Twenty-five years ago to this date, Atmósfera joined the already established journals in the field of the atmospheric sciences and provided a new venue for the dissemination of results of research in that area.

We are very thankful to Dr. Graciela B. Raga and her coeditors for the preparation of this thematic issue, which initiates the celebration of Atmósfera's 25th anniversary.

In this anniversary issue of Atmósfera we include an excellent revision of the literature on chlorine in the stratosphere prepared by Thomas von Clarmann, who is a senior researcher and head of the Satellite-Borne Remote Sensing of Trace Gases group…

The year 2014 will be full of challenges for all who are devoted to atmospheric sciences. The weather events of 2013 warn us that the effects of climate change are becoming increasingly severe. In Mexico, for example, for the first…

In this issue we continue to publish review articles focused mainly in mid-latitudes and the Latin American area, as a way of celebrating the 25th anniversary of Atmósfera. In this occasion, Chilean researchers P. Monsalves Gavilán, J. Pincheira Ulbrich and…

In this article synthetic records of longer duration than the historic records of the North Atlantic Oscillation Index were compared. The synthetic records were obtained using the year interchange method and the Svanidze fragments method, as well as the Fiering…

This paper presents a preliminary analysis of thermal anomalies before the Baja California M7.2 earthquake occurred on April 4, 2010. The results show that surface air temperature of the Mexicali station, which is the closest one to the epicenter, reaches…

Lack of data in maximum daily rainfall frequency analysis can generate inefficient estimates for design purposes. An approach to diminish these errors is to apply regional estimation techniques, which require that all stations be located at the same homogeneous region.…

Atmospheric pollution in urban areas of Mexico has become a serious problem. The study of spatio-temporal evolution of concentrations of particulate matter is an important issue. A total of 188 samples were randomly collected at 24-hour running time within the…

Air pollution has been considered one of the most important environmental challenges because of its direct effect on ecosystems and human health. Temporal changes in the composition of 20 samples of rainwater in the arid region of Karachi, Pakistan during…