Underway Sensors Provide Data from Ships of Opportunity
Above: Exploration area. Integrated Marine Observing System (IMOS)/Google Maps
Thermosalinographs are used to collect information about the sea surface, typically in flow-through systems operating continuously throughout a cruise. Thermosalinograph data can be used to calculate salinity, density, sound velocity, and other parameters of interest. They are usually installed inside and near to the hull of a ship in order to make measurements on uncontaminated seawater, with optional sensors plumbed into the system for a wider range of measurements.
The RV Cape Ferguson and RV Solander of the Australian Institute of Marine Science (AIMS) routinely record underway measurements of near-surface water temperature, salinity, chlorophyll (fluorescence) and turbidity (NTU) during scientific operations in the tropical waters of northern Australia. Measurements are made with an SBE 21 Thermosalinograph and an ECO FLNTU, providing data at 10-second intervals throughout a cruise that can be used to improve calibration and validation of satellite sea surface temperature and ocean color data.
For more information, go to The Australian Institute of Marine Science's page and click on links in the section "Data and Resources".
High-Resolution Biophysical Observations on a Towed Vehicle
in the Chukchi Sea
Photo: Sea-Sciences Acrobat on deck before deployment. The Sea-Bird FastCAT and ECO Puck are mounted horizontally in the reinforced sled underneath the wings and main body.
Biological processes in the upper ocean are complex, and understanding them requires measurements of multiple biological and physical properties across a wide range of temporal and spatial scales. In the summertime, the Chukchi Sea is a two-layer system: warm, fresh meltwater formed by ice melting at the surface overlies cold, salty winter water formed during freeze-up. At the interface between these two layers, temperature and practical salinity can change as much as 5 ºC and 3 PSU over 2 meters. Resolving these thin layers requires fast sampling, high resolution instrumentation.
An SBE 49 FastCAT CTD (conductivity, temperature, and pressure) and ECO Puck (chlorophyll-a, CDOM, and turbidity) were integrated onto a towed vehicle, providing high resolution physical and biological maps of the upper ocean in the Chukchi Sea. These instruments were chosen for their high sampling frequency, compact size and ability to transit the data back in real-time, enabling adaptive sampling and the resolution of thin and patchy biological and physical properties.
Read the Case Study [PDF]
Tech Tip: Getting Good CTD Data on Moving Platforms
Originial Photo: WHOI. Digital Editing: Sea-Bird Scientific.
When making measurements from a moving platform, instrument limitations and sampling methodology need to be considered. Obtaining accurate CTD measurements is more difficult when moving vertically (profiling) or horizontally (surface mapping), or both vertically and horizontally (AUVs, towed vehicles). The combination of platform velocity, sensor response time, and instrument and platform data acquisition traits (including sampling frequency) all play a part in the quality and resolution of the final data set. For example, faster responding sensors allow for faster moving platforms, but may be limited by sampling frequency. Faster sampling frequency instruments also allow for faster moving platforms, but may be limited by sensor response time.
Accurate and stable pumped CTD sensors that have very fast response times and that sample at rapid and constant frequencies are preferred. These CTDs offer the most flexibility in application, and can accommodate most moving platform technologies.
See Considerations for CTD Spatial and Temporal Resolution on Moving Platforms [PDF]
Customer Feedback Survey:
WET Labs ac-s In-Situ Spectrophotometer
Sea-Bird Scientific would like to invite you to take part in a survey about your experience with WET Labs' ac-s. The purpose of this survey is to get feedback on these instruments, so we can improve customer experience. It should take you no more than 6 minutes to complete the survey.
Your opinion is very important to us, please be honest.
Meet Our People: Jennifer Zimmerman, East Coast Sales Manager
Jennifer is a native Floridian and has worked in the aquatic science industry for 20 years. Her previous role was with Sea-Bird Scientific’s sister company, OTT Hydromet, providing water quality and quantity instrumentation and systems to agencies and researchers. Jennifer has a B.S. in Biology from Florida State University and holds many specialized certifications. She has worked in both the public and private sectors, conducting research in marine and fresh waters with a focus on water quality.
Jennifer is passionate about ocean research and is pleased to be part of the Sea-Bird Scientific team. In her spare time, Jennifer loves boating and spending time at the beach.
Social Media Spotlight