Diagnosis of the MJO Modulation of Tropical Cyclogenesis Using an Empirical Index

The modulation of tropical cyclone activity by the Madden–Julian oscillation (MJO) is explored using an empirical genesis potential (GP) index. Composite anomalies of the genesis index associated with the different MJO phases are consistent with the composite anomalies in TC genesis frequency that occur in the same phases, indicating that the index captures the changes in the environment that are at least in part responsible for the genesis frequency changes. Of the four environmental variables that enter the genesis potential index, the midlevel relative humidity makes the largest contribution to the MJO composite GP anomalies. The second largest contribution comes from the low-level absolute vorticity, and only very minor contributions come from the vertical wind shear and potential intensity. When basin-integrated MJO composite anomalies of the GP index are regressed against basin-integrated composite anomalies of TC genesis frequency, the results differ quantitatively from those obtained from the analogous calculation performed on the annual climatologies in the two quantities. The GP index captures the MJO modulation of TC genesis to a lesser degree than the climatological annual cycle of genesis (to which it was originally tuned). This may be due to weaknesses of the reanalysis or indicative of the importance of precursor disturbances, not well captured in the GP index computed from weekly data, to the intraseasonal TC genesis frequency fluctuations.

Mathematical simulation of electrochemical machining taking into account the influence of electrode polarization, electrolyte temperature and bubble formation on the form of the workpiece

To study the influence of polarization on the form of the workpiece, a method of transformation of the interelectrode space to a rectangle (for a two-dimensional system) was proposed. The potentials in this region were calculated by the superrelaxation method. The results of the calculation show a pronounced effect of polarization on the final form of the workpiece in comparison with an analogous calculation involving no electrode polarization. The Joule heat evolved in the streaming electrolyte and gas bubbles formed during electrolysis have also a pronounced influence on the course of the machining process.

A Study of the Efficiency of Spectrochemical Buffers. I. Influence of Buffer Cations

A method is described for the determination of the efficiency of spectrochemical buffers by using the differences in intensity values of the analytical lines of a group of elements contained in different matrices. By an analogous calculation, efficiency can also be determined using temperature index values. Efficiency values, in both cases, are given as numerical values. A study of five different cations was completed, and the results are given.