ISSN 2070-7401 (Print), ISSN 2411-0280 (Online)
Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa
CURRENT PROBLEMS IN REMOTE SENSING OF THE EARTH FROM SPACE

  

Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2023, Vol. 20, No. 6, pp. 211-221

Mesoscale eddies of the Aleutian Trench

S.P. Khudyakova 1 , V.S. Travkin 1, 2 , T.V. Belonenko 1 
1 Saint Petersburg State University, Saint Petersburg, Russia
2 N. N. Zubov’s State Oceanographic Institute, Moscow, Russia
Accepted: 20.10.2023
DOI: 10.21046/2070-7401-2023-20-6-211-221
The study investigates the trajectories of mesoscale anticyclonic and cyclonic vortices south of the Aleutian Ridge at areas with different bottom topography. It is demonstrated that anticyclonic vortices propagate along the Aleutian Islands’ shelf zone, while cyclonic vortices’ trajectories are located further south — along the Aleutian Trench at depths of 5–7 km. Estimates of the quantity of mesoscale vortices and their generation per a 0.25×0.5°  grid cell (in latitude and longitude, respectively) were obtained. It was established that anticyclones dominate in the studied area, with the maximum number observed south of Near and Rat Islands. The physical mechanisms influencing the propagation of mesoscale vortices in the region were analyzed. A comparative analysis of the contributions to the dispersion equation for barotropic topographic Rossby waves was conducted, including the β-effect, meridional gradient of zonal flow, topographic factor, and the combined effect of currents and topography. Calculations based on mean values of the zonal component of velocity reveal the predominance of the topographic factor over most of the water area. However, for certain days, the meridional gradient of zonal flow prevails over the other components. It was shown that vortices detach from the trench under the influence of currents in the region of 171–176° E longitude.
Keywords: mesoscale eddies, satellite altimetry, Aleutian Trench, META3.2 DT, GLORYS12V1
Full text

References:

  1. Andreev A. G., Aleutian eddies and their impact on temperature and dissolved oxygen in the Western Subarctic Pacific, J. Oceanological Research, 2020, Vol. 48, No. 3, pp. 109–122 (in Russian), DOI: 10.29006/1564-2291.JOR-2020.48(3).7.
  2. Belonenko T. V., Kubryakov A. A., Temporal variability of the phase velocity of Rossby waves in the North Pacific, Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2014, Vol. 11, No. 3, pp. 9–18 (in Russian).
  3. Gnevyshev V. G., Frolova A. V., Kubryakov A. A. et al., Interaction of Rossby waves with a jet stream: basic equations and their verification for the Antarctic circumpolar current, Izvestiya, Atmospheric and Oceanic Physics, 2019, Vol. 55, No. 5, pp. 412–422, DOI: 10.1134/S0001433819050074.
  4. Gnevyshev V. G., Frolova A. V., Koldunov A. V., Belonenko T. V., Topographic Effect for Rossby Waves on a Zonal Shear Flow, Fundamentalnaya i prikladnaya gidrofizika, 2021, Vol. 14, No. 1, pp. 4–14, DOI: 10.7868/S2073667321010019.
  5. Prants S. V., Trench Eddies in the Northwest Pacific: An Overview, Izvestiya, Atmospheric and Oceanic Physics, 2021, Vol. 57, pp. 341–353, DOI: 10.1134/S0001433821040216.
  6. Travkin V. S., Belonenko T. V., Kochnev A. V., Topographic waves in the Kuril region, Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2022, Vol. 19, No. 5, pp. 222–234 (in Russian), DOI: 10.21046/2070-7401-2022-19-5-222-234.
  7. Budyansky M. V., Prants S. V., Uleysky M. Yu., Odyssey of Aleutian eddies, Ocean Dynamics, 2022, Vol. 72, No. 6, pp. 455–476, DOI: 10.1007/s10236-022-01508-w.
  8. Chelton D. B., DeSzoeke R. A., Schlax M. G. et al., Geographical variability of the first baroclinic Rossby radius of deformation, J. Physical Oceanography, 1998, Vol. 28, No. 3, pp. 433–460, DOI: 10.1175/1520-0485(1998)028<0433:GVOTFB>2.0.CO;2.
  9. Chelton D. B., Schlax M. G., Samelson R. M., Global observations of nonlinear mesoscale eddies, Progress in Oceanography, 2011, Vol. 91, No. 2, pp. 167–216, DOI: 10.1016/j.pocean.2011.01.002.
  10. Gnevyshev V. V., Frolova A. V., Belonenko T. V., Topographic Effect for Rossby Waves on Non-Zonal Shear Flow, Water Resources, 2022, Vol. 49, No. 2, pp. 240–248, DOI: 10.1134/S0097807822020063.
  11. Mysak L. A., LeBlond P. H., Waves in the Ocean, Elsevier, 1978, 602 p., DOI: 10.1017/S002211207923228X.
  12. Okkonen S. R., The shedding of an anticyclonic eddy from the Alaskan Stream as observed by the Geosat altimeter, Geophysical Research Letters, 1992, Vol. 19, No. 24, pp. 2397–2400.
  13. Saito R., Yasuda I., Komatsu K. et al., Subsurface hydrographic structures and the temporal variations of Aleutian eddies, Ocean Dynamics, 2016, Vol. 66, No. 5, pp. 605–621, DOI: 10.1007/s10236-016-0936-0.
  14. Ueno H., Freeland H. J., Crawford W. R. et al., Anticyclonic eddies in the Alaskan Stream, J. Physical Oceanography, 2009, Vol. 39, No. 4, pp. 934–951, DOI: 10.1175/2008JPO3948.1.
  15. Ueno H., Crawford W. R., Onishi H., Impact of Alaskan Stream eddies on chlorophyll distribution in the North Pacific, J. Oceanography, 2010, Vol. 66, No. 3, pp. 319–328, DOI: 10.1007/s10872-010-0028-6.