Antecedentes y justificación:
As últimas décadas indicam que a circulação atmosférica extratropical está migrando em direção ao polo. No Hemisfério Sul (HS) isso estão associadas a duas tendências: Modo Anular do Hemisfério Sul (SAM) positivo e expansão da célula de Hadley. O SAM é o principal modo de variabilidade atmosférica do HS. Sua fase positiva fortalece os ventos de oeste sobre o oceano circumpolar (por volta de 60°S) e enfraquece ao norte devido a intensificação da baroclinia entre essas duas regiões. Quando o SAM está positivo, a altura da tropopausa aumenta na região subtropical e conduz à expansão da circulação de Hadley em direção à Antártica.
Planteamiento del problema y objetivos:
Acoplado a migração da circulação extratropical ocorre o deslocamento dos giros oceânicos, com impactos no transporte de calor e aumento regional do nível do mar. Considerando os fatores acima apresentados, discutimos as relações entre a variabilidade do nível do mar na costa sul do Brasil e a expansão da célula de Hadley.
Materiales y Métodos:
Utilizamos dois períodos de monitoramento altimétrico por satélite de anomalias do nível do mar (SLA/XTRACK) e campos de vento (U e V/ERA5). Entre 1993-2021 podemos observar a elevação crescente do nível do mar a partir de 2009.
Resultados y Discusión:
Foram observadas também mudanças consistentes na circulação atmosférica sobre o Atlântico Sul antes e depois de 2009, associadas a variações nos campos de pressão, ventos e fluxos de temperatura entre latitudes altas e médias.
Conclusiones:
Este resultado é uma evidência do impacto regional que o aquecimento global está provocando pelo acoplamento oceano-atmosfera.
Agradecimientos:
CNPq/FAPERGS
Referencia:
Church, J. A., Clark, P. U., Cazenave, A. & Gregory, J. M. Sea Level Change. In: Climate Change 2013: The Physical Science Basis. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (eds Stocker, T. F. et al.) 1137–1216 (Cambridge University Press, 2013).2.Gregory, J. M. et al. Concepts and Terminology for Sea Level: Mean, Variability and Change, Both Local and Glo bal. Surv Geophys. 40, 1251–1289; 10.1007/s10712-019-09525-z (2019).3.Ponte, R. M. et al. Towards Comprehensive Observing and Modeling Systems for Monitoring and Predicting Regional to Coastal Sea Level. Front Mar Sci.6, 437; 10.3389/fmars.2019.00437 (2019). 4.Han, W. et al. Spatial Patterns of Sea Level Variability Associated with Natural Internal Climate Modes. Surv Geophys. 38, 217–250; 10.1007/s10712-016-9386-y (2017). 5.Fu, L. Wind-Forced Intraseasonal Sea Level Variability of the Extratropical Oceans. J Phys Oceanogr. 33, 436–449; 10.1175/1520-0485(2003)033<0436:WFISLV>2.0.CO;2 (2003). 6.Timmermann, A., McGregor, S. & Jin, F. F. Wind effects on past and future regional sea level trends in the southern Indo-Pacific. J Clim. 23, 4429–4437; 10.1175/2010JCLI3519.1(2010). 7.Thompson, D. W. J. & Wallace, J. M. Annular modes in the extratropical circulation. Part I: Month-to-mo nth variabilit y. J Clim. 13, 1000–1016; 10.1175/15200442(2000)013%3C1000:AMITEC%3E2.0.CO;2(2000). 8.Hall, A. & Visbeck, M. Synchronous Variability in the Southern Hemisphere Atmosphere, Sea Ice, and Ocean Resulting from the Annular Mode. J Clim. 15, 3043–3057; 10.1175/1520-0442(2002)015%3C3043:SVITSH%3E2.0.CO;2 (2002). 9.Roemmich, D. et al. Decadal spinup of the South Pacific subtropical gyre. J Phys Oceanogr. 37, 162–173; 10.1175/JPO3004 (2007). 10.Cai, W., Shi, G., Cowan, T., Bi, D. & Ribbe, J. The response of the Southern Annular Mode, the East Australian Current, and the Southern mid-latitude ocean circulation to global warming. Geophys Res Lett. 32(23); 10.1029/2005GL024701 (2005). 11.Cai, W. (2006) Antarctic ozone depletion causes na intensification of the Southern Ocean super-gyre circulat ion. Geophys Res Lett. 33(3); http://10.1029/2005GL024911 (2006). 