Seasonal Cycle of the Mixed Layer Heat Budget in the Northeastern Tropical Atlantic Ocean

Foltz, Gregory R.; Schmid, Claudia; Lumpkin, Rick

doi:10.1175/jcli-d-13-00037.1

Cited by 38 publications

(63 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…5b). This was also reported in the recent study of Foltz et al (2013). Similar residuals (around 80 W m −2 ) have been reported in previous observational studies from the central equatorial Pacific (Wang and McPhaden 1999) as well as from the western equatorial ACT , where the diapycnal contribution could not be estimated.…”

Section: °N 23°wsupporting

confidence: 91%

“…The ML budgets within different phases of the seasonal cycle associated with the absence, development and mature phase of the ACT are described. Microstructure observations allowed estimating the contribution of the diapycnal heat flux within the entire ACT region directly and not as a residual as has been done previously (Wang and McPhaden 1999;Foltz et al 2003Foltz et al , 2013Wade et al 2011). Here, the heat budgets are presented for four PIRATA buoy sites at 0°N, 23°W; 0°N, 10°W; 0°N, 0°E and 10°S, 10°W thus extending the work of Hummels et al (2013) focusing on the heat budget at 0°N, 10°W.…”

Section: Summary and Discussionmentioning

confidence: 91%

“…In the study of Foltz et al (2003), the residual excluding the diapycnal ML heat loss at 23°W on the equator is of maximum 50 W m −2 and only present during the first half of the year. In a more recent study Foltz et al (2013) revised this estimate using another surface velocity product. The differences between Foltz et al (2003) and the results presented here can be attributed to extremely large zonal advection on the order of about 120 W m −2 during June-August and extremely low eddy advection from October to December, which reduce the residual in Foltz et al (2003) during the second half of the year.…”

Section: Summary and Discussionmentioning

confidence: 99%

“…In this section, the new and unique data set of microstructure observations acquired in the central and eastern equatorial Atlantic (Hummels et al 2013) is used to estimate the diapycnal ML heat loss directly, rather than relying on residual estimates of this quantity as has been done previously (Wang and McPhaden 1999;Foltz et al 2003Foltz et al , 2013Wade et al 2011). The main findings relevant for this study from Hummels et al (2013) concerning the regional and seasonal variability of turbulent mixing are summarized in the following: Turbulent dissipation rates (ε) at the equator are significantly increased in the upper thermocline compared to off-equatorial locations (cf.…”

Section: Turbulent Mixing Within the Actmentioning

confidence: 99%

“…Nevertheless, many of these studies lack information on the contribution of the diapycnal heat flux due to turbulent mixing at the base of the ML to the heat budget. Instead, this term is assessed as the residual of the budget, which additionally includes all accumulated uncertainties (Foltz et al 2003(Foltz et al , 2013Wade et al 2011). Model studies of the ACT as well as the Pacific cold tongue (PCT) have suggested that diapycnal mixing is an important contributor to the ML heat budget (Chang 1993;Peter et al 2006;Jouanno et al 2011b).…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Diapycnal heat flux and mixed layer heat budget within the Atlantic Cold Tongue

et al. 2014

View full text Add to dashboard Cite

Section: °N 23°wsupporting

confidence: 91%

Section: Summary and Discussionmentioning

confidence: 91%

Section: Summary and Discussionmentioning

confidence: 99%

Section: Turbulent Mixing Within the Actmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Diapycnal heat flux and mixed layer heat budget within the Atlantic Cold Tongue

et al. 2014

View full text Add to dashboard Cite

Mixed layer heat and salinity budgets during the onset of the 2011 Atlantic cold tongue

Schlundt

Brandt

Dengler

et al. 2014

J. Geophys. Res. Oceans

View full text Add to dashboard Cite

The mixed layer (ML) temperature and salinity changes in the central tropical Atlantic have been studied by a dedicated experiment (Cold Tongue Experiment (CTE)) carried out from May to July 2011. The CTE was based on two successive research cruises, a glider swarm, and moored observations. The acquired in situ data sets together with satellite, reanalysis, and assimilation model data were used to evaluate box-averaged ML heat and salinity budgets for two subregions: (1) the western equatorial Atlantic cold tongue (ACT) (23 -10 W) and (2) the region north of the ACT. The strong ML heat loss in the ACT region during the CTE was found to be the result of the balance of warming due to net surface heat flux and cooling due to zonal advection and diapycnal mixing. The northern region was characterized by weak cooling and the dominant balance of net surface heat flux and zonal advection. A strong salinity increase occurred at the equator, 10 W, just before the CTE. During the CTE, ML salinity in the ACT region slightly increased.Largest contributions to the ML salinity budget were zonal advection and the net surface freshwater flux. While essential for the ML heat budget in the ACT region, diapycnal mixing played only a minor role for the ML salinity budget. In the region north of the ACT, the ML freshened at the beginning of the CTE due to precipitation, followed by a weak salinity increase. Zonal advection changed sign contributing to ML freshening at the beginning of the CTE and salinity increase afterward.

show abstract

On the seasonal variations of salinity of the tropical Atlantic mixed layer

et al. 2015

View full text Add to dashboard Cite

The physical processes controlling the mixed layer salinity (MLS) seasonal budget in the tropical Atlantic Ocean are investigated using a regional configuration of an ocean general circulation model. The analysis reveals that the MLS cycle is generally weak in comparison of individual physical processes entering in the budget because of strong compensation. In evaporative regions, around the surface salinity maxima, the ocean acts to freshen the mixed layer against the action of evaporation. Poleward of the southern SSS maxima, the freshening is ensured by geostrophic advection, the vertical salinity diffusion and, during winter, a dominant contribution of the convective entrainment. On the equatorward flanks of the SSS maxima, Ekman transport mainly contributes to supply freshwater from ITCZ regions while vertical salinity diffusion adds on the effect of evaporation. All these terms are phase locked through the effect of the wind. Under the seasonal march of the ITCZ and in coastal areas affected by river (7°S:15°N), the upper ocean freshening by precipitations and/or runoff is attenuated by vertical salinity diffusion. In the eastern equatorial regions, seasonal cycle of wind forced surface currents advect freshwaters, which are mixed with subsurface saline water because of the strong vertical turbulent diffusion. In all these regions, the vertical diffusion presents an important contribution to the MLS budget by providing, in general, an upwelling flux of salinity. It is generally due to vertical salinity gradient and mixing due to winds. Furthermore, in the equator where the vertical shear, associated to surface horizontal currents, is developed, the diffusion depends also on the sheared flow stability.

show abstract

Seasonal Cycle of the Mixed Layer Heat Budget in the Northeastern Tropical Atlantic Ocean

Cited by 38 publications

References 59 publications

Diapycnal heat flux and mixed layer heat budget within the Atlantic Cold Tongue

Diapycnal heat flux and mixed layer heat budget within the Atlantic Cold Tongue

Mixed layer heat and salinity budgets during the onset of the 2011 Atlantic cold tongue

On the seasonal variations of salinity of the tropical Atlantic mixed layer

Contact Info

Product

Resources

About