Intraseasonal Modulation of the Surface Cooling in the Gulf of Guinea
Open accessAbstract
Abstract A regional numerical model of the tropical Atlantic Ocean and observations are analyzed to investigate the intraseasonal fluctuations of the sea surface temperature at the equator in the Gulf of Guinea. Results indicate that the seasonal cooling in this region is significantly shaped by short-duration cooling events caused by wind-forced equatorial waves: mixed Rossby–gravity waves within the 12–20-day period band, inertia–gravity waves with periods below 11 days, and equatorially trapped Kelvin waves with periods between 25 and 40 days. In these different ranges of frequencies, it is shown that the wave-induced horizontal oscillations of the northern front of the mean cold tongue dominate the variations of mixed layer temperature near the equator. But the model mixed layer heat budget also shows that the equatorial waves make a significant contribution to the mixed layer heat budget through modulation of the turbulent cooling, especially above the core of the Equatorial Undercurrent (EUC). The turbulent cooling variability is found to be mainly controlled by the intraseasonal modulation of the vertical shear in the upper ocean. This mechanism is maximum during periods of seasonal cooling, especially in boreal summer, when the surface South Equatorial Current is strongest and between 2°S and the equator, where the presence of the EUC provides a background vertical shear in the upper ocean. It applies for the three types of intraseasonal waves. Inertia–gravity waves also modulate the turbulent heat flux at the equator through vertical displacement of the core of the EUC in response to equatorial divergence and convergence.
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Integrity signals
Registry
Cites
Statistics
Claims the paper makes
The claims and statistics of this paper haven’t been checked yet.
Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.
Claims other papers make about this one
Each is checked against this paper’s own text: does it say what the citing paper says it does?
Mixed Rossby-gravity waves, inertia-gravity waves, and Kelvin waves are believed to contribute to cooling the Atlantic cold tongue through both northward advection of cold tongue water and vertical mixing, although no calculations of the heat budget were done.
“Mixed Rossby-gravity waves, inertia-gravity waves, and Kelvin waves are believed to contribute to cooling the Atlantic cold tongue through both northward advection of cold tongue water and vertical mixing (Houghton and Colin, 1987;Marin et al., 2009;Jouanno et al., 2013), although no calculations of the heat budget were done.”
From Physical drivers of the nitrate seasonal variability in the Atlantic cold tongue (2020) · cites this paper as Jouanno et al., 2013
Split into 2 atoms — 1 confirmed, 0 partially supported, 1 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.
Checked by a reasoning model — may be wrong.
Experimental — accuracy not yet measuredIntraseasonal nitrate variations may have the same origins as temperature modulations observed at periods between 10 and 50 days in the cold tongue.
“The intraseasonal nitrate variations may have the same origins as temperature modulations observed at periods between 10 and 50 days in the cold tongue”
From Physical drivers of the nitrate seasonal variability in the Atlantic cold tongue (2020) · cites this paper as Jouanno et al., 2013
Section 3 reports intraseasonal sea-surface-temperature fluctuations in the Gulf of Guinea cold tongue, especially at 12–20-day periods. Section 5 also describes distinct temperature-related signals at 30–45 days. The paper does not examine nitrate variations or establish that they share the origins of those temperature fluctuations. (LLM, conf=0.86)
Experimental — accuracy not yet measuredTIW are observed west of 10° W at periods between 20 and 50 days.
“TIW are observed west of 10° W at periods between 20 and 50 days (Jochum et al., 2004;Athié and Marin, 2008;Jouanno et al., 2013).”
From Physical drivers of the nitrate seasonal variability in the Atlantic cold tongue (2020) · cites this paper as Jouanno et al., 2013
The Discussion and summary says that west of 10°W, the 30–45-day signal shows TIWs, in agreement with observations. It does not establish TIWs across the full 20–50-day range claimed. (LLM, conf=0.87)
Experimental — accuracy not yet measuredOne reason the conclusion on the nature of intraseasonal processes affecting the nitrate budget east of 10° W is not straightforward could be that the low frequency signal captures part of the Kelvin wave induced variability as there is no sharp cutoff at 30 days in the spectrum of Kelvin waves.
