The occurrence of major avalanche episodes in the Eastern Pyrenees (NE Spain) is estimated by means of the Poisson and the negative binomial distributions, assuming that they are rare events. The differences observed in their spatial distribution along the seven regions in which Eastern Pyrenees have been divided, suggests us to look for spatial variations in the relationship between extreme av...

Shaw, Keefer, Refsdsl and others (1) have shown that goopotential height is represented on the tcphigrani by an area, and that an isentropic at'mosphere XY (figure l), equal in geopotential height to a given atmosphe,re AB, may be const8ruct8ed by so placing the line XY on the tepliigram t,hat the area XAZ is equal to the area YBZ. The effect of moistmure is normally negligible, but may be allo...

Results from a global climate model including an interactive parameterization of stratospheric chemistry show how upper stratospheric ozone changes may amplify observed, 11-year solar cycle irradiance changes to affect climate. In the model, circulation changes initially induced in the stratosphere subsequently penetrate into the troposphere, demonstrating the importance of the dynamical coupli...