Ocean temperature and salinity components of the Madden-Julian oscillation observed by Argo floats

New diagnostics of the Madden-Julian Oscillation (MJO) cycle in ocean temperature and, for the first time, salinity are presented. The MJO composites are based on 4 years of gridded Argo float data from 2003 to 2006, and extend from the surface to 1,400 m depth in the tropical Indian and Pacific Oceans. The MJO surface salinity anomalies are consistent with precipitation minus evaporation fluxes in the Indian Ocean, and with anomalous zonal advection in the Pacific. The Argo sea surface temperature and thermocline depth anomalies are consistent with previous studies using other data sets. The near-surface density changes due to salinity are comparable to, and partially offset, those due to temperature, emphasising the importance of including salinity as well as temperature changes in mixed-layer modelling of tropical intraseasonal processes. The MJO-forced equatorial Kelvin wave that propagates along the thermocline in the Pacific extends down into the deep ocean, to at least 1,400 m. Coherent, statistically significant, MJO temperature and salinity anomalies are also present in the deep Indian Ocean

A new S-shaped MEMS PZT cantilever for energy harvesting from low frequency vibrations below 30 Hz

10.1007/s00542-012-1424-1Microsystem Technologies184497-50

Kinetic energy harvesting

This chapter introduces principles of normal kinetic energy harvesting and adaptive kinetic energy harvesting. Kinetic energy harvesters, also known as vibration power generators, are typically, although not exclusively, inertial spring-mass systems. Electrical power is extracted by employing one or a combination of different transduction mechanisms. Main transduction mechanisms are piezoelectric, electromagnetic and electrostatic. As most vibration power generators are resonant systems, they generate maximum power when the resonant frequency of the generator matches ambient vibration frequency. Any difference between these two frequencies can result in a significant decrease in generated power. Recent development in adaptive kinetic energy harvesting increases the operating frequency range of such generators. Possible solutions include tuning resonant frequency of the generator and widening the bandwidth of the generator. In this chapter, principles and operating strategies for adaptive kinetic energy harvesters will be presented and compared