12.Sen Gupta, A. & England, M. H. Coupled ocean–atmosphere–ice response to variations in the Southern Annular Mode. J Clim. 19, 4457–4486; 10.1175/JCLI3843.1 (2006). 13.Fyfe, J. C. & Saenko, O. A. Simulated changes in the extratropical Southern Hemisphere winds and currents. Geophys Res Lett. 33(6); 10.1029/2005GL025332 (2006). 14.Sen Gupta, A. et al. Projected changes to the Southern Hemisphere ocean and sea ice in the IPCC AR4 climate models. J Clim. 22, 3047–3078; 10.1175/2008JCLI2827.1 (2009). 15.Willis, J. K., Roemmich, D. & Cornuelle, B. Interannual variability in upper ocean heat content, temperature, and thermosteric expansion on global scales. J. Geophys. Res. 109(C120360); 10.1029/2003JC002260 (2004). 16.Munk, W. H. On the wind-driven ocean circulation. J Atmos Sci. 7, 80–93; 10.1175/1520-0469(1950)007%3C0080:OTWDOC%3E2.0.CO;2 (1950). 17.Wu, L. et al. Enhanced warming over the global subtropical western boundary currents. Nat Clim Chang. 2, 161–166; 10.1038/nclimate1353 (2012). 1318.Yang, H. et al. Poleward shift of the major ocean gyres detected in a warming climate. Geophys Res Lett. 47(5); 10.1029/2019GL085868 (2020). 19.Fyfe, J. C., Boer, G. J., Flato, G. M. The Arctic and Antarctic oscillations and their projected changes under global warming. Geophys Res Lett.26, 1601–1604; 10.1029/1999GL900317 (1999). 20.Thompson, D. W. J. & Solomon, S. Interpretation of recent Southern Hemisphere climate change. Science. 296, 895–899; 10.1126/science.1069270 (2002). 21.Seidel, D. J., Randel, R. J. Recent widening of the tropical belt: Evidence from tropopause observations. J Geophys Res. 112(D20); 10.1029/2007JD008861 (2007). 22.Hu, Y. & Fu, Q. Observed poleward expansion of the Hadley circulation since 1979. Atmos Chem Phys. 7, 5229–5236; 10.5194/acp-7-5229-2007 (2007). 23.Seidel, D., et al. Widening of the tropical belt in a changing climate. Nature Geosci.1, 21–24; 10.1038/ngeo.2007.38 (2008). 24.Stachnik, J. P. & Schumacher, C. A comparison of the Hadley circulation in modern reanalyses. J GeophysRes. 116(D22); 10.1029/2011JD016677 (2011). 25.Davis, S. M. & Rosenlof, K. H. A multidiagnostic intercomparison of tropical-width time series using reanalyses and satellite observations. J Clim.25, 1061–1078; 10.1175/JCLI-D-11-00127.1 (2012). 26.Liu, J., Song, M., Hu, Y. & Ren, W. Changes in the strength and width of the Hadley circulation since 1871. Clim Past. 8, 1169–1175; 10.5194/cp-8-1169-2012 (2012). 27.Nguyen, H., Evans, A., Lucas, C., Smith, I. & Timbal, B. The Hadley circulation in reanalyses: climatology, variability, and change. J Clim. 26, 3357–3376; 10.1175/JCLI-D-12-00224 (2013). 28.Adam, O., Schneider, T. & Harnik, N. Role of changes in mean temperatures versus temperature gradients in the recent widening of the Hadley circulation. J Clim.27, 7450–7461; 10.1175/JCLI-D-14-00140.1(2014). 29.Solman, S. A. & Orlanski, I. Poleward shift and change of frontal activity in the Southern Hemisphere over the last 40 years. J Atmos Sci.71, 539–552; 10.1175/JAS-D-13-0105 (2014). 30.D’Agostino, R. & Lionello, P. Evidence of global warming impact on the evolution of the Hadley circulation in ECMWF centennial reanalyses. Clim Dyn.48, 3047–3060; 10.1007/s00382-016-3250-0(2017). 31.Davis, N. A. & Davis, S. M. Reconciling Hadley cell expansion trend estimated in reanalysis. Geophys Res Lett. 28, 439–446; 10.1029/2018GL079593 (2018). 32.Previdi, M. & Liepert, B. G. Annular modes and Hadley cell expansion under global warming. Geophys Res Lett.34(22); 10.1029/2007GL031243 (2007).33.Monn, H. & Ha, K. Distinguishing changes in the Hadley circulation edge. Theor Appl Climatol. 139, 1007–1017; 10.1007/s00704-019-03017-1 (2019). 34.Merrifield, M. A. & Maltrud, M. E. Regional sea level trends due to a Pacific trade wind intensification. Geophys Res Lett.38(21);10.1029/2011GL049576 (2011). 