“One reason could be that the low frequency signal captures part of the Kelvin wave induced variability as there is no sharp cutoff at 30 days in the spectrum of Kelvin waves (Athié and Marin, 2008;Athié et al., 2009;Jouanno et al., 2013).”
From Physical drivers of the nitrate seasonal variability in the Atlantic cold tongue (2020) · cites this paper as Jouanno et al., 2013
Split into 2 atoms — 1 confirmed, 1 partially supported, 0 disputed, 0 misattributed, 0 unverifiable. Expand the claim to see per-atom verdicts.
Experimental — accuracy not yet measured
Self-check
Percentages, sums and reported differences re-computed from the paper’s own numbers.
The self-check needs the paper’s full text.
The citation lists haven’t been fetched yet
References 41 · Cited by 28
Research works printed but not linked: 15
- Barnier, B., and Coauthors, 2006: Impact of partial steps and mo- mentum advection schemes in a global ocean circulation model at eddy-permitting resolution. Ocean Dyn., 56 (5-6), 543-567.
- Bentamy, A., K. B. Katsaros, W. M. Drennan, and E. B. Forde, 2002: Daily surface wind fields produced by merged satellite data. Gas Transfer at Water Surfaces, Geophys. Monogr., Vol. 127, Amer. Geophys. Union, 343-349.
- Bunge, L., C. Provost, and A. Kartavtseff, 2007: Variability in horizontal current velocities in the central and eastern equa- torial Atlantic in 2002. J. Geophys. Res., 112, C02014, doi:10.1029/2006JC003704. · DOI
- de Coe ¨tlogon, S. J., G. Madec, A. S. Fischer, A. Lazar, and D. Iudicone, 2010: Intraseasonal variability of the ocean- atmosphere coupling in the Gulf of Guinea during boreal spring and summer. J. Geophys. Res., 109, C120031, doi:10.1029/ 2004JC002378. · DOI
- Dee, D. P., and Coauthors, 2011: The ERA-Interim reanalysis: Configuration and performance of the data assimilation sys- tem. Quart. J. Roy. Meteor. Soc., 137, 553-597, doi:10.1002/ qj.828. · DOI · Paper page
- Dewitte, B., S. Illig, L. Renault, K. Goubanova, K. Takahashi, D. Gushchina, K. Mosquera, and S. Purca, 2011: Modes of covariability between sea surface temperature and wind stress intraseasonal anomalies along the coast of Peru from satellite observations (2000-2008). J. Geophys. Res., 116, C04028, doi:10.1029/2010JC006495. · DOI
- Hummels, R., M. Dengler, and B. Bourle `s, 2013: Seasonal and regional variability of upper ocean diapycnal heat flux in the Atlantic Cold Tongue. Prog. Oceanogr., doi:10.1016/j.pocean. 2012.11.001, in press. · DOI · Paper page
- --, --, --, J. Sheinbaum, and J.-M. Molines, 2011b: Sea- sonal heat balance in the upper 100 m of the equatorial Atlantic Ocean. J. Geophys. Res., 116, C09003, doi:10.1029/ 2010JC006912. · DOI
- Lien, R.-C., E. A. D'Asaro, and C. E. Menkes, 2008: Modulation of equatorial turbulence by tropical instability waves. Geophys. Res. Lett., 35, L24607, doi:10.1029/2008GL035860. · DOI
- Perez, R. C., R. Lumpkin, W. E. Johns, G. R. Foltz, and V. Hormann, 2012: Interannual variations of Atlantic tropical instability waves. J. Geophys. Res., 117, C03011, doi:10.1029/2011JC007584. · DOI
- Peter, A.-C., M. Le He ´naff, Y. Du Penhoat, C. E. Menkes, F. Marin, J. Vialard, G. Caniaux, and A. Lazar, 2006: A model study of the seasonal mixed layer heat budget in the equatorial Atlantic. J. Geophys. Res., 111, C06014, doi:10.1029/2005JC003157. · DOI · Paper page
