Skip to main content
Springer Nature Link
Log in

Interannual variations in salt flux at 80°E section of the equatorial Indian Ocean

  • Article
  • Published:
Science China Earth Sciences Aims and scope Submit manuscript

Abstract

The interannual variations in salt flux on the 80°E section in the equatorial Indian Ocean were explored based on the ORAS5 data, which was quite consistent with the observational data among the four available reanalysis datasets. The results indicated that the area with significant interannual variations in salt flux coincided with that of significant climatological mean salt flux in general and was mainly located in the upper 150 m layer. Specifically, three important areas were identified in the north-south direction, i.e., (1) the Equatorial Indian Ocean Area (EIOA, 3°S–3°N), where the mean salt flux was eastward with the largest value on the section and associated with the most significant interannual variations mainly modulated by the Wyrtki Jets and the Equatorial Undercurrent; (2) the South Equatorial Indian Ocean Area (SEIOA, 3°S–6°S), where the mean salt flux changed in the vertical direction from strong eastward flux in the upper layer to weak westward flux in the subsurface layer and associated with significant interannual variations in the upper 100 m layer, which was affected by the South Equatorial Countercurrent; and (3) the North Equatorial Indian Ocean Area (NEIOA, 3°N–6°N), where the mean salt flux changed in the north-south direction from strong westward flux to the north of 5°N to weak eastward flux in the south and associated with relatively significant interannual variations, which was mainly influenced by the South Sri Lanka Coastal Current. Two leading interannual variation modes were revealed by the empirical orthogonal function decomposition. The first mode accounted for 39% of the total variance and had four significant spatial antinodes; two of those in-phase antinodes were located at SEIOA and upper 75 m of EIOA, and the other two opposite in-phase antinodes were located at NEIOA and below 75 m of EIOA. The second mode accounted for 17% of the total variance having four antinodes with two dominant out-of-phase antinodes located at the subsurface of EIOA and SEIOA. The temporal components of the two leading modes showed a 1–4 year variation with a main period of 2 years, in which the first mode showed a greater correlation with the Indian Ocean Dipole, while the second mode showed a weak correlation with the Indian Ocean Dipole and the El Niño-Southern Oscillation. Variance analysis showed that the interannual variations in salt flux were mainly determined by the variations in the current, and the spatial distribution was modulated by temporal mean salinity. Composite strong interannual events showed interannual variations in current, and so the salt flux was driven by the interannual anomaly of the wind field and sea surface temperature associated with the Indian Ocean Dipole.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Subscribe and save

Springer+ Basic
$34.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or eBook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Bamston A G, Chelliah M, Goldenberg S B. 1997. Documentation of a highly ENSO-related SST region in the equatorial Pacific: Research note. Atmosphere-Ocean, 35: 367–383

    Google Scholar 

  • Behera S K, Luo J J, Masson S, Rao S A, Sakuma H, Yamagata T. 2006. A CGCM study on the interaction between IOD and ENSO. J Clim, 19: 1688–1705

    Google Scholar 

  • Bleck R. 2002. An oceanic general circulation model framed in hybrid isopycnic-Cartesian coordinates. Ocean Model, 4: 55–88

    Google Scholar 

  • Bruce J G, Johnson D R, Kindle J C. 1994. Evidence for eddy formation in the eastern Arabian Sea during the northeast monsoon. J Geophys Res, 99: 7651–7664

    Google Scholar 

  • Carton J A, Giese B S. 2008. A reanalysis of ocean climate using simple ocean data assimilation (SODA). Mon Weather Rev, 136: 2999–3017

    Google Scholar 

  • Chowdary J S, Gnanaseelan C. 2007. Basin-wide warming of the Indian Ocean during El Niño and Indian Ocean Dipole years. Int J Clim, 27: 1421–1438

    Google Scholar 

  • Chu X, Han W, Zhang L, Chen G. 2023. Effects of climate modes on interannual variability of the equatorial currents in the Indian Ocean. Clim Dyn, 60: 3681–3694

    Google Scholar 

  • D’Addezio J M, Subrahmanyam B, Nyadjro E S, Murty V S N. 2015. Seasonal variability of salinity and salt transport in the northern Indian Ocean. J Phys Oceanogr, 45: 1947–1966

    Google Scholar 

  • Deng K, Cheng X, Feng T, Ma T, Duan W, Chen J. 2021. Interannual variability of the spring Wyrtki Jet. J Ocean Limnol, 39: 26–44

