后，结果显示各传感器间存在显著偏差；但由于整体参数变化范围极窄，并行运行时段内两台传感器的相关性并不理想。因此，本次SO300/1航次的传感器比对结果被用于校正数据，最终得到一致性良好的叶绿素a时间序列。此外，本数据集还提供了校正后的叶绿素a数据与采用GlobColour CHL1产品的卫星遥感数据的比对结果：由于整体参数取值范围较小，皮尔逊相关系数（Pearson correlation coefficient）偏低，但绝大多数数据点均落在1:1参考线的测量不确定度范围内。所有质量控制步骤及与卫星数据的比对细节均可查阅数据处理报告。请注意，本套仪器已完成出厂校准，但因缺乏配套参考数据，未开展事后校准工作。本数据集包含原始数据及通过质量控制算法得到的对应质量标记；针对叶绿素a数据，还额外提供了校正后的数据及其对应的质量标记。数据来源通过当前工作的SMB编号进行标识。数据集涵盖航渡时段与站位作业期间的全部观测数据。建议通过船舶航速对数据进行筛选，仅保留航渡阶段的数据。