Recent changes in the surface salinity of the North Atlantic subpolar gyre

Sea surface salinity (SSS) was measured since 1896 along 60°N between Greenland and the North Sea and since 1993 between Iceland and Newfoundland. Along 60°N away from the shelves, and north of 53°N, the amplitude of the seasonal cycle is comparable to or less than interannual variability. In these parts of the North Atlantic subpolar gyre, large-scale deviations from the seasonal cycle correlate from one season to the next. This suggests that in these regions, summer and autumn surface data are useful for monitoring changes in upper ocean salinity best diagnosed from less common winter surface data. Further south near the subarctic front, the Labrador Current or near shelves where seasonal variability is strong, this is not the case. Along 60°N, the multiannual low-frequency variability is well correlated across the basin and exhibits fresher surface water since the mid 1970s than in the late 1920s to 1960s. SSS in the Irminger Sea along 60°N lags by 1-year SSS farther east in the Iceland Basin. Variability between Iceland and Newfoundland within the Irminger Sea north of 54°N presents similar characteristics to what is observed along 60°N. Variability near the northwest corner of the North Atlantic Current (52°N/45°W) is larger and is not correlated to what is found further north. Maps of SSS were constructed for a few recent seasons between July 1996 and June 2000, which illustrate the fresh conditions found usually during that period across the whole North Atlantic subpolar gyre, although this includes an episode of higher salinity. The SSS anomaly maps have large uncertainties but suggest that the highest SSS occurred before the spring of 1998 in the Iceland Basin, and after that, in the Irminger Sea. This is followed by fresher conditions, first in the Labrador and Iceland Basin, reaching recently the Irminger Sea

Modeled surface dynamic height in 1964-1984 : an effort to assess how well the low frequencies in the Equatorial Atlantic were sampled in 1982-1984

A wind-forced linear model has been used to produce 21 years (1964--1984) of monthly time series of surface dynamic height in the Equatorial Atlantic. Theclimatological seasonal cycle is substracted, and the statistical characteristics of the residuals are analyzed. An empirical orthogonal function analysis reveals that the most significant pattern has deviations of one sign in the Western Equatorial Atlantic. The anomalies in the last 2 years, 1983 and 1984, are particularly large. The time component of the first empirical orthogonal function peaks in july 1983, changes sign at the end of 1983, and has an extremun of the opposite sign in April 1984. At that time, the zonal slope of dynamic height had reversed with respect to normal along the equator. (D'aprèsrésumé d'auteur

Thyrotoxicosis-facilitated bridge to recovery with a continuous-flow left ventricular assist device

The HeartMate II is a continuous-flow left ventricular assist device that can be explanted from patients after cardiac recovery. We implanted a HeartMate II in a 21-year-old man who had idiopathic cardiomyopathy. A year later, he developed thyrotoxicosis, presumably secondary to amiodarone administered for ventricular fibrillation. Four months after the diagnosis of thyrotoxicosis, thyroid hormone levels had returned to normal, and native cardiac function had improved remarkably. After a support period of 24 months, the HeartMate II was explanted. Six years later, the patient continues to be in New York Heart Association functional Class I. Amiodarone-induced thyrotoxicosis may have contributed to myocardial recover

Study of the potential for existing bathythermic string drifters

Evaluation report on the use of subsurface temperature buoy data and on their ability to provide suitable measurements in the ocean boundary laye

Diurnal Warming Observations with ASIP in the subtropical Northern Atlantic

European Geosciences Union General Assembly 2015 (EGU2015), 12-17 April 2015, Vienna, Austria.-- 1 pageQuantification of air-sea exchange fluxes of energy, moisture, momentum and gases require in situ-measurements of the near-surface layer of the ocean. In the framework of the Salinity Processes in the Upper Ocean Regional Study (SPURS) project, we participated in two cruises to the North Atlantic Salinity Maximum (NASM) region. Observations in the upper ocean are obtained with the Air Sea Interaction Profiler (ASIP), which is an upwardly-rising microstructure instrument designed to study processes in the mixing layer of the ocean. ASIP operates autonomously for up to two days, obtaining undisturbed profiles within the water column from depth to the immediate surface. During the SPURS experiment, ASIP was deployed on several occasions, resulting in a total of over 1000 profiles of the ocean surface boundary layer. ASIP is equipped with microstructure sensors for temperature (FP07), conductivity (SBE07), shear, accurate C-T sensors, a PAR and an oxygen sensor. The high resolution temperature profiles obtained, combined with information on local meteorological variables, allow for an accurate study of the temporal and vertical variability of diurnal warming of the upper ocean boundary layer. Characteristics of the measured diurnal warming at the ocean surface and at specific depth levels are compared to physics-based models of near-surface warming. Mixing rates in the upper ocean are determined from the turbulent dissipation rate, calculated from profiles of the turbulent shear. This information is used to quantify variability between the modeled and observed diurnal warming signalPeer Reviewe