Climate Dynamics

, Volume 38, Issue 11–12, pp 2559–2573 | Cite as

Mixed layer modeling in the East Pacific warm pool during 2002

Article

Abstract

Two vertical mixing models (the modified dynamic instability model of Price et al.; PWP, and K-Profile Parameterizaton; KPP) are used to analyze intraseasonal sea surface temperature (SST) variability in the northeast tropical Pacific near the Costa Rica Dome during boreal summer of 2002. Anomalies in surface latent heat flux and shortwave radiation are the root cause of the three intraseasonal SST oscillations of order 1°C amplitude that occur during this time, although surface stress variations have a significant impact on the third event. A slab ocean model that uses observed monthly varying mixed layer depths and accounts for penetrating shortwave radiation appears to well-simulate the first two SST oscillations, but not the third. The third oscillation is associated with small mixed layer depths (<5 m) forced by, and acting with, weak surface stresses and a stabilizing heat flux that cause a transient spike in SST of 2°C. Intraseasonal variations in freshwater flux due to precipitation and diurnal flux variability do not significantly impact these intraseasonal oscillations. These results suggest that a slab ocean coupled to an atmospheric general circulation model, as used in previous studies of east Pacific intraseasonal variability, may not be entirely adequate to realistically simulate SST variations. Further, while most of the results from the PWP and KPP models are similar, some important differences that emerge are discussed.

