Scientia Marina, Vol 72, No 4 (2008)

XBT profilers for operational purposes: application and validation in real exercises


https://doi.org/10.3989/scimar.2008.72n4779

Francisco Machín
Institut de Ciències del Mar, Centre Mediterrani d’Investigacions Marines i Ambientals (CSIC), Spain

Mikhail Emelianov
Institut de Ciències del Mar, Centre Mediterrani d’Investigacions Marines i Ambientals (CSIC), Spain

Pablo Rodríguez
Unitat de Tecnologia Marina, Centre Mediterrani d’Investigacions Marines i Ambientals (CSIC), Spain

Emilio García-Ladona
Institut de Ciències del Mar, Centre Mediterrani d’Investigacions Marines i Ambientals (CSIC), Spain

Javier Menéndez
Sociedad de Salvamento y Seguridad Marítima (SASEMAR), Spain

Jordi Salat
Institut de Ciències del Mar, Centre Mediterrani d’Investigacions Marines i Ambientals (CSIC), Spain

Abstract


A methodology for recovering salinity from expendable bathythermograph (XBT) data is presented. The procedure exploits climatological relationships between temperature, salinity and depth to build regional characteristic curves by fitting a polynomial function that minimises both the variance of residuals and unknowns. Hence, salinity is computed and recovered as a function of temperature and depth. Empirical formula are provided to recover the salinity field from temperature-depth measurements for the Cantabrian Sea and Galician Area. The method is validated and applied in the context of two marine rescue exercises carried out in the Bay of Biscay close to the north coast of Spain and in the Finisterre region, where a series of XBT and conductivity-temperature-depth (CTD) profiles were acquired during fast samplings. The results agree reasonably well with independent data in terms of the spatial structure, with the largest errors in the upper 100 m of the ocean and at intermediate levels. The first diagnoses of the surface geostrophic velocity fields obtained through the salinity reconstruction are coherent and may help in rescue and safety operations during marine emergencies. Hence, we recommend that a technical unit should consider this kind of expandable sampling strategy with both XBT and XCTD data during marine emergencies, since it provides useful and comprehensive information rapidly with minimal interference by means of formal operations on board search and rescue ships.

Keywords


XBT probes; operational oceanography; inverse method

Full Text:


PDF

References


Álvarez, E., I. Losada, J. Tintoré, J. Menéndez, M. Espino, G. Parrilla, I. Martínez and V. Pérez-Muñuzuri. – 2007. The ESEOO Project: developments and perspectives for Operational Oceanography at Spain. Proceedings of ISOPE-2007: The 17th International Offshore Ocean and Polar Engineering Conference, Lisbon, Portugal.

Antonov, J.I., R.A. Locarnini, T.P. Boyer, A.V. Mishonov and H.E. Garcia. – 2006. World Ocean Atlas 2005, Volume 2: Salinity.Technical Report 62, NOAA Atlas NESDIS 62, Washington D.C.

Caballero, A., M. Espino, Y. Sagarminaga, L. Ferrer, A. Uriarte and M. González. – 2008. Simulating the migration of drifters deployed in the Bay of Biscay, during the Prestige crisis. Mar. Pollut. Bull., 56(3): 475-482. doi:10.1016/j.marpolbul.2007.11.005 PMid:18155734

Carracedo, P., S. Torres-López, M. Barreiro, P. Montero, C. Balseiro, E. Penabad, P. Leitao and V. Pérez-Muñuzuri. – 2006. Improvement of pollutant drift forecast system applied to the Prestige oil spills in Galicia Coast (NW of Spain): Development of an operational system. Mar. Pollut. Bull., 53: 350-360. doi:10.1016/j.marpolbul.2005.11.014 PMid:16376949

Castanedo, S., R. Medina, I. Losada, C. Vidal, F. Méndez, A. Osorio, J. Juanes and A. Puente. – 2006. The Prestige oil spill in Cantabria (Bay of Biscay). Part I: Operational forecasting system for quick response, risk assessment, and protection of natural resources. J. Coast. Res., 22(6): 1474–1490. doi:10.2112/04-0364.1

Daniel, P., P. Josse, P. Dandin, J. Lefevre, G. Lery, F. Cabioch and V. Gouriou. – 2004. Forecasting the Prestige oil spill, Interspill 2004 Conference, Trondheim, Norway. http://www.meteorologie.eu.org/mothy/references/Interspill_2004.pdf

Emery, W.J. – 1975. Dynamic height from temperature profiles. J. Phys. Oceanogr., 5: 369-375. doi:10.1175/1520-0485(1975)005<0369:DHFTP>2.0.CO;2

Emery, W.J. and J.S. Dewar. – 1982. Mean temperature-salinity, salinity-depth and temperature-depth curves for the North-Atlantic and the North Pacific. Prog. Oceanogr., 11: 219-305. doi:10.1016/0079-6611(82)90015-5

Fiúza, A. and D. Halpern. – 1982. Hydrographic Observations of the Canary Current Between 21ºN and 25.5ºN in March/April 1974. Rapp. p-v. Réun., 180: 58–64.

Flierl, G.R. – 1978. Correcting expandable bathythermograph (XBT) data for salinity effects to compute dynamic heights in Gulf Stream rings. Deep-Sea Res. Part. I, 25: 129-134.

Font, J., G. Lagerloef, D. Le Vine, A. Camps and O.-Z. Zanifé.– 2004. The determination of surface salinity with the European SMOS Space Mission. IEEE Trans. Geosci. Remote, 42(10): 2196-2205. doi:10.1109/TGRS.2004.834649

González-Pola, C., A. Lavín and M. Vargas-Yáñez. – 2005. Intense warming and salinity modification of intermediate water masses in the southeastern corner of the Bay of Biscay for the period 1992-2003. J. Geophys. Res. C, 110(C05020), 10.1029/2004JC002367.

Hackett, B. – 2004. The impact of global ocean model forcing data on oil spill fate prediction: a comparative study of the ‘Prestige’ accident. Technical Report 13, Norwegean Meteorological Institute. http://met.no/english/r_and_d_activities/publications/2004/13_2004/013-2004.pdf

Hansen, D.V. and W.C. Thacker. – 1999. Estimation of salinity profiles in the upper ocean. J. Geophys. Res. C, 104(C4): 7921-7933. doi:10.1029/1999JC900015

Harvey, J. – 1982. q-S relationships and water masses in the eastern North Atlantic. Deep-Sea Res. Part A, 29(8A): 1021-1033.

Kessler, W. and B. Taft. – 1987. Dynamic heights and zonal geostrophic transports in the central Pacific during 1979–84. J. Phys. Oceanogr., 17: 97-122. doi:10.1175/1520-0485(1987)017<0097:DHAZGT>2.0.CO;2

Koblinsky, C., P. Hildebrand, D. Le Vine, F. Pellerano, Y. Chao, W. Wilson, S. Yueh and G. Lagerloef. – 2003. Sea surface salinity from space: Science goals and measurement approach. Radio Sci., 38. doi:10.1029/2001RS002584

Krasnopolsky, V., D. Chalikov, L. Breaker and D. Rao. – 2000. Application of neural networks for efficient calculation of sea water density or salinity from the UNESCO equation of state. Long Beach, CA (USA), pp. 27-30.

Lagerloef, G., C. Swift and D. LeVine. – 1995. Sea Surface Salinity: the next remote sensing challenge. Oceanography, 8: 44-50.

Lavín, A., L. Valdés, F. Sánchez, P. Abaunza, A. Forest, J. Boucher, P. Lazure and A. Jegou. – 2006. The Sea Volume 14B: The Global Coastal Ocean. Interdisciplinary Regional Studies and Syntheses, chapter The Bay of Biscay: the encountering of the ocean and the shelf. Harvard University Press.

Locarnini, R.A., A.V. Mishonov, J.I. Antonov, T.P. Boyer and H. E. Garcia. – 2006. World ocean atlas 2005, volume 1: Temperature. Technical report, NOAA Atlas NESDIS 61, Washington D.C.

Maes, C., D. Berhinger, R. Reynolds and M. Ji.– 2000. Retrospective analysis of the salinity variability in the Western tropical Pacific Ocean using an indirect minimization approach. J. Atmos. Oceanic Technol., 17: 512–5243. doi:10.1175/1520-0426(2000)017<0512:RAOTSV>2.0.CO;2

Marrero-Díaz, A. – 2002. Acoplamiento entre el giro subtropical del Atlántico Norte y el afloramiento costero en el noroeste africano. Ph.D. thesis, Univ. Las Palmas de Gran Canaria.

Marrero-Díaz, A., J.L. Pelegrí, A. Rodríguez-Santana and P. Sangrà.– 2001. Applicability of T-S algorithms to the Canary Islands region. Sci. Mar., 65(S1): 195–204. doi:10.3989/scimar.2001.65s1195

Marrero-Díaz, A., A. Rodríguez-Santana, F. Machín and J.L. Pelegrí. – 2006. Analitic salinity-temperature relations for the upper thermocline waters of the eastern North Atlantic subtropical gyre. Sci. Mar., 70(2): 167-175. doi:10.3989/scimar.2006.70n2167

Menke, W. – 1984. Geophysical Data Analysis: Discrete Inverse Theory. Academic Press, INC., Orlando, 46.

Montero, P., J. Blanco, J. Cabanas, J. Maneiro, Y. Pazos, A. Moroño, C. Balseiro, P. Carracedo, B. Gomez, V. Penabad, V. Perez-Muñuzuri, F. Braumschweig, R. Fernandes, P. Leitao and R. Neves. – 2003. Oil Spill Monitoring and Forecasting on the Prestige-Nassau Accident, volume 2, 26th Arctic and Marine Oil Spill Program (AMOP). http://www.meteogalicia.es/galego/informacion/documentos/AMOP.pdf

Olivella, R., E. García-Ladona, J. Salat, A. Julià and E. del Río. – 2007. Lagrangian buoys tracking system: Operational exercises. Technical report, ESEOO Technical Report. http://www.icm.csic.es/oce/people/emilio/papers/Olivella-etal-2006-IT.pdf

Pérez, F.F., A. Ríos, B. King and R. Pollard. – 1995. Decadal changes of the q-S relationship of the eastern North Atlantic Central Water. Deep-Sea Res. Part I, 42(11/12): 1849-1864. doi:10.1016/0967-0637(95)00091-7

Ríos, A.F., F.F. Pérez and F. Fraga. – 1992. Water masses in the upper and middle North Atlantic Ocean east of the Azores. Deep-Sea Res. Part I, 39: 645-658. doi:10.1016/0198-0149(92)90093-9

Ruiz-Villarreal, M., C. González-Pola, G. Díaz del Río, A. Lavín, P. Otero, S. Piedracoba and J. Cabanas. – 2006. Oceanographic conditions in North and Northwest Iberia and their influence on the Prestige oil spill. Mar. Pollut. Bull., 53: 220-238. doi:10.1016/j.marpolbul.2006.03.011 PMid:16698046

Sabia, R., A. Camps, M. Vall-Ilossera and N. Reul. – 2006. Impact on sea surface salinity retrieval of different auxiliary data within the SMOS mission. IEEE Trans. Geosci. Remote, 44(10): 2769–2778. doi:10.1109/TGRS.2006.879108

Siedler, G. and L. Stramma. – 1983. The applicability of the T/S method to geopotential anomaly computations in the northeast Atlantic. Oceanol. Acta, 6(2): 167-172.

Sotillo, M.G., E. Álvarez, S. Castanedo, A. Abascal, J. Menéndez, M. Emelianov, R. Olivella, E. García-Ladona, M. Ruiz-Villareal, J. Conde, M. Gómez, P. Conde, A. Gutierrez and R. Medina.– 2008. Towards an operational system for oil spill forecast over Spanish waters: initial developments and implementation test. Mar. Pollut. Bull., 56.

Stommel, H. – 1947. Note on the use of T/S correlation for dynamic height anomaly computations. J. Mar. Res., 6(2): 85-92.

Thacker, W. and L. Sindlinger. – 2007. Estimating salinity to complement observed temperature: 2. Northwestern Atlantic. J. Mar. Sys., 65: 249-267. doi:10.1016/j.jmarsys.2005.06.007

Thacker, W.C. – 2007. Estimating salinity to complement observed temperature: 1. Gulf of Mexico. J. Mar. Sys., 65: 224-248. doi:10.1016/j.jmarsys.2005.06.008

van Aken, H. – 2000. The hydrography of the mid-latitude northeast Atlantic Ocean II: The intermediate water masses. Deep-Sea Res. Part I, 47: 789–824. doi:10.1016/S0967-0637(99)00112-0

van Aken, H. 2001. The hydrography of the mid-latitude Northeast Atlantic Ocean – Part III: the subducted thermocline water mass. Deep-Sea Res. Part I, 48: 237-267. doi:10.1016/S0967-0637(00)00059-5

van Aken, H. – 2002. Surface currents in the Bay of Biscay as observed with drifters between 1995 and 1999. Deep-Sea Res. Part I, 49(6): 1071-1086. doi:10.1016/S0967-0637(02)00017-1

Wilkin, J., H. Arango, D. Haidvogel, C. Lichtenwalner, S. Glenn and K. Hedstrom. – 2005. A regional ocean modeling system for the Long-term Ecosystem Observatory. J. Geophys. Res. C, 110(C6): C06S91 doi:10.1029/2003JC002218




Copyright (c) 2008 Consejo Superior de Investigaciones Científicas (CSIC)

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.


Contact us scimar@icm.csic.es

Technical support soporte.tecnico.revistas@csic.es