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The Gulf of Aqaba is a semi enclosed water basin attached to the Semi enclosed Red Sea.The Gulf is deep,narrow,receives no fresh water inputs,strongly oligotrophic,accommodates highly diverse ecosystem,experiences typical natural oceanic cycles and relatively unaffected by anthropogenic inputs,which makes it an ideal oceanic basin for studying natural atmospheric oceanic interactions.Thermohaline characteristics of the Gulf of Aqaba depict a well-defined seasonal pattern of winter mixing from December to April and summer stratification from May to November.This thermohaline structure is a major controlling factor of the nutrient,chlorophyll a and primary productivity seasonal cycles.Nitrate and chlorophyll a concentration records generated down to 200m at a vertical resolution of 25m; weekly during 1994,1995 and biweekly from April 1997 through to December 2000,have been employed to assess the nitrogen flux across the summer thermocline of the Gulf of Aqaba.The flux calculations are based on a simple diffusion model that incorporates the physical stress eddy diffusivity factor “Kz” and a biological stress factor “k”.Both Kz and k are calculated using the Michaelis-Menten equation and the nitrate concentration gradient.The total nitrate flux during the seven summer months (May- November) of the Gulf of Aqaba is estimated at 0.52 moleNm-2.This in relation to established primary productivity values (75.5 g.C.m-2 (May November)-1) and the generated chlorophyll a records makes an “f” fraction of new to total primary production of 0.50.This relatively high “f” value is discussed in relation to the geophysical characteristics of the Gulf of Aqaba and similar oceanic basins.The remaining 50% is accounted for by cross sectional flow from the relatively nutrient rich coral reef coastal habitat and rapid recycling,triggered by high irradiance and water temperature.Our efforts in understanding the CO2 absorptive capacity of the Gulf of Aqaba,verifying and improving our "f" estimates are still continuing by focusing more directly on the inorganic and organic carbon cycles in coastal and deep waters of the Gulf.