Keywords

Mixed layer modeling SST variability KPP PWP Costa Rica Dome 

References

  1. Anderson S, Weller R, Lukas R (1996) Surface buoyancy forcing and the mixed layer of the western Pacific warm pool: observations and 1D model results. J Clim 9:3056–3085CrossRefGoogle Scholar
  2. Bernie D, Woolnough S, Slingo J, Guilyardi E (2005) Modeling diurnal and intraseasonal variability of the ocean mixed layer. J Clim 18:1190–1202CrossRefGoogle Scholar
  3. Chelton D (2005) The impact of sst specification on ecmwf surface wind stress fields in the eastern tropical pacific. J Clim 18:530–550CrossRefGoogle Scholar
  4. Cronin MF, Bond N, Fairall C, Hare J, McPhaden MJ, Weller RA (2002) Enhanced oceanic and atmospheric monitoring underway in Eastern Pacific. EOS, Transactions, AGU 83(19):205, 210–211Google Scholar
  5. Cronin MF, Fairall CW, McPhaden MJ (2006) An assessment of buoy-derived and numerical weather prediction surface heat fluxes in the tropical Pacific. J Geophys Res Oceans 111. doi:10.1029/2005JC003324
  6. Danabasoglu G, Large W, Tribbia J, Gent P, Briegleb B, McWilliams J (2006) Diurnal coupling in the tropical oceans of CCSM3. J Clim 19:2347–2365CrossRefGoogle Scholar
  7. Fairall C, Bradley E, Hare J, Grachev A, Edson J (2003) Bulk parameterization of air-sea fluxes: updates and verification for the coare algorithm. J Clim 16:571–591CrossRefGoogle Scholar
  8. Hendon H, Glick J (1997) Intraseasonal air-sea interaction in the tropical Indian and Pacific Oceans. J Clim 10:647–661CrossRefGoogle Scholar
  9. Jackson L, Hallberg R, Legg S (2008) A parameterization of shear-driven turbulence for ocean climate models. J Phys Oceanogr 38:1033–1053. doi:10.1175/2007JPO3779.1 CrossRefGoogle Scholar
  10. Large WG, McWilliams JC, Doney SC (1994) Oceanic vertical mixing—a review and a model with a nonlocal boundary-layer parameterization. Rev Geophys 32:363–403CrossRefGoogle Scholar
  11. Maloney E, Hartmann D (2000) Modulation of hurricane activity in the gulf of mexico by the madden-julian oscillation. Science 287:2002–2004CrossRefGoogle Scholar
  12. Maloney E, Kiehl J (2002a) Intraseasonal eastern pacific precipitation and sst variations in a gcm coupled to a slab ocean model. J Clim 15:2989–3007CrossRefGoogle Scholar
  13. Maloney E, Kiehl J (2002b) MJO-related SST variations over the tropical eastern Pacific during northern hemisphere summer. J Clim 15:675–689CrossRefGoogle Scholar
  14. Maloney ED, Chelton DB, Esbensen SK (2008) Subseasonal SST variability in the tropical eastern north Pacific during boreal summer. J Clim 21:4149–4167. doi:10.1175/2007JCLI1856.1 CrossRefGoogle Scholar
  15. Maloney ED, Esbensen SK (2007) Satellite and buoy observations of boreal summer intraseasonal variability in the tropical northeast Pacific. Mon Weather Rev 135:3–19. doi:10.1175/MWR3271.1 CrossRefGoogle Scholar
  16. McPhaden MJ, Cronin MF, McClurg DC (2008) Meridional structure of the seasonally varying mixed layer temperature balance in the eastern tropical Pacific. J Clim 21:3240–3260. doi:10.1175/2007JCLI2115.1 CrossRefGoogle Scholar
  17. Montegut C, Madec G, Fischer A, Lazar A, Iudicone D (2004) Mixed layer depth over the global ocean: an examination of profile data and a profile-based climatology. J Geophys Res Oceans 109. doi:10.1029/2004JC002378
  18. Monterey GI, Levitus S (1997) Seasonal variability of mixed layer depth for the world ocean, vol 14. US Dept. of Commerce, NOAA-NESDIS, WashingtonGoogle Scholar
  19. Price J, Mooers C, Van Leer J (1978) Observation and simulation of storm-induced mixed-layer deepening. J Phys Oceanogr 8:582–599CrossRefGoogle Scholar
  20. Price J, Weller R, Pinkel R (1986) Diurnal cycling—observations and models of the upper ocean response to diurnal heating, cooling, and wind mixing. J Geophys Res Oceans 91:8411–8427CrossRefGoogle Scholar
  21. Raymond D, Esbensen S, Paulson C, Gregg M, Bretherton C, Petersen W, Cifelli R, Shay L, Ohlmann C, Zuidema P (2004) EPIC2001 and the coupled ocean-atmosphere system of the tropical east Pacific. Bull Am Meteorol Soc 85:1341. doi:10.1175/BAMS-85-9-1341 CrossRefGoogle Scholar
  22. Reynolds R, Smith T (1994) Improved global sea-surface temperature analyses using optimum interpolation. J Clim 7:929–948CrossRefGoogle Scholar
  23. Schudlich R, Price J (1992) Diurnal cycles of current, temperature, and turbulent dissipation in a model of the equatorial upper ocean. J Geophys Res Oceans 97:5409–5422CrossRefGoogle Scholar
  24. Shinoda T (2005) Impact of the diurnal cycle of solar radiation on intraseasonal SST variability in the western equatorial Pacific. J Clim 18:2628–2636CrossRefGoogle Scholar
  25. Shinoda T, Hendon H (1998) Mixed layer modeling of intraseasonal variability in the tropical western Pacific and Indian Oceans. J Clim 11:2668–2685CrossRefGoogle Scholar
  26. Small RJ, Xie SP, Maloney E, de Szoeke R, Miyama T (2010) Intraseasonal variability in the far-east Pacific: investigation of the role of air-sea coupling in a regional coupled model. Clim Dyn. doi:10.1007/s00382-010-0786-2
  27. Sprintall J, Tomczak M (1992) Evidence of the barrier layer in the surface-layer of the tropics. J Geophys Res Oceans 97:7305–7316CrossRefGoogle Scholar
  28. Waliser D, Graham N (1993) Convective cloud systems and warm-pool sea-surface temperatures—coupled interactions and self-regulation. J Geophys Res Atmos 98:12881–12893CrossRefGoogle Scholar
  29. Weller R, Anderson S (1996) Surface meteorology and air-sea fluxes in the western equatorial Pacific warm pool during the TOGA coupled ocean-atmosphere response experiment. J Clim 9:1959–1990CrossRefGoogle Scholar
  30. Wijesekera H, Rudnick D, Paulson C, Pierce S, Pegau W, Mickett J, Gregg M (2005) Upper ocean heat and freshwater budgets in the eastern Pacific warm pool. J Geophys Res Oceans 110. doi:10.1029/2004JC002511
  31. Xie S, Xu H, Kessler W, Nonaka M (2005) Air-sea interaction over the eastern Pacific warm pool: gap winds, thermocline dome, and atmospheric convection. J Clim 18:5–20CrossRefGoogle Scholar
  32. Zaron ED, Moum JN (2009) A new look at Richardson number mixing schemes for equatorial ocean modeling. J Phys Oceanogr 39:2652–2664. doi:10.1175/2009JPO4133.1 CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2011

Authors and Affiliations

  1. 1.Department of Atmospheric ScienceColorado State UniversityFort CollinsUSA
  2. 2.University of Colorado at BoulderBoulderUSA

Personalised recommendations