35.Han, W. et al. Patterns of Indian Ocean sea level change in a warming climate. Nat Geosci. 3, 546–550; 10.1038/ngeo901 (2010). 36.Ruiz-Etcheverry, L. A. & Saraceno, M. Sea Level Trend and Fronts in the South Atlantic Ocean. Geosciences, 10(6); 10.3390/geosciences10060218 (2020). 1437.Saraceno, M., Simionato, G. C. & Ruiz-Etcheverry, L. A. Sea surface high trend at seasonal and interannual time scales in the Southeastern South American continental shelf between 27º S and 40°S. Cont Shelf Res. 91, 82–94; 10.1016/j.csr.2014.09.002 (2014). 38.O'Neill, L. W., Chelton, D. B., & Esbensen, S. K. Observations of SST-Induced Perturbations of the Wind Stress Field over the Southern Ocean on Seasonal Timescales. J Clim.16, 2340–2354; 10.1175/2780.1(2003). 39.Grotjahn, R. Global at mosphere circulations-observations and theories. Oxford University Press (1993). 40.Held, I. M. The general circulation of the atmosphere, Geophysical Fluid Dynamics Program. Woods Hole Oceanographic Institute.https://www.gfdl.noaa.gov/wpcontent/uploads/files/user_files/ih/lectures/woods_hole.pdf (2000). 41.Hu, Y. & Fu, Q. Observed poleward expansion of the Hadley circulation since 1979. Atmos Chem Phys. 7, 5229–5236; 10.5194/acp-7-5229-2007 (2007). 42.Korty, R. L. & Schneider, T. Extent of Hadley circulations in dry atmospheres. Geophys Res Lett.35(L23803); 10.1029/2008GL03584 (2008). 43.Frierson, D. M. W., Lu, J. & Chen, G. Width of the Hadley cell in simple and comprehensive general circulat ion models. Geophys Res Lett.34(18); 10.1029/2007GL031115(2007). 44.Lu, J., Vecchi, G. & Reichler, T. Expansion of the Hadley cell under global warming. Geophys Res Lett. 34(6); 10.1029/2006GL028443 (2007). 45.Lu, J., Chen, G. & Frierson, D. M. W. Response of the zonal mean atmospheric circulation to El Niño versus global warming. J Clim. 21, 5835–5851; 10.1175/2008JCLI2200.1(2008). 46.Son, S. W. et al. Impact of stratospheric ozone on Southern Hemisphere circulation change: a multimodel assessment. J Geophys Res. 115(D3); 10.1029/2010JD014271 (2010). 47.Kang, S. M., Polvani, L. M., Fyfe, J. C. & Sigmond, M. Impact of polar ozone depletion on subtropical precipitat ion. Science. 332, 951–954; 10.1126/science.1202131 (2011). 48.Johanson, C. M. & Fu, Q. Hadley cell widening: model simulations versus observations. J Clim. 22, 2713–2725; 10.1175/2008JCLI2620.1 (2006). 49.Kang, S. M. & Lu, J. Expansion of the Hadley cell under global warming: winter versus summer. J Clim. 25, 8387–8393; 10.1175/JCLI-D-12-00323.1 (2012). 50.Ceppi, P. & Hartmann, D. L. On the speed of the eddy-driven jet and the width of the Hadley cell in the Southern Hemisphere. J Clim. 26, 3450–3465; 10.1175/JCLI-D-12-00414.1 (2013). 51.Seo, K. H., Frierson, D. M. F. & Son, J. H. A mechanism for future changes in Hadley circulation strength in CMIP5 climate change simulations. Geophys Res Lett.41, 5251-5258; 10.1002/2014GL060868 (2014). 52.Tao, L., Hu, Y. & Liu, J. Anthropogenic forcing on the Hadley circulation in CMIP5 simulations. Clim Dyn. 46, 3337–3350; 10.1007/s00382-015-2772-1 (2016). 53.D'Agostino, R., Lionello, P., Adam, O. & Schneider, T. Factors controlling Hadley circulation changes from the Last Glacial Maximum to the end of the 21st century. Geophys Res Lett. 44, 8585-8591; 10.1002/2017GL074533 (2017). 54.Hartmann, D. L. & Lo, F. Wave-Driven Zonal Flow Vacillation in the Southern Hemisphere. J Atmos Sci. 55, 1303–1315; https://doi.org/10.1175/1520-0469(1998)055%3C1303:WDZFVI%3E2.0.CO;2 (1998). 55.Gong, D. & Wang, S. Definition of Antartic Oscillation Index. Geophys Res Lett. 26, 459–462; 10.1029/1999GL900003 (1999). 1556.Kidson, J. W. & Watterson, I. G. The structure and predictability of the “high-latitude mode” in the CSIRO9 general circulation model. J Atmos Sci.56, 3859–3873; 10.1175/15200469(1999)056%3C3859:TSAPOT%3E2.0.CO;2 (1999). 