Précédent|Prochain

Dipole eddy detection from satellite and its dynamic modulation in the global ocean

  • role： First author第一作者
  • Affiliation：

    School of Information Science and Engineering, Ocean University of China, Qingdao 266100, China

  • Email：yulele3200@163.com
  • Introduction：禹乐乐，研究方向为海洋遥感与海洋大数据分析。E-mail： yulele3200@163.com
YU Lele1,  
  • Affiliation：

    School of Information Science and Engineering, Ocean University of China, Qingdao 266100, China

CAO Chuanchuan1,  
  • Affiliation：

    School of Information Science and Engineering, Ocean University of China, Qingdao 266100, China

    School of Physics and Optoelectronics Engineering, Weifang University, Weifang 261061, China

WANG Xuan13,  
  • role： Corresponding author通信作者
  • Affiliation：

    School of Information Science and Engineering, Ocean University of China, Qingdao 266100, China

    Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China

  • Email：gechen@ouc.edu.cn
  • Introduction：陈戈，研究方向为海洋遥感与大数据海洋学。E-mail： gechen@ouc.edu.cn
CHEN Ge12*

résumé

Eddies play an important role in water transport and energy balance in the ocean. Ocean observations show that eddies are not isolated, and cyclonic eddies and anti-cyclonic eddies always form more stable structures: dipole eddies. Dipole eddies have a more evident dynamic modulation compared with monopole eddies. Moreover, dipole eddies enhance the vertical movement of water to ensure that they promote the propagation and distribution of heat, energy, and organic matter in the ocean, which affects the global biochemical process. The parameters’ variations of dipole eddies during propagation must be examined to extensively understand the coupling state of eddies. The quantitative analysis of the modulation effect can provide a reference for exploring the dynamic mechanism of dipole eddies.In this work, the Archiving, Validation, and Interpretation of Satellite Oceanographic (AVISO) merged data from a combination of T/P, Jason-1, Jason-2, Jason-3, and Envisat missions are used to identify and track eddies in the global ocean during 1993—2020. These data have a daily temporal resolution and a 1/4°×1/4° spatial resolution. We established criteria for extracting dipole eddies based on eddy identification and track data: the distance of eddy cores is less than twice the sum of their radii, and their concomitant time is more than 60 days. We analyze the variations of eddies’ parameters to reveal the role of the dipole in modulating eddies based on over 67,500 dipole eddies that we found.The results show that dipoles are distributed in 10°N—60°N and 11°S—66°S. The dipole eddies are composed of eddies at a probability of over 15% and in the strong currents region, the frequency of dipole eddies formation is higher, even more than 35%. Given that the dipole structure influences the movement and propagation of eddies, we demonstrate it by using four dominating parameters of eddies, including amplitude, radius, EKE, and vorticity. Result showed that the dipole structures increase the amplitude by 5%—14%, radius by 2%—9%, and EKE by 4%—13% but suppress the vorticity of eddies by less than 3%. Furthermore, the various ratios of the parameters reach the peak at the middle of eddy normalized life. The dipole structures also promote the geostrophic and propagation velocities. The geostrophic velocity of eddies is significantly enhanced in strong current areas. In addition, the enhancement of geostrophic velocity of eddy is zonally distributed and gradually decreases from the equator to the poles.We conclude that dipole structures change the initial state of the eddies, causing some parameter variations: amplitude, radius, and EKE of eddies are increased by less than 13%, while vorticity is reduced. The dipole structures also have a certain acceleration effect on eddies at propagation and geostrophic velocities. Futhermore, the coupling of eddies with opposite polarity enhances their fluctuation and causes them to interact. The dynamic mechanism and ecological effect of eddies coupling based on better data sets are also the focus of future work.

mots-clés

remote sensing;satellite altimeter;mesoscale eddy;dipole eddy;parametric statistics;modulation effect

References

  1. 1.
    Ahlnäs K, Royer T C and George T H. 1987. Multiple dipole eddies in the Alaska coastal current detected with Landsat thematic mapper data. Journal of Geophysical Research: Oceans, 92(C12): 13041-13047
  2. 2.
    Amores A, Jordà G, Arsouze T and Le Sommer J. 2018. Up to what extent can we characterize ocean eddies using present-day gridded altimetric products? Journal of Geophysical Research: Oceans, 123(10): 7220-7236
  3. 3.
    Bryden H L and Brady E C. 1989. Eddy momentum and heat fluxes and their effects on the circulation of the equatorial pacific ocean. Journal of Marine Research, 47(1): 55-79
  4. 4.
    Chaigneau A, Le Texier M, Eldin G, Grados C and Pizarro O. 2011. Vertical structure of mesoscale eddies in the eastern South Pacific Ocean: a composite analysis from altimetry and Argo profiling floats. Journal of Geophysical Research: Oceans, 116(C11): C11025
  5. 5.
    Chelton D B, Gaube P, Schlax M G, Early J J and Samelson R M. 2011b. The influence of nonlinear mesoscale eddies on near-surface oceanic chlorophyll. Science, 334(6054): 328-332
  6. 6.
    Chelton D B, Schlax M G and Samelson R M. 2011a. Global observations of nonlinear mesoscale eddies. Progress in Oceanography, 91(2): 167-216
  7. 7.
    Chen G, Han G Y and Yang X Q. 2019. On the intrinsic shape of oceanic eddies derived from satellite altimetry. Remote Sensing of Environment, 228: 75-89
  8. 8.
    Chen G, Yang J and Han G Y. 2021a. Eddy morphology: egg-like shape, overall spinning, and oceanographic implications. Remote Sensing of Environment, 257: 112348
  9. 9.
    Chen G X, Hou Y J and Chu X Q. 2011. Mesoscale eddies in the South China Sea: mean properties, spatiotemporal variability, and impact on thermohaline structure. Journal of Geophysical Research: Oceans, 116(C): C06018
  10. 10.
    Chen G X, Hou Y J, Zhang Q L and Chu X Q. 2010. The eddy pair off eastern Vietnam: interannual variability and impact on thermohaline structure. Continental Shelf Research, 30(7): 715-723
  11. 11.
    Chen X Y, Li H T, Cao C C and Chen G. 2021b. Eddy-induced pycnocline depth displacement over the global ocean. Journal of Marine Systems, 221: 103577
  12. 12.
    Durán-Campos E, Monreal-Gómez M A, De León D A S and Coria-Monter E. 2019. Impact of a dipole on the phytoplankton community in a semi-enclosed basin of the southern gulf of California, Mexico. Oceanologia, 61(3): 331-340
  13. 13.
    Fu L L. 2009. Pattern and velocity of propagation of the global ocean eddy variability. Journal of Geophysical Research: Oceans, 114(C11): C11017
  14. 14.
    Fu L L, Chelton D B, Le Traon P V and Morrow R. 2010. Eddy dynamics from satellite altimetry. Oceanography, 23(4): 14-25
  15. 15.
    Han G Y, Tian F L, Ma C Y and Chen G. 2021. The geometry of mesoscale eddies in the South China Sea: characteristics and implications. International Journal of Digital Earth, 14(4): 464-479
  16. 16.
    Hughes C W and Miller P I. 2017. Rapid water transport by long-lasting modon eddy pairs in the southern midlatitude oceans. Geophysical Research Letters, 44(24): 12375-12384
  17. 17.
    L’Hégaret P, Carton X, Ambar I, Ménesguen C, Hua B L, Chérubin L, Aguiar A, Le Cann B, Daniault N and Serra N. 2014. Evidence of Mediterranean Water dipole collision in the Gulf of Cadiz. Journal of Geophysical Research: Oceans, 119(8): 5337-5359
  18. 18.
    Li R H, Xu J, Cen X R, Zhong W X, Liao J Z, Shi Z, Zhou S Q. 2021. Nitrate fluxes induced by turbulent mixing in dipole eddies in an oligotrophic ocean. Limnology and Oceanography, 66(7): 2842-2854
  19. 19.
    McGillicuddy D J. 2016. Mechanisms of physical-biological-biogeochemical interaction at the oceanic mesoscale. Annual Review of Marine Science, 8: 125-159
  20. 20.
    Ni Q B, Zhai X M, Wang G H and Hughes C W. 2020. Widespread mesoscale dipoles in the global ocean. Journal of Geophysical Research: Oceans, 125(10): e2020JC016479
  21. 21.
    Pallàs-Sanz E and Viúdez Á. 2007. Three-dimensional ageostrophic motion in mesoscale vortex dipoles. Journal of Physical Oceanography, 37(1): 84-105
  22. 22.
    Qiu S, Chen X E and Tang S Q. 2020. Life cycle of mesoscale dipole structure near the coast of indo-chian peninsula. Oceanologia et Limnologia Sinica, 51(6): 1332-1343
  23. 23.
    Ridderinkhof W, Le Bars D, Von der Heydt A S and De Ruijter W P M. 2013. Dipoles of the South east Madagascar current. Geophysical Research Letters, 40(3): 558-562
  24. 24.
    Rodríguez-Marroyo R and Viúdez A. 2009. Vortex Rossby waves in mesoscale dipoles. Journal of Geophysical Research: Oceans, 114(C10): C10009
  25. 25.
    Salas-de-León A D, Monreal-Gómez M A, Signoret M and Aldeco J. 2004. Anticyclonic-cyclonic eddies and their impact on near-surface chlorophyll stocks and oxygen supersaturation over the Campeche canyon, gulf of Mexico. Journal of Geophysical Research: Oceans, 109(C5): C05012
  26. 26.
    Simpson J J and Lynn R J. 1990. A mesoscale eddy dipole in the offshore California current. Journal of Geophysical Research: Oceans, 95(C8): 13009-13022
  27. 27.
    Sun M, Tian F L, Liu Y J and Chen G. 2017. An improved automatic algorithm for global eddy tracking using satellite altimeter data. Remote Sensing, 9(3): 206
  28. 28.
    Tian F L, Wu D, Yuan L M and Chen G. 2020. Impacts of the efficiencies of identification and tracking algorithms on the statistical properties of global mesoscale eddies using merged altimeter data. International Journal of Remote Sensing, 41(8): 2835-2860
  29. 29.
    Tian F L, Yuan Z H, Liu W, Cheng L Q and Chen G. 2021. An automatic recognition algorithm of global mesoscale dipole based on eddy tracking data. Haiyang Xuebao, 43(1): 122-136
  30. 30.
    Toner M, Kirwan Jr A D, Poje A C, Kantha L H, Müller-Karger F E and Jones C K R T. 2003. Chlorophyll dispersal by eddy-eddy interactions in the Gulf of Mexico. Journal of Geophysical Research: Oceans, 108(C4): 3105
  31. 31.
    Wang X, Zhang S Q, Lin X P, Qiu B and Yu L S. 2021. Characteristics of 3-dimensional structure and heat budget of mesoscale eddies in the South Atlantic Ocean. Journal of Geophysical Research: Oceans, 126(5): e2020JC016922
  32. 32.
    Wang Z F, Li Q Y, Sun L, Li S, Yang Y J and Liu S S. 2015. The most typical shape of oceanic mesoscale eddies from global satellite sea level observations. Frontiers of Earth Science, 9(2): 202-208
  33. 33.
    Wei Y, Zhang R and Jiao N Z. 2018. A long-standing complex tropical dipole shapes marine microbial biogeography. Applied and Environmental Microbiology, 84(18): e00614-18
  34. 34.
    Yang G, Yu W D, Yuan Y L, Zhao X, Wang F, Chen G X, Liu L and Duan Y L. 2015. Characteristics, vertical structures, and heat/salt transports of mesoscale eddies in the southeastern tropical Indian Ocean. Journal of Geophysical Research: Oceans, 120(10): 6733-6750
  35. 35.
    Zhan P, Krokos G, Guo D Q and Hoteit I. 2019. Three-dimensional signature of the red sea eddies and eddy-induced transport. Geophysical Research Letters, 46(4): 2167-2177
  36. 36.
    Zhang Z G, Zhang Y, Wang W and Huang R X. 2013. Universal structure of mesoscale eddies in the ocean. Geophysical Research Letters, 40(14): 3677-3681

Lire l'article complet

The above content is generated by Large Model Translation. The translated content is for reference only. We do not assume any commercial or legal responsibilty for any consequences arising from the use of our website