Abstract
The short-lived events of high SST are called hot events (HEs) and can only be generated under the conditions of large daily heat gain due to strong solar radiation and weak wind. We investigated the thermal structure below HEs in the western equatorial Pacific by using in situ data obtained from TAO/TRITON buoys. We found that the occurrence of HEs can be identified by the typical vertical thermal structure within the isothermal layer. During the development stage of a HE, heat is accumulated in the surface layer due to strong solar radiation and weak wind, increasing temperature and creating strong stratification in the upper layer. During the decay stage, strong westerly winds induce current convergence which transports the heat from the upper layer to the deeper layer. Thus, temperature decreases at the surface and increases in the deeper layer. Furthermore, this mechanism indicates the important role of HEs in maintaining the warm isothermal layer in the western Pacific warm pool. The more HEs occur, the more heat in the surface layer gained from solar radiation is transported to the deeper layer. This process makes areas of frequent HE occurrences coincident with areas of warm pool. Since surface winds control the heat accumulation and heat transport in the isothermal layer by influencing current divergence and latent heat flux, surface winds become the key factor for the occurrence of HEs and the formation of the thermal structure in the Pacific warm pool.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Akima H (1996) Algorithm 761 - scattered-data surface fitting that has the accuracy of a cubic polynomial. Assoc Comput Machin Transact Math Softw 22(3):362–371
Anderson SP, Weller RA, Lukas RB (1996) Surface buoyancy forcing and the mixed layer of the western Pacific warm pool: observation and 1d model result. J Clim 9:3056–3085
Ando K, McPhaden MJ (1997) Variability of surface layer hydrography in the tropical Pacific Ocean. J Geophys Res 102(C10):23063–23078
Bathen KH (1972) On the seasonal changes in the depth of the mixed layer in the North Pacific Ocean. J Geophys Res 77:7138–7150
Clement A, Seager R (1999) Climate and the Tropical Ocean. J Clim 12:3383–3400
Clement A, Seager R, Murtugudde R (2005) Why are there tropical warm pools? J Clim 18:5294–5310
Garric G, Parent L (2018a) Product user manual for Global Ocean reanalysis products GLOBAL-REANALYSIS-PHY-001-025. Version 4.1. Marine Copernicus eu. http://resources.marine.copernicus.eu/documents/PUM/CMEMS-GLO-PUM-001-025.pdf. Accessed on 2 September 2019
Garric G, Parent L (2018b) Quality information document for Global Ocean reanalysis products GLOBAL-REANALYSISPHY-001-025. Marine Copernicus eu. http://resources.marine.copernicus.eu/documents/QUID/CMEMS-GLO-QUID-001-025.pdf Accessed on 2 September 2019
Herweijer C, Seager R, Winton M, Clement A (2005) Why ocean heat transport warms the global mean climate. Tellus 57a:662–675
Hosoda K (2013) Empirical method of diurnal correction for estimating sea surface temperature at dawn and noon. J Oceanogr 69:631–646. https://doi.org/10.1007/s10872-013-0194-4
Hosoda K, Kawamura H, Sakaida F (2015) Improvement of new Generation Sea surface temperature for Open Ocean (NGSST-O): a new sub-sampling method of blending microwave observations. J Oceanogr 71:205–220. https://doi.org/10.1007/s10872-015-0272
Hu S, Hu D, Guan C, Xing N, Li J, Feng J (2017) Variability of the western Pacific warm pool structure associated with El Niño. Clim Dyn 49(7–8):2431–2449. https://doi.org/10.1007/s00382-016-3459-y
Huffman G, Bolvin D, Braithwaite D, Hsu K, Joyce R, Xie P (2014) Integrated multi-satellitE retrievals for GPM (IMERG), version 4.4. NASA's precipitation processing center, accessed 31 January, 2015, ftp://arthurhou.pps.eosdis.nasa.gov/gpmdata/
Kawamura H, Qin H, Ando K (2008) In-situ diurnal sea surface temperature variations and near-surface thermal structure in the tropical hot event of the indo-Pacific warm pool. J Oceanogr 64:847–857
Lukas R (1988) On the role of western Pacific air-sea interaction in the El Nino/southern oscillation phenomenon. Proceedings of the U.S. TOGA-8, University Corporation for Atmospheric Research, Boulder, Colorado
Lukas R, Lindstorm E (1991) The mixed layer of the western equatorial Pacific Ocean. J Geophys Res 96(S01):3343–3357. https://doi.org/10.1029/90JC01951
Marshall J, Plumb RA (2008) Atmosphere, Ocean and Climate Dynamics: An Introductory Text. Elsevier Academic Press, Cambridge
McPhaden MJ, Ando K, Bourles B, Freitag HP, Lumpkin R, Masumoto Y, Murty VSN, Nobre P, Ravichandran M, Vialard J, Vousden D, Yu W (2009) The global tropical moored buoy array. In hall J, Harrison DE, stammer D (eds) proceedings of the “OceanObs ‘09: Sustained Ocean observations and information for society” conference, vol 2, 723 Venice, Italy, ESA publication, WPP-306. https://doi.org/10.5270/OceanObs09.cwp.61