57.Lorenz, D. J. & Hartmann, D. L. Eddy-zonal flow feedback in the Southern Hemisphere. J Atmos Sci. 58, 3312–3327; 10.1175/1520-0469(2001)058%3C3312:EZFFIT%3E2.0.CO;2 (2001). 58.Li, J. P. & Wang, J. X. L. A modified zonal index and its physical sense. Geophys Res Lett.30 (12); 10.1029/2003GL017441 (2003). 59.Ciasto, L. M. & Thompson, D. W. J. Observations of large–scale ocean–atmosphere interaction in the Southern Hemisphere. J Clim. 21, 1244–1259; 10.1175/2007JCLI1809.1 (2008). 60.Leyba, I. M., Solman, S. A. & Saraceno, M. Trends in sea surface temperature and air–sea heat fluxes over the South Atlantic Ocean. Clim Dyn.53, 4141–4153;10.1007/s00382-019-04777-2 (2019). 61.Chiang, J. C. H. & Bitz, C. M. Influence of high latitude ice cover on the marine Intertropical Convergence Zone. Clim Dyn. 25, 477–496; 10.1007/s00382-005-0040-5 (2005). 62.Yamazaki, K. & Watanabe, M. Effects of extratropical warming on ENSO amplitudes in an ensemble of a coupled GCM. Clim Dyn. 44, 679–693; 10.1007/s00382-014-2145-1 (2015). 63.Zheng, F., Li, J. P., Kucharski, F., Ding, R. Q. & Liu, T. Dominant SST mode in the Southern Hemisphere extratropics and its influence on atmospheric circulation. Adv. Atmos. Sci.35, 881–895; 10.1007/s00376-017-7162-7 (2018). 64.Goni, G. J., Bringas, F. & DiNezio, P. N. Observed low frequency variability of the Brazil Current front. J Geophys Res.116 (C10); 10.1029/2011JC007198 (2011). 65.Kushner, P. J., Held, I. M. & Delworth, T. L. Southern Hemisphere Atmospheric Circulation Response to Global Warming. J Clim. 14(10), 2238–2249; 10.1175/1520-0442(2001)014%3C0001:SHACRT%3E2.0.CO;2 (2001). 66.Yin, J. & Goddard, P. B. Oceanic control of sea level rise patterns along the East Coast of the United States. Geophys Res Lett. 40, 5514–5520; 10.1002/2013GL057992 (2013). 67.Lique, C. & Thomas, M. D. Latitudinal shift of the At lant ic Meridional Overturning Circulat ion source regions under a warming climate. Nat Clim Chang. 8, 1013–1020; 10.1038/s41558-018-0316-5 (2018). 68.Hamlington, B. D. et al. Investigating the acceleration of regional sea level rise during the satellite altimeter era. Geophys Res Lett.47 (5); 10.1029/2019GL086528 (2020). 69.LEGOS. X-TRACK: Along track Sea Level Anomalies, date of acess. http://doi.org/10.6096/CTOH_X-TRACK_2017_02 (2020). 70.Biro l, F. et al. Coastal applications from nadir altimetry: example of the X-TRACK regional products. Adv Space Res. 59, 936–953; 10.1016/j.asr.2016.11.005 (2017). 71.Nan, S. L. & Li, J. P. The relationship between the summer precipitation in the Yangtze River valley and the boreal spring Southern Hemisphere annular mode. Geophys Res Lett. 30 (24); 10.1029/2003GL018381(2003). 72.Hersbach, H. et al. The ERA5 global reanalysis. Q J R Meteorol Soc. 146, 1999–2049; 10.1002/qj.3803(2020). 73.Copernicus Climate Change Service (C3S): ERA5: Fifth generation of ECMWF atmospheric reanalyses of the global climate. Copernicus Climate Change Service Climate Data Store (CDS), date of access. https ://cds.clima te.coper nicus .eu/cdsap p#!/home (2017). 1674.Climate Reanalyzer (Data/Image) from Climate Reanalyzer, Climate Change Institute, University of Maine, USA. date of access. https://ClimateReanalyzer.org (2020). 75.FNMOC. Fleet Numerical Meteorology and Oceanography Center: FNMOC Wind and Ekman Transport Data, 360x180, Monthly, from 6-hr Pressure. date of acess. https://coastwatch.pfeg.noaa.gov/erddap/griddap/index.html?page=1&itemsPerPage=1000 (2020). 76.OISST. Optimum Interpolation Sea Surface Temperature: Ocean temperature departure from average (Monthly Sea Surface Temperature Anomaly – SSTA), date of acess. http://www.ncdc.noaa.gov/oa/climate/research/sst/oi-daily-information.php (2020). 77.OISST. Optimum Interpolation Sea Surface Temperature: Sea surface height departure from the historical average (Monthly Sea Surface High Anomaly – SSHA). date of acess. http://ibis.grdl.noaa.gov/SAT/SeaLevelRise (2020).