- Praveen Kumar, B., J. Vialard, M. Lengaigne, V. S. N. Murty, M. J. McPhaden, M. Cronin, F. Pinsard, and K. Gopala Reddy, 2013: TropFlux wind stresses over the tropical oceans: Evaluation and comparison with other products, Climate Dyn., doi:10.1007/ s00382-012-1455-4, in press. · DOI
- Wade, M., G. Caniaux, and Y. du Penhoat, 2011a: Variability of the mixed layer heat budget in the eastern equatorial Atlantic during 2005-2007 as inferred using Argo floats. J. Geophys. Res., 116, C08006, doi:10.1029/2010JC006683. · DOI
- --, --, --, M. Dengler, H. Giordani, and R. Hummels, 2011b: A one-dimensional modeling study of the diurnal cycle in the equatorial Atlantic at the PIRATA buoys during the EGEE-3 campaign. Ocean Dyn., 61, 1-20, doi:10.1007/s10236-010-0337-8. · DOI
- Yu, W., W. Han, E. D. Maloney, D. Gochis, and S.-P. Xie, 2011: Observations of eastward propagation of atmospheric intra- seasonal oscillations from the Pacific to the Atlantic. J. Geo- phys. Res., 116, D02101, doi:10.1029/2010JD014336. · DOI
- Authors
- Jouanno, J., Marin, F., du Penhoat, Y., & Molines, J.-M.
- Affiliations
- Centro de Investigación Científica y de Educación Superior de Ensenada (MX)
- Université Toulouse III - Paul Sabatier (FR)
- IRD, CRHOB, Cotonou, Bénin, and UPS (OMP-PCA), LEGOS, Université de Toulouse, Toulouse, France
- Centre National de la Recherche Scientifique (FR)
- Venue
- Journal of Physical Oceanography
- Publisher
- American Meteorological Society
- Published
- 2013-02-01
- Volume
- 43
- Issue
- 2
- Pages
- 382-401
- ISSN
- 0022-3670 (ISSN-L)
- 1520-0485
- OpenAlex
- W2048475581
- Cited by
- 28
- References
- 41
- Citations by year
- 2026: 2 · 2025: 1 · 2024: 4 · 2023: 1 · 2022: 1 · 2021: 1 · 2020: 3 · 2019: 1 · 2018: 2 · 2017: 2 · 2016: 1 · 2015: 3 · 2014: 4 · 2013: 2
- FWCI
- 2.13
- Type
- journal article
- Language
- en
- Open access
- hybrid
- doi.org
- Licence
- other-oa
- Locations
- Journal of Physical Oceanography (publishedVersion, other-oa)
- HAL (submittedVersion, other-oa)
- Funders
- National Aeronautics and Space Administration
- National Oceanic and Atmospheric Administration
- Centro de Investigación Científica y de Educación Superior de Ensenada, Baja California
- Topics
- Physical Sciences › Earth and Planetary Sciences › Oceanography › Oceanographic and Atmospheric Processes
- Physical Sciences › Environmental Science › Global and Planetary Change › Climate variability and models
- Physical Sciences › Earth and Planetary Sciences › Atmospheric Science › Meteorological Phenomena and Simulations
- Keywords
- intraseasonal variability, sea surface temperature, Gulf of Guinea, equatorial waves, mixed Rossby-gravity waves, inertia-gravity waves, Kelvin waves, Equatorial Undercurrent, South Equatorial Current, mixed layer heat budget, turbulent heat flux, vertical shear, cold tongue
About these checks
Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.
Statistics and arithmetic are recomputed, not judged.
Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.
What counts as a claim ›How we measure confidence ›How we check this ›
Are you an author, or do you see a problem with this page? Request a review
