[1] This paper reports multiplatform observations of leader radiation preceding initial cloud-to-ground lightning return strokes by <6 ms. Specifically, we present multistation ground-based LF/VLF recordings of events with large-amplitude leader activity (comparable in amplitude to the return stroke amplitude). The events were selected for their coincidence with VHF observations by the FORTE sa...

We propose a new model for RR interval records based on the empirical finding that the amplitude of RR records is negatively correlated with its regularity. We develop the mathematics needed to define rigorously this model, as well as the statistical tools necessary for estimating the parameters of the model on sampled data. We use this to analyze finely the impact of ventricular extrasystole o...

The sensitivity of El Niño-Southern Oscillation (ENSO) to changes in mean climate is investigated for simulations of pre-industrial and mid-Holocene (6000 years before present) climate using the Hadley Centre coupled atmosphere-ocean model, HadCM3. Orbitally-forced changes in insolation in the mid-Holocene produce changes in seasonality which may alter ENSO amplitude and frequency. The model si...

− In this paper, improved sine-fitting algorithms for the measurement of amplitude and phase difference between two records of digitized sine waves with the same frequency are presented. These algorithms can be used for example in impedance measurements or to accurately measure the input and the output of a linear system to be characterized in the frequency domain both in amplitude and in phase.

One of the most common and challenging problems in seismology is the prediction of source-receiver paths taken by seismic energy in the presence of lateral variations in wavespeed. The solution to this problem is required in many applications that exploit the high frequency component of seismic records, such as body wave tomography, migration of reflection data and earthquake relocation. The pr...

We demonstrate how an exponentially strong redshift creates a sharp boundary layer at null infinity for strong gravitational fields. This leads to saturation effects by which the gravitational energy depends only linearly on amplitude, as opposed to the quadratic dependence in the weak field case.