the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Reviews and syntheses: Expanding the global coverage of gross primary production and net community production measurements using BGC-Argo floats
Adam C. Stoer
David P. Nicholson
Abstract. This paper provides an overview and demonstration of emerging float-based methods for quantifying gross primary production (GPP) and net community production (NCP) using Biogeochemical-Argo (BGC-Argo) float data. Recent publications have described GPP methods that are based on the detection of diurnal oscillations in upper ocean oxygen or particulate organic carbon concentrations using single profilers or a composite of BGC-Argo floats. NCP methods rely on budget calculations to partition observed tracer variations into physical or biological processes occurring over timescales greater than one day. Presently, multi-year NCP time-series are feasible at near-weekly resolution, using consecutive or simultaneous float deployments at local scales. Results, however, are sensitive to the choice of tracer used in the budget calculations and uncertainties in the budget parametrizations employed across different NCP approaches. Decadal, basin-wide GPP calculations are currently achievable using data compiled from the entire BGC-Argo array, but finer spatial and temporal resolution requires more float deployments to construct diurnal tracer curves. A projected, global BGC-Argo array of 1000 floats should be sufficient to attain annual GPP estimates at 10-degree latitudinal resolution, if floats profile at off-integer intervals (e.g., 5.2 or 10.2 days). Addressing the current limitations of float-based methods should enable enhanced spatial and temporal coverage of marine GPP and NCP measurements, facilitating global-scale determinations of the carbon export potential, training of satellite primary production algorithms, and evaluations of biogeochemical numerical models.
- Preprint
(2717 KB) - Metadata XML
- BibTeX
- EndNote
Robert W. Izett et al.
Status: final response (author comments only)
-
RC1: 'Comment on bg-2023-46', Anonymous Referee #1, 25 Mar 2023
This is a generally well written and timely manuscript reviewing approaches for assessing ocean gross primary production and net community production from observations from BioArgo floats. I have only a few minor comments.
Line 44: choose a different word than ‘sinks’ as not all export is a sinking flux
Equation 1,2,3: it seems counterintuitive to have CR added to GPP in equations 1 & 2 rather than subtracted. I think the reason it is shown this way is because CR is assumed to have a negative value. However, on page 8 it is stated that the first term on the right of equation 5.1 = GPP and the second term on the right = CR, making the relationship GPP – CR, which is inconsistent with equations 1 & 2. It also seems nonintuitive inequations 1 and 3 to have a + sign in front of the last term on the right for equation 1 and a minus sign for the last term of equation 3. Should these both be ‘+/-‘ since they represent source and sink terms?
Line 160 – 164: Here it is stated that POC is estimated from published relationships (Loisel et al, Cetinic et al, Graff et al.). I would suggest explicitly giving these relationships in a table in the appendix. The Graff et al. paper, for example, is primary focused on estimating phytoplankton carbon from bbp and the POC relationship is a secondary result. Explicitly providing the equations used will prevent any confusion.
Line223: add ‘relationship’ after photosynthesis-versus-irradiance
Equation 7.1: should ‘+/-‘ be used in front of the final term on the right rather than ‘-‘ ?
Line 229: Define OSP on first use
Line 348: replace ‘are’ with ‘is’
Line 445: add ‘is’ after ‘values’
Figure 5: define ‘Y17’, ‘H22’ and ‘H20’
Line 493: Check the wording of the sentence beginning ‘Our calculation…’, something is wrong here
Line 532: replace ‘of’ with ‘our’
Line 569: add ‘between’ after ‘observed.’
General: When calculations of production are made where nighttime changes in a given tracer are assumed to be applicable to daytime rates, what error might be introduced because of impacts of diel vertical migrators?
Line 690: Delete ‘And’ at the beginning of the sentence and just begin with ‘To’
Line 760: Since the previous statements include assessments of satellites, it is not clear what is implied by stating that float data are ‘publicly available’ since satellite data are also publicly available.
Line 771: add ‘be’ after ‘can’
Line 775: I’m not sure I would advocate using BioArgo production products to train satellite algorithms as my guess is that there is more error/uncertainty in the former than in the latter. I do not see evidence in the current manuscript to conclusively demonstrate otherwise.
Citation: https://doi.org/10.5194/bg-2023-46-RC1 -
AC1: 'Reply on RC1', Robert Izett, 26 Apr 2023
Dear Reviewer,
We are grateful for your thoughtful and thorough evaluation of our manuscript. In the attached document, we respond to each of your comments and concerns, identifying how we intend to address them in a revised version of the manuscript. Our responses are indicated with a blue font. We have endeavoured to address all of your comments as you recommended. Overall, we believe that our manuscript will be improved by addressing your comments and we thank you again for your time reviewing this document.
Sincerely,
R. Izett & co-authors.
-
AC1: 'Reply on RC1', Robert Izett, 26 Apr 2023
-
RC2: 'Comment on bg-2023-46', Anonymous Referee #2, 28 Mar 2023
-
AC2: 'Reply on RC2', Robert Izett, 26 Apr 2023
Dear Reviewer,
We are grateful for your thoughtful and thorough evaluation of our manuscript. In the attached document, we respond to each of your comments and concerns, identifying how we intend to address them in a revised version of the manuscript. Our responses are indicated with a blue font. We have endeavoured to address all of your comments following your recommendations. In some cases, however, we feel the recommended changes are unnecessary, and explain why we think so. We believe that our manuscript will be improved by addressing your comments and we thank you again for your time reviewing this document.
Sincerely,
R. Izett & co-authors.
-
AC2: 'Reply on RC2', Robert Izett, 26 Apr 2023
Robert W. Izett et al.
Robert W. Izett et al.
Viewed
HTML | XML | Total | BibTeX | EndNote | |
---|---|---|---|---|---|
516 | 191 | 15 | 722 | 10 | 10 |
- HTML: 516
- PDF: 191
- XML: 15
- Total: 722
- BibTeX: 10
- EndNote: 10
Viewed (geographical distribution)
Country | # | Views | % |
---|
Total: | 0 |
HTML: | 0 |
PDF: | 0 |
XML: | 0 |
- 1