Quantifying mesoscale variability in ocean transient tracer fields
A powerful way to test the realism of ocean general circulation models is to systematically compare observations of passive tracer concentration with model predictions. The general circulation models used in this way cannot resolve a full range of vigorous mesoscale activity (on length scales betwee...
Published in: | Journal of Geophysical Research: Oceans |
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American Geophysical Union
2001
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ftunivreading:oai:centaur.reading.ac.uk:7648 2024-06-23T07:55:28+00:00 Quantifying mesoscale variability in ocean transient tracer fields Haine, T. W. N. Gray, Suzanne Louise 2001 https://centaur.reading.ac.uk/7648/ unknown American Geophysical Union Haine, T. W. N. and Gray, S. L. <https://centaur.reading.ac.uk/view/creators/90000250.html> orcid:0000-0001-8658-362X (2001) Quantifying mesoscale variability in ocean transient tracer fields. Journal of Geophysical Research, 106 (C7). pp. 13861-13878. ISSN 0148-0227 doi: https://doi.org/10.1029/1999JC000036 <https://doi.org/10.1029/1999JC000036> Article PeerReviewed 2001 ftunivreading https://doi.org/10.1029/1999JC000036 2024-06-11T14:45:14Z A powerful way to test the realism of ocean general circulation models is to systematically compare observations of passive tracer concentration with model predictions. The general circulation models used in this way cannot resolve a full range of vigorous mesoscale activity (on length scales between 10–100 km). In the real ocean, however, this activity causes important variability in tracer fields. Thus, in order to rationally compare tracer observations with model predictions these unresolved fluctuations (the model variability error) must be estimated. We have analyzed this variability using an eddy‐resolving reduced‐gravity model in a simple midlatitude double‐gyre configuration. We find that the wave number spectrum of tracer variance is only weakly sensitive to the distribution of (large scale slowly varying) tracer sources and sinks. This suggests that a universal passive tracer spectrum may exist in the ocean. We estimate the spectral shape using high‐resolution measurements of potential temperature on an isopycnal in the upper northeast Atlantic Ocean, finding a slope near k −1.7 between 10 and 500 km. The typical magnitude of the variance is estimated by comparing tracer simulations using different resolutions. For CFC‐ and tritium‐type transient tracers the peak magnitude of the model variability saturation error may reach 0.20 for scales shorter than 100 km. This is of the same order as the time mean saturation itself and well over an order of magnitude greater than the instrumental uncertainty. Article in Journal/Newspaper Northeast Atlantic CentAUR: Central Archive at the University of Reading Journal of Geophysical Research: Oceans 106 C7 13861 13878 |
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CentAUR: Central Archive at the University of Reading |
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A powerful way to test the realism of ocean general circulation models is to systematically compare observations of passive tracer concentration with model predictions. The general circulation models used in this way cannot resolve a full range of vigorous mesoscale activity (on length scales between 10–100 km). In the real ocean, however, this activity causes important variability in tracer fields. Thus, in order to rationally compare tracer observations with model predictions these unresolved fluctuations (the model variability error) must be estimated. We have analyzed this variability using an eddy‐resolving reduced‐gravity model in a simple midlatitude double‐gyre configuration. We find that the wave number spectrum of tracer variance is only weakly sensitive to the distribution of (large scale slowly varying) tracer sources and sinks. This suggests that a universal passive tracer spectrum may exist in the ocean. We estimate the spectral shape using high‐resolution measurements of potential temperature on an isopycnal in the upper northeast Atlantic Ocean, finding a slope near k −1.7 between 10 and 500 km. The typical magnitude of the variance is estimated by comparing tracer simulations using different resolutions. For CFC‐ and tritium‐type transient tracers the peak magnitude of the model variability saturation error may reach 0.20 for scales shorter than 100 km. This is of the same order as the time mean saturation itself and well over an order of magnitude greater than the instrumental uncertainty. |
format |
Article in Journal/Newspaper |
author |
Haine, T. W. N. Gray, Suzanne Louise |
spellingShingle |
Haine, T. W. N. Gray, Suzanne Louise Quantifying mesoscale variability in ocean transient tracer fields |
author_facet |
Haine, T. W. N. Gray, Suzanne Louise |
author_sort |
Haine, T. W. N. |
title |
Quantifying mesoscale variability in ocean transient tracer fields |
title_short |
Quantifying mesoscale variability in ocean transient tracer fields |
title_full |
Quantifying mesoscale variability in ocean transient tracer fields |
title_fullStr |
Quantifying mesoscale variability in ocean transient tracer fields |
title_full_unstemmed |
Quantifying mesoscale variability in ocean transient tracer fields |
title_sort |
quantifying mesoscale variability in ocean transient tracer fields |
publisher |
American Geophysical Union |
publishDate |
2001 |
url |
https://centaur.reading.ac.uk/7648/ |
genre |
Northeast Atlantic |
genre_facet |
Northeast Atlantic |
op_relation |
Haine, T. W. N. and Gray, S. L. <https://centaur.reading.ac.uk/view/creators/90000250.html> orcid:0000-0001-8658-362X (2001) Quantifying mesoscale variability in ocean transient tracer fields. Journal of Geophysical Research, 106 (C7). pp. 13861-13878. ISSN 0148-0227 doi: https://doi.org/10.1029/1999JC000036 <https://doi.org/10.1029/1999JC000036> |
op_doi |
https://doi.org/10.1029/1999JC000036 |
container_title |
Journal of Geophysical Research: Oceans |
container_volume |
106 |
container_issue |
C7 |
container_start_page |
13861 |
op_container_end_page |
13878 |
_version_ |
1802648079450505216 |