A quick look at the map of the global Argo array reveals that the floats inhabit all parts of the world, including some in Earth’s frigid zones. Recognizing the importance of polar deployments, Sea-Bird Scientific conducted unique experiments to test the CTD’s ability to withstand extreme cold.

To verify the CTD’s ability to retain accuracy in freezing environments, Sea-Bird R&D subjected an SBE 41 Argo CTD to a series of freezing/thawing/recalibration trials, freezing it over a dozen times and exposing it to freezing air and water for extended periods. The results – freezing and thawing of the conductivity cell did not impair the original calibration of the sensor, paving the way for subzero deployments.

To learn more about characterization of Argo CTD accuracy and stability, read the technical paper.