Qin H, Kawamura H (2009a) Atmosphere response to a hot SST event in November 2006 as observed by AIRS instrument. Adv Space Res 44:395–400. https://doi.org/10.1016/j.asr.2009.03.003
Qin H, Kawamura H (2009b) Surface heat fluxes during hot events. J Oceanogr 65:605–613
Qin H, Kawamura H (2010) Air-sea interaction throughout the troposphere over a very high sea surface temperature. Geophys Res Lett 37:1–4. https://doi.org/10.1029/2009GL041685
Qin H, Kawamura H, Kawai Y (2007) Detection of hot event in the equatorial indo-Pacific warm pool using advanced satellite sea surface temperature, solar radiation, and wind speed. J Geophys Res 112:C07015. https://doi.org/10.1029/2006JC003969
Qin H, Kawamura H, Sakaida F, Ando K (2008) A case study of the tropical hot event in November 2006 (HE0611) using a geostationary meteorological satellite and the TAO/TRITON mooring array. J Geophys Res 113:C08045. https://doi.org/10.1029/2007JC004640
Renka RJ, Cline AK (1984) A Triangle-based C1 Interpolation Method. Rocky Mountain Journal of Mathematics 14(1): 223-237
Rydbeck AV, Jensen TG, Flatau M (2019) Characterization of Intraseasonal kelvin waves in the equatorial Pacific Ocean. J Geophys Res 124(3):2028–2053. https://doi.org/10.1029/2018JC014838
Waliser DE (1996) Formation and limiting mechanisms for very high sea surface temperature : Linking the dynamics and the thermodynamics. J Climate 9:161–188
Waliser DE, Graham NE (1993) Convective cloud systems and warm-pool sea-surface temperatures: coupled interactions and self-regulation. J Geophys Res 98(D7):12881–12893
Wirasatriya A, Kawamura H, Shimada T, Hosoda K (2015) Climatology of hot events in the western equatorial Pacific. J Oceanogr 71:77–90. https://doi.org/10.1007/s10872-014-0263-3
Wirasatriya A, Kawamura H, Shimada T, Hosoda K (2016) Atmospheric structure favoring high sea surface temperatures in the western equatorial Pacific. J Geophys Res 121:1–14. https://doi.org/10.1002/2016JD025268
Wirasatriya A, Sugianto DN, Helmi M (2017) The influence of madden Julian oscillation on the formation of the hot event in the Western equatorial Pacific, 2nd international conference on tropical and coastal region eco development 2016, IOP Conf. Series: Earth Environ Sci 55:012006. https://doi.org/10.1088/1755-1315/55/1/012006
Wirasatriya A, Sugianto DN, Helmi M, Maslukah L, Widiyandono RT, Herawati VE, Subardjo P, Handoyo G, Haryadi MJ, Suryoputro AAD, Atmodjo W, Setiyono H (2019) Heat flux aspects on the seasonal variability of sea surface temperature in the Java Sea. Ecol Environ Conserv 25(1):434–442
Wyrtki K (1964) The thermal structure of the eastern Pacific Ocean. Dstch Hydrography Zeitzschel, Ergänzungsheft A 8:6–84
Wyrtki K (1989) Some thoughts about the west Pacific warm pool. Paper presented at Western Pacific international meeting and workshop on TOGA COARE, Noumẻa, New Caledonia 99-109
Yu L, Weller RA (2007) Objectively Analyzed air-sea heat Fluxes for the global ice-free oceans (1981–2005). Bull Am Meteor Soc 88: 527–539
Acknowledgment
NGSST-O-Global-V2.0a is produced by Center for Atmospheric and Oceanic Studies, Tohoku University, Japan. Contact for data inquiry and request is Dr. Kohtaro Hosoda (khosoda@gmail.com). OAFLUX data can be downloaded at http://oaflux.whoi.edu/data.html. GLOBAL-REANALYSIS-PHY-001-025 is accessible at http://marine.copernicus.eu/. TAO/TRITON buoy data is provided by GTMBA Project Office of NOAA/PMEL and can be accessed at https://www.pmel.noaa.gov/tao/drupal/disdel/. The 3-h real-time TRMM Multi-satellite precipitation analysis data were provided by the NASA/Goddard Space Flight Center and PPS, which develop and compute the 3-h real-time TRMM Multi-satellite precipitation analysis data as a contribution to TRMM, and archived at the NASA GES DISC.
Funding
First author would like thanks to Diponegoro University for Postdoctoral/Sabbatical Program of World Class University and the research fund under the scheme of International Publication Research 2016-2018 with contract No 1052-24/UN7.5.1/PG/2016; 276/22/UN7.5.1/PG/2017; and 474-78/UN7.P4.3/PP/2018.
Author information
Authors and Affiliations
Corresponding author
Additional information
Responsible Editor: Alejandro Orfila
Rights and permissions
About this article
Cite this article
Wirasatriya, A., Kawamura, H., Helmi, M. et al. Thermal structure of hot events and their possible role in maintaining the warm isothermal layer in the Western Pacific warm pool. Ocean Dynamics 70, 771–786 (2020). https://doi.org/10.1007/s10236-020-01362-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10236-020-01362-8