Publication Date:
2022-05-26
Description:
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Martini, K. I., Murphy, D. J., Schmitt, R. W., & Larson, N. G. Reply to "comments on 'corrections for pumped SBE 41CP CTDs determined from stratified tank experiments'". Journal of Atmospheric and Oceanic Technology, 37(2), (2020): 357-363, doi:10.1175/JTECH-D-19-0171.1.
Description:
The response in Johnson (2020) that the method used to determine cell thermal mass correction coefficients for SBE 41CP CTD data from Argo floats is biased as determined by Martini et al. (2019) is valid. However, the recommendation for correction coefficients should not be followed due to these three errors in Johnson (2020):
Alignment is as large a source of dynamic error as cell thermal mass in the SBE 41CP CTD.
Order of operations was overlooked, so that cell thermal mass is used to correct for alignment errors caused by the temporal mismatch of temperature and conductivity.
The cell thermal mass corrections determined in Johnson et al. (2007) and Johnson (2020) also bias salinity.
In this response we will do the following:
Detail how the corrections in Johnson (2020) are biased because the optimization procedure does not accurately model physics in the tank and conductivity cell.
Verify using in situ data from Argo floats deployed in the ocean that alignment is a significant source of error for the SBE 41CP as shown in Martini et al. (2019).
Determine cell thermal mass correction coefficients from the stratified tank experiment merging the methods of Johnson (2020) and Martini et al. (2019) to optimize against a model that better represents the physics in the tank and conductivity cell.
Compare the corrections using in situ data using the coefficients determined in Johnson et al. (2007), Martini et al. (2019), Johnson (2020), and this manuscript.
Description:
Thanks to Pelle Robbins for finding the in situ profiles used for this analysis in the vast database of Argo floats, John Gilson showing me how to access that high-resolution data, Ray Schmitt for use of the stratified tank, Susan Wijffels, Breck Owens, and Annie Wong for intellectual support, and Diego Sorrentino and Vlad Simontov for validating the sampling scheme in the SBE 41CP.
Description:
2020-08-24
Keywords:
Ocean
;
Algorithms
;
Data processing
;
In situ oceanic observations
;
Measurements
;
Profilers, oceanic
Repository Name:
Woods Hole Open Access Server
Type:
Article
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