Sea surface cooling at the Equator by subsurface mixing in tropical instability waves Export

@article{citeulike:6056945, abstract = {Changes in sea surface temperature of equatorial waters have critical effects on the large-scale atmospheric circulation1, 2, 3. So far, large-scale, energetic tropical instability waves in equatorial waters have been thought to warm the sea surface through both meridional and zonal advection4, 5. Here, we present shipboard profiling measurements of turbulence kinetic-energy dissipation rate that reveal unanticipated vigorous mixing associated with tropical instability waves. The meridional tropical instability-wave shear increases the shear above the core of the Equatorial Undercurrent, which is already large, nudging the flow toward instability. As a consequence, turbulence dissipation rates and heat fluxes are many times greater than previous measurements at the same location but in the absence of tropical instability waves. The vertical divergence of turbulence heat flux is sufficient to cool the upper layer by 2 K per month, and heat the core of the Equatorial Undercurrent by 10 K per month. Long-term records at 140° W further reveal that cooling of the sea surface is significantly correlated to tropical-instability-wave kinetic energy. Thus, seasonal surface cooling in the central equatorial Pacific may be largely caused by mixing induced by tropical instability waves.}, author = {Moum, J. N. and Lien, R. C. and Perlin, A. and Nash, J. D. and Gregg, M. C. and Wiles, P. J.}, citeulike-article-id = {6056945}, citeulike-linkout-0 = {http://dx.doi.org/10.1038/ngeo657}, citeulike-linkout-1 = {http://dx.doi.org/10.1038/ngeo657}, day = {11}, doi = {10.1038/ngeo657}, issn = {1752-0894}, journal = {Nature Geoscience}, keywords = {atmosphere, climate, cooling, energy, ocean, teleconnection, tropics, turbulence, vertical-mixing}, month = {October}, number = {11}, pages = {761--765}, posted-at = {2009-11-02 17:16:38}, priority = {2}, publisher = {Nature Publishing Group}, title = {Sea surface cooling at the Equator by subsurface mixing in tropical instability waves}, url = {http://dx.doi.org/10.1038/ngeo657}, volume = {2}, year = {2009} }

TY - JOUR ID - citeulike:6056945 L3 - citeulike-article-id:6056945 N2 - Changes in sea surface temperature of equatorial waters have critical effects on the large-scale atmospheric circulation1, 2, 3. So far, large-scale, energetic tropical instability waves in equatorial waters have been thought to warm the sea surface through both meridional and zonal advection4, 5. Here, we present shipboard profiling measurements of turbulence kinetic-energy dissipation rate that reveal unanticipated vigorous mixing associated with tropical instability waves. The meridional tropical instability-wave shear increases the shear above the core of the Equatorial Undercurrent, which is already large, nudging the flow toward instability. As a consequence, turbulence dissipation rates and heat fluxes are many times greater than previous measurements at the same location but in the absence of tropical instability waves. The vertical divergence of turbulence heat flux is sufficient to cool the upper layer by 2 K per month, and heat the core of the Equatorial Undercurrent by 10 K per month. Long-term records at 140° W further reveal that cooling of the sea surface is significantly correlated to tropical-instability-wave kinetic energy. Thus, seasonal surface cooling in the central equatorial Pacific may be largely caused by mixing induced by tropical instability waves. IS - 11 JF - Nature Geoscience SN - 1752-0894 EP - 765 TI - Sea surface cooling at the Equator by subsurface mixing in tropical instability waves PB - Nature Publishing Group VL - 2 SP - 761 KW - atmosphere KW - climate KW - cooling KW - energy KW - ocean KW - teleconnection KW - tropics KW - turbulence KW - vertical-mixing AU - Moum, JN AU - Lien, RC AU - Perlin, A AU - Nash, JD AU - Gregg, MC AU - Wiles, PJ PY - 2009/10/11/ UR - http://dx.doi.org/10.1038/ngeo657 ER -