DOI: 10.14466/CefasDataHub.198

Description

ESM2 CTD (Conductivity, Temperature and Depth) profile data for CEND2013, CEND2014, CEND2215, CEND2216, part of the annual autumn pelagic survey in the English Channel, Celtic Sea and Bristol Channel running from 2012-2016. ESM2 is a Cefas developed micro logger for applications requiring a small low power logger with integrated sensors and battery. It has standard sensors for conductivity, temperature, depth, optical backscatter and roll and pitch, and was also fitted with an oxygen optode, sea point fluorometer and light profiler.

An ESM2 profiler was deployed, either attached to a CTD rosette or independently where conditions were too rough to deploy the rosette.

Data were subject to a full quality assurance procedure which assigned flags to poor quality data (e.g. for sensor malfunction, drift). Only good quality data is included here, with flags to show the QA level:

QA2: Manually reviewed and quality controlled. QA3: Data calibrated against field samples to produce derived scientific measurements. QA4: Additional correction applied to dissolved oxygen measurements to account for effects of salinity, temperature and pressure. Data were extracted from the database and binned to 0.5m depth resolution from the upcast data only.

Chlorophyll a analysis results from HPLC (high-performance liquid chromatography, see https://doi.org/10.14466/CefasDataHub.75) were used to convert fluorescence measurements from the ESM2 profiler to chlorophyll a concentration. ESM2 profiles were binned to 0.1m bins, and matched with the discrete HPLC samples using the survey name, and depth and location (closest match, with filters applied to exclude any bad matches). The relationship between total chlorophyll a and fluorescence (using simple linear regression for each survey) was then used to convert fluorescence to chlorophyll a where this relationship was of sufficient quality.

Contributors

Collingridge, Kate / Capuzzo, Elisa / Hull, Tom / van der Kooij, Jeroen

Subject

Water column temperature and salinity / Raw fluorometer output / Dissolved oxygen parameters in the water column / Chlorophyll pigment concentrations in the water column

Start Date

13/10/2013

End Date

17/10/2016

Year Published

2026

Version

1

Citation

Collingridge et al. (2026). CTD (Conductivity, Temperature and Depth) ESM2 profile data for the POSEIDON project in the Celtic Seas and English Channel for autumn 2012 to 2016. V1. doi: https://doi.org/10.14466/CefasDataHub.198

Rights List

Open Government Licence

DOI

10.14466/CefasDataHub.198