    Google Scholar 

  • Ding R, Huang D, Xuan J, Zhou F, Pohlmann T. 2019. Temporal and spatial variations of cross-shelf nutrient exchange in the East China Sea, as estimated by satellite altimetry and in situ measurements. J Geophys Res-Oceans, 124: 1331–1356

    Google Scholar 

  • Ding R, Kang I S, Farneti R, Kucharski F, Sante F D, Xuan J, Zhou F, Zhang T. 2022. The internal and ENSO-forced modes of the Indian Ocean sea surface temperature. J Clim, 35: 4191–4206

    Google Scholar 

  • Du Y, Zhang Y. 2015. Satellite and Argo observed surface salinity variations in the tropical Indian Ocean and their association with the Indian Ocean Dipole mode. J Clim, 28: 695–713

    Google Scholar 

  • Du Y, Zhang Y, Feng M, Wang T, Zhang N, Wijffels S. 2015. Decadal trends of the upper ocean salinity in the tropical Indo-Pacific since mid-1990s. Sci Rep, 5: 16050

    Google Scholar 

  • Du Y, Zhang Y, Shi J. 2019. Relationship between sea surface salinity and ocean circulation and climate change. Sci China Earth Sci, 62: 771–782

    Google Scholar 

  • Forget G, Campin J M, Heimbach P, Hill C N, Ponte R M, Wunsch C. 2015. ECCO version 4: An integrated framework for non-linear inverse modeling and global ocean state estimation. Geosci Model Dev, 8: 3071–3104

    Google Scholar 

  • Han W, McCreary Jr. J P. 2001. Modeling salinity distributions in the Indian Ocean. J Geophys Res, 106: 859–877

    Google Scholar 

  • Hormann V, Centurioni L R, Gordon A L. 2019. Freshwater export pathways from the Bay of Bengal. Deep Sea Res Part II-Topic Stud Oceanogr, 168: 104645

    Google Scholar 

  • Huang K, Wang D, Wang W, Xie Q, Chen J, Chen L, Chen G. 2018. Multiscale variability of the tropical Indian Ocean circulation system revealed by recent observations. Sci China Earth Sci, 61: 668–680

    Google Scholar 

  • Jensen T G. 2001. Arabian Sea and Bay of Bengal exchange of salt and tracers in an ocean model. Geophys Res Lett, 28: 3967–3970

    Google Scholar 

  • Jensen T G. 2003. Cross-equatorial pathways of salt and tracers from the northern Indian Ocean: Modelling results. Deep Sea Res Part II-Topic Stud Oceanogr, 50: 2111–2127

    Google Scholar 

  • Jensen T, Wijesekera H, Nyadjro E, Thoppil P, Shriver J, Sandeep K K, Pant V. 2016. Modeling salinity exchanges between the equatorial Indian Ocean and the Bay of Bengal. Oceanography, 29: 92–101

    Google Scholar 

  • Kjerfve B. 1986. Circulation and salt flux in a well mixed estuary. Phys Shallow Estuar Bays, 16: 22–29

    Google Scholar 

  • Lee T, Awaji T, Balmaseda M, Greiner E, Stammer D. 2009. Ocean state estimation for climate research. Oceanography, 22: 160–167

    Google Scholar 

  • Li J, Liang C, Tang Y, Liu X, Lian T, Shen Z, Li X. 2018. Impacts of the IOD-associated temperature and salinity anomalies on the intermittent equatorial undercurrent anomalies. Clim Dyn, 51: 1391–1409

    Google Scholar 

  • Liu Y, San Liang X, Weisberg R H. 2007. Rectification of the bias in the wavelet power spectrum. J Atmos Ocean Tech, 24: 2093–2102

    Google Scholar 

  • McPhaden M J, Wang Y, Ravichandran M. 2015. Volume transports of the Wyrtki jets and their relationship to the Indian Ocean Dipole. J Geophys Res-Oceans, 120: 5302–5317

    Google Scholar 

  • Nyadjro E S. 2021. Impacts of the 2019 strong IOD and monsoon events on Indian Ocean sea surface salinity. Remote Sens Earth Syst Sci, 4: 158–171

    Google Scholar 

  • Nyadjro E S, McPhaden M J. 2014. Variability of zonal currents in the eastern equatorial Indian Ocean on seasonal to interannual time scales. J Geophys Res-Oceans, 119: 7969–7986

    Google Scholar 

  • Nyadjro E S, Subrahmanyam B, Giese B S. 2013. Variability of salt flux in the Indian Ocean during 1960–2008. Remote Sens Environ, 134: 175–193

    Google Scholar 

  • Nyadjro E S, Subrahmanyam B, Murty V S N, Shriver J F. 2010. Salt transport in the near-surface layer in the monsoon-influenced Indian Ocean using HYCOM. Geophys Res Lett, 37: L15603

    Google Scholar 

  • Nyadjro E S, Subrahmanyam B, Shriver J F. 2011. Seasonal variability of salt transport during the Indian Ocean monsoons. J Geophys Res, 116: C08036

    Google Scholar 

  • Palmer M D, Roberts C D, Balmaseda M, Chang Y S, Chepurin G, Ferry N, Fujii Y, Good S A, Guinehut S, Haines K, Hernandez F, Köhl A, Lee T, Martin M J, Masina S, Masuda S, Peterson K A, Storto A, Toyoda T, Valdivieso M, Vernieres G, Wang O, Xue Y. 2017. Ocean heat content variability and change in an ensemble of ocean reanalyses. Clim Dyn, 49: 909–930

    Google Scholar 

  • Rao A D. 2002. Variability of wind stress curl over the Indian Ocean during years 1970–1995. Indian J Marine Sci, 31: 87–92

    Google Scholar 

  • Rao R R, Sivakumar R. 2003. Seasonal variability of sea surface salinity and salt budget of the mixed layer of the north Indian Ocean. J Geophys Res, 108: 3009

    Google Scholar 

  • Reynolds R W, Rayner N A, Smith T M, Stokes D C, Wang W. 2002. An improved in situ and satellite SST analysis for climate. J Clim, 15: 1609–1625

    Google Scholar 

  • Sachidanandan C, Lengaigne M, Muraleedharan P M, Mathew B. 2017. Interannual variability of zonal currents in the equatorial Indian Ocean: Respective control of IOD and ENSO. Ocean Dyn, 67: 857–873

    Google Scholar 

  • Saji N H, Goswami B N, Vinayachandran P N, Yamagata T. 1999. A dipole mode in the tropical Indian Ocean. Nature, 401: 360–36

    Google Scholar 

  • Schott F A, McCreary Jr. J P. 2001. The monsoon circulation of the Indian Ocean. Prog Oceanogr, 51: 1–123

    Google Scholar 

  • Schott F A, Xie S P, McCreary Jr. J P. 2009. Indian Ocean circulation and climate variability. Rev Geophys, 47: RG1002

    Google Scholar 

  • Torrence C, Compo G P. 1998. A practical guide to wavelet analysis. Bull Amer Meteor Soc, 79: 61–78

    Google Scholar 

  • Trott C B, Subrahmanyam B, Murty V S N, Shriver J F. 2019. Large-scale fresh and salt water exchanges in the Indian Ocean. J Geophys Res-Oceans, 124: 6252–6269

    Google Scholar 

  • Venugopal T, Bhaskar T U, Rahaman H, De L P, Erik S, Anna R, Ravichandran M, Ramakrishna S. 2020. A sea-level monopole in the equatorial Indian Ocean. NPJ Clim Atmos Sci, 3: 25

    Google Scholar 

  • Vinayachandran P N, Masumoto Y, Mikawa T, Yamagata T. 1999. Intrusion of the Southwest Monsoon Current into the Bay of Bengal. J Geophys Res, 104: 11077–11085

    Google Scholar 

  • Wickramage C H, Wang W, Arulananthan K, Jayathilake R. 2021. Dynamics of counter wind current along the south Sri Lanka coast during the Southwest Monsoon. Ocean Dyn, 71: 1051–1067

    Google Scholar 

  • Wickramasinghe L A A N, Wang W Q, Liu Y, Abeyratne M K, Hemamali W C, Ekanayake K B S S J. 2020. Seasonal variations of mass transport and its related salinity changes in the Eastern Indian Ocean (in Chinese). J Nanjing Univ Inform Sci Tech (Natur Sci Edit), 12: 472–482

    Google Scholar 

  • Wu W, Du Y, Qian Y, Cheng X, Wang T, Zhang L, Peng S. 2020. Structure and seasonal variation of the Indian Ocean tropical gyre based on surface drifters. J Geophys Res-Oceans, 125: e2019JC015483

    Google Scholar 

  • Wyrtki K. 1973. An equatorial jet in the Indian Ocean. Science, 181: 262–264

    Google Scholar 

  • Zhang D, McPhaden M J, Lee T. 2014. Observed interannual variability of zonal currents in the equatorial Indian Ocean thermocline and their relation to Indian Ocean Dipole. Geophys Res Lett, 41: 7933–7941

    Google Scholar 

  • Zhang L, Du Y, Tozuka T, Kido S. 2021. Revisiting ENSO impacts on the Indian Ocean SST based on a combined linear regression method. Acta Oceanol Sin, 40: 47–57

    Google Scholar 

  • Zhang Y, Du Y, Zhang Y H, Yang Y L. 2015. Asymmetric influences of positive and negative IOD events on salinity transport by the fall Wyrtki Jet along the equatorial Indian Ocean (in Chinese). J tropical oceanogr, 34: 1–10

    Google Scholar 

  • Zhang Y, Du Y. 2012. Seasonal variability of salinity budget and water exchange in the northern Indian Ocean from HYCOM assimilation. Chin J Ocean Limnol, 30: 1082–1092

    Google Scholar 

  • Zhang Y, Du Y, Qu T. 2016. A sea surface salinity dipole mode in the tropical Indian Ocean. Clim Dyn, 47: 2573–2585

    Google Scholar 

  • Zhang Y H, Du Y, Xu H M. 2012. Seasonal variability of the west-east water mass exchange on the section of central equatorial Indian Ocean and its regional difference (in Chinese). Haiyang Xuebao, 34: 30–38

    Google Scholar 

  • Zhang Y, Du Y, Zheng S, Yang Y, Chen X. 2013. Impact of Indian Ocean Dipole on the salinity budget in the equatorial Indian Ocean. J Geophys Res-Oceans, 118: 4911–4923

    Google Scholar 

  • Zhang Y H, Xu H M, Du Y, Wang D X. 2009. Seasonal variability of salinity budget in the southeastern Arabian Sea (in Chinese). J tropical oceanogr, 28: 66–74

    Google Scholar 

  • Zhang Z, Wang J, Yuan D. 2022. Mixed layer salinity balance in the eastern tropical Indian ocean. J Geophys Res-Oceans, 127: e2021JC018229

    Google Scholar 

  • Zhou Z Q, Xie S P, Zhang R. 2021. Historic Yangtze flooding of 2020 tied to extreme Indian Ocean conditions. Proc Natl Acad Sci USA, 118: e2022255118

    Google Scholar 

  • Zuo H, Balmaseda M A, Tietsche S, Mogensen K, Mayer M. 2019. The ECMWF operational ensemble reanalysis-analysis system for ocean and sea ice: A description of the system and assessment. Ocean Sci, 15: 779–808

    Google Scholar 

Download references

Acknowledgements

We appreciate the various data developers and websites for providing the ORAS5 data (http://marine.copernicus.eu/services-portfolio/access-to-products/), SODA data (https://www2.atmos.umd.edu/~ocean/index_files/soda3.3.2_mn_download.htm), HYCOM data (https://ncss.hycom.org/thredds/ncss/grid/GLBv0.08/latest/dataset.html), ECCO data (https://www.ecco-group.org/products-ECCO-V4r4.htm), Argo data (https://argo.ucsd.edu/data/argo-data-products/), RAMA data (https://www.pmel.noaa.gov/tao/drupal/rama-display/), CCMP data (https://www.remss.com/measurements/ccmp/) and OISST data (https://psl.noaa.gov/data/gridded/data.noaa.oisst.v2.Html). This work was supported by the Scientific Research Fund of the Second Institute of Oceanography, Ministry of Natural Resources, China (Grant No. JB2102), the National Natural Science Foundation of China (Grant No. 42276021), the Special Project on Global Change and Air-Ocean Interaction (Grant Nos. GASI-01-EIND-STwin & GASI-04-WLHY-03), the Special Support Program for High-Level Talents of Zhejiang Province (Grant No. 2020R52038) and the China Ocean Development Foundation (Grant No. GJ0219304).

Author information

Authors and Affiliations

  1. State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China

    Cuncun Xie, Ruibin Ding, Jiliang Xuan & Daji Huang

  2. Guangxi Key Laboratory of Beibu Gulf Marine Resources, Environment and Sustainable Development, Fourth Institute of Oceanography, Ministry of Natural Resources, Beihai, 536015, China

    Cuncun Xie, Jiliang Xuan & Daji Huang

  3. Institute of Polar and Ocean Technology, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, 310012, China

    Ruibin Ding

Authors
  1. Cuncun Xie
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Ruibin Ding
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Jiliang Xuan
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Daji Huang
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Daji Huang.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Xie, C., Ding, R., Xuan, J. et al. Interannual variations in salt flux at 80°E section of the equatorial Indian Ocean. Sci. China Earth Sci. 66, 2142–2161 (2023). https://doi.org/10.1007/s11430-022-1140-x

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11430-022-1140-x

Keywords

Search

Navigation

pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.


Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy