Naldmann et al. 
10.3389/fmars.2022.1002153 
| hl 
5. A. 
— 
Data ac- 
äuisition 
Quality 
Assurance 
FT 
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"IGURE 2 
schematic of information (blue) flow and their corresponding uncertainty (yellow) defining a single field measurement. The top part shows the 
environmental signal which is intended to be measured. The data acquisition box shows the different information and their uncertainty a 
measurement is facing: natural fluctuations of the environmental signal between the selected sampling interval, the sensor response capabilities, 
‚elated measurement of time facing clock drift or data storage delays, uncertainty of location because of movement within the water column or 
f bottom mounted, change of water depth due to tidal effects. The quality assurance box is representing the information an uncertainty from 
:he sensor calibration as detected in the laboratory under stable and well-known conditions. 
4.1 Temperature data analysis 
Every environmental measurement shows a certain degree of 
variability that cannot be assigned to any known process and 
cherefore can be seen as a purely statistical phenomena that 
reflects the continuous transition of the water body into a new 
state. To estimate this type of variability and derive from that a 
contribution to the uncertainty of the temperature 
measurements, data sets from six sensors were evaluated 
within specific measurement periods. Figure 3 shows the 
measured temperature data over the entire period. Total data 
availability of the individual sensors varies between 69.7% and 
100% (see Supplementary Materials, Appendix 1, Table A3) The 
different data availability is due to the temporal removal (for 
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A 
calibration and functional testing) of individual sensors and 
short telemetry interruptions. However, the data avajilability is 
acceptable and sufficient for an evaluation. 
The study uses data collected using the O2A NRT data 
infrastructure which has been published at PANGAEA as 
described above. The data sets are available in the form of 
measured values with a maximum sampling frequency 
depending on the individual sensor configuration (see 
Appendix 1, Table Al). Sampling intervals vary between 1 s 
{or sensors 1-3 and 10 s for sensors 4-6. 
From the entire data set (covering almost four months), 
selected periods were chosen for further evaluation. The 
selection of time periods includes the beginning and end of 
feldwork as well as periods of high and low variability during 
Sensor: 1 
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ı Sensor: ? 
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4 
2 
5 
Sensor 5 
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Sensor: 6 | 
FIGURE 3 
Measured temperature data of the six sensors for the whole measurement period (June 22 — Nov 10). Grey shaded areas indicate selected 
analvsis periods. Unlabeled data gaps are due to different download speeds or caused by telemetry interruption 
Zrontiers in Marine Science 
16, 
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