Sustainable Marine Structures

Contribution of Gulf of Aqaba Water (GAW) to Red Sea waters

Mohideen Wafar

Center for Environment and Water, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261, Kingdom of Saudi Arabia

DOI: https://doi.org/10.36956/sms.v2i1.291

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Abstract

Data obtained on hydrography and currents in meridional sections in the Gulf of Aqaba and the Red Sea in November 2013 and March 2015 were used to determine the extent of contribution of Gulf of Aqaba Water (GAW) to the formation of Red Sea waters. The southward flow across the Strait of Tiran was ~0.02 Sv in both periods which is direct evidence of significant contribution of GAW to Red Sea waters in autumn-winter. A multiple tracer analysis using temperature, salinity, and dissolved oxygen showed that the GAW, on entry into Red Sea, bifurcates into two branches. The upper branch exiting the Strait in the depth range 150-220 m has densities between 28.3 and 28.5, continues to flow at the same depths, and feeds the Red Sea Overflow Water (RSOW). The lower branch that exits between 220 and 250 m above the sill cascades down its southern face, mixes with northward recirculating branch of Red Sea Deep Water (RSDW) and sinks to the bottom and forms part of southward-flowing RSDW. Contribution of GAW to northern Red Sea waters below 100 m depth was 36 ± 0.4% in November 2013 and 42.1 ± 5.4% in March 2015. GAW is traceable down to 17-19 °N in RSDW and RSOW. Volume contribution of GAW to RSOW was 9.6 * 1012 m3, about 50% higher than that for RSDW (6 * 1012 m3). Analyses of the data from R.V. Maurice Ewing cruise in 2001 gave similar results and lend support for these deductions.

Keywords: Hydrography; Currents; Red Sea; Gulf of Aqaba; Red Sea Overflow Water; Gulf of Aqaba Water

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References

[1] Maillard, C. Eaux intermédiaires et formation d’eau profonde en Mer Rouge. L’océanographie physique de la Mer Rouge. Cent. Natl. pour l’Exploitation des Océans, Paris, 1974: 105-133.

[2] Woelk, S., Quadfasel, D. Renewal of deep water in the Red Sea during 1982-1987. J. Geophys. Res., 1996, 101, 18, 155-18,165.

[3] Plähn, O., Baschek, B., Badewien, B., Walter, T., Rhein, M. Importance of the Gulf of Aqaba for the formation of bottom water inthe Red Sea. J. Geo?phys. Res., 2002, 107, 22-1-22-18.

[4] Wyrtki, K. On the deep circulation of the Red Sea, in L’océanographie Physique de la MerRouge, 1974:135-163. CNEXO Publ. No.2.

[5] Kuntz, R. Bestimmung der Tiefenwasserzirkulation des RotenMeeresanhandeinerBoxmodellauswertung von Tritium, 3He- und Salinitatsdaten, Ph. D. thesis, RuprechtKarls Univ., 1985:76.

[6] Cember, R. P. On the sources, formation, and circu?lation of the Red Sea deep water, J. Geophys. Res., 1988, 93, 8175-8191.

[7] Sofianos, S. S., Johns, W. E. Observations of the summer Red Sea circulation. J. Geophys. Res, 2007, 112, C06025.DOI:10.1029/2006JC003886

[8] Sofianos, S., Johns, W. E. Water Mass Formation, Overturning Circulation, and the Exchange of the Red Sea with the Adjacent Basins, in: N.M.A Rasul and I.C.F Stewart (eds.), The Red Sea, Springer Earth System Sciences, 2015. DOI:http://dx.doi.org/10.1007/978-3-662-45201-1_20

[9] Zhai, P., Bower, A. S., Smethie, W. M. Jr., Pratt, L. J. Formation and spreading of Red Sea outflow water in the Red Sea. J. Geophys. Res., Oceans, 2015, 120, 6542-6563.

[10] Hall, J. K. Bathymetric chart of the Straits of Tiran, Isr. J. Earth. Sci., 1975, 24, 69-72.

[11] Mackas, D.L., Denman, K.L., Bennett, A.F. Least squares multiple tracer analysis of water mass composition. J. Geophys. Res. C, 1987, 92, 2907-2918.

[12] Maamaatuaiahutapu, K., Garcon, V. C., Provost, C., Boulahdid, M., Bianchi, A. Spring and winter wa?ter-mass composition in the Brazil-Malvinas Conflu?ence, J. Marine Res., 1994, 52, 397-426.

[13] Larqué, L., Maamaatuaiahutapu, K., Garcon, V. On the intermediate and deep water flows in the South Atlantic ocean, J. Geophys. Res., 1994, 102(6):12,425-12,440.

[14] You, Y. Seasonal variations of thermocline circula?tion and ventilation in the Indian ocean, J. Geophys. Res., 1997, 102(5):10+391-10+422.

[15] Goyet, C., Coatanoan, C., G. Eischeid, G., Amaoka, T., Okuda, K., Healy, R., Tsunogai, S. Spatial varia?tion of total CO2 and total alkalinity in the northern Indian Ocean: A novel approach for the quantifica?tion of anthropogenic CO2 in seawater, J. Marine Res., 1999, 57: 135-163.

[16] Louarn, E., Morin, P. Antarctic Intermediate Water influence on Mediterranean Sea Water outflow. Deep?Sea Res., 2011, 58: 932-942.

[17] Wafar, M., Qurban, M. A., Ashraf, M., Manikandan, K.P., Flandez, A. V., Balala, A. C. Patterns of distri?bution of inorganic nutrients in Red Sea and their im?plications to primary production. J. Mar. Sys, 2016, 156: 86-98.

[18] Murray, S. P., Hecht, A., Babcock, A. On the mean flow in the Tiran Strait in winter, J. Mar. Res., 1984, 42: 265-287.

[19] Klinker, J., Reiss, Z., Kropach C. Levanon, I., Har?paz, H., Haliez, E. Observations on the circulation pattern in the Gulf of Elat (Aqaba), Red Sea, Israel J. Earth Sci., 1976, 25: 85-103.

[20] Biton, E., Gildor, H. The general circulation of the Gulf of Aqaba (Gulf of Eilat) revisited: The interplay between the exchange flow through the Straits of Ti?ran and surface fluxes. J. Geophys. Res., 2011, 116: C08020.DOI:http://dx.doi.org/10.1029/2010JC006860

[21] Menzel, D. W., Ryther, J. H. Organic carbon and the oxygen minimum in the South Atlantic Ocean. Deep?Sea Res., 1968, 15: 327-337.

[22] Arhan. M., Mercier, H., Bourles, B, Gouriou, Y. Hy?drographic sections across the Atlantic at 7’30N and 4”30S. Deep-Sea Res.,1998, 145: 829-872.

[23] You, Y., N. Suginohara, M. Fukasawa, H. Yorita?ka, K. Mizuno, Y. Kashino, D. Hartoyo. Transport of North Pacific Intermediate Water across Japanese WOCE sections, J. Geophys. Res., 2003, 108(6): 3196.DOI:http://dx.doi.org/10.1029/2002JC001662

[24] Ramesh, S., Ramadass, G. A., Ravichandran, M., At?manand, M. A. Dissolved oxygen as a tracer for in?termediate water mixing characteristics in the Indian Ocean. Curr. Sci., 2013, 105: 1724-1729.

[25] Anati, D. A. Water transports in the Gulf of Aqaba. L’Océanographie Physique de la Mer Rouge, 1974, 2: 165-173. CNEXO Publ.

[26] Manasrah, R., Badran, M., Lass, H. U., Fennel, W. Circulation and winter deep water formation in the northern Red Sea. Oceanologia, 2004, 46: 5-23.

[27] Yao, F., Hoteit, I. Rapid red sea deep water renewals caused by volcanic eruptions and the north Atlantic Oscillation. Science advances, 2018, 4(6): 5637.

[28] Paldor, N., Anati, D. A. Seasonal changes of temperature and salinity in the Gulf of Elat (Aqaba). DeepSea Res., 1979, 26: 661-672.

[29] Sofianos S., Johns, W. E. The Summer Circulation in the Gulf of Suez and Its Influence in the Red Sea Thermohaline Circulation, J. Phys. Oceanogr, 2017.DOI:http://dx.doi.org/10.1175/JPO-D-16-0282.1

[30] Papadopoulos, V. P., et al. Factors governing the deep ventilation of the Red Sea. J. Geophys. Res., Oceans, 2015, 120(11): 7493-7505.

[31] Sofianos, S. S., Johns, W. E. An Oceanic General Circulation Model (OGCM) investigation of the Red Sea circulation: 1. Exchange between the Red Sea and the Indian Ocean. J. Geophys Res, 2002, 107(11): 3196. DOI:http://dx.doi.org/10.1029/2001JC001184