Multiple causes of interannual sea surface temperature variability in the equatorial Atlantic Ocean

The eastern equatorial Atlantic Ocean is subject to interannual fluctuations of sea surface temperatures, with climatic impacts on the surrounding continents. The dynamic mechanism underlying Atlantic temperature variability is thought to be similar to that of the El Nino/Southern Oscillation (ENSO) in the equatorial Pacific, where air-sea coupling leads to a positive feedback between surface winds in the western basin, sea surface temperature in the eastern basin, and equatorial oceanic heat content. Here we use a suite of observational data, climate reanalysis products, and general circulation model simulations to reassess the factors driving the interannual variability. We show that some of the warm events can not be explained by previously identified equatorial wind stress forcing and ENSO-like dynamics. Instead, these events are driven by a mechanism in which surface wind forcing just north of the equator induces warm ocean temperature anomalies that are subsequently advected toward the equator. We find the surface wind patterns are associated with long-lived subtropical sea surface temperature anomalies and suggest they therefore reflect a link between equatorial and subtropical Atlantic variability

Saturation Magnetostriction and Volume Magnetostriction of Amorphous Ribbons Based on Fe-Ni and Fe-Co

The saturation magnetostriction and the forced volume magnetostriction of Fe-Ni and Fe-Co amorphous ribbons were measured from 77°K to room temperature by a three terminal capacitance method. It was found that the magnetostriction was nearly isotropic. In Fe-Ni amorphous system, the saturation λ_s and the volume magnetostriction constants δω/δH decreased monotonously with the increase of Ni concentration from 31×10^ and 21×10^/Oe respectively for Fe_P_C_ to 15×10^ and 7×10^/Oe respectively for Fe_Ni_P_C_. The temperature dependence of the saturation magnetostriction was not simple decreasing function of the temperature. In Fe-Co system, there was a remarkable change of the sign of the magnetostriction nearly equal to Fe_Co_Si_B_

GIANT OPTICAL NONLINEARITY OF HETEROSTRUCTURES WITH InP SELF-ASSEMBLED QUANTUM DOTS

A nonlinear reection of the heterostructures with InP self-assembled quantumdots is studied by pump-probe technique. A saturation of pump-probe signal inthe spectral region of the absorption of quantum dots is found at extremely lowpump power density of about 1 W/cm2. This value together with estimation ofthe absorption coefficient leads to the conclusion that saturation of the nonlinearreection occurs when quantum dot absorbs only single quantum of the light. Thisis a real evidence of the giant optical nonlinearity of the quantum dots.24th International Conference on the Physics of Semiconductors : Jerusalem, Israel August 2-7, 199

FRANZ-KELDYSH OSCILLATIONS IN PUMP-PROBE SPECTRA OF InP SELF-ASSEMBLED QUANTUM DOTS

Heterostructures with InP self-assembled quantum dots were studied. StrongFranz-Keldysh oscillations were found in their nonlinear reection spectra mea-sured by pump-probe method. These oscillations manifest built-in electric field ofabout 30 kV/cm. We suppose that this field originates from electric charge cap-tured by the structural defects on the dots interface. An estimated areal densityof electric charge is about 2×1011cm-2.24th International Conference on the Physics of Semiconductors : Jerusalem, Israel August 2-7, 199

Orobothriurus atiquipa, a new bothriurid species (Scorpiones) from Lomas in southern Perú

Orobothriurus atiquipa new species (Scorpiones, Bothriuridae) from Lomas formations in the coastal desert of southern Perú is described and illustrated. This species belongs to the alticola species-group, and within the group, it is closely related to O. alticola (Pocock), O. paessleri (Kraepelin) and O. curvidigitus (Kraepelin). The spine formula (4 + 3) on tarsi III–IV is probably an autapomorphy for the new species. Some features of the habitat (the Lomas formation are green isolates in the coastal desert), as well as a distribution map are provided.Fil: Ochoa, José Antonio. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Cátedra de Diversidad Animal I; ArgentinaFil: Acosta, Luis Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentin

Zero Magnetostriction and Extremely Low Residual Magnetic Loss in Fe-Co Amorphous Ribbons

application/pdfThe initial permeability μ_i, the loss factor tan δ, and the inverse quality factor tan δ/μ_i of Fe_5Co_Si_B_ ribbons 35 μm, 30 μm, 25 μm and 21 μm in thickness were measured with a Maxwell Bridge from room temperature to 140℃ in the high-frequency region from 3 kHz to 500 kHz. The initial permeability of the ribbon 21 μm in thickness was about 10, 600 at 3 kHz and 4300 at 500 kHz. The residual loss coefficient C_1 and the hysteresis loss coefficient h_1 were extremely low, about 8×10^ and 60 (cm/A), respectively. In the high-frequency region, the eddy current loss term increases with the square of the thickness of the ribbons and plays the most important part of all the magnetic losses.紀要類(bulletin)70514 bytesdepartmental bulletin pape

Giant ΔE Effect and Magnetomechanical Coupling Factor in Amorphous Fe80P13C7 Ribbons

The magnetomechanical coupling factor k, the Young\u27s modulus E and the ΔE effect as a function of bias field were measured by a mechanical resonance method of amorphous Fe80P13C7 ribbons which were annealed at different temperatures in a magnetic field. In the ribbon which was annealed at 350℃ for 20 minutes, a remarkably large coupling factor k was found in the bias field 5 Oe to be 0.53, which was almost the same as the value of the high magnetostrictive rare earth-Fe2. The ΔE effect increased with the increase of the bias field, took a gigantic value 0.8 at about 5 Oe and then decreased monotonically with the increase of the bias field. The ΔE effect is known to correspond to a change in sound velocity, so that the change of the sound velocity was also observed as a function of the frequency from 100 kHz to 1MHz in a delay line using the ribbons

Observation of the Magnetostriction in Ferromagnetic Amorphous Thin Ribbons

The first observation of the magnetostriction of the amorphous thin ribbons was made at room temperature, and it was found that in Fe_P_C_, the saturation magnetostriction λ in the plane was 18.5×10^ which was several times bigger than that of bulk iron in the polycrystalline state