The heat storage variability in the Brazil Current
DOI:
https://doi.org/10.1590/Keywords:
Oceanic Heat Storage, Brazil Current, ECCO model, Interannual Variability, Volume TransportAbstract
We investigated the variability of the oceanic heat storage on the western boundary of the South Atlantic Ocean. We aimed to understand the specific contribution of the Brazil Current as it travels southwards. The heat storage is evaluated near three latitudes, namely at 15◦S, 24◦S and 34.5◦S. Numerical outputs of the oceanic potential temperature, salinity, and meridional components of the current’s velocity resulting from the Estimating the Circulation and Climate of the Ocean (ECCO) model were used. We examined the time series of the heat storage from 1992 to 2015 for the three latitudes. The mean heat storage increased towards the south with a maximum at 24◦S. At 34.5◦S, there is a decrease in this property possibly due to its proximity to the Brazil-Malvinas Confluence. The Brazil Current’s volume transport time series was correlated with the corresponding heat storage. The latitude that presented the highest correlation at interannual scale was 15◦S with a value of 0.84 at a 95% of confidence level. The model outputs were also compared with in situ expendable bathythermograph measurements. Despite the presence of gaps and peaks indicating extreme events in the in situ data, both time series were statistically close and they showed similar mean annual cycles. No significant long-term HS trend was found at any of the three latitudes.
References
CALADO, L., GANGOPADHYAY, A. & DA SILVEIRA, I. 2006. A parametric model for the Brazil Current meanders and eddies off southeastern Brazil, Geophysical Research Letters 33(12), 1-5.
CAMPOS, E. J., GONÇALVES, J. & IKEDA, Y. 1995. Water mass characteristics and geostrophic circulation in the South Brazil Bight: Summer of 1991, Journal of Geophysical Research: Oceans 100(C9), 18537-18550.
CHAMBERS, D. P., TAPLEY, B. & STEWART, R. 1997. Long-period ocean heat storage rates and basin-scale heat fluxes from topex, Journal of Geophysical Research: Oceans 102(C5), 10525-10533.
CHIDICHIMO, M. P., PIOLA, A. R., MEINEN, C. S., PEREZ, R., CAMPOS, E., DONG, S., LUMP-KIN, R. & GARZOLI, S. 2021. Brazil Current Volume Transport Variability During 2009- 2015 From a Long-Term Moored Array at 34.5◦S, Journal of Geophysical Research: Oceans 126(5), e2020JC017146.
CIRANO, M., MATA, M. M., CAMPOS, E. J. & DEIRÓ, N. F. 2006. A circulação oceânica de larga-escala na região oeste do Atlântico Sul com base no modelo de circulação global OCCAM, Revista Brasileira de Geofísica 24(2), 209-230.
DONG, S. & KELLY, K. A. 2004. Heat budget in the Gulf Stream region: The importance of heat storage and advection, Journal of Physical Oceanography 34(5), 1214-1231.
DUNXIN, H. & MAOCHANG, C. 1991. The western boundary current of the Pacific and its role in the climate, Chinese Journal of Oceanology and Limnology 9(1), 1-14.
FORGET, G., CAMPIN, J.-M., HEIMBACH, P., HILL, C. N., PONTE, R. M. & WUNSCH, C. 2015. ECCO version 4: An integrated framework for non-linear inverse modeling and global ocean state estimation, Geoscientific Model Development 8(10), 3071-3104.
FUKUMORI, I., WANG, O., FENTY, I., FORGET, G., HEIMBACH, P. & PONTE, R. M. 2017. ECCO version 4 release 3, Technical report, Jet Propulsion Laboratory/NASA, Pasadena, CA, USA.
GARZOLI, S. L. & BARINGER, M. O. 2007. Meridional heat transport determined with expandable bathythermographs-Part II: South Atlantic transport, Deep Sea Research Part I: Oceanographic Research Papers 54(8), 1402-1420.
GARZOLI, S. L. & GARRAFFO, Z. 1989. Transports, frontal motions and eddies at the Brazil-Malvinas Currents Confluence, Deep Sea Research Part A. Oceanographic Research Papers 36(5), 681-703.
GARZOLI, S. L. & MATANO, R. 2011. The south atlantic and the atlantic meridional overturning circulation, Deep Sea Research Part II: Topical Studies in Oceanography 58(17), 1837-1847.
GOES, M., CIRANO, M., MATA, M. & MAJUMDER, S. 2019. Long-Term Monitoring of the Brazil Current Transport at 22◦S From XBT and Altimetry Data: Seasonal, Interannual, and Extreme Variability, Journal of Geophysical Research: Oceans 124(6), 3645-3663.
GORDON, A. L. 1989. Brazil-Malvinas Confluence- 1984, Deep Sea Research Part A. Oceanographic Research Papers 36(3), 359-384.
GORDON, A. L. & GREENGROVE, C. L. 1986. Geostrophic circulation of the Brazil-Falkland confluence, Deep Sea Research Part A. Oceanographic Research Papers 33(5), 573-585.
JOHNS, W. E., BARINGER, M. O., BEAL, L. M., CUNNINGHAM, S., KANZOW, T., BRYDEN, H. L., HIRSCHI, J., MAROTZKE, J., MEINEN, C., SHAW, B. ET AL. 2011. Continuous, array-based estimates of Atlantic Ocean heat transport at 26.5◦N, Journal of Climate 24(10), 2429-2449.
KELLY, K. A. & DONG, S. 2004. The relationship of western boundary current heat transport and storage to midlatitude ocean-atmosphere interaction, Earth’s Climate: The Ocean-Atmosphere Interaction, Geophys. Monogr 147, 347-363.
KOKOSKA, S. & ZWILLINGER, D. 2000. CRC standard probability and statistics tables and formulae, Crc Press.
LEHMAN, A., O’ROURKE, N., HATCHER, L. & STEPANSKI, E. J. 2013. JMP for Basic Univariate and Multivariate Statistics: Methods for Researchers and Social Scientists, Second Edition, 2nd edn, SAS Institute Inc., Cary, NC, USA, chapter Measures of Bivariate Association, 121-162.
LEVITUS, S., ANTONOV, J. & BOYER, T. 2005. Warming of the world ocean, 1955-2003, Geophysical Research Letters 32(2), 1-5.
LEVITUS, S., ANTONOV, J. I., BOYER, T. P. & STEPHENS, C. 2000. Warming of the world ocean, Science 287(5461), 2225-2229.
LEVITUS, S., ANTONOV, J. I., WANG, J., DEL-WORTH, T. L., DIXON, K. W. & BROCCOLI, A. J. 2001. Anthropogenic warming of earth’s climate system, Science 292(5515), 267-270.
LOCARNINI, R., MISHONOV, A., BARANOVA, O., BOYER, T., ZWENG, M., GARCIA, H., REAGAN, J., SEIDOV, D., WEATHERS, K., PAVER, C. & SMOLYAR, I. 2019. World Ocean Atlas 2018, Volume 1: Temperature, NOAA Atlas NESDIS 81 52.
MACDONALD, A. M. 1998. The global ocean circulation: A hydrographic estimate and regional analysis, Progress in Oceanography 41(3), 281-382.
MCDOUGALL, T. J. & BARKER, P. M. 2011. Getting started with TEOS-10 and the Gibbs Seawater (GSW) oceanographic toolbox, SCOR/IAPSO WG 127, 1-28.
MEINEN, C. S., GARZOLI, S. L., PEREZ, R. C., CAMPOS, E., PIOLA, A. R., CHIDICHIMO, M. P., DONG, S. & SATO, O. T. 2017. Characteristics and causes of Deep Western Boundary Current transport variability at 34.5◦S during 2009-2014, Ocean Science 13(1), 175-194.
MÜLLER, T. J., IKEDA, Y., ZANGENBERG, N. & NONATO, L. V. 1998. Direct measurements of western boundary currents off Brazil between 20◦S and 28◦S, Journal of Geophysical Research: Oceans 103(C3), 5429-5437.
PETERSON, R. G. & STRAMMA, L. 1991. Upper-level circulation in the South Atlantic Ocean, Progress in Oceanography 26(1), 1-73.
PFAHL, S., MADONNA, E., BOETTCHER, M., JOOS, H. & WERNLI, H. 2014. Warm conveyor belts in the era-interim dataset (1979- 2010). part ii: Moisture origin and relevance for precipitation, Journal of Climate 27(1), 27-40.
PIECUCH, C. G. & PONTE, R. M. 2012. Importance of circulation changes to atlantic heat storage rates on seasonal and interannual time scales, Journal of Climate 25(1), 350-362.
ROBERTS, J. & ROBERTS, T. D. 1978. Use of the butterworth low-pass filter for oceanographic data, Journal of Geophysical Research: Oceans 83(C11), 5510-5514.
SATO, O. & POLITO, P. 2008. Influence of salinity on the interannual heat storage trends in the Atlantic estimated from altimeters and Pilot Research Moored Array in the Tropical Atlantic data, Journal of Geophysical Research: Oceans 113(C2).
SELESNICK, I. W. & BURRUS, C. S. 1998. Generalized digital butterworth filter design, IEEE Transactions on signal processing 46(6), 1688- 1694.
SIGNORINI, S. R. 1978. On the circulation and the volume transport of the Brazil Current between the Cape of São Tomé and Guanabara Bay, Deep Sea Research 25(5), 481-490.
SILVEIRA, I. C. A. D., SCHMIDT, A. C. K., CAMPOS, E. J. D., GODOI, S. S. D. & IKEDA, Y. 2000. A corrente do brasil ao largo da costa leste brasileira, Revista Brasileira de Oceanografia 48, 171-183.
SONNEWALD, M., HIRSCHI, J.-M., MARSH, R., MCDONAGH, E. & KING, B. 2013. Atlantic meridional ocean heat transport at 26◦N: impact on subtropical ocean heat content variability, Ocean Science 9(6), 1057-1069.
STRAMMA, L. 1989. The Brazil Current transport south of 23◦S, Deep Sea Research Part A. Oceanographic Research Papers 36(4), 639-646.
STRAMMA, L. & ENGLAND, M. 1999. On the water masses and mean circulation of the South Atlantic Ocean, Journal of Geophysical Research: Oceans 104(C9), 20863-20883.
STRAMMA, L., IKEDA, Y. & PETERSON, R. G. 1990. Geostrophic transport in the Brazil Current region north of 20◦S, Deep Sea Research Part A. Oceanographic Research Papers 37(12), 1875-1886.
TALLEY, L. D., PICKARD, G. L., EMERY, W. J. & SWIFT, J. H. 2011. Descriptive Physical Oceanography: an introduction, Academic press.
VILLAS BÔAS, A., SATO, O., CHAIGNEAU, A. & CASTELÃO, G. 2015. The signature of mesoscale eddies on the air-sea turbulent heat fluxes in the South Atlantic Ocean, Geophysical Research Letters 42(6), 1856-1862.
VIVIER, F., KELLY, K. A. & THOMPSON, L. A. 2002. Heat budget in the Kuroshio Extension region: 1993-99, Journal of Physical Oceanography 32(12), 3436-3454.
ZWENG, M. M., REAGAN, J., SEIDOV, D., BOYER, T., LOCARNINI, R., GARCIA, H., MISHONOV, A., BARANOVA, O., WEATHERS, K., PAVER, C. & SMOLYAR, I. 2019. World Ocean Atlas 2018, Volume 2: Salinity, NOAA Atlas NESDIS 82 50.
