Desarrollo de la Antártica

Jí'íctor T. Neal I INTERNATlONAL SOUTHERN OCEAN STUDlES and to the east of a line about 28 km northwest of the current meter moorings. A sharp deflection of the Polar Front to the southeast was obser– ved at about 57° 50'S, 62 0 30'W during the first 10 days of Leg 1. W'hen observed 15 days later (on Leg 11), llhe meander had increased in size. THOMPSON reponed a cyclon te ring had been shed to the north of the front. The first survey of th~ ring by YlELCHO showed its radii (center at about 570 26'S, 63° 3S'W aS determined by the cold water core, i. e. OOC) ranged from about 24 to 41 km. The feature extended to a depth of 750 m. A later survey showed that the ring had enlar– ged and its shape ihad changed (with radii ranging from about 28 to 71 km) and that the "center" had moved north north-east at a'bout 10 cm/seco FDlMKE 75 In :January and February 1977 the third phase of the fieId work in the First Dynamics Response and Kinematics Experiment (FDRAKE) was carried out in the Drake Passage on board the R/V MELVlLLE. A U. S. scientific team, led by!DT. Worth D. Nowlin, Jr. (Texas A~M University) and Dr. R. Dale Pillsbury (Oregon State University) , and scÍentists from Instituto Hidrográfico de la Armada de Chile and Instituto IAntártico Argentino panicipated in the work. MELVILLE sailed from Valparaiso, Chile, on 10 ]anuary. Six of tlhe seven moorings deployed during FDRAKE 76 were recove– red. Attempts to recover the mooring near 58 0S were unsuccessful. The tide gauges at each side of the passage, as well as deep pressure gauges which were deployed in the passage the previous year, were al– So recovered. Of the nine current meten recovered, only two provided less than 10 months of data. The tide gauges and deep pressure gau– ges operated for the entire year. Most of the current meters that were reo()Vered were refurbished in t:the field for re-deployment; data tapes were translated and analyzed on board to check the performance of the meters. Twenty-two current meters were deployed on five moorings in a "cluster" array in the cen– tral part of the passage. This array is designed to measure the 'Vana– bility of currents and temperatures on space scales of 10 io 40 km during a ¡period of approximately one year. Tide gauges were also installed on each side of the passage. [n addition to launching a to– tal of 109 XBT'S during the cruise, hydrographic/sTD stations were occupied before and after deployment of the new array. The density