Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosa, 2018, Vol. 15, No. 5, pp. 44-51
An improved technique for the retrieval of coastal upwelling indices from satellite data
1 Institute of Natural and Technical Systems RAS, Sevastopol, Russia
Accepted: 23.08.2018
DOI: 10.21046/2070-7401-2018-15-5-44-51
The paper considers an improved technique for the retrieval of coastal upwelling indices from satellite maps of sea surface temperature and near-surface wind. The main distinguishing feature of this technique is the determination of parameters of upwelling by monthly climatic masks. The algorithm for selecting monthly climatic masks is considered in detail. A justification of the choice of an area remote from the upwelling waters in the open sea for calculation of the thermal index of upwelling and its modifications is given. In addition to the generally accepted upwelling indices (thermal and Ekman), new indices were introduced: the cumulative and visible upwelling power, that allow to consider the surface area of upwelled waters. The technique is considered by the example of the Canary upwelling. This technique allows defining upwelling borders in each climatic month, and therefore more precisely calculate its indices and parameters of the environs of the upwelled area (near-surface wind, sea level, geostrophic current, etc.).
Keywords: thermal upwelling index, Ekman transport, Ekman pump, sea surface temperature, near-surface wind
Full textReferences:
- Polonskii A. B., Serebrennikov A. N., Mezhgodovye i vnutrimesyachnye fluktuatsii polya vetra i temperatury poverkhnosti okeana v zone Zapadno-Afrikanskogo apvellinga po sputnikovym dannym (Interannual and intra-monthly fluctuations of wind field and sea surface temperature in the West African upwelling region based on satellite data), Issledovanie Zemli iz kosmosa, 2017, No. 5, pp. 14–19.
- Aouni A. E., Minaoui K., Tamim A., Daoudi K., Yahia H., Mohammed D. A., An improved method for accurate computation of coastal upwelling index using Sea Surface Temperature Images, 13th ACS/IEEE Intern. Conf. Computer Systems and Applications, Morocco, 2016.
- Cropper T. E., Hanna E., Bigg G. R., Spatial and temporal seasonal trends in coastal upwelling off Northwest Africa, 1981–2012, J. Deep-Sea Research, 2014, Part I, Vol. 86, pp. 94–111.
- Cushing D. H., Upwelling and Fish Production, FAO Fisheries Technical Paper, Rome, 1969, No. 84, 38 p.
- Gómez-Gesteira M., Moreira C., Alvarez I., deCastro M., Ekman transport along the Galician coast (northwest Spain) calculated from forecasted winds, J. Geophysical Research, 2006, Vol. 111, C10005, DOI: 10.1029/2005JC003331.
- Hagen E., Northwest African upwelling scenario, Oceanologica Acta, 2001, Vol. 24, Suppl. 1, pp. 113–128.
- Oram J. J., McWilliams J. C., Stolzenbach K. D., Gradient-based edge detection and feature classification of sea-surface images of the Southern California Bight, J. Remote Sensing of Environment, 2008, Vol. 112(5), pp. 2397–2415.
- Santos A. M. R., Kazmin A. S., Peliz A., Decadal changes in the Canary upwelling system as revealed by satellite observations: Their impact on productivity, J. Marine Research, 2005, Vol. 63, pp. 359–379.
- Santos F., deCastro M., Gomez-Gesteira M., Alvarez I., Differences in coastal and oceanic SST warming rates along the Canary upwelling ecosystem from 1982 to 2010, Continental Shelf Research, 2012, Vol. 47, pp. 1–6.
- Taufikurahman Q., Hidayat R., Coastal upwelling in Southern Coast of Sumbawa Island, Indonesia, IOP Conf. Series: Earth and Environmental Science, 2017, Vol. 54, 012075.