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- Author or Editor: Denise E. Hagan x
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Abstract
The North American Slope and Gulf Stream components that constitute the initial water masses within a cyclonic ring can combine with Sargasso Sea water to generate Western North Atlantic Water (WNAW) common to the main anticyclonic gyre in the Sargasso Sea. Evidence from the 1967 ring survey indicates that warm, saline water from above mixes with cooler, fresher water from below to produce WNAW in the region of the mid-thermocline (7–12°C). At mid-thermocline depths, WNAW can be traced along σ t surfaces from the ring center to the Sargasso Sea. Vertical stability conditions support the mixing concept. Distributions of the zooplankton species Nematoscelis megalops found for the 1975–76 Ring D survey can be interpreted as indicating mixing and detrainment through the mid-thermocline region.
Abstract
The North American Slope and Gulf Stream components that constitute the initial water masses within a cyclonic ring can combine with Sargasso Sea water to generate Western North Atlantic Water (WNAW) common to the main anticyclonic gyre in the Sargasso Sea. Evidence from the 1967 ring survey indicates that warm, saline water from above mixes with cooler, fresher water from below to produce WNAW in the region of the mid-thermocline (7–12°C). At mid-thermocline depths, WNAW can be traced along σ t surfaces from the ring center to the Sargasso Sea. Vertical stability conditions support the mixing concept. Distributions of the zooplankton species Nematoscelis megalops found for the 1975–76 Ring D survey can be interpreted as indicating mixing and detrainment through the mid-thermocline region.
Abstract
Eight cruises over a 10-month period in the North Atlantic have provided the Cyclonic Ring Experiment with observations of two rings. Life histories, structure and structural changes have been studied with emphasis on the effects of Stream interaction and spindown processes. Ring AL was generated in September 1976 with a central water mass composed of Slope and anticyclonic ring waters. Ring BOB separated from the Stream in March 1977 with a Shelf and Slope Water core. Both rings had a 7-month lifetime, interacted with the Gulf Stream and were regenerated. The Stream interaction altered the core structures, and in the case of BOB, cruise observations show significant changes in ring size and shape. BOB's spatial extent decreased with interaction and increased during spindown while eccentricity of the ring behaved in an opposite manner.
Abstract
Eight cruises over a 10-month period in the North Atlantic have provided the Cyclonic Ring Experiment with observations of two rings. Life histories, structure and structural changes have been studied with emphasis on the effects of Stream interaction and spindown processes. Ring AL was generated in September 1976 with a central water mass composed of Slope and anticyclonic ring waters. Ring BOB separated from the Stream in March 1977 with a Shelf and Slope Water core. Both rings had a 7-month lifetime, interacted with the Gulf Stream and were regenerated. The Stream interaction altered the core structures, and in the case of BOB, cruise observations show significant changes in ring size and shape. BOB's spatial extent decreased with interaction and increased during spindown while eccentricity of the ring behaved in an opposite manner.
Abstract
Field observations provide a data base that supports a comparison of ring structures in terms of the background Sargasso Sea environment. Five ring surveys, three from the 1967 sequence, a big baby ring and ring AL, were selected for this study. Anomalies of temperature, salinity, transport potential energy density, heat content and sound velocity have been examined using a reference which closely approximates Iselin's characteristic T-S relation for the western gyre.
The results for the 1967 sequence demonstrate an initial reduction in anomaly strengths followed by strong ring stability. Comparison of two different rings, possibly equal in age, show the effect of the initial water mass conditions on anomaly strengths. Comparison of a cyclonic ring and the big baby ring reveals similar anomaly strengths and sizes in the same geographical region for rings that are assumed to be two and eleven months in age, respectively. This suggests that big baby rings can initially represent more intense perturbations to the Sargasso Sea than cyclonic ring counterparts.
Abstract
Field observations provide a data base that supports a comparison of ring structures in terms of the background Sargasso Sea environment. Five ring surveys, three from the 1967 sequence, a big baby ring and ring AL, were selected for this study. Anomalies of temperature, salinity, transport potential energy density, heat content and sound velocity have been examined using a reference which closely approximates Iselin's characteristic T-S relation for the western gyre.
The results for the 1967 sequence demonstrate an initial reduction in anomaly strengths followed by strong ring stability. Comparison of two different rings, possibly equal in age, show the effect of the initial water mass conditions on anomaly strengths. Comparison of a cyclonic ring and the big baby ring reveals similar anomaly strengths and sizes in the same geographical region for rings that are assumed to be two and eleven months in age, respectively. This suggests that big baby rings can initially represent more intense perturbations to the Sargasso Sea than cyclonic ring counterparts.
