diff --git a/sections/data_sharing.md b/sections/data_sharing.md index 7ae6782..1b74539 100644 --- a/sections/data_sharing.md +++ b/sections/data_sharing.md @@ -1,3 +1,4 @@ +(data-sharing)= # Data sharing OceanGliders strongly encourages all glider operators to share their data to the public and provide open access both in real time and delayed mode. diff --git a/sections/oxygen_dmqc.md b/sections/oxygen_dmqc.md index 3fefa32..fef7879 100644 --- a/sections/oxygen_dmqc.md +++ b/sections/oxygen_dmqc.md @@ -1,3 +1,4 @@ +(dmqc)= # Delayed Mode Quality Control ## Calculation of oxygen variables diff --git a/sections/oxygen_introduction.md b/sections/oxygen_introduction.md index 9c2b3a3..cd4c661 100644 --- a/sections/oxygen_introduction.md +++ b/sections/oxygen_introduction.md @@ -2,6 +2,42 @@ This standard operating procedure (SOP) document for dissolved oxygen (DO) aims to guide the user through the steps necessary to collect good quality dissolved oxygen data using ocean gliders for both real time and post deployment data streams. +## Overview cheat sheet +The most important actions to be taken are summarised in this simple cheat sheet below. +This short summary allows the reader check under time pressure whether key points are taken into account prior to deployment. +We recommend to read each chapter in detail to ensure best quality data. + +**Pre-deployment/Deployment** +(1) Check that sensors are in good condition and you have selected the best option for the planned mission. + - BEST: Do two-point calibration ({numref}`two_point_calibration`). + +(2) Mount the sensor(s) ({numref}`sensors_integration`). +(3) Configure sensor for deployment ({numref}`sensor_configuration`). Make sure your glider is configured to record phase with correct timings. +(4) Keep sensor foil wet at least 8 hours before deployment. If it cannot be kept submerged in water, have a wet sponge covering the foil ({numref}`storage_and_cleaning`). +(5) Do two-point calibration shortly before deployment ({numref}`two_point_calibration`). +(6) In-situ reference measurements recommended to do, using hierarchy of decreasing quality: + - BEST: Optodes attached to a CTD ({numref}`deployment_ship_CTD`). + - BEST: multiple co-located CTD casts in well mixed waters (including Winkler samples at different depths) and in-air drift correction. + - GOOD: single point Winkler sample and CTD from nearby and no drift correction (see section {numref}`deployment_small_boat`). + - OK: in-air calibration only ({numref}`in-air-calibration`). + +**Mission and Real Time data flow** ({numref}`mission-execution`) +(7) Ensure data stream is set up correctly including relevant metadata is sent to allow real time data corrections ({numref}`rtqc`). + +**Recovery** ({numref}`post-recovery`) +(8) Keep sensor foil wet until finish post deployment in-situ reference measurements. +(9) Download data. +(10) In-situ reference measurements recommended to do, using hierarchy of decreasing quality as mentioned above. +(11) Clean and store the sensor. + +**DMQC** ({numref}`dmqc`) +(12) Determine and correct optode lag. + +**Data sharing** ({numref}`data-sharing`) +(13) Share high quality data in public open access archives. + +## Overview sensor glider combinations + *Table 1: List of the known sensor/glider combinations. We aim to cover all combinations in this document.* | Sensor / Glider | Slocum | Autosub/ ALR (NOC) | Seaglider | Deepglider | SeaExplorer | Spray | Information | @@ -14,4 +50,4 @@ This standard operating procedure (SOP) document for dissolved oxygen (DO) aims | RBRcoda T.ODO | | | | | X | | [Link](https://rbr-global.com/products/sensors/rbrcoda-odo) | | Contros Hydroflash (1) | | | X | | | | [Link](https://www.kongsberg.com/globalassets/maritime/km-products/product-documents/hydroflash-accurate-fast-and-versatile-oxygen-optode/Download) | -(1)The advanced, optical sensor is based on the principle of fluorescence quenching. Contros are no longer in operation, the sensors cannot be calibrated so they are likely to become obsolete in the future. +(1) The advanced, optical sensor is based on the principle of fluorescence quenching. Contros are no longer in operation, the sensors cannot be calibrated so they are likely to become obsolete in the future. diff --git a/sections/oxygen_mission_execution.md b/sections/oxygen_mission_execution.md index aaea2d0..07a548d 100644 --- a/sections/oxygen_mission_execution.md +++ b/sections/oxygen_mission_execution.md @@ -1,3 +1,4 @@ +(mission-execution)= # Missions execution This section covers the activities of those deploying and recovering the gliders in the field in addition to best practices for glider pilots. @@ -120,6 +121,7 @@ In regions with known oxygen concentrations i.e. within the core of the Peruvian For this glider can be parked at this depth to get a 0 calibration at the beginning and at the end of the deployment. This can also be done by adding different depth/temperature levels if the anoxic layer is thick enough to cover different temperatures. i.e. further offshore where the OMZ is several 100 m thick. +(in-air-calibration)= #### In-air calibration In-air calibration can be carried out if optodes are attached in a way that they reach out of the water when the glider is surfacing {cite}`NicholsonFeen2017` as done also for long float deployments {cite}`Bittig2018` This can be valuable in particular if no 0 / 100 % lab calibration or CTD intercomparison is available as well as for long deployments. diff --git a/sections/oxygen_post_recovery.md b/sections/oxygen_post_recovery.md index 27dc5db..ff89408 100644 --- a/sections/oxygen_post_recovery.md +++ b/sections/oxygen_post_recovery.md @@ -1,3 +1,4 @@ +(post-recovery)= # Post-recovery operations and calibrations At first users should report that their mission is over to support(at)oceanobs.org diff --git a/sections/oxygen_pre_deployment.md b/sections/oxygen_pre_deployment.md index 33bf30e..43d1e97 100644 --- a/sections/oxygen_pre_deployment.md +++ b/sections/oxygen_pre_deployment.md @@ -1,5 +1,6 @@ # Pre-deployment operations and calibrations +(storage_and_cleaning)= ## Storage and cleaning Optode foils typically drift more while in storage than while in use, the reasons for this are thought to be due to exposure to UV radiation and dry air {cite}`Bittig2018`, {cite}`Aanderaa2018`. We recommend that all optodes should be stored away from the light (especially fluorescent lights), keep the foil humid and use the plastic caps provided with the sensor. Two-point calibration prior to deployment is always recommended. @@ -20,6 +21,7 @@ After recovery the sensor has to be cleaned to remove any biofouling. The follow *NOTE: Don’t change the foil unless it is physically damaged.* +(sensor_configuration)= ## Sensor configuration for deployment Salinity configuration: 0 PSU. For optode sensors: when there is a small variation in salinity (less than 1 g/kg), it can be set to the mid value avoiding the need of salinity compensation. @@ -56,6 +58,7 @@ You will need to leave the sensor logging outside in the free air for several ho ## Pre-deployment calibration Optodes and similar instruments generally drift more while in storage than in use. It is therefore essential that these instruments are recalibrated prior to glider deployment. This is necessary even if in-situ reference (Winkler) samples are taken during the deployment as they will not cover the full range of oxygen concentrations during the period of the mission. As the instrument drift manifests as an increasing offset from zero in addition to a reducing sensitivity, a two point calibration is required to rescale the optodes measuring range. +(two_point_calibration)= ### Two point calibration procedure, optode example This protocol is recommended to do for at least two different temperatures, which cover the expected in-situ temperature range. There are several possibilities in order to achieve this, some examples: diff --git a/sections/oxygen_rtqc.md b/sections/oxygen_rtqc.md index 0ab49dc..7e37067 100644 --- a/sections/oxygen_rtqc.md +++ b/sections/oxygen_rtqc.md @@ -1,3 +1,4 @@ +(rtqc)= # Required Metadata, Real Time Data Processing & Quality Control ## Required Metadata and Real Time Data Processing diff --git a/sections/oxygen_sensors_integration.md b/sections/oxygen_sensors_integration.md index 1848349..8d0ab42 100644 --- a/sections/oxygen_sensors_integration.md +++ b/sections/oxygen_sensors_integration.md @@ -1,3 +1,4 @@ +(sensors_integration)= # Sensors and integrations ## Oxygen sensors