List of publications

The effects of solar activity on the Earth's atmosphere and our weather systems is a very complex but interesting task for research. The purpose with this work is to see whether one can see which aspects of solar activity are best correlated with the local weather in Kiruna using neural networks. This has its interest in choosing future research directions in the area. After a discussion of which measurable parameters of the solar activity might be relevant, a study is made to see if one can see any correlation between the solar activity and the local weather using time dependent neural networks. The result is, unfortunately, negative. The rest of the study is spent in study the correlation between solar activity and the ionosphere, where the connection is simpler, deterministic and well understood. By studying this system one can learn much about the influences of solar activity on the Earth's upper atmosphere. Because this is a well understood system I could also learn much about the performance of the neural networks in resolving different changes.

A brief climatology of ozone using more than 8 years of ozonesonde data in the troposphere and lower stratosphere at two northern high latitude stations, Sodankyla and Ny-Ålesund, is presented. The climatology of ozone clearly shows a significant seasonal cycle with the ozone maxima changing with height. The monthly variability of ozone as well as its seasonal maximum is found near the tropopause. Variation in tropopause height is due mainly to the passage of tropospheric weather systems and is responsible for the large monthly variability of ozone near the tropopause. In the lower stratosphere, interannual variations are at a maximum in winter and spring, and are the result of variations in wave driven stratospheric circulation, which peaks in winter. The present climatology forms a basis for 3-D chemistry transport models to test its ability at high latitudes.

DESCARTES is a balloon-borne grab-sampler instrument sampling stratospheric trace gases. Sampling and pre-concentration is done by adsorption traps and analysis by gas chromatography. In order to get good focusing for the chromatography the traps should be as small as possible and the lower limit is set by the breakthrough of the adsorbate during sampling. This study focuses on the adsorption behaviour of these traps under different circumstances. The results show that simple theory does not explain adsorption at high flow speed.

DESCARTES is a lightweight balloon-borne grab-sampler instrument for the long-lived chemical tracer CFC-11 developed at the University of Cambridge. From Dec 3, 1999 and throughout 2000 it made 15 flights from Esrange and Andø ya. Simultaneous balloon-borne ozone measurements were made during most flights. The evolution of the polar airmass over the whole year is studied from these flights and compared to model profiles at Kiruna and other subsidence studies.

DESCARTES is a lightweight instrument for in-situ measurements of long-lived stratospheric tracers from balloons. The instrument is designed to fly piggyback on other payloads; it weighs 16kg and there is no need for telemetry. The instrument collects samples by letting a measured amount of air pass though a tube containing a carboxen adsorbent. The instrument can measure CFC-11, CFC-113, CCl₄ and CH₃CCl₃ quantitatively. Results from the four flights with DESCARTES during the THESEO-O₃-loss campaign in the spring of 1999 are presented.

DESCARTES is a lightweight instrument for in-situ measurements of long-lived stratospheric tracers from balloons. The instrument is designed to fly piggyback on other payloads; it weighs 16kg and there is no need for telemetry. The instrument collects samples by letting a measured amount of air pass though a tube containing a carboxen adsorbent. The instrument can measure CFC-11 and CFC-113 quantitatively, CCl₄ and CH₃CCl₃ is adsorbed and might give quantitative results after further laboratory analysis. Preliminary results from the four flights with DESCARTES during the THESEO-O₃-loss campaign in the spring of 